Polyarthrosis (generalized osteoarthritis): clinical guidelines

List of Abbreviations

ACR – American College of Rheumatology

ALT – alanine aminotransferase

AST – aspartate aminotransferase

anti-CCP – antibodies to cyclic citrullinated peptide

ATC – Anatomical Therapeutic Chemical classification

dietary supplement – dietary supplements

DMARDs – disease-modifying antirheumatic drugs (M01AX05, M01AX21, M01AX25, M01AX26, M01BX, M09AX)

VAS – visual analogue scale

VRS – verbal rating scale

AH – arterial hypertension

GC – glucocorticoids

GRLS – State Register of Medicines

CI – confidence interval

DIPJs – distal interphalangeal joints

DCT-pheresis – diadynamic current electrophoresis taking into account individual patient characteristics

GI – gastrointestinal tract

CMC joint – carpometacarpal joint

CHD – coronary heart disease

IL – interleukin

BMI – body mass index

CBT – cognitive behavioral therapy

CP – clinical guidelines

CT – computed tomography

medicines – medicinal products

HDL – high-density lipoproteins

LDL – low-density lipoproteins

PT – physical therapy

MAPK – mitogen-activated protein kinase

MicroRNA – small non-coding ribonucleic acid molecules

ICD-10 – International Classification of Diseases 10th Revision

INN – international nonproprietary name

MRI – magnetic resonance imaging

ADR – adverse drug reactions

NSAIDs – non-steroidal anti-inflammatory and antirheumatic drugs

NSAIDs – non-selective non-steroidal anti-inflammatory drugs (M01AB Acetic acid derivatives and related substances, M01AC Oxicams, M01AE Propionic acid derivatives, M01AX Other non-steroidal anti-inflammatory and antirheumatic products)

AR – adverse reaction

ASU – avocado and soybean oil unsaponifiables

OA – osteoarthrosis/osteoarthritis

OP – osteoporosis

SPECT – single-photon emission computed tomography

MTPJs – metatarsophalangeal joints

PIPJs – proximal interphalangeal joints

MCPJs – metacarpophalangeal joints

RCT – randomized controlled trial

eGFR – estimated glomerular filtration rate

RF – rheumatoid factor

DM – diabetes mellitus

SPT – sanatorium-resort treatment

GFR – glomerular filtration rate

SMT therapy – sinusoidal modulated currents

sNSAIDs – selective non-steroidal anti-inflammatory drugs (ATC Coxibs M01AH01, M01AH05)

ESR – erythrocyte sedimentation rate

CRP – C-reactive protein

CVS – cardiovascular system

TG – triglycerides

LCE – level of confidence of evidence

US – ultrasound examination

FJs – facet joints

TNF-α – tumor necrosis factor alpha

PTL – physical therapy treatment

CHF – chronic heart failure

CNS – central nervous system

COX-2 – cyclooxygenase-2 inhibitor

EGD – esophagogastroduodenoscopy

UHF EP – ultra-high frequency electric fields

NRS – numerical rating scale

TENS – transcutaneous electrical nerve stimulation

ACR – American College of Rheumatology

AUSCAN – Australian/Canadian Hand Osteoarthritis Index

CCL – C-C motif chemokine ligand

DMOADs – Disease-Modifying Osteoarthritis Drugs (M01AX Other non-steroidal anti-inflammatory and antirheumatic products, M01BX Other anti-inflammatory/antirheumatic agents in combinations with other drugs, M09AX Other drugs for disorders of the musculoskeletal system)

DN4 – Douleur Neuropathique en 4 Questions (DN4)

ESCEO – European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases

EULAR – European League Against Rheumatism

FDA – Food and Drug Administration

FIHOA – Functional Index for Hand Osteoarthritis

FRAX – Fracture Risk Assessment Tool

HOOS – Hip injury and Osteoarthritis Outcome Score

KOOS – Knee injury and Osteoarthritis Outcome Score

MMPs – matrix metalloproteinases

NF-κB – nuclear factor kappa-light-chain-enhancer of activated B cells

NICE – National Institute for Health and Care Excellence

OARSI – Osteoarthritis Research Society International

SYSADOA – Symptomatic Slow-Acting Drugs for Osteoarthritis ((M01AX Other anti-inflammatory and antirheumatic agents, non-steroids, M01BX Other anti-inflammatory/antirheumatic agents in combination with other drugs, M09AX Other drugs for disorders of the musculoskeletal system))

Wnt – cellular signaling pathway

WHO/ILAR – World Health Organization / International League of Associations for Rheumatology

WOMAC – Western Ontario and McMaster Universities Arthritis Index

Terms and Definitions

Osteoarthrosis/osteoarthritis (OA) is a joint disease occurring under the influence of various endogenous and exogenous causes that lead to damage to all joint components.

Disease-Modifying Osteoarthritis Drugs (DMOADs) — a group of medicinal products with various structures, pharmacological characteristics, and mechanisms of action belonging to different ATC codes (M01AX, M09AX, M01BX), which exert complex symptomatic and anti-inflammatory effects and possess a structure-modifying effect upon long-term administration.

Nonsteroidal anti-inflammatory and antirheumatic drugs (NSAIDs) — a group of synthetic medicinal products possessing symptomatic analgesic, antipyretic, and anti-inflammatory effects primarily associated with the inhibition of cyclooxygenase activity, an enzyme regulating prostaglandin synthesis (M01A).

Glucocorticoids (GCs) — synthetic steroid hormones possessing intrinsic anti-inflammatory activity (H02AB).

Adverse reaction (AR) — any unfavorable medical occurrence that develops during the clinical use of a medicinal product and is not part of its purposefully expected therapeutic effects.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Osteoarthritis – a heterogeneous group of diseases of various etiologies with similar biological, morphological, clinical manifestations, and outcomes, based on damage to all joint components: cartilage, subchondral bone, synovial membrane, ligaments, capsule, and periarticular muscles.

Osteoarthritis is characterized by cellular stress and extracellular matrix degradation of all joint tissues arising against the background of macro- and microinjuries, wherein normal adaptive repair responses are activated, including pro-inflammatory pathways of the immune system. Initially, changes occur at the molecular level followed by anatomical and physiological disorders (cartilage degradation, bone remodeling, osteophyte formation, synovitis, etc.) leading to the development of the disease.

Polyosteoarthritis (generalized osteoarthritis) – involvement of three or more joint groups in the pathological process. The following localizations are taken into account: knee joints, hip joints, small joints of the hands (first carpometacarpal joint [CMCJ], distal [DIP] and proximal [PIP] interphalangeal joints, first interphalangeal joint), first metatarsophalangeal joint (MTPJ), and facet joints [1–10].

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

Osteoarthritis is a multifactorial disease affecting all joint structures (cartilage, synovial membrane, subchondral bone, periarticular tissues) arising as a result of the interaction of age-related, hormonal, genetic, and environmental factors [11,12].

Systemic predictors (age, sex, race, hormonal status, burdened family history of OA, genetic factors, high bone mineral density), local predictors (trauma, quadriceps weakness, joint axis malalignment, musculoskeletal developmental anomalies, in particular joint hypermobility), and external predictors (obesity, athletic load, occupational activity) play a significant role in the development of OA. However, depending on the localization of the pathological process, the factors of OA development and progression vary [13,14].

Pathogenesis of osteoarthritis

To date, a large amount of data has accumulated confirming the key role of cytokine imbalance favoring pro-inflammatory cytokines in the pathogenesis of the disease. These cytokines induce inflammatory reactions that contribute to altered metabolism of osteoblasts, osteocytes, chondrocytes, and synoviocytes, as well as an imbalance between anabolic and catabolic processes with a predominance of the latter, ultimately leading to degradation of cartilage and other intra-articular structures [15]. Among pro-inflammatory cytokines, IL-1β, TNF-α, IL-6, IL-15, IL-17, IL-18, IL-21, and IL-22 are of the greatest importance. These cytokines are activators of multiple different inflammatory signaling pathways (specifically NF-κB, Wnt, and MAPK) that cause overexpression of other cytokines, thereby initiating a vicious cycle. Chemokines (IL-8, CCL2, CCL3, CCL4, CCL5), which are stimulated by cytokines and recruit "inflammatory cells" to joint tissues, further contributing to the secretion of inflammatory mediators and disease progression, are also part of this process [16]. It has been proven that many soluble pro-inflammatory mediators can increase the production of matrix metalloproteinases, collagenases, etc., which enhance catabolic processes in cartilage. Furthermore, pro-inflammatory cytokines are capable of inhibiting enzyme inhibitor synthesis, leading to increased activity of proteases that degrade proteoglycans, which are the main structural component of the cartilage matrix.

Neutrophils, macrophages, and T cells (critical regulators of innate and adaptive immunity) also play a significant role in the pathogenesis of this disease [17]. In particular, macrophages secrete metalloproteinases and inflammatory cytokines, whereas neutrophils secrete destructive proteases, including neutrophil elastase, which can initiate both the development and progression of OA. In recent years, much attention has been paid to microRNAs, which are small non-coding RNAs used as biomarkers and modulators of post-transcriptional gene expression in many pathological conditions, including OA. Numerous studies have demonstrated that mechanical loading induces differential expression of microRNAs in cartilage involved in the regulation of autophagy and matrix-degrading enzymes, as well as in the modulation of the inflammatory response and chondrocyte apoptosis [18,19].

In OA, the angioarchitecture and structure of subchondral bone change; due to accelerated bone metabolism, the functions of osteoblasts and osteoclasts are impaired, which promotes bone resorption and accelerates osteoclastogenesis [20]. Concurrently, overexpression of many pro-inflammatory cytokines/chemokines and growth factors is observed, which facilitate vascular invasion from the subchondral bone into the cartilage and degradation of the cartilaginous tissue. Accelerated bone remodeling causes the development of subchondral bone marrow lesions. Inflammatory biological factors, overload, and abnormal joint biomechanics trigger the activation of endochondral ossification, resulting in osteophyte formation.

Metabolic disorders and infrapatellar fat pad are considered important in the development and progression of OA [21]. On the one hand, a large volume of fat mass increases the mechanical load on the joints and promotes activation of mechanoreceptors in the joint tissues. Under in vitro conditions, "mechanical stress" induces proliferation of osteoblast culture, increased expression of microRNAs of bone proteins involved in osteoid formation and the mineralization process, and release of local growth factors and adhesion molecules. On the other hand, adipose tissue is an independent endocrine organ producing a large amount of proinflammatory mediators (cytokines, adipokines, fatty acids, and reactive oxygen species), which negatively affect joint tissues and also provoke the development and maintenance of low-grade "metainflammation". Recent data indicate that infrapatellar fat pad also contributes to the maintenance of inflammation and degradation of cartilage tissue [22].

1.3 Epidemiology of the Disease or Condition

Osteoarthritis is one of the most common joint disorders among musculoskeletal diseases, and its incidence is steadily increasing. According to the 2020 Global Burden of Disease study estimates, OA is diagnosed in 7.6% of the global population, which amounts to 595 million people (95% UI 535–656 million). From 1990 to 2020, the number of patients with OA increased by 132.2% (95% UI 130.3–134.1%), and according to projections, by 2050 the number of individuals with knee OA will increase by 74.9% (95% UI 59.4–89.9), hand OA by 48.6% (35.9–67.1%), hip OA by 78.6% (95% UI 57.7–105.3%), and OA of other sites by 95.1% (95% UI 68.1–135%) [23].

In the Russian Federation, according to official statistics for 2017, there are more than 4 million 300 thousand patients with this disease, and almost 40% of them are of working age [24].

However, these data do not reflect the true number of patients because they only account for detected and registered cases. Thus, according to epidemiological studies, knee and/or hip OA is detected in 13% of the country's population over 18 years of age (13,000 thousand patients per 100,000 population), which amounts to about 15 million people [25]. OA is more common in women, and its prevalence increases with age (this trend is characteristic of patients up to 75–80 years).

1.4 Features of Coding the Disease or Condition

Polyarthrosis (M15)

M15.0 Primary generalized osteoarthritis

M15.1 Heberden's nodes (with arthropathy)

M15.2 Bouchard's nodes (with arthropathy)

M15.4 Erosive osteoarthritis

M15.8 Other polyarthrosis

Considering the pathogenetic mechanisms of the disease, it is more appropriate to use the term osteoarthritis.

1.5 Classification of the disease or condition

1.5.1 Clinical classification

There are two main forms of OA: primary (idiopathic) and secondary, arising against the background of various diseases. Primary OA can be local, affecting a single joint group, or generalized, involving three or more joint groups.

Clinical classification of OA

1. Primary OA

• Knee joints

• Hip joints

• Hand joints

• Foot joints

• Spine

• Other joints

2. Secondary OA

• Post-traumatic (joint trauma, fractures, or osteonecrosis), surgical interventions on the joint (e.g., meniscectomy), occupational joint disease.

• Congenital, acquired, endemic diseases (Blount's disease, hemophilia, Paget's disease, joint hypermobility syndrome [Marfan syndrome, Ehlers-Danlos syndrome, etc.], Legg-Calvé-Perthes disease, congenital dislocation of the hip, congenital acetabular protrusion, epiphyseal dysplasia, and other musculoskeletal dysplasias).

• Metabolic and endocrine diseases (acromegaly, hyperparathyroidism, ochronosis, hemochromatosis, Wilson's disease, Gaucher's disease, crystal-induced arthropathies [gout, calcium pyrophosphate deposition disease, hydroxyapatite deposition disease], diabetes mellitus, Charcot's arthropathy).

• Other bone and joint diseases (rheumatoid arthritis [RA], infectious arthritis, spondyloarthritis, etc.).

1.5.2 Radiologic classification

To determine the radiographic stage of OA, the Kellgren and Lawrence classification is used [26]:

Stage I – Doubtful radiographic features;

Stage II – Minimal changes (slight joint space narrowing, single osteophytes at the margins of joint surfaces);

Stage III – Moderate manifestations (moderate joint space narrowing, multiple small or moderately pronounced osteophytes at the joint margins, mild subchondral osteosclerosis, minor deformities of joint surfaces);

Stage IV – Marked changes (severely narrowed joint space, multiple large osteophytes at the joint margins, pronounced subchondral osteosclerosis, varying degrees of deformity of the bone epiphyses forming the joint).

1.6 Clinical presentation of the disease or condition

In polyarthrosis (generalized OA), three or more joint groups are involved in the pathological process. The following localizations are considered: knee joints, hip joints, small joints of the hands (DIP, PIP, 1st interphalangeal joint, 1st CMC), 1st MTP, facet joints.

The clinical presentation of OA is described by several symptoms: pain, morning stiffness in the joint lasting less than 30 minutes, functional impairment, gradual onset of pain, crepitus, stiffness, surrounding muscle atrophy, joint deformation, and enlargement. The leading clinical sign of OA is joint pain occurring on most days of the previous month. The causes of joint pain are numerous: the source can be the synovium, capsule, ligamentous apparatus, periarticular muscles, subchondral bone, etc. It is believed that the most sensitive pain structures are located in the infrapatellar fat pad, synovium, and ligaments. Articular cartilage is aneural and therefore cannot be a direct source of pain. However, vascular invasion into affected areas of articular cartilage can lead to the appearance of sensory nerve fibers in normally aneural cartilage. In addition, subchondral bone changes in OA—such as the development of osteosclerosis, osteophyte formation, microfractures, osteitis, and increased intramedullary pressure—can also cause pain. Pain is a subjective sensation largely shaped by psychological, social, demographic, genetic, and other factors. In recent years, it has been proven that pain in OA can have not only a nociceptive nature (caused by structural and biochemical changes in bone, synovium, muscles, and periarticular tissues) but also a neuropathic and/or nociplastic component.

Clinical manifestations of OA depend on the localization of the pathological process. Thus, involvement of the knee joint is characterized by pain during walking, worsening towards the end of the day, relief with rest, "starting" pain, brief morning stiffness, and restricted joint function. Night pain occurs in more advanced stages of OA. Symptoms of OA at the onset of the disease are usually episodic, but as the disease progresses, they become more prolonged and sometimes constant [27]. Weakness and atrophy of the quadriceps femoris, tenderness upon palpation along the joint line and/or periarticular areas (most commonly the pes anserinus) are frequently observed in knee OA. In 30–50% of patients, knee deformity with an outward deviation (genu varum) and joint instability develop.

In the early stages of OA, pain in the knee joints is more often noted, which intensifies with load, squatting, going down/up stairs, and is accompanied by brief "starting" stiffness.

OA of the hip joints is also characterized by pain during walking, most commonly localized in the groin area, which may radiate to the buttock, the anterolateral thigh, the knee, or the lower leg; pain worsens towards the end of the day and eases with rest, accompanied by brief morning stiffness and limited joint function [28]. At the onset of the disease, pain may occur not in the affected joint itself, but in the knee, the outer surface of the thigh, the buttock, or the lumbar region, which complicates diagnosis. In these cases, limitation of joint movement, pain upon internal rotation of the leg in a flexed position, and tenderness upon palpation of the groin area lateral to the femoral artery pulse can be detected. With a prolonged course of the disease, atrophy of the thigh and gluteal muscles develops. The limb assumes a forced posture—slight flexion at the hip joint with impaired rotation and abduction—resulting in compensatory lumbar lordosis, pelvic tilt toward the affected joint, and scoliosis. All of this can cause back pain. Hip joint involvement leads to a gait change: initially a limp, followed by limb shortening and a lurching gait. In bilateral involvement, a "waddling gait" develops.

The main symptoms of OA of the hand joints are pain upon movement and mild morning stiffness (less than 30 minutes) or joint stiffness at any time of the day; symptoms usually have an intermittent course and occur in the DIPJs, PIPJs, CMCPJs, and less commonly affect the 1st – 3rd MCPJs [28].

In lesions of the 1st CMC joint, there is a restriction of movement in it, pain upon movement, especially upon flexion. Over time, pain can become constant and limits patients' daily activities. Joint deformation appears [29,30].

In OA of the facet joints, pain is usually bilateral and localized in the paraspinal region, and can vary in intensity.

It intensifies with movement, in certain postures (often with prolonged standing and extension), and with walking, while decreasing at rest. Pain sensations can be either periodic (after exertion) or constant. Osteoarthritis of the lumbar facet joints is one of the leading causes of chronic nonspecific low back pain [31].

2. Diagnostics, medical indications and contraindications for diagnostic methods

Diagnostic criteria

Comments: the diagnosis of knee, hip, and hand OA is based on the ACR classification criteria (Tables 1–3). To date, criteria for early-stage knee and hip OA are under development and cannot be used in real clinical practice. The diagnosis of OA of the 1st CMC joint and facet joints is based on clinical symptoms of the affected joints, radiological and laboratory signs confirming the diagnosis of OA, and ruling out specific causes of pain [35,36].

Table 1. Classification criteria for knee OA (ACR) [32]

* If 4 additional criteria out of 6 are present, the sensitivity is 84% and specificity is 89%.

Table 2. Classification criteria for hand small joint OA (ACR) [34]

Note: * - 2nd and 3rd DIPJs; 2nd and 3rd PIPJs; 1st CMCPJs of both hands

Table 3. Classification criteria for hip OA (ACR) [33]

2.1 Complaints and Anamnesis

When examining a patient with suspected OA, a thorough medical history taking and a complete clinical examination are recommended in order to accurately diagnose the disease and rule out other musculoskeletal disorders [13]. It is necessary to determine the age of onset, localization of pain, its character, intensity, duration, relation to movement, duration, time of onset, and the efficacy of previous therapy. It is extremely important to clarify the characteristics of pain experienced by the patient for differential diagnosis and to determine its genesis.

Limbs deformities develop gradually (Hallux valgus, varus or valgus deformities of the knee joints, "square" hand, Heberden's and Bouchard's nodes in the distal and proximal interphalangeal joints of the hands, respectively) [13,27,32,37–47].

Level of Evidence BLevel of Confidence 2Level of recommendation B (level of evidence – 2).

2.2 Physical Examination

All patients with generalized OA are recommended to assess pain intensity using the visual analogue scale (VAS, see Appendix G1. Visual Analogue Scale) or the numerical rating scale (NRS, see Appendix G1. Numerical Rating Scale), or the verbal rating scale (VRS) (see Appendix G1. Verbal Rating Scale) at the time of presentation and dynamically in the most painful joint.

Additionally, it is recommended to determine deformities (flexion contractures, limb shortening, flatfoot, varus or valgus deformities), instability, periarticular tissue edema, and muscle atrophy. The patient is examined in both standing and lying positions.

By palpation, it is recommended to detect: tenderness of the joint and periarticular tissues, joint crepitus, presence of synovitis, and the state of the ligamentous-muscular apparatus.

To determine joint function, it is recommended to study the range and quality of active and passive movements.

Level of Evidence BLevel of Confidence 2Level of recommendation B (level of evidence – 2).

Comments: all patients with knee pain must be examined to detect movement limitation, crepitus, and synovitis – the main symptoms of knee OA. It is necessary to determine joint axis deviation, instability, and pain upon palpation of the patella and periarticular tissues (their edema).

Characteristic signs of hip OA upon examination include limited range of motion in the joint (internal rotation <15° (sensitivity – 66%) and flexion >115° (sensitivity – 96%)), pain during internal rotation, and tenderness upon palpation of the inguinal region lateral to the femoral artery pulsation site. Attention should be paid to fixed flexion and/or external rotation of the joint, and limb shortening [33].

Typical signs of hand OA are Heberden's and Bouchard's nodes or bone overgrowths with or without deformity (i.e., lateral deviation of interphalangeal joints, subluxation, and adduction of the base of the 1st digit of the hand) involving characteristic joints – DIPJs, PIPJs, the base of the 1st digit, and MCPJs of the 1st, 2nd, and 3rd digits [34].

When the 1st MTPJ is affected, it is necessary to assess the presence of tenderness upon joint palpation and range of motion in the joint (normal: 70–90º dorsiflexion and 30º plantarflexion. Limitation of dorsiflexion is most common at the onset of the disease, and plantarflexion is limited in more advanced stages), as well as the presence of deformity and synovitis.

Severe synovitis accompanied by hyperemia and hyperthermia is not typical for OA [49].

A somatic examination is performed on all patients to rule out specific causes of back pain. It is aimed at detecting spinal fractures, malignancies, infectious processes, and somatic diseases that can manifest as back pain, and includes checking for fever, weight loss, skin changes, lung auscultation, abdominal palpation, and lymph node examination. Local tenderness in the projection of the facet joints is one of the most informative tests, which is recommended to be performed in the sitting and prone positions to eliminate the influence of muscle tone on test results; frequent signs of OA in this localization also include increased pain upon extension, rotation, and lateral flexion of the spine, as well as tenderness upon palpation of the paraspinal region.

• All patients with polyarthrosis are recommended to undergo a general therapeutic examination to detect obesity, diabetes mellitus, cardiovascular diseases, and renal and digestive disorders [55,56].

GPP CLOE 4Grade of Recommendation C (Level of Evidence – 4).

Comments: the presence of comorbid conditions is associated with worse OA outcomes, and their presence or treatment may determine contraindications for prescribing OA medications.

2.3 Laboratory Diagnostics

There are currently no specific laboratory tests for OA.

Comment: laboratory blood tests are not required for the diagnosis of OA, but are prescribed primarily for:

– identifying potential contraindications to pharmacotherapy;

– differential diagnosis.

Comment: laboratory urine tests are not required for the diagnosis of OA, but are prescribed primarily for:

– identifying potential contraindications to pharmacotherapy;

– differential diagnosis.

• In the presence of synovitis, for differential diagnosis, it is recommended to perform:

– determination of serum C-reactive protein (CRP) level, anti-cyclic citrullinated peptide antibodies (anti-CCP) in the blood, and rheumatoid factor (IgM RF) in the blood [60–63].

ACR CLEL 5Level of Clinical Recommendation C (Level of Evidence – 5).

– synovial fluid analysis (cytological examination of synovial fluid, examination of chemical properties of synovial fluid, protein level in synovial fluid, and physical properties of synovial fluid) is recommended as an additional examination method for all patients with synovitis for differential diagnosis with rheumatoid arthritis, microcrystalline, or septic arthritides [27,64–68].

ACR BLEL 3Level of Clinical Recommendation B (Level of Evidence – 3).

Comments: in the presence of knee joint synovitis, joint puncture with evacuation of synovial fluid and its subsequent analysis is necessary. OA is characterized by a non-inflammatory nature of the synovial fluid: sterile, clear or slightly turbid, viscous, with a leukocyte concentration of less than 2000/mm³. Higher values are characteristic of inflammatory joint diseases. Aocytosis exceeding 100,000 cells per mm³ suggests the presence of infectious arthritis. RF and especially anti-CCP are predominantly not detected in OA.

2.4 Instrumental Diagnostics

X-ray examination is the most thoroughly studied and reliable instrumental diagnostic method for OA. One of the most important radiographic symptoms allowing indirect assessment of the articular cartilage status is the joint space width. According to WHO/ILAR recommendations, the joint space width should be measured at its narrowest point.

Normal values of the radiological joint space in adults (according to Schinz–Friedler) [69]:

• shoulder joint – 2.0–4.0 mm;

• metacarpophalangeal and interphalangeal joints – 1.5 mm;

• hip joint – 4.0–5.0 mm;

• knee joint – 6.0–8.0 mm;

• metatarsophalangeal joints – 2.0–2.5 mm.

The stage of OA is determined based on the severity of joint space narrowing, subchondral osteosclerosis, and the size of marginal osteophytes (see the Kellgren and Lawrence classification).

• In case of suspected knee OA, it is recommended to perform anteroposterior and lateral weight-bearing radiographs of the knee joints, and for the evaluation of the patellofemoral joint — a flexed lateral view for diagnosis, determination of the radiological stage, and assessment of progression [27,45,70–72].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: anteroposterior weight-bearing knee radiography (capturing both knee joints in a standing position with semi-flexed knees) along with an additional lateral view is the "gold standard" for diagnosing knee OA. Classic radiographic characteristics include joint space narrowing, osteophytes, subchondral bone sclerosis, and subchondral cysts. If these signs are present, further instrumental examinations (MRI, ultrasound, CT) are not required to diagnose OA. It is advisable to perform knee radiography every 1–2 years to evaluate treatment efficacy and rule out a "rapidly progressive" form of the disease.

• In case of suspected hip OA, it is recommended to perform pelvic radiography for diagnosis, determination of the radiological stage, and assessment of progression [33,73,74].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: it is advisable to perform anteroposterior pelvic radiography with up to 20° of internal rotation of the feet in all patients with suspected hip OA. Classic radiographic characteristics include joint space narrowing, osteophytes, subchondral bone sclerosis, and subchondral cysts (sensitivity 61–91%, specificity 60–90% for individual features) [33].

Targeted radiography of the hip joints in a standing or supine position is used only as an auxiliary method to clarify the diagnosis or prior to planned surgical intervention on the joint [74].

It is necessary to perform pelvic radiography every 1–2 years to evaluate treatment efficacy and rule out a "rapidly progressive" form of the disease.

• In case of suspected small joint OA, it is recommended to perform hand radiography for diagnosis, determination of the radiological stage, and assessment of progression [28,75].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: radiography of both hands in a direct view on a single film is recommended for diagnosis, including differential diagnosis. Typical features include joint space narrowing, osteophyte formation, subchondral bone sclerosis, and subchondral cysts. Involvement of the wrist joints and subluxations in the MCP joints are not characteristic of OA at this localization [76,77].

Some patients with hand joint OA present with an erosive form: interphalangeal joint deformities resembling "seagull wings" or "saw teeth" are identified. This OA phenotype is characterized by frequent involvement of the interphalangeal joints of the hands in the pathological process [78].

Comments: radiography of the feet in two projections is advisable to perform only for differential diagnosis, prior to consultation with an orthopedic trauma surgeon, or before planned surgical intervention. The anteroposterior view is performed as follows: the distance from the X-ray tube to the examined foot must be 1 meter, which allows precise determination of the metatarsal bone dimensions, and is taken at a 15-degree angle relative to the vertical plane, ultimately yielding a strictly perpendicular projection to the metatarsal bones [49,80,81].

Comments: radiography of a spinal segment, with functional tests if necessary, is advisable when the patient has subacute or chronic spinal pain to rule out a specific nature of the disease [82,83].

Spinal radiography allows the detection of congenital anomalies and deformities, vertebral fractures, spondylolisthesis, and instability during functional tests. Classic radiographic signs of facet joint OA include joint space narrowing, osteophytes, subchondral cysts and/or erosions, and articular process hypertrophy [31].

• As an additional method to detect osteonecrosis, osteitis, synovitis, tendon, ligament, and/or muscle damage, joint MRI is recommended [52,84,85].

GPP CLOE 4Grade of Recommendation C (Level of Evidence – 4).

Comments: indications for MRI of the knee, hip joints (one joint), and foot include suspected osteonecrosis, osteitis, synovitis, meniscal tears (in knee OA), tendon, ligament, and/or muscle damage. Knee MRI helps detect early structural damage that helps clarify the diagnosis in early-stage disease.

- In hand joint OA, MRI is advisable to perform only in patients with erosive OA to determine the severity of the inflammatory process. MRI in this disease phenotype allows the detection of OA-associated erosions in the proximal interphalangeal joints and cortical defects in the MCP joints more frequently than standard radiography.

- MRI, CT, and SPECT of a spinal segment are used primarily in the presence of "red flag" signs of dangerous diseases to rule out trauma, tumor, septic conditions, spondyloarthritis, etc.

• As an additional method to detect synovitis, tendon, ligament, and/or muscle damage, joint ultrasound is recommended [52,84–87].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: indications for knee and hip joint ultrasound in OA include diagnosis of synovitis; suspected meniscal injury (for knee joints), tendon, ligament, and muscle damage; suspected presence/rupture of a Baker's cyst (for knee joints), detection of bursitis; during intra-articular administration of medications or registered medical devices in OA.

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

Main management principles for patients with OA

1. OA is a potentially severe [88] heterogeneous disease with diverse phenotypes (metabolic, inflammatory, "osteoporotic", mixed, etc.), usually requiring a multidisciplinary therapeutic approach [56,89–95].

2. Therapy must be optimal and based on shared decision-making between the physician and the patient [96,97].

3. Optimal OA therapy is based on a combination of non-pharmacological, pharmacological, and surgical treatment methods [50,51,98–102].

Comments: for a long time, OA therapy was aimed exclusively at reducing pain, improving quality of life and joint function, and preventing/limiting radiographic disease progression. In recent years, approaches to OA treatment have expanded significantly: much attention is paid to the correction of inflammatory, biomechanical, and metabolic changes, as well as the alleviation of social isolation, depression, and anxiety. Today, effective pain control in OA requires considering not only the type of pain (nociceptive, neuropathic, and/or nociplastic), but also psychological (mood, depression, catastrophizing, negative behavioral responses, etc.) and demographic (age, gender, etc.) characteristics of the patient, environmental factors and social conditions, lifestyle, physical well-being, biological and medical aspects, as well as the patient's beliefs and values. Only by acknowledging the importance of a comprehensive, patient-centered approach to OA management can physicians effectively treat patients with OA.

3.1 Conservative Treatment

Substantial progress in understanding the pathogenetic mechanisms of OA has led to the development of strategies for its early detection, as well as interdisciplinary and multimodal treatment [102, 107, 108]. For a long time, OA therapy was aimed exclusively at reducing pain, improving quality of life and joint function, and preventing/limiting disease progression. In recent years, approaches to OA treatment have expanded significantly: much attention is paid to correcting inflammatory, biomechanical, and metabolic changes, and eliminating social isolation, depression, and anxiety. Today, for effective pain control in OA, it is necessary to consider not only its type (nociceptive, neuropathic, and/or nociplastic), but also the patient's psychological (mood, depression, catastrophizing, negative behavioral reactions, etc.) and demographic (age, gender, etc.) characteristics, environmental factors and social conditions, lifestyle, physical well-being, biological and medical aspects, and the patient's beliefs and values. Thanks to the understanding of the need for a comprehensive and patient-centered approach in the treatment of OA, it becomes possible to create more personalized and effective plans tailored to the individual needs of patients.

Before prescribing medications, it is important to discuss all the pros and cons of each option with the patient, including potential side effects. This will increase adherence to treatment, reduce anxiety, and allow for the consideration of the patient's individual characteristics. Open dialogue builds trust and promotes effective treatment. At the same time, disease-modifying osteoarthritis drugs (DMOADs) occupy a fundamental position in OA therapy [109].

Previously, medications included in this group were called symptomatic slow-acting drugs (SYSADOA) or "chondroprotectors," which, according to the international anatomical therapeutic chemical (ATC) classification of drugs, belong to group M01 – "Anti-inflammatory and antirheumatic products". Currently, they are classified as basic therapy drugs for this disease and, in accordance with international and national OA treatment algorithms, should be prescribed immediately after diagnosis is established.

3.1.1 Disease-modifying therapy for osteoarthritis

Table 4. ATC codes and pharmacotherapeutic groups of disease-modifying drugs

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: the symptomatic effect of disease-modifying drugs in OA develops 4–12 weeks after the start of administration, and for the structure-modifying action of the drugs, the duration of treatment should be at least 2 years. Unlike NSAIDs, after discontinuation of treatment, they have a carry-over effect for 2–4 months. However, recent studies show that positive results obtained with the use of pharmacologically substantiated and well-studied medicinal products cannot be extended to dietary supplements and other substances lacking an evidence base [100, 124, 125]. It should be emphasized that the evidence base for the efficacy of disease-modifying drugs varies depending on the localization of the lesion.

Comments: glucosamine, chondroitin sulfate, and their combinations are the most studied in the treatment of generalized OA. They have an analgesic effect, slow down the disease progression (evidence obtained in OA of the knee and hip joints, as well as hand joint OA, including the erosive form of the disease), and reduce the risks of needing knee and hip arthroplasty [133–135].

A pronounced effect occurs after 4–12 weeks. Recommended daily doses: 1500 mg/day for glucosamine and 1000 mg/day for chondroitin sulfate. When used in combination, the dosages of glucosamine and chondroitin sulfate can be adjusted due to the synergistic effect. A high safety profile allows these drugs to be prescribed to patients with various comorbidities [136–138].

In addition, data are accumulating on the favorable pleiotropic effects of these drugs, determining the possibility of their use not only in OA, but also in other significant comorbid conditions [139].

At the beginning of therapy, to increase bioavailability and achieve a more rapid analgesic effect, chondroitin sulfate and glucosamine preparations can be administered parenterally as intramuscular injections [119, 140].

Comments: ASU at a dose of 300 mg/day has proven efficacy in reducing pain intensity in knee and hip OA [141–143]; isolated studies confirm the analgesic effect of the drug in hand and spine OA [144, 145]. Two- and three-year studies have demonstrated the structure-modifying effect of ASU in hip OA [146, 147].

This medicinal product is characterized by high safety: the frequency of adverse reactions during its use is comparable to placebo [117, 118].

Comments: diacerein has proven efficacy in knee OA, and isolated studies confirm the analgesic effect of the drug in hip, hand, and spine OA [157–161]. A three-year study showed the presence of a structure-modifying effect of diacerein in hip OA [156]. Diacerein has an efficacy comparable to NSAIDs, but unlike the latter, it has a "carry-over" effect [154, 155, 162]. It is the drug of choice in patients with OA and metabolic syndrome [157, 163–168]. It is prescribed 1 capsule (50 mg) for 4 weeks, then, if well tolerated, 1 capsule 2 times/day for a course of at least 4 months. The safety profile of diacerein is characterized as good; the most frequent adverse reaction is an increased frequency of bowel movements [169, 170]. Urine discoloration from yellow to brown (depending on pH) may occur, which does not require dose reduction (discontinuation) of the drug.

Comments: the drug has an analgesic effect in generalized OA [175], slows down disease progression in knee OA (evidence obtained from a 2-year double-blind placebo-controlled study). The use of a bioactive concentrate from small marine fish shows a faster development of the analgesic effect compared to oral agents. It is prescribed intramuscularly at 1 ml daily for 20 days or 2 ml every other day for 10 days – 2 courses per year. The drug can also be administered intra-articularly. This medicinal product is characterized by good safety, including in patients with comorbidity [175,178]. The frequency of adverse reactions during its use is comparable to placebo.

Comments: glycosaminoglycan-peptide complex has a symptomatic effect in generalized OA; its structure-modifying effect has also been demonstrated in long-term studies in hip and knee OA. The drug is characterized by a favorable safety profile, including in patients with severe comorbidity [187]. It is prescribed according to the following scheme: day 1 – 0.3 ml intramuscularly, day 2 – 0.5 ml intramuscularly, starting from day 3 – 1 ml every other day. A full course of therapy is 25 intramuscular injections of 1 ml each (over 8 weeks) or 15 injections of 2 ml each (over 5 weeks), repeated 2–4 times a year.

• In the absence of a significant clinical effect (pain reduction of less than 40 mm on the VAS) during monotherapy with one of the disease-modifying drugs, it is possible to recommend a combination of drugs from different pharmacological groups [188–191].

GRC CLOE 2Grade of Recommendation C (Level of Evidence – 2).

Comments: there is a limited amount of evidence confirming the advantage of combination therapy over monotherapy in the treatment of OA: combinations most often considered are diacerein plus glucosamine, diacerein plus a combination of chondroitin sulfate and glucosamine, and diacerein plus glycosaminoglycan-peptide complex.

3.1.2 Symptomatic medicinal products for OA

• Patients with generalized OA are recommended the prescription of local (topical) NSAID formulations, which contribute to the effective relief of OA symptoms [39,95,98–100,132,192–202].

GGR BLOE 1Grade of Recommendation B (Level of Evidence – 1).

Comments: local NSAID formulations have proven analgesic efficacy in knee and hand OA [201]. In hip OA, their use is impractical, and for other localizations, efficacy has not been studied. These agents should be used for a duration of up to 2 weeks with a frequency of at least 3-4 times a day.

For mild pain (less than 40 mm on the VAS), they can be used independently. For more intense pain (greater than 40 mm on the VAS), to achieve a better effect, it is advisable to prescribe topical NSAIDs along with tablet formulations, which makes it possible to increase efficacy and reduce potential risks from systemic NSAIDs [195].

Topical NSAIDs, due to low systemic absorption (less than 10% of the concentration achieved after oral administration) [203], have a favorable safety profile, making it possible to prescribe them to patients with severe multimorbidity. The frequency of systemic adverse reactions with topical NSAID use is extremely low and comparable to that of placebo [198]. The vast majority of adverse reactions are local skin reactions: redness, rashes, and/or itching [204,205], which quickly resolve after drug discontinuation.

• Patients with generalized OA with moderate or severe pain are recommended the prescription of systemic NSAIDs (acetic acid derivatives and related compounds (diclofenac**, aceclofenac, etodolac, ketorolac**, etc.), oxicams (meloxicam, tenoxicam, lornoxicam, etc.), propionic acid derivatives (ibuprofen**, naproxen, ketoprofen**, flurbiprofen, dexketoprofen**, etc.), coxibs (celecoxib, etoricoxib, etc.), and other nonsteroidal anti-inflammatory and antirheumatic drugs (nimesulide) taking into account patient comorbidity [98–102,132,195,206–208].

Table 5. ATC codes and pharmacotherapeutic groups of systemic and local NSAIDs

GCR CLOE 5Grade of Recommendation C (Level of Evidence – 5).

Comments: NSAIDs occupy a central place in the pharmacotherapy of pain in OA of any localization, possessing good analgesic potential [207]. However, in routine clinical practice, the prescription of NSAIDs is associated with a number of difficulties, in particular the lack of monitoring of adverse reactions and consideration of concomitant conditions, unjustifiably long treatment courses, and the simultaneous prescription of several drugs from this group to the patient, which leads to a significant increase in the risk of complications without increasing efficacy. When treating patients with OA, it is advisable to limit NSAID intake both in terms of dosage and duration of administration.

It is important to know that:

- the efficacy of most both selective NSAIDs (sNSAIDs) (M01AH01, M01AH05) and non-selective NSAIDs (nsNSAIDs) (M01AB05, M01AB16, M01AB08, M01AB15, M01AC06, M01AC02, M01AC05, M01AE01, M01AE02, M01AE03, M01AE09, M01AE17, M01AX17) is comparable and depends on the dose, as well as the individual patient response to a specific drug.

- The use of injectable NSAID formulations, as well as fast-dissolving oral preparations, may have an advantage in the speed of onset of the analgesic effect compared to oral administration.

- The main risk factors for gastrointestinal adverse reactions are age >65 years, gastric and duodenal ulcer, a history of upper gastrointestinal bleeding, and concomitant use of antithrombotic agents [206].

- The main risk factors for cardiovascular adverse reactions are cardiovascular diseases (IHD, hypertension, CHF, etc.), as well as high cardiovascular risk [209].

- A differentiated approach to the choice of NSAIDs is necessary depending on the presence of concomitant diseases in the patient.

- Patients at high risk of gastrointestinal adverse reactions are recommended to use NSAIDs whose mechanism involves preferential COX-2 inhibition [210].

- In the presence of risk factors for NSAID-induced gastropathy and/or enteropathy, non-selective NSAIDs can be prescribed with proton pump inhibitors (A02BC) and/or rebamipide (A02BX14) [210].

- In patients with cardiovascular diseases, NSAIDs should be used at the minimum effective dose for the shortest possible duration. Cardiovascular adverse events are characteristic of all NSAID preparations. The risk of their development depends on the individual characteristics of the drug and the dose used, rather than on cyclooxygenase-2 (COX-2) selectivity. A contraindication for prescribing any NSAIDs is a very high risk of cardiovascular complications, as well as dual or triple anticoagulant therapy. For moderate/high cardiovascular risk, short-term use is recommended for propionic acid derivatives (naproxen (M01AE02), ibuprofen** (M02AA13), celecoxib (M01AH01)), acetic acid derivatives and related compounds (aceclofenac (M01AB16)), and oxicams (lornoxicam (M01AC05) and tenoxicam (M01AC02)) [60,206,209,211].

- The intake of any NSAIDs can provoke acute kidney injury, especially during the first month of treatment. This risk is lower in patients with normal renal function. NSAIDs can also cause other renal complications, such as membranous nephropathy, interstitial nephritis with nephrotic syndrome, acute papillary necrosis, and the development and progression of chronic kidney disease, particularly in patients with type 2 diabetes mellitus or hypertension. Therefore, it is important to measure the glomerular filtration rate in patients for whom a drug from this group is planned to be prescribed. NSAIDs are not recommended for patients with a glomerular filtration rate of less than 30 mL/min.

- When prescribing NSAIDs, the potential for drug interactions should be considered. Simultaneous intake of NSAIDs from different groups is not recommended, as it significantly increases the risk of adverse reactions.

- The decision to modify NSAID therapy should be made 5–7 days after initiating treatment with drugs of this group [209].

- When using NSAIDs, it is advisable to monitor the gastrointestinal tract, liver and kidney function, and blood pressure [206,212].

• Paracetamol** (N02BE01) is conditionally recommended for short-term use in generalized OA for mild joint pain or when NSAID use is contraindicated [13,100,132,192,213–222].

GPP ALOE 1Grade of Recommendation A (Level of Evidence – 1).

Comments: paracetamol** should not be prescribed long-term for OA; it can be used in short courses for mild joint pain or when NSAIDs are contraindicated, at a dose of less than 3 g/day. Recent meta-analyses indicate its low efficacy in OA [214,219].

According to these studies, paracetamol** is not effective for most patients with OA of various localizations [98]. In the OARSI guidelines (2019) [101], the drug is not prescribed for generalized OA due to low efficacy and the risk of adverse reactions.

At therapeutic doses, adverse effects of paracetamol** are rare and limited primarily to potential allergic skin reactions [223]. However, high doses and prolonged administration of the drug can lead to gastrointestinal complications (including severe hepatotoxicity) [218,224–226], renal complications [226] and cardiovascular complications [215,227,228]. The drug should not be prescribed to patients with liver disease and chronic alcoholism.

• Tramadol** (N02AX02, State Register of Medicines pharmacotherapeutic group: analgesics; opioids; other opioids) is conditionally recommended for short-term use in generalized OA to control severe pain refractory to prior conservative therapy, or when there are medical contraindications to it [98,100,229–232].

GGR BLOE 1Grade of Recommendation B (Level of Evidence – 1).

Comment: tramadol** is recommended for relieving severe pain for a short period when NSAIDs and paracetamol** are ineffective or when optimal doses of these drugs cannot be administered. The absence of direct ulcerogenic and prothrombotic effects of tramadol** makes its administration possible in patients with high gastrointestinal and cardiovascular risk.

During the first days of intake, a dose of 50 mg per day is recommended, followed by an increase, if necessary, to 200–300 mg per day. The drug exerts a dose-dependent analgesic effect in OA, with the maximum pain-relieving effect noted at a dose of 300 mg. However, as the dose increases, there is an increase in the risks of adverse reactions, especially from the gastrointestinal tract and central nervous system (nausea, constipation, sleep disturbances, dizziness, potential for habituation, etc.). There are also concerns regarding the use of tramadol** in OA due to increased mortality, venous thromboembolism, and hip fractures compared to commonly prescribed NSAIDs [233,234]. Tramadol** intoxication, although rare, can be accompanied by serious side effects, including altered consciousness (up to 30%), seizures (about 15%), agitation (up to 10%), and respiratory depression (up to 5%) [235,236]. Additionally, tramadol** use carries a risk of serotonin syndrome associated with excessive serotonergic activity in the central nervous system [237].

• Duloxetine (N06AX21, State Register of Medicines pharmacotherapeutic group: psychoanaleptics; antidepressants; other antidepressants) is conditionally recommended to control chronic pain in generalized OA when prior conservative therapy is ineffective and when there are signs of central sensitization, neuropathic pain, and/or depression [98,100,101,232,238–245].

GPP ALOE 1Grade of Recommendation A (Level of Evidence – 1).

Comments: duloxetine belongs to the group of selective serotonin and norepinephrine reuptake inhibitors, and also contributes to weak inhibition of dopamine uptake. The drug is considered an alternative therapy in patients with signs of central sensitization, depression, and widespread/chronic pain.

Results of recent meta-analyses demonstrate mixed results regarding the efficacy of duloxetine in OA [238,239,244]. An analysis of short-term drug use (up to 2 weeks) reveals no significant analgesic effect, whereas longer treatment courses (from 6 weeks to a year) demonstrate a statistically significant, although clinically modest, improvement [238]. Most studies investigating the efficacy of duloxetine were conducted in knee OA; data on its use in hip involvement and chronic lower back pain are limited. Consequently, duloxetine is not included in the OARSI (2019) list of recommended drugs for treating generalized OA [101]. At the same time, the ACR (2019) acknowledges that, despite the predominance of data in knee involvement, the potential effect of duloxetine may be similar in hip and hand OA [98]. Treatment with duloxetine is associated with a high risk of adverse reactions, such as nausea, constipation, hyperhidrosis, cough, myalgia, arthralgia, tachycardia, dry mouth, etc. This necessitates careful monitoring by medical staff and cautious titration of the drug, starting with the minimum dose of 30 mg per day [238].

• Antiepileptic drugs (pregabalin** (N02BF02, State Register of Medicines pharmacotherapeutic group: analgesics; other analgesics and antipyretics), gabapentin (N03AX12, State Register of Medicines pharmacotherapeutic group: antiepileptic drugs; other antiepileptic drugs)) are conditionally recommended to control chronic pain in generalized OA when prior conservative therapy is ineffective and in the presence of signs of central sensitization and neuropathic pain [246–249].

Leveled recommendation BLevel of recommendation evidence B (level of evidence – 2).

Comments: pregabalin** or gabapentin may be recommended for patients with generalized OA in the presence of neuropathic pain and/or central sensitization refractory to prior conservative therapy. Several studies have shown that adding one of these drugs to the combination therapy in patients with knee and hand OA led not only to a decrease in pain intensity but also to an improvement in their functional status [250–252].

Therapy should be initiated with minimum doses (pregabalin** – 75 mg, gabapentin – 300 mg), gradually titrating the dose until an analgesic effect is achieved (maximum doses in RCTs for pregabalin** – 600 mg, gabapentin – 1800 mg) [368–371]. The prescription, dose titration, and duration of administration must be determined by a neurologist.

The use of pregabalin** and gabapentin may cause various adverse events, including dizziness, somnolence, peripheral edema, and nausea. Given the potential risk of suicidal behavior and fatal outcomes [253–256], strict medical monitoring of patients taking these drugs is required.

3.1.3 Intra-articular injections

• In cases of synovitis in generalized OA that is not controlled by other methods of conservative therapy, it is recommended to administer intra-articular glucocorticoids [102,104,105,354], no more than 2–3 times a year per joint.

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: intra-articular GC injections are recommended for synovitis and lack of response to prior therapy in knee OA by most guidelines for the management of this disease [98,100,101,232]. For hand or hip OA, local GC use is conditionally recommended [132,232]. These discrepancies are due to the limited number of publications on the efficacy and safety of intra-articular GC injections for these disease locations [257].

GCs demonstrate greater efficacy compared to placebo; however, their effect is mostly short-term, with peak efficacy observed 1–2 weeks after the injection [258].

Currently, the following GCs are available for intra-articular use: triamcinolone (40 mg/mL) (H02AB08, ATC drug classification: systemic corticosteroids; glucocorticoids), betamethasone (0.25 – 2 mL) (H02AB, Glucocorticoids), and hydrocortisone acetate + lidocaine (25 mg + 5 mg/mL) (H02AB09, Glucocorticoids).

No more than 2–3 injections per year should be administered into the same joint due to the risk of osteonecrosis [259] and cartilage volume reduction [260,261]. These injections should be performed under visual control (ultrasound), which increases therapeutic efficacy and reduces the risk of adverse events.

• Intra-articular administration of synovial fluid substitutes*** (viscosupplements) based on hyaluronic acid is conditionally recommended for generalized OA in the most affected large joint to control pain resistant to previous conservative therapy or when there are medical contraindications to it [262–269].

GGR BLOE 1Grade of Recommendation B (Level of Evidence – 1).

Comments: intra-articular administration of sodium hyaluronate derivatives is indicated when previous treatments are ineffective and in the absence of synovitis ("dry" joint). It is advisable to administer these medications under ultrasound guidance or, at least, to perform this examination prior to the procedure [270,271].

Hyaluronate-based drugs for knee or hip OA help reduce pain, improve joint function, and enhance the patient's quality of life [264,272,273].

The maximum clinical effect is achieved on average 8 weeks after administration, after which a gradual decrease in therapeutic efficacy is observed by 6 months [273].

There is a limited number of studies confirming the efficacy of these agents in hand OA (first carpometacarpal joint) [274–277], and no evidence for first metatarsophalangeal joint involvement [278].

The use of hyaluronate derivatives has a more favorable safety profile compared to NSAIDs and can be an alternative to the latter in the treatment of knee and/or hip OA, especially in patients with contraindications to NSAIDs and in individuals with high comorbidity. Accumulating data indicate the superiority of high-molecular-weight hyaluronic acids over low-molecular-weight ones [265,268]; it has also been noted that repeated intra-articular injections of these drugs are both effective and safe [213,266,267].

Nevertheless, it is worth noting factors that can reduce therapy efficacy: high BMI, advanced radiographic stage, incorrect intra-articular injection technique, off-label administration (not into a "dry" joint), etc. [272,279].

• Intra-articular administration of platelet-rich plasma is conditionally not recommended in generalized OA [98,100,101].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: non-standardized methods of platelet-rich plasma preparation, along with variability in dosing and injection frequency, as well as compositional inconsistency, make it difficult to objectively evaluate the efficacy of this treatment method [280]. Therefore, further studies are required to clarify their symptomatic and structural effects.

At the same time, this treatment method can be conditionally recommended for patients with knee and/or hip OA who have not achieved adequate pain control with prior conservative therapy, in the presence of contraindications to it, and at the patient's initiative. Administration of these drugs is advisable under ultrasound guidance or, at least, this examination should be performed prior to the procedure [270,271].

According to available data, intra-articular injections of platelet-rich plasma help reduce pain for six to twelve months and improve joint function in knee and hip OA [272,281–287]. It is also noted that repeated intra-articular injections of these drugs are both effective and safe in knee OA [288]. There are isolated studies demonstrating the efficacy of this treatment method in first carpometacarpal joint OA [289], lumbar facet joints, and sacroiliac joints [290–295].

The safety profile of this therapy is comparable to placebo. The most frequent adverse event is a short-term (within 1–3 days) increase in pain [296–298], which typically resolves spontaneously or after taking paracetamol.

It must be remembered that it is recommended to discontinue all NSAIDs, including acetylsalicylic acid**, four to five half-lives prior to the injection (specifically, acetylsalicylic acid** one week prior). These medications should also be avoided after the procedure for four to eight weeks, which corresponds to the period of peak biological product efficacy. Following the administration of platelet-rich plasma, joint load should be restricted for 2–7 days (the duration of restrictions is determined individually by the attending physician based on the clinical situation and patient needs) [290].

• Intra-articular administration of autologous stromal vascular fraction and/or red bone marrow autologous cells into the joint cavity in generalized OA is conditionally not recommended [98,100,101].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: non-standardized methods for preparing autologous stromal vascular fraction and/or red bone marrow autologous cells, significant heterogeneity in cell source (allogeneic or autologous) and type, alongside variability in dosing and injection frequency, as well as compositional inconsistency, hinder the objective evaluation of this treatment's efficacy. Therefore, further studies are required to clarify their symptomatic and structural effects.

At the same time, this treatment method can be conditionally recommended for patients with knee and/or hip OA who have not achieved adequate pain control with prior conservative therapy, in the presence of contraindications to it, and at the patient's initiative [290,299–306].

Administration of these agents is advisable under ultrasound guidance or, at least, this examination should be performed prior to the procedure. To date, there are isolated studies demonstrating the efficacy of this treatment method in first carpometacarpal joint OA [289] and lumbar facet joint OA [307]. The safety profile of this therapy is characterized as good [272]. The material harvesting procedure may be accompanied by adverse events such as pain and hematoma formation at the puncture site. Rarely, lipoaspiration may lead to minor cosmetic defects. To minimize the risk of these complications, strict adherence to aspiration technique rules is required [308].

3.2 Surgical Treatment

• In case of ineffectiveness of previous therapy, progression of pain, presence of deformations leading to significant impairment of joint function and a decrease in quality of life, all patients with generalized OA are recommended an initial consultation (examination, consultation) with an orthopedic traumatologist to decide on the possibility and expediency of surgical intervention on the joints [50,51,100,132,309–313].

Level of Evidence BLevel of Confidence 2Level of recommendation B (level of evidence – 2).

Comments: surgical treatment methods are indicated when previous treatment is ineffective in patients with persistent pronounced symptoms. Currently, the most effective methods of surgical treatment for OA are corrective periarticular osteotomies and partial/total arthroplasty for knee and hip OA; trapeziectomy for 1st CMC OA; arthrodesis/arthroplasty for interphalangeal joint OA; and arthrodesis for 1st MTP joint OA.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

• All patients with OA are recommended education on disease management principles, which should begin immediately after diagnosis and accompany treatment throughout its course [50–52,60,98–102,132,208,314–320].

GPP ALOE 1Grade of Recommendation A (Level of Evidence – 1).

Comments: patient education is an obligatory component of all therapeutic interventions for OA of any localization, including generalized OA, carried out taking into account the individual characteristics of the patient and includes information about the disease, lifestyle modification recommendations, weight loss and the need for physical exercises. The main goal of educational programs is to increase the effectiveness of ongoing therapy by actively involving the patient in the treatment process. These programs have a positive impact on disease symptoms, improve joint and spinal function, quality of life, and treatment adherence. Educational programs should be organized on an ongoing basis.

• Patients with OA are strongly recommended to lose weight in the presence of overweight or obesity [50,51,60,98–102,314,315,317,321–327].

GGR BLOC 1Grade of Recommendation B (Level of Evidence – 1).

Comments: weight correction must necessarily be included in the complex treatment program for OA, since weight loss, especially in combination with exercise therapy, leads to a decrease in pain, improvement in the functional state of the knee and hip joints, and positively affects structural changes in cartilage tissue.

Overweight patients (body mass index greater than 25 kg/m²) are recommended to reduce body mass by at least 5-7.5% from baseline figures. Greater weight loss will lead to increased benefit. Recent studies have convincingly demonstrated that a 1% weight loss reduces the risk of total knee arthroplasty by 2% [328].

In the case of hand osteoarthritis, a 5% weight loss in long-term prospective observation did not lead to a significant reduction in the risk of development and relief of hand pain [329].

There is evidence that obesity increases the risk of symptomatic 1st MTP osteoarthritis and, conversely, weight loss can reduce pain intensity and manifestations of synovitis (level of evidence reliability – 3) [36,330,331].

The weight loss program should be tailored to the needs of the individual. Clear goals and ways to achieve them should rely on social support, individual nutritional characteristics, portion size control, fat and sugar intake restriction, meal timing regulation, and work with behavioral triggers such as stress or poor sleep.

In general, this is not about strict dietary restrictions that are difficult to implement on a long-term basis, but about the gradual formation of an eating style that meets current therapeutic goals. Drastic, non-physiological dietary restrictions and fasting are contraindicated.

Comments: there is growing evidence that dietary supplements, including pharmaconutraceuticals containing active ingredients such as: oral collagens, methylsulfonylmethane, vitamin D, boswellic acids, L-carnitine, rose hip extract, etc., lead to a decrease in pain and an improvement in the functional activity of the OA patient. Patients are recommended to be prescribed dietary supplements that have an evidence base.

• Patients with OA are recommended regular exercise programs that help reduce pain and improve joint functional activity [52,98,100,101,208,315,317,343–356].

GPP ALOE 1Grade of Recommendation A (Level of Evidence – 1).

Comments: motor rehabilitation plays a major role in therapy and is indicated for all patients with OA, being regarded as the most effective treatment method. Various types of exercises: muscle strengthening, stretching, increasing flexibility and mobility, resistance, neuromuscular and aerobic exercises - can reduce pain intensity, improve function and quality of life in patients with various stages of the disease of any localization. Currently, there is no convincing data on the superiority of any specific exercise therapy method or set of exercises. Regularity of performance is of primary importance, and they should be used for at least 8 weeks, while the volume of training should be constantly increased. Exercises should not be performed through pain; they must be done without static loads - lying down, sitting or in a pool. The method of exercise performance (e.g., individual or group classes, supervised or unsupervised, in-person or using digital technologies, on land or in water) and the choice of physical activity should be based on the patient's mobility and individual characteristics, as well as service availability and patient preferences [357]. Contraindications and precautions are determined by the presence of OA complications and comorbidities. To improve the quality of treatment, a consultation with a physical rehabilitation specialist (kinesiospecialist) / exercise therapy instructor is advisable. The use of new telemedicine technologies is also indicated, which can increase treatment adherence, monitor the quality of exercise performance and compliance with recommendations, and as a consequence, increase the effectiveness of non-pharmacological treatment [358]. Also, all patients with generalized OA are shown walking, which significantly improves the clinical manifestations of OA [359–362].

• Patients with generalized OA are recommended orthotics in the absence of contraindications [98–102,132,363–373].

GCR BLOE 2Grade of Recommendation B (Level of Evidence – 2).

Comments: orthoses (braces) help reduce pain, increase functional activity (increase stride length, walking speed) and quality of life in patients with knee OA.

Joint fixation using malleable lateral rigid stays and hinges makes it possible to correct the altered axis of the limb, unload the internal or external compartments of the knee joint and, with the help of stabilizers, center the patellar motion relative to the femoral condyles. In case of medial knee joint damage and varus deformity, orthoses that unload the medial compartments of the joint can be used. In the presence of valgus deformity – orthoses that unload the lateral compartments of the joint (evidence for this type of deformity is available only in the short-term observation period).

Individuals with signs of knee instability are also indicated the use of orthoses with semi- or rigid fixation.

To reduce pain in the 1st CMC joints in OA, long-term wearing of orthoses is indicated. Long rigid orthoses are effective in reducing pain intensity, while short rigid ones improve functional activity in this joint [366].

Wearing corsets, braces, belts and other special devices is not recommended for patients with facet joint OA, but is indicated for those who have specific orthopedic problems requiring correction.

There are isolated studies investigating the effectiveness of orthoses in hip OA, demonstrating an analgesic effect (reduced pain during walking and at night), improved gait biomechanics (increased stride length and walking speed) and increased range of pelvic motion in the sagittal plane [364,374].

Works studying the effectiveness of orthoses in 1st MTP OA have demonstrated pain reduction and improved function in this joint [375–377].

Despite the proven efficacy of orthoses (braces) in OA, patient compliance with this treatment method is low. The main reasons for the infrequent use of orthoses, especially in hip OA, are their cost, weight, rigidity, restriction of freedom of movement, and aesthetic factor.

• Patients with generalized OA are recommended to use walking aids and wear shoes with shock-absorbing soles [98,100–102,208,373–375,378–381].

GCR BLOE 2Grade of Recommendation B (Level of Evidence – 2).

Comments: patients with generalized OA are advised to wear comfortable shoes with shock-absorbing properties. To unload the knee and/or hip joints in advanced stages of OA, walking with a cane in the hand (opposite to the affected lower limb), using crutches, or other assistive devices is recommended. It is important that the cane is of the appropriate height and light for the patient. It is recommended to consult a physical and rehabilitation medicine physician not only for the correct choice of a cane or crutches but also for training in their proper use. Also, if necessary, patients are recommended to use:

- Dressing aids (necessary for severe OA of the hand joints, including the erosive form): special buttons, fasteners, shoe-donning devices.

- Home mobility aids: support rails, stair lifts, special (high) armchairs and chairs, etc.

- Bathroom safety aids: adjustable shower chairs, special toilet seats, etc.

There is evidence that custom foot orthoses with a 5–10° raised lateral or medial edge (depending on the axis of the lower limb), providing good shock absorption and arch support, help improve movement biomechanics, functional outcomes, and reduce pain in the lower extremity joints [382].

• All patients with generalized OA in the absence of contraindications are recommended physical therapy methods [36,98,100,102,208,383–413].

GGR BLOC 1Grade of Recommendation B (Level of Evidence – 1).

Comments: physical therapy methods are prescribed by a physical and rehabilitation medicine physician or a physical therapist. The inclusion of physical therapy in the comprehensive medical rehabilitation program for patients with OA helps reduce joint and back pain, improve functional status, motor activity, and locomotor parameters. The choice of a specific physical therapy method depends on the clinical symptoms of the disease, comorbid conditions, the availability of a particular method, and is based on the patient's needs.

Physical therapy methods remain a common way of treating OA of various localizations in our country and are offered as a pain self-management strategy/adjunct to exercise if the patient finds it useful [52,101].

In OA, Russian experts recommend prescribing local cryotherapy (especially in the presence of signs of inflammation in the knee joints, small joints of the hands and feet); it is possible to use transcutaneous electrical nerve stimulation / transcutaneous short-pulse electrical stimulation (A17.30.006), ultrasound therapy (medicinal ultraphonophoresis in joint diseases (A22.04.002.001)), ultra-high-frequency electric field (UHF therapy) (ultra-high-frequency current therapy in bone pathology (A17.03.006)), sinusoidal modulated currents (SMT therapy), and high-frequency electromagnetic fields (inductothermy). Combined pulsed currents, phonophoresis, drug magnetophoresis, general and local magnetotherapy can be used. Drug electrophoresis, pulsed current electrophoresis, diadic current electrophoresis (DCT-phoresis) are recommended, taking into account the individual characteristics of patients. When performing external ultraphonophoresis, topical agents recommended for the treatment of patients with OA are used. In case of a significant increase in pain intensity after several procedures of a particular physical therapy method, it is advisable to discontinue this therapy.

• Acupuncture is generally not recommended for the treatment of generalized OA [208,354,383,414,415].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: it is possible to prescribe a time-limited course of acupuncture as an adjunctive treatment when the patient has positive expectations of this therapy.

• Therapeutic taping is recommended as an auxiliary therapy method in OA [98,100,416,417].

GGR BLOC 1Grade of Recommendation B (Level of Evidence – 1).

Comments: therapeutic taping has become one of the popular methods for treating OA of the knee joints, spine, and 1st carpometacarpal joints in recent years, associated with a decrease in pain intensity and improved functional activity. However, there is currently no convincing evidence of the efficacy of this method.

• Cognitive behavioral therapy (CBT) is recommended as an auxiliary treatment method for generalized OA [98,101,418,419].

GGR BLOE 1Grade of Recommendation B (Level of Evidence – 1).

Comments: CBT teaches patients to use their resources to cope with pain and live a full life. It includes training in pain-reduction strategies; this therapy helps restructure negative thoughts and behavioral patterns that contribute to its development, as a result of which pain occupies less and less space in the patient's daily life. This therapy can be administered by specially trained professionals. These methods are highly effective and have evidence regarding the reduction of joint and back pain intensity. CBT is also indicated for OA patients who have coexisting sleep problems, depression, or psychological factors such as fear of movement and/or pain catastrophizing.

• All patients with generalized OA in the absence of contraindications are recommended spa and resort treatment (SRT) [420–426].

GPP ALOE 1Grade of Recommendation A (Level of Evidence – 1).

Comments: patients with generalized OA in the absence of disease "exacerbation" are indicated for SRT at mud and balneological resorts with chloride sodium, siliceous thermal, hydrogen sulfide, radon, and iodine-bromine mineral waters, which helps reduce pain, improve functional activity, and quality of life.

• Spinal massage and/or spinal/joint manipulative therapy are recommended as an auxiliary therapy method for generalized OA [52,100,389,427–430].

GGR BLOC 1Grade of Recommendation B (Level of Evidence – 1).

Comments: manipulative therapy and massage can be considered as an additional and alternative treatment option in patients with OA of the knee, hip, and facet joints. These methods help reduce pain intensity, stiffness duration, and improve functional activity in the short-term observation period (up to 9 weeks) [431]. Currently, there is no convincing evidence of the long-term efficacy of this therapy or in OA of other localizations.

5. Prevention and Dispensary Observation

5.1 Prevention of generalized OA

Population aging, unfavorable lifestyle changes (overeating, a sharp decrease in physical activity, chronic stress, etc.), and the increasing prevalence of obesity lead to an annual increase in the number of OA patients.

Currently, there are no developed methods of primary prevention for the development of OA. The main goal of preventive measures is to influence known risk factors contributing to the onset of the disease.

• To reduce the risk of developing OA, it is recommended to maintain a normal body weight (bringing the body mass index to normal values, no more than 25 kg/m²) [432–436].

Level of Evidence BLevel of Confidence 2Level of recommendation B (level of evidence – 2).

Comments: studies demonstrate an inverse relationship between body weight and the risk of developing knee OA. A 2-unit reduction in BMI is accompanied by a 50% decrease in the risk of knee OA.

• To reduce the risk of developing OA, it is recommended to control comorbid conditions: strive to maintain target blood pressure levels, normalize sleep, and correct dyslipidemia, hyperuricemia, and glycemia [437–440].

GPP BLOE 3Grade of Recommendation B (Level of Evidence – 3).

Comments: to date, it has been established that many comorbidities and conditions increase the risk of developing OA. This means that improving the control of these comorbidities is a key factor in reducing the risk of OA development.

• All individuals engaged in various sports, especially professional athletes, are recommended to prevent the development of OA through properly designed exercise programs that reduce the likelihood of injuries to a particular joint, including the use of special devices to protect joints under load [441–449].

Level of Evidence BLevel of Confidence 2Level of recommendation B (level of evidence – 2).

Comments: special training programs help strengthen muscles, improve stretching and balance, and reduce the risk of injuries to joints of various localizations, which in turn prevents the development of OA.

• Correction of impaired lower limb axis biomechanics is recommended to reduce the risks of symptomatic OA [373,450–457].

GPP BLOE 3Grade of Recommendation B (Level of Evidence – 3).

Comments: limited data indicate that correction of the lower limb alignment may reduce the risk of symptomatic knee and hip OA, and correction of hallux valgus may prevent OA in the 1st MTPJ.

Comments: quadriceps weakness is associated with an increased risk of symptomatic knee OA.

• To reduce the risk of OA in physically demanding occupations, it is recommended to avoid excessive joint stress, use personal protective equipment, master proper working techniques, and maintain a healthy lifestyle [462–477].

Level of Evidence BLevel of Confidence 2Level of recommendation B (level of evidence – 2).

Comments: occupations involving heavy physical labor increase the risk of knee and hip OA. Specifically, prolonged kneeling, climbing, frequent squatting, and prolonged standing have been shown to increase the likelihood of knee OA. Stair climbing, heavy lifting, prolonged standing and running, as well as vibration exposure are associated with an increased risk of hip OA. Occupational activities involving hand-arm vibration and pinch grip are correlated with hand OA.

5.2 Dispensary monitoring of patients

Given the high comorbidity in patients with generalized OA, to assess the presence and severity of complications and concomitant diseases, it is advisable to perform a complete blood count (CBC), urinalysis, general clinical blood chemistry (levels of glucose, creatinine, uric acid, total protein, cholesterol, low-density lipoprotein [LDL] cholesterol, high-density lipoprotein [HDL] cholesterol, triglycerides, total bilirubin, total calcium, inorganic phosphorus, and the activity of aspartate aminotransferase [AST], alanine aminotransferase [ALT], and alkaline phosphatase) at least once a year. All OA patients should also undergo estimation of the glomerular filtration rate (eGFR) to determine renal function, which is essential for ensuring the safe use of NSAIDs and many other medicinal products.

• EGD is recommended for OA patients to assess the safety of ongoing NSAID therapy [206].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comment: during long-term NSAID therapy, to rule out erosive and ulcerative lesions of the stomach and duodenum, all patients are recommended to undergo EGD at least 1–2 times a year.

Comments: the frequent coexistence of these two conditions requires close attention from specialists for osteoporosis screening. Chronic back pain is one of the symptoms of osteoporotic damage to the spinal bone structures.

Comments: neuropathic pain and/or central sensitization occur in nearly a third of OA patients [483–485]. It is important to pay attention to the "qualities" of pain: numbness, burning, tingling, crawling sensations (formication), hypersensitivity to touch (allodynia), and other symptoms uncharacteristic of nociceptive pain may be signs of these conditions. To identify neuropathic pain and/or central sensitization, physicians may use special questionnaires, such as the DN4 neuropathic pain diagnostic questionnaire (see Appendix G8) or PainDETECT (see Appendix G9). These questionnaires enable the detection of neuropathic pain in OA patients with high accuracy.

If the DN4 score is 4 or higher, or the PainDETECT score is 19 or higher, an initial consultation (examination) by a neurologist is required. The specialist will assess the patient's neurological status and decide on the appropriateness of additional examination and/or treatment.

Comments: subjective pain assessment methods are routinely used via scales and/or indices completed by the patient or with the assistance of medical staff. The evaluation process involves identifying the type of pain (nociceptive, neuropathic, nociplastic), its intensity (mild, moderate, severe), and duration (acute or chronic); establishing the location; and determining treatment efficacy.

Pain intensity is assessed using various scales, the most commonly used of which, and the one recommended in real-world clinical practice, is the visual analog scale (VAS), a 10 cm line without graduation that reflects pain intensity in millimeters from 0 to 100 mm (see Appendix G1. Visual analog scale). A numerical rating scale with numeric graduation corresponding to scores from 0 to 10, or a verbal rank scale (VRS) containing adjectives and/or numeric designations (0 – "no pain," 1 – "mild," 2 – "moderate," 3 – "severe," 4 – "very severe," 5 – "unbearable") may also be used (see Appendix G1. Numerical rating scale and Appendix G1. Verbal rank scale). The VAS format has greater sensitivity compared to other scale formats.

A 20% reduction in pain intensity from baseline is considered clinically significant, and a 50% reduction on one of these scales is considered pronounced. An inadequate response to therapy is defined as persistent pain in the analyzed (most painful) joint exceeding 40 mm on the VAS [60,512].

To assess not only pain, but also functional activity and/or quality of life and/or stiffness, the following indices/scales are also frequently used:

- for knee OA: WOMAC (see Appendix G3), KOOS (see Appendix G4);

- for hip OA: WOMAC (see Appendix G3), HOOS (see Appendix G5);

- for hand OA: AUSCAN (see Appendix G6), FIHOA (see Appendix G7);

- for spinal OA: Oswestry (see Appendix G8).

6. Organization of Medical Care

• Treatment of OA patients is recommended to be carried out by rheumatologists, general practitioners, family physicians, or orthopedic trauma surgeons, with periodic consultative support from a rheumatologist, involving other specialists (rehabilitation specialists, cardiologists, neurologists, endocrinologists, etc.) and based on close interaction between the physician and the patient [513].

Level CLevel 5Level of recommendation evidence C (reliability level of evidence – 5).

Comments: a multidisciplinary approach to managing OA patients helps reduce the impact of comorbid pathology on the disease course, improve pharmacotherapy efficacy, and enhance the disease prognosis.

An initial consultation (examination) by a rheumatologist is indicated in the presence of synovitis, failure of standard therapy, the need for local injection therapy, and for differential diagnosis.

Indications for hospitalization in a medical organization:

Form — elective; setting — inpatient, day care:

- clinically significant worsening of the underlying disease, its complications, and concomitant pathologies;

- pronounced synovitis or recurrent/chronic synovitis;

- intense pain not relieved by standard therapy or worsening of pain during treatment;

- performance of invasive interventions aimed at treating OA;

- implementation of rehabilitation measures.

Indications for discharging a patient from a medical organization are determined based on:

1) the patient's condition;

2) completion of the diagnostic process;

3) performance of an invasive intervention;

4) treatment outcome achieved. Achievement of improvement, reduction of pain intensity on the VAS or NRS in the most painful joint.

7. Additional Information

Making a diagnosis

The diagnosis of osteoarthritis (OA) of the knee, hip, and hand joints is established based on the ACR classification criteria [32–34]. The diagnosis of OA of the spinal joints and the 1st metatarsophalangeal joint is established based on the clinical and radiological presentation.

a. In generalized OA, it is necessary to specify at least 3 groups of joints involved in the pathological process.

b. When formulating the diagnosis, it is necessary to indicate the radiological stage according to Kellgren & Lawrence. Although the severity of radiological changes does not always correlate with pain intensity and functional impairment, the radiological findings can be useful for differential diagnosis, assessing treatment efficacy, identifying complications (e.g., development of osteonecrosis), and determining indications for major joint arthroplasty.

c. It is recommended to include OA complications and concomitant periarticular soft tissue pathology (e.g., synovitis, enthesitis), as well as the presence of deformities, in the diagnosis.

d. When establishing the diagnosis, the degree of functional limitations (functional class) should be indicated using the classifications and criteria applied in medical and social expertise of citizens by federal state institutions of medical and social expertise (in accordance with Order of the Russian Ministry of Health No. 585n dated August 27, 2019).

Examples of clinical diagnosis formulations

• M15.0 Generalized osteoarthritis: involving spinal joints, nodular form (Heberden's and Bouchard's nodes), bilateral hip osteoarthritis stage 2, bilateral knee osteoarthritis stage 3 on the right and stage 2 on the left. Synovitis of the right knee joint. Varus deformity of the knee joints. Transverse flatfoot. FC II.

• M15.0 Generalized osteoarthritis: erosive form, bilateral knee osteoarthritis stage 2, patellofemoral osteoarthritis. FC III.

  Complications: M87 Osteonecrosis of the right femoral head.

Additional information affecting the course and outcome of the disease

Comorbidity

• Patients with OA are recommended to regularly assess cardiovascular risk factors (age, body mass index and/or waist circumference, smoking status, family history of cardiovascular disease in first-degree relatives [males <55 years, females <65 years], arterial hypertension, diabetes mellitus, and dyslipidemia) and to correct modifiable factors in accordance with Russian national guidelines [53, 54, 56].

GPP CLOE 4Grade of Recommendation C (Level of Evidence – 4).

Comments: The nature of concomitant (comorbid) conditions is of great importance for selecting treatment tactics in patients with OA in terms of both efficacy and safety of therapy [55–57].

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Lila, Alexander Mikhailovich – Director of the V.A. Nasonova Research Institute of Rheumatology, Head of the Department of Rheumatology at the Russian Medical Academy of Continuous Professional Education of the Russian Ministry of Health, Doctor of Medical Sciences, Professor, Corresponding Member of the RAS, Moscow, Member of the Board and Presidium of the All-Russian Public Organization "Association of Rheumatologists of Russia".

2. Nasonov, Evgeny Lvovich – Scientific Advisor of the V.A. Nasonova Research Institute of Rheumatology, Doctor of Medical Sciences, Professor, Academician of the RAS, Moscow, President of the All-Russian Public Organization "Association of Rheumatologists of Russia".

3. Alekseeva, Lyudmila Ivanovna – Scientific Consultant of the Osteoarthritis Laboratory at the V.A. Nasonova Research Institute of Rheumatology, Doctor of Medical Sciences, Moscow, Professor at the Department of Rheumatology of the Russian Medical Academy of Continuous Professional Education of the Russian Ministry of Health, Member of the Presidium of the All-Russian Public Organization "Association of Rheumatologists of Russia".

4. Taskina, Elena Aleksandrovna – Head of the Osteoarthritis Laboratory at the V.A. Nasonova Research Institute of Rheumatology, Candidate of Medical Sciences, Moscow, Member of the All-Russian Public Organization "Association of Rheumatologists of Russia".

5. Kashevarova, Natalia Gavriilovna – Researcher at the Osteoarthritis Laboratory at the V.A. Nasonova Research Institute of Rheumatology, Candidate of Medical Sciences, Moscow, Member of the All-Russian Public Organization "Association of Rheumatologists of Russia".

6. Strebkova, Ekaterina Aleksandrovna – Senior Researcher at the Osteoarthritis Laboratory at the V.A. Nasonova Research Institute of Rheumatology, Candidate of Medical Sciences, Moscow, Member of the All-Russian Public Organization "Association of Rheumatologists of Russia".

7. Savushkina, Natalia Mikhailovna – Researcher at the Osteoarthritis Laboratory at the V.A. Nasonova Research Institute of Rheumatology, Candidate of Medical Sciences, Moscow, Member of the All-Russian Public Organization "Association of Rheumatologists of Russia".

Conflict of interest: all members of the working group declare no conflict of interest regarding the preparation of the clinical guidelines for polyarthrosis.

Appendix A2. Methodology for Developing Clinical Guidelines

Clinical guidelines for the provision of medical care to patients with polyarthrosis have been drawn up in accordance with the requirements for the development of clinical guidelines by medical professional non-profit organizations, Part 2 of Article 76 of Federal Law No. 323-FZ dated November 21, 2011, "On the Basics of Protecting the Health of Citizens in the Russian Federation", and Order of the Ministry of Health of the Russian Federation No. 103n dated February 28, 2019, "On approval of the procedure and timelines for the development of clinical guidelines and requirements for their structure, composition, and scientific validity of the information included in the clinical guidelines." The clinical guidelines are based on evidence-based clinical experience describing the physician's actions regarding the diagnosis, differential diagnosis, treatment, rehabilitation, and prevention of generalized forms of OA.

Target audience for these clinical guidelines:

1. Rheumatologist;

2. Traumatologist-orthopedist;

3. Physical and rehabilitation medicine physician;

4. General practitioner (internist);

5. General practitioner (family physician);

6. Physicians of other specialties involved in the diagnosis and management of patients with OA.

Medical professionals should adhere to these guidelines when making clinical decisions. At the same time, the guidelines do not replace the personal responsibility of medical professionals in making clinical decisions, taking into account the individual course of generalized OA and patient preferences. These guidelines take into account accumulated Russian and international experience in the management of these patients and are based on clinical guidelines published by the All-Russian Public Organization "Association of Rheumatologists of Russia" [60], the European League Against Rheumatism (EULAR) 2019 [132], ACR 2019 [98], ESCEO 2019 [100], and NICE [102].

Appendix A2-1. Levels of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)

Appendix A2-2. Levels of Evidence (LoE) grading scale for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitation interventions)

Appendix A2-3. Grades of Recommendation (GoR) scale for prevention, diagnostic, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitation interventions)

The mechanism for updating clinical guidelines provides for their systematic revision at least once every three years, as well as upon the emergence of new evidence-based medicine data on the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

These clinical guidelines have been developed taking into account the following regulatory and legal documents:

1. Procedure for the provision of medical care to the adult population in the specialty "Rheumatology" (Order of the Ministry of Health of the RF No. 900n dated November 12, 2012)

2. State Guarantee Programs for the provision of high-tech medical care in the specialties of rheumatology and dermatovenereology (Government Resolution No. 1382 dated December 19, 2015).

3. On classifications and criteria used in carrying out medical and social expertise of citizens by federal state institutions of medical and social expertise (Order of the Ministry of Health of the RF No. 585n dated August 27, 2019).

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

General description of the disease

Osteoarthritis (osteoarthrosis) is a disease characterized by a breakdown in the repair and destruction processes of joint tissues, primarily in the cartilage, subchondral bone, synovial membrane lining the joint capsule, and the ligaments and muscles surrounding the joint.

There are two main forms of osteoarthritis: primary, where the cause of the disease is unknown, and secondary, arising against the background of various diseases or joint injuries. Primary OA typically develops after the age of 40. Its most frequent and characteristic locations are the knees, interphalangeal joints of the hands, hips, spine, and the base of the first toe. Secondary OA does not differ in its clinical manifestations from primary OA, can develop in almost any joint, and has a specific underlying cause (often following a severe injury, in the context of another rheumatic disease, etc.).

It is important to emphasize that osteoarthritis does not pose an immediate threat to the patient's life; however, its social impact is extremely significant. Pain and joint function impairment lead to considerable suffering, temporary and permanent disability, and chronic joint pain becomes a major factor influencing the progression not only of OA itself, but also of comorbid conditions, primarily cardiovascular diseases.

Risk factors

Osteoarthritis develops as a result of the interaction of various factors, the main ones of which are presented below.

Advanced age is a well-known predictor of osteoarthritis development. The increase in incidence with age is a consequence of the cumulative effect of various risk factors and biological changes occurring during body aging.

Sex. The study of the influence of sex on the prevalence and incidence of osteoarthritis has shown that women, especially after the onset of menopause, are more prone to developing OA of the hand, foot, and knee joints.

Body mass index (BMI). Overweight holds a special place among risk factors for the development of osteoarthritis (particularly of the knee joint). Thus, overweight women (BMI from 25 to 30 kg/m²) have an almost 2.5-fold increased risk of knee OA, while with obesity (BMI of 30 kg/m² or more), the risk increases 4.6-fold. As a rule, patients with osteoarthritis and overweight (or obesity) also exhibit other manifestations of metabolic syndrome: arterial hypertension, elevated blood uric acid levels, and impaired glucose tolerance, which likewise contribute to a more severe course of the disease.

Occupation, physical activity, and trauma. Physical activity, especially therapeutic exercise, is particularly beneficial for joints by strengthening periarticular muscles that help stabilize the joint and improving blood supply, but it can also be harmful if it places excessive stress on a joint, especially one already vulnerable due to other risks. In particular, repetitive monotonous loads—work requiring kneeling or squatting—are associated with an increased risk of knee joint damage, while heavy lifting and prolonged static loads are associated with the development of hip osteoarthritis.

Lower limb deformities. Varus or valgus curvature of the lower limbs increases the future probability of developing knee osteoarthritis by almost 4 times.

Prevention

OA prevention should begin with lifestyle modifications: weight loss in cases of obesity or overweight, regular physical exercise, injury prevention during sports, wearing insoles, etc.

Control of overweight/obesity. To effectively combat obesity and overweight, a combined approach of daily physical activity and diet therapy is necessary. Daily caloric intake should be reduced by 500–700 kcal from physiological needs, which are calculated based on anthropometric parameters (body weight, age, sex, daily physical activity). The diet must be balanced in basic nutritional ingredients: proteins, fats, and carbohydrates. Diets based on fasting principles lack scientific justification and are therefore not recommended.

Physical activity. Regular physical activity not only contributes to weight loss and improved joint mobility, but also has a favorable effect on the course of concomitant chronic conditions. In particular, training the quadriceps femoris muscle reduces the risk of knee OA. Regular moderate-intensity aerobic activity (e.g., walking) for at least 150 minutes per week is recommended. For elderly individuals and people with chronic diseases, aerobic training should start with 30 minutes per day with a gradual increase to 60 minutes. It is advisable to combine strength training and aerobic exercises, taking into account the patient's functional requirements and preferences. To increase the effectiveness of physical loads and reduce the likelihood of injury, taking a training course with an instructor or exercise therapy physician before moving on to the main training phase is recommended.

Correction of biomechanical disorders. The use of orthopedic devices (orthoses, knee braces, arch supports) is aimed at reducing stress on the joints. In the presence of flat feet, wearing orthopedic insoles and shoes that help support the arch of the foot and reduce the load on the lower limb joints is recommended. It is recommended to use stable-heeled shoes no higher than 4 cm with a thick, shock-absorbing sole. Shoes should be of the correct size and not cause mechanical compression of the foot.

In case of knee joint instability, wearing custom-fitted knee braces is recommended, as they slow down the progression of osteoarthritis. For varus knee deformity, braces that unload the inner compartments of the joint should be used, while for valgus deformity, those unloading the outer compartments of the knee joint should be used.

Symptoms

The main symptom of osteoarthritis is joint pain that occurs during or after physical exertion. In more severe cases of the disease, joint pain may persist at rest and at night. Other characteristic symptoms include morning stiffness in the joint lasting up to 30 minutes, "start-up" pain (pain and stiffness in the joint after a period of rest, which diminishes after movement begins), restricted range of motion, "clicking" or "grating" sounds during movement, and swelling of periarticular soft tissues.

Most frequently, OA involves the knees, hips, and small joints of the hands, which have their own clinical features. Thus, knee involvement is characterized by "start-up" pains occurring at the onset of walking (especially when descending stairs), localized along the anterior and inner surfaces of the knee joint and worsening upon flexion.

In hip OA, pain at the onset of the disease is often localized not in the affected joint itself, but in the groin, the knee joint, the outer surface of the thigh, and the lumbar region. Patients frequently complain of difficulty putting on shoes or getting in and out of a car.

Typical clinical signs of hand OA include pain upon palpation and movement, as well as the appearance of bone enlargements around the distal and proximal interphalangeal joints (so-called Heberden's and Bouchard's nodes).

Diagnostics

The diagnosis of OA is based on an analysis of the patient's complaints and clinical examination findings. There are no specific laboratory markers. Joint radiography allows staging of the disease, while magnetic resonance imaging is performed when traumatic injury to joint structures is suspected.

Basic principles and approaches to treatment

Comprehensive OA therapy includes non-pharmacological and pharmacological methods, and surgical intervention when necessary. The main objective is to reduce/relieve pain and inflammation, improve joint movement, and slow disease progression.

OA patients are recommended to attend patient schools where they can receive comprehensive information about their disease and the advisability of weight loss, and learn how to properly perform therapeutic exercises and modify their lifestyle. Specialists will explain the basic principles of treatment and answer your questions. Within these schools, preventive talks, exercise therapy training, Nordic walking master classes, and other activities are conducted.

Regular therapeutic exercise leads to reduced pain and improved joint movement, but it is best to start exercising under the guidance of a specialist, for example, in health groups. Physical exercises for OA should be performed without static loads (sitting, lying down, in a swimming pool). The main principle of exercise therapy is the frequent repetition of exercises throughout the day. Exercises should not be performed through pain. They are performed slowly, smoothly, with a gradual increase in load. You should exercise for at least 30–40 minutes a day, divided into 10–15 minute sessions several times a day.

In knee OA, the primary exercises are those that strengthen the thigh muscles (e.g., lifting a straightened leg 25 cm while lying on your back and holding it for a few seconds); exercises aimed at increasing the range of motion ("air cycling"); and exercises that improve overall aerobic muscle conditioning (walking on flat terrain at a moderate pace). Walking should begin at a distance that does not cause pain and gradually increase in duration to 30–60 minutes (five to seven days a week). Patients should also be aware of the specific movement regimen for OA, the main principle of which is unloading the affected joint. Prolonged walking, standing, and frequent stair climbing are not recommended. A patient with severe joint pain and limited movement needs a consultation with an exercise therapy specialist to draw up an individual training program.

In OA, reducing joint load is extremely important, which is achieved through the use of various devices. Patients should wear low, wide-heeled shoes with soft, elastic soles, which helps reduce the impact that propagates through the leg during walking and damages the cartilage. Shoes should be sufficiently wide and soft on top. For knee involvement, wearing knee braces is recommended, as they stabilize the joints, reduce instability, and slow disease progression. To reduce load, walking with a cane is indicated, which should be held in the hand opposite to the affected joint. In addition, it is very important to properly adjust the cane's height—its handle should be at the level of the base of the patient's thumb. For bilateral hip or knee involvement, walking with Canadian crutches is advisable. In the presence of flat feet, permanent wearing of custom-made insoles is recommended.

To reduce pain in OA, nonsteroidal anti-inflammatory and antirheumatic drugs are prescribed locally (gels, creams, ointments) or systemically in tablet form (in the absence of contraindications from comorbid conditions). From the time of diagnosis, all OA patients are recommended to take "chondroprotectants" (ATC M01AX Other nonsteroidal anti-inflammatory and antirheumatic drugs) (glucosamine and/or chondroitin sulfate, or diacerein, etc.), which are used long-term. The longer a patient takes "chondroprotectants", the lower the risks of disease progression. In some cases, intra-articular injection of hyaluronic acid (synovial fluid substitutes (synovial fluid prostheses) based on hyaluronic acid) (only into a "dry" joint, therefore ultrasound is recommended before or during the injection) or glucocorticoids (in the presence of synovitis, but no more than 2–3 injections per year into the same joint) is indicated. Various surgical interventions are also performed, ranging from osteotomy to total joint arthroplasty (replacement).

It is important to know that for the prescription or adjustment of OA pharmacotherapy, you must consult your attending physician, who, taking into account your individual characteristics, comorbidities, and risk factors, will select the most effective and safe medications. Be sure to discuss all medications you are taking with your doctor, because even natural, over-the-counter remedies can cause adverse effects. Only a qualified specialist can give you the best recommendations and help you avoid unpleasant consequences from treatment.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Appendix G1. Pain intensity assessment scales

Russian title: visual analogue scale (VAS), numeric rating scale (NRS), verbal rating scale (VRS)

Original title: Visual Analog Scale, Numeric Rating Scale, Verbal Rating Scale

Source: [486–489]

Type (underline): -rating scale

Purpose: assessment of pain intensity

Content (template):

Key (interpretation): 

Up to 4 points or 40 mm – mild pain;

From 4 to 7 points or from 40 to 70 mm – moderate pain;

More than 7 points or 70 mm – severe pain.

Notes: NRS and VRS are similar to VAS and represent its modification.

VAS. The patient independently, in the presence of a doctor and/or medical staff, assesses pain intensity using the VAS, which is a straight line of 100 mm. The starting point of the line indicates no pain (0 mm), the endpoint indicates unbearable pain (100 mm), and the midpoint indicates moderate pain. The patient must make a mark on this line corresponding to the intensity of pain experienced in the evaluated joint at the present moment (or over a certain period, e.g., the last week). The distance between the start of the line (0) and the patient's mark is measured in millimeters.

NRS is a horizontal line 10 cm long with numbers from 0 to 10 placed along it, where 0 is "no pain" and 10 is "excruciating pain". The patient is asked to mark a number from 0 to 10 corresponding to the severity of their pain sensations.

VRS consists of adjectives describing pain, arranged in order of increasing intensity. Sometimes a scale containing both adjectives and numbers is used (0 – "no pain", 1 – "mild", 2 – "moderate", 3 – "severe", 4 – "very severe", 5 – "unbearable"). The workflow is the same as for VAS.

Appendix G2. FRAX scale

Russian title: FRAX – Fracture Risk Assessment Tool

Original title: FRAX ®

Source: [509–511]

Type (underline): questionnaire

Purpose: assessment of fracture risk.

Content: to calculate the 10-year probability of fracture using bone mineral density, answer the following questions.

Questionnaire:

Key (interpretation): Fracture risk assessment result in the orange zone: dual-energy X-ray absorptiometry (DXA) of the lumbar spine and proximal femur is recommended. If osteoporosis is detected (T-score ≤ -2.5), anti-osteoporotic therapy is indicated without reassessing fracture risk.

Appendix G 3. WOMAC Osteoarthritis Index for Knee and/or Hip Osteoarthritis (Western Ontario and McMaster Universities Arthritis Index)

Russian title: WOMAC Index for Knee and/or Hip Osteoarthritis

Original title: Western Ontario and McMaster Universities Arthritis Index

Source: [490,491]

Type (underline): - index

Purpose: to assess pain, stiffness, and function of the knee and/or hip joints.

Content (template):      

Stiffness assessment

Difficulty with daily activities

Key (interpretation): The WOMAC index is used not only to assess pain, stiffness, and function of the knee and/or hip joints, but can also be used to evaluate the effectiveness of ongoing therapy. The rating scales for each indicator can be presented as a VAS, NRS, or 5-point Likert scale. However, VAS assessment has a higher sensitivity compared to other scale formats.

Possible score ranges depending on the scale:

• when using VAS:

- "Pain" subscale: 0 to 500 mm;

- "Stiffness" subscale: 0 to 200 mm;

- "Physical Function" subscale: 0 to 1700 mm.

• when using the Likert scale:

- "Pain" subscale: 0 to 20 points;

- "Stiffness" subscale: 0 to 8 points;

- "Physical Function" subscale: 0 to 68 points.

• when using NRS:

- "Pain" subscale: 0 to 50 cm or points;

- "Stiffness" subscale: 0 to 20 cm or points;

- "Physical Function" subscale: 0 to 170 cm or points.

Explanations: The patient independently assesses the state of the target knee or hip joint over the past 24 hours in each of the WOMAC categories ("pain", "stiffness", "difficulty with daily activities"). The "pain" category contains 5 questions, "stiffness" has 2 questions, and "difficulty with daily activities" has 17 questions. The patient answers each question using, for example, a VAS. In this case, the patient must make a mark on the VAS straight line (100 mm) corresponding to the intensity of pain, stiffness, and difficulty in daily activities experienced in the analyzed joint. The distance between the start of the line (0) and the patient's mark is measured in millimeters. Next, the physician evaluates the results by summing the scores (in mm) in each category (WOMAC pain, WOMAC stiffness, and WOMAC physical function) and overall to obtain the total WOMAC index values.

Appendix G4. The Knee injury and Osteoarthritis Outcome Score (KOOS).

Russian title: Functional state of the knee joint

Original title: The Knee injury and Osteoarthritis Outcome Score

Source: https://orthotoolkit.com/koos/ [497[493,4[492,493,514]

Type (underline): - rating scale

Purpose: a specifically designed instrument developed to assess the patient's opinion about their knee joint and related problems. It evaluates the patient's pain, symptoms, knee function, quality of life, and activity in daily and sports life.

Content (template):

Symptoms

When answering these questions, the patient should summarize their experiences over the past week.

Stiffness

The following questions concern the assessment of knee joint stiffness experienced by the patient over the past week. Stiffness is the sensation of restricted range of motion or slowed movement in the knee joint.

Pain

Daily Activities

The following questions relate to the patient's physical activity, specifically the ability to move and care for oneself. For each of the questions presented, the patient should indicate the degree of difficulty experienced over the past week due to the knee joint condition.

Sports activity

The following questions relate to higher-level physical activity: during sports or active play. For each of the questions below, the patient should indicate the severity of difficulties experienced during the past week due to the knee joint condition.

Quality of life

Key (interpretation): the score is presented as a percentage from 0 to 100, where 0 indicates extreme problems and 100 indicates no problems.

Notes: the scale includes 42 questions across 5 domains: "symptoms and stiffness", "pain", "difficulty performing daily living activities", "sports and recreational activities", and "quality of life". The patient answers the questions in each subsection independently or in the presence of a physician, choosing only a single response option. Numerical values are assigned to the answers, with 0 corresponding to the absence of a feature (favorable situation) and 4 to the maximum severity of a feature (worst situation). The 5 domains are evaluated separately as the sum of all corresponding items. The scores are then converted using a mathematical formula into a 0-100 scale (percentage of the total possible score achieved), where 0 indicates the worst possible symptoms of knee joint damage and 100 indicates their absence.

Appendix G5. Hip osteoarthritis functional assessment scale

Russian title: Functional state of the hip joint

Original title (if applicable): The Hip injury and Osteoarthritis Outcome Score

Source: [494–498]  

Type (underline):

- rating scale

Purpose: a specially designed tool developed to assess the patient's opinion about their hip joint and related problems. It assesses the patient's pain, symptoms, knee joint function, quality of life, and activity in daily and sports life.

Symptoms

When answering these questions, the patient should summarize their experiences over the past week. These questions concern sensations in the hip joint and the difficulties the patient experienced with movement over the past week.

Stiffness

The following questions assess hip joint stiffness experienced by the patient over the past week. Stiffness is the sensation of limited range or slowed movement in the hip joint.

Pain

Daily Activities

The following questions relate to the patient's physical activity, specifically mobility and self-care. For each of the questions below, the patient should indicate the severity of difficulties experienced during the past week due to hip disease.

Sports activity

The following questions relate to higher-level physical activity during sports or active play. For each of the questions below, the patient should indicate the severity of difficulties experienced during the past week due to hip disease.

Quality of life

Key (interpretation): the score is presented as a percentage from 0 to 100, where 0 indicates extreme problems and 100 indicates no problems.

Explanations: The scale includes 40 questions across 5 domains: "symptoms and stiffness", "pain", "difficulty with daily activities", "activity, sports and recreation", and "quality of life". The patient answers the questions in each subsection independently or in the presence of a physician, choosing only one answer option. Answers are assigned numerical values, where 0 corresponds to the absence of a symptom (favorable situation) and 4 to the maximum severity of a symptom (worst situation). The 5 domains are evaluated separately as the sum of all corresponding items. The scores are then converted to a 0–100 scale (percentage of the total possible score), where 0 indicates the worst possible symptoms of hip damage and 100 indicates their absence.

Appendix G6. Australian/Canadian Hand Osteoarthritis Index (AUSCAN)

Russian title: AUSCAN Hand Osteoarthritis Index

Original title: Australian/Canadian Hand Osteoarthritis Index

Source: [499–502]

Type - index

Purpose: assessment of clinical manifestations (pain, stiffness, functional impairment) in patients with hand osteoarthritis. Used in clinical practice and research protocols, as well as for evaluating therapeutic efficacy.

Content (template):

Key (interpretation): the index is used not only to assess pain, stiffness, and function in hand osteoarthritis, but can also be used to evaluate the efficacy of ongoing therapy. The rating format for each indicator can be presented as a VAS, NRS, or 5-point Likert scale. However, VAS assessment has greater sensitivity compared to other scale formats.

Explanations: the index contains 15 questions regarding pain, stiffness, and functional impairment in the hand joints over the past 48 hours. The patient fills out the questionnaire independently. The patient answers each question using, for example, a VAS. In this case, the patient makes a mark on a straight VAS line (100 mm) corresponding to the intensity of pain, stiffness, and difficulty in daily activities experienced in the small joints of the hands. The distance between the start of the line (0) and the patient's mark is measured in millimeters. Next, the physician evaluates the results by summing the scores (in mm) in each category (AUSCAN pain, AUSCAN stiffness, and AUSCAN physical disability) and overall, obtaining the total AUSCAN index values.

Appendix G7. Functional Index of Hand OA (FIHOO) (Functional Index of Hand OA)

Russian title: Functional Index for Hand Osteoarthritis (FIHOA or Dreiser's index)

Original title: Functional Index for Hand Osteoarthritis or Dreiser’s index

Sources: [503]

Type (underline): - index

Purpose: assessment of the degree of functional impairment in hand OA. Used in clinical practice and research protocols, as well as to evaluate therapy efficacy.

Content (template):

Key (interpretation):

0 – possible without difficulty;

1 – possible with minor difficulty;

2 – possible with moderate difficulty;

3 – impossible.

Explanation: FIHOA assesses functional impairment associated with hand joint OA on a scale from 0 (no functional impairment) to 30 points (maximum impairment). It consists of 10 questions scored on a 4-point scale. It evaluates the functional impact of OA of this localization on the patient's daily life.

Appendix G8. Oswestry Index (Oswestry)

Russian title: Oswestry Index

Original title: The Oswestry Disability Index

Sources: [504–506]

Type (underline): - questionnaire

Purpose: assessment of the degree of functional impairment (disability) in chronic low back pain.

Content (template):

Key (Interpretation): The Oswestry Disability Index consists of 10 sections. In each section, the first answer corresponds to a minimum score of (0), and the subsequent answers correspond to 1, 2, 3, 4, and 5 points, respectively.

Notes: When all 10 sections are completed, the Oswestry Index is calculated as follows: (Total score / 50 [maximum possible score]) × 100 = %. If one of the sections is not completed or cannot be assessed (e.g., sex life), the Oswestry Index is calculated as follows: (Total score / 45 [maximum possible score]) × 100 = %. The higher the index, the more significant the disability. The questionnaire can also be used to assess the patient's condition over time, e.g., during treatment.

Appendix G9. Douleur Neuropathique en 4 Questions (DN 4)

Russian title: Douleur Neuropathique en 4 Questions (DN4) questionnaire

Original title: Douleur Neuropathique en 4 Questions (DN4)

Sources: [507, 508]

Type (underline): questionnaire

Purpose: Identification of neuropathic pain or a neuropathic component in mixed nociceptive-neuropathic pain syndromes.

Content (template):

The questionnaire consists of two parts. The first part is completed based on the patient interview, and the second part is based on the clinical examination. The first part evaluates positive sensory symptoms, while the second part identifies allodynia and negative sensory symptoms.

Question 1: Does the pain experienced by the patient match one or more of the following definitions?

Question 2: Is the pain associated with one or more of the following symptoms in the same area?

PHYSICAL EXAMINATION

Question 3: Is the pain located in an area where the physical examination reveals one or both of the following symptoms?

Question 4: Can the pain be caused or increased in the area by:

Key (interpretation): If the total score is 4 or more points, it indicates that the patient's pain is neuropathic or that there is a neuropathic component of pain (in mixed nociceptive-neuropathic pain syndromes).

Appendix G10. Pain DETECT Questionnaire

Russian name: pain DETECT questionnaire

Original name: questionnaire Pain DETECT

Source: [509–511]

Type (underline):

• questionnaire

Purpose: assessment of the nature of pain progression and diagnosis of the neuropathic component of pain.

Content (template):

Key (interpretation): a total score of 19 points and above indicates the presence of a pronounced neuropathic component.

Explanations: the questionnaire is intended to be filled out by a physician and combines a pain distribution diagram in the form of an image with the VAS scale and a questionnaire aimed at identifying spontaneous and evoked symptoms of neuropathic pain. The diagram is also used to assess the nature of the pain course: constant, paroxysmal, constant with attacks, etc. Pain DETECT includes 9 items: 7 items assess the intensity of sensory perceptions ranging from "never" to "very strongly", and 2 items use a diagram to assess pain radiation and the temporal characteristics of the individual pain pattern. The severity of each symptom is scored, and then the total score is calculated. The questionnaire most fully reflects all possible parameters of pain and allows for a very visual tracking of the pain syndrome pattern over time.