Knee Cartilage Injuries: Clinical Guidelines

List of Abbreviations

AB – antibacterial drugs

ATOR – All-Russian Public Organization "Association of Traumatologists and Orthopedists of Russia"

VTE – venous thromboembolism

SSI – surgical site infection

PCA – patient-controlled analgesia

CT – computed tomography

PT – physical therapy

OATS – osteochondral autograft transfer system

MMA – multimodal analgesia

MRI – magnetic resonance imaging

NSAIDs – non-steroidal anti-inflammatory and antirheumatic drugs

PRP – platelet-rich plasma

RA – regional anesthesia

SCT – spiral computed tomography

TCL – transchondral lesion

PRM – physical and rehabilitation medicine

PTL – physical therapy treatment

Surgical antibiotic prophylaxis

CM – chondromalacia

EMS – electrical muscle stimulation

ICRS – International Cartilage Repair Society.

NMDA – N-methyl-D-aspartate (receptors).

Terms and Definitions

Mosaic osteochondral arthroplasty – replacement of an area of the affected articular surface located in the weight-bearing area with a cylindrical osteochondral autograft.

PRP therapy (platelet-rich plasma therapy) is an injection procedure involving the administration of the patient's platelet-rich plasma into an area of their body that requires rapid healing, i.e., aimed at accelerating regeneration and stimulating the growth of the body's own cells.

Chondromalacia – localized structural changes in the cartilage resulting from trauma or dystrophic diseases (mostly limited to a single compartment of the joint).

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Cartilage injuries of the knee joint are disruptions in the integrity of its cartilage covering resulting from trauma or diseases, limited primarily to a single compartment of the joint, extending to the depth of the articular cartilage or reaching the subchondral bone in the absence of widespread degenerative-dystrophic joint disease.

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

The causes of cartilage injury include acute trauma or chronic microtrauma to the knee joint. Often, cartilage pathology is secondary and develops in the presence of meniscus and ligament tears of the knee joint. Both acute and chronic injury lead to the progressive destruction of this vital knee structure and ultimately contribute to the development of osteoarthritis.

1.3 Epidemiology of the Disease or Condition

Cartilage injuries are a common cause of pain and knee joint dysfunction, detected either in isolation or in combination with other pathology in 14-26% of patients [1, 2, 3].

1.4 Features of Coding the Disease or Condition

S83.3 Fresh tear of articular cartilage of knee;

M23.4 Loose body in knee;

M94.2 Chondromalacia;

M94.8 Other specified disorders of cartilage.

1.5 Classification of the disease or condition

A number of classifications have been developed to assess the severity of acute articular cartilage injuries [4]. The systems proposed by Outerbridge in 1961 [5] and Bauer and Jackson in 1988 [6] are the most widely used in clinical practice due to their simplicity.

Outerbridge [5] described four grades of cartilage injury:

- Grade I – local edema and softening of the cartilage,

- Grade II – superficial fibrillation, fragmentation, and fissuring of the cartilage in an area no more than 1.25 cm in diameter,

- Grade III – partial-thickness fibrillation, fragmentation, and fissuring of the cartilage greater than 1.25 cm in diameter,

- Grade IV – cartilage defect with exposure of the subchondral bone.

Bauer and Jackson [6] identified six types of cartilage injury:

Type I – linear fissure of the cartilage;

Type II – irregular stellate fissuring of the cartilage;

Type III – flap tear;

Type IV – crater-like lesion penetrating to the subchondral bone;

Type V – cartilage fibrillation;

Type VI – degenerative (exposure of subchondral bone with cartilage fibrillation at the defect edges).

According to the authors, traumatic factors are the predominant cause of type I-IV injuries, whereas types V and VI are mainly detected in degenerative-dystrophic diseases of the knee joint. When describing the condition of the articular cartilage, in addition to the type and depth of the injury, it is customary to note its dimensions, as well as its anatomical and functional location (weight-bearing zones, non-weight-bearing areas).

The most common classification of articular cartilage injuries based on magnetic resonance imaging (MRI) data was developed by Yulish B.S. et al. (1987); the authors identified 4 grades of destruction depending on signal changes within the cartilage layer and at the base of the defect:

Grade 1 – changes within the cartilage without disruption of its integrity;

Grade 2 – moderate disruption of cartilage continuity with local lesions up to 50% of the depth;

Grade 3 – severe disruption of cartilage continuity with local changes greater than 50%;

Grade 4 – absence of articular cartilage, exposure of subchondral bone.

The most comprehensive, thorough, and versatile cartilage injury scoring system was proposed by the International Cartilage Repair Society (ICRS) (2000):

Traumatic cartilage defects are classified as follows:

Grade 0 (normal): cartilage with no macroscopically apparent defects;

Grade 1 (nearly normal): superficial cartilage lesion;

1A: cartilage with intact surface, but soft on probing and/or with some fibrillation;

1B: cartilage with superficial fissures and cracks;

2 (abnormal): lesion extending deeper, but less than 50% of cartilage depth;

Grade 3 (severely abnormal): defect extending deeper than 50% of cartilage depth, but not penetrating the subchondral bone;

3A: defects not reaching the calcified layer;

3B: defects affecting the calcified layer;

3C: defects extending through the calcified layer, but not involving the subchondral bone plate;

3D: cartilage edema (also included in this group);

Grade 4 (severely abnormal): full-thickness osteochondral lesions;

4A: defect extending to the subchondral plate;

4D: defect penetrating into the underlying bone.

1.6 Clinical presentation of the disease or condition

Anamnestic data: patellofemoral cartilage injury is characterized by deep, dull pain that worsens with physical activity or prolonged sitting with bent knees. Complaints are often vague, making it difficult to determine whether they originate from the anterior knee compartment or the patellofemoral joint. Patellar subluxation causes a feeling of instability in the anterior part of the joint. Sometimes there is a history of patellar dislocation, but more often symptoms indicate extensor mechanism dysfunction. Symptoms worsen during movements that increase the contact area between the patella and the femur: running, stair climbing, and deep squats. Joint effusion may occur periodically, often during intense physical exertion. Clicking and crepitation are common. As a rule, physical activity exacerbates symptoms, while they become less pronounced after rest. When the lesion sites are located on the femoral and tibial condyles, pain along the medial or lateral joint line is characteristic.

According to the severity of the injury, four stages of the disease are distinguished.

I – during this period, the first signs of chondromalacia of the cartilage surfaces appear. Clinical manifestations are mild or absent.

II – cartilage delamination appears, small fissures form, and damage to these leads to severe pain.

III – irreversible cartilage destruction, with some damaged areas reaching the bone tissue.

IV – appearance of large zones of destruction, physiological restoration of joint elements is impossible.

2. Diagnostics, medical indications and contraindications for diagnostic methods

The following methods are used to diagnose and assess other cartilage injuries of the knee joint:

- clinical (complaints and medical history, physical examination of the patient);

- radiologic (radiography, computed tomography (CT), and MRI);

- instrumental (ultrasonography);

- arthroscopy.

Criteria for establishing the diagnosis/condition: the physician establishes a provisional diagnosis of knee cartilage lesions based on the patient's complaints, physical examination findings, and test results.

2.1 Complaints and Anamnesis

Comments. The primary complaint in all patients with localized cartilage lesions is knee pain. In most patients, the pain is aching, worsening after physical exertion and changes in the weather. In one-third of patients, the pain has a different character: sharp, cramping, occurring and worsening during walking, especially when going up and down stairs. The localization of the pain syndrome is determined by the intra-articular site of the cartilage lesion: frontal pain is noted in transchondral fracture (TCF) of the patella, pain spreads along the anteromedial surface of the joint in cartilage lesions of the medial femorotibial compartment, and along the anterolateral surface of the joint in cartilage lesions of the lateral femorotibial compartment. In a quarter of patients, the pain is diffuse without a clear localization [8].

A characteristic complaint of patients with TCF in the joint is crepitus, which they refer to as a "crunching" sound in the joint.

Periodic joint swelling is characteristic of less than half of patients.

The range of motion in most patients with cartilage lesions is full; about one-third of patients experience periodic "soft", easily reducible joint blockages.

When taking the medical history, the physician should pay attention to systemic and extra-articular manifestations, as well as signs of joint involvement. Many symptoms, including fever, chills, malaise, weight loss, Raynaud's phenomenon, skin and mucosal changes (e.g., skin rashes, redness or eye pain, photosensitivity), gastrointestinal, cardiovascular, and respiratory disorders, may be due to various joint diseases.

2.2 Physical Examination

Comments: Assessment of the following symptoms is indicated:

- acute or gradual onset of pain;

- increased pain with walking;

- "start-up pain" that occurs after periods of rest and resolves with physical activity;

- joint swelling due to fluid accumulation in the suprapatellar pouch or synovial thickening;

- crunching/crepitus with movement;

- restriction of joint motion;

- gait changes

As the disease progresses, signs of synovitis appear. The patient begins to be troubled by superficial pain that occurs exclusively during physical exertion. The patient experiences pain attacks even at rest. Subsequently, chondromalacia leads to the development of symptoms such as clicking with loads, inflammation in the area of the patella and medial condyle, synovitis, local hyperthermia, and skin hyperemia. The main sign of knee joint involvement is pain localized along the joint line. The pain syndrome can be acute or chronic and most commonly increases gradually. Symptoms of the disease are most pronounced during joint loading, such as prolonged walking, stair climbing, and squatting. A sharp attack of pain and a feeling of stiffness in the knee may occur after prolonged sitting. Involvement of the lateral condyle is accompanied by pain along the anterolateral surface, and patellar involvement by frontal pain. At the stage of necrosis focus formation and dissection, the pain is almost constant, "aching", and worsens with exertion. The character of the pain syndrome changes when a osteochondral fragment detaches: entrapment of an intra-articular body causes sharp pains whose localization is determined by the position of the entrapped fragment in the joint, while constant pain along the anteromedial surface is observed after significant physical exertion. About one-third of patients report vague pain without clear localization. More than half of patients note joint "crunching" and periodic swelling.

Comments. The main symptom during the physical examination of patients with localized knee cartilage lesions is tenderness to palpation, most often located in the projection of the lesion, less frequently without clear localization.

No correlation was found between the grade of TCF and the severity of palpation tenderness. In one out of five patients with chondromalacia (CM) of varying grades, tenderness cannot be localized and is distributed throughout the joint.

Hemarthrosis (synovitis) of the knee joint presenting as diffuse thickening of the synovial membrane is observed in less than half of patients.

TCF of various grades is characterized by restriction of active flexion to 45–50 degrees, while passive flexion and extension correspond to physiological norms (values of the contralateral healthy joint). Moderate hypotrophy of the thigh and leg muscles is detected in almost half of patients. A fairly frequent symptom in TCF is crepitus during active and passive movements in the knee joint [8, 9].

When patellar chondromalacia or arthrosis is suspected, it is advisable to pinpoint the site of the lesion. This can be done by pressing the patella against the femur and, while moving the lower leg in various directions, determining the area or areas of maximum tenderness. The angle between the quadriceps tendon and the femur (Q-angle) is determined with the knee slightly flexed and flexed at 90°. An abnormal Q-angle and a positive apprehension sign (attempting to displace the patella laterally relative to the trochlear groove) may result from patellar subluxation or tension of the lateral patellar retinaculum.

2.3 Laboratory Diagnostics

No specific clinical tests have been developed for diagnosis.

• In all patients diagnosed with knee articular cartilage lesions for whom surgical treatment is planned, it is recommended to perform the following laboratory tests for diagnostic purposes:

- complete blood count;

- urinalysis;

- general clinical blood biochemistry analysis;

- determination of main blood groups by the ABO system and determination of the D antigen of the Rhesus system (Rh factor);

- determination of hepatitis B virus surface antigen (HBsAg) in the blood;

- determination of hepatitis C virus class G antibodies (anti-HCV IgG) in the blood;

- determination of antibodies to Treponema pallidum in the blood;

- determination of antibodies of classes M and G (IgM, IgG) to human immunodeficiency virus HIV-1/2 and p24 antigen (Human immunodeficiency virus HIV 1/2 + Agp24) in the blood;

- coagulogram (screening hemostasis test);

- determination of the international normalized ratio (INR) [99-101].

LEL 5Grade of Recommendation C (Level of Evidence – 5).

2.4 Instrumental Diagnostics

Comments. The diagnostic value of radiography – is low [9, 11, 34]. In grade II–III TCF, signs of osteochondral pathology are absent on radiographs; in grade III–IV, minor subchondral sclerosis is detected.

Comments. Higher radiation dose compared to radiography. Detects excessive intra-articular fluid accumulation, inflammatory changes (arthritis, bursitis), degenerative-dystrophic disorders (arthrosis, osteoarthritis), osteochondropathies.

Comments. It allows the examination of bones, cartilage, ligaments, synovial fluid, and other parts of the knee joint, helps determine the nature and amount of joint effusion, and detects synovitis, arthritis, and tendinitis.

Comments. It allows for the visualization of all knee joint structures, including the patellar cartilage. Changes in signal intensity and disruption of the articular surface contour often allow for the identification of superficial lesions up to 1 mm deep, and when the defect size increases to 3 mm, diagnostic accuracy approaches 100%. In study [31], a negative MRI result with high probability (97–98%) predicted a negative result of diagnostic arthroscopy. Conversely, a positive MRI diagnosis of cartilage damage was not confirmed arthroscopically in 48–50% of cases.

Comments. Grade I damage (according to Outerbridge, 1961) is characterized by edema and softening upon palpation of the cartilage or its mild fibrillation in an area up to 1 cm in diameter; Grade II is characterized by mild cartilage fibrillation in an area greater than 2 cm in diameter or coarse fibrillation of the articular surface less than 1 cm in diameter on only one of the articulating surfaces; Grade III features coarse fibrillation greater than 1 cm in diameter on one of the articular surfaces or less than 1 cm on both articular surfaces, with possible isolated exposure of the subchondral bone up to 2 mm in diameter; Grade IV is accompanied by exposure of the subchondral bone in an area greater than 2 mm in diameter with degenerative changes in the surrounding cartilage tissue.

2.5 Other Procedures

No.

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

Treatment for traumatic cartilage lesions (TCL) of the knee joint involves a combination of conservative (pharmacological and non-pharmacological) and surgical methods. The goal of treatment is to reduce pain, stimulate cartilage regeneration, and prevent functional insufficiency of the joint.

3.1 Conservative Treatment

The main goals of conservative treatment in TCL of the knee joint are: effective control of symptoms, primarily pain in the affected joint, preservation and improvement of function, as well as relief of hemarthrosis (synovitis), and slowing the progression of the pathological process.

Comments. Patients are recommended complex therapy, necessarily including [10, 11]:

- limitation of general physical exertion and load on the joint;

- therapeutic physical training, pool exercises;

- isometric contractions of the quadriceps femoris muscle in the knee extension position, repeated multiple times throughout the day;

- non-steroidal anti-inflammatory and antirheumatic drugs (ATC group code: M01A).

Comments. The issue regarding the appropriateness of using medical services such as "electromagnetic therapeutic effect on organs and tissues" (e.g., drug electrophoresis for joint diseases), "treatment with climatic influences (e.g., water, air)" (e.g., therapeutic mud application for bone system diseases), "treatment using radiation (sound, light, ultraviolet, laser) exposure," e.g., intra-articular laser therapy, as well as drugs from the group "Other non-steroidal anti-inflammatory and antirheumatic drugs" (M01AX), such as glucosamine + chondroitin sulfate, within the complex conservative treatment of knee cartilage injuries remains debatable due to the lack of convincing data reliably confirming their clinical significance in the treatment of acute and chronic articular cartilage injuries.

Comments. Orthoses (braces), due to moldable rigid stays and hinges, allow correction of the limb axis to unload the medial or lateral compartments of the joint and, using stabilizers, center the patella movement relative to the femoral condyles, as well as regulate the range of active movements in the joint

Comments. With a significant decrease in pain intensity, but persisting discomfort in the knee joint during load, it is advisable to limit physical activity and undergo a repeat course of conservative treatment after 2–3 months. If conservative therapy has not led to improvement or if it was insignificant, the patient is hospitalized for surgical treatment [11, 37].

3.2 Intra-articular injections

• Adult patients with traumatic cartilage injuries of the knee joint are recommended intra-articular injection of a synovial fluid substitute based on sodium hyaluronate (301790 Synovial fluid substitute***) at the patient's initiative with the goal of restoring cartilage tissue, eliminating pain, and improving joint mobility [92, 93, 94].

GRC BLEL 2Grade of Recommendation B (Level of Evidence – 2)

Comments: intra-articular administration of sodium hyaluronate derivatives can lead to a positive clinical effect of varying severity, the average duration of which is 4–6 months. The number of intra-articular injections depends on the physicochemical characteristics of the medical device and the clinical features of the patient, typically varying from 1 to 5. The preparations are injected intra-articularly under aseptic conditions in specialized medical institutions. After the clinical effect wears off, the course of injections can be repeated. Preparations should only be administered in the absence of synovitis.

Comments: A meta-analysis of 30 randomized clinical trials showed the superiority of intra-articular injections of platelet-rich plasma compared to hyaluronic acid and placebo [96].

3.3 Surgical Treatment

The limited reparative capabilities of the adult hyaline cartilage generally do not allow for the restoration of an articular surface defect, which gradually leads to the development of degenerative-dystrophic lesions of the knee joint. Therefore, in clinical practice, various surgeries are used for local cartilage defects aimed at mesenchymal stimulation—i.e., promoting defect repair through blood clot formation and stem cell migration from the bone marrow, or implantation of new cells capable of chondrogenesis: debridement of the affected cartilage or its complete excision, subchondral bone perforation by tunneling, abrasive chondroplasty, microfracture, osteochondral allografting, periosteal or perichondral transplantation, mesenchymal stem cells, autologous chondrocyte culture, mosaic osteochondral autografting [11-14]. In children and adolescents, damage to functioning growth plates must be avoided.

Comments. Diagnostic arthroscopy allows for the assessment of all intra-articular structures and provides the opportunity to accurately determine the severity, extent, and localization of articular cartilage damage [4, 9]. Most reconstructive procedures or their individual stages can be performed without arthrotomy, under arthroscopic control.

Comments. The transplantation is performed using a cylindrical osteochondral autograft harvested from a less weight-bearing portion of the lateral or medial femoral condyle or the intercondylar notch. Harvesting and transplantation of autografts are performed using a specialized instrument set.

3.4 Other treatment

3.4.1 Surgical antibiotic prophylaxis

• In the surgical treatment of patients with cartilage lesions involving the implantation of foreign materials, it is recommended to administer surgical antibiotic prophylaxis (SAP) to prevent surgical site infections via a single preoperative systemic antibacterial dose to reduce the risk of surgical site infections [121].

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

Comments. In accordance with international clinical guidelines for the prevention of surgical site infections [121], the goal of SAP is to achieve bactericidal concentrations of a systemic antibacterial agent in tissues susceptible to microbial contamination during surgery. The necessity of SAP is determined by the surgical wound class of the upcoming procedure: SAP is not required for "clean" surgical wounds not involving the placement of orthopedic implants and metal hardware. SAP should be administered for clean-contaminated and contaminated surgical wounds, as well as for "clean" surgical wounds involving the implantation of orthopedic implants and metal hardware. For infected ("dirty") wounds, SAP is not indicated; instead, antibiotic therapy is administered.

• In patients undergoing meniscus repair, it is recommended to use first- and second-generation cephalosporins (cefazolin**, cefuroxime**) as the primary medications for surgical antibiotic prophylaxis in trauma and orthopedic surgeries, or glycopeptide antibiotics (vancomycin**) and lincosamides (#clindamycin**) as alternatives in case of beta-lactam allergy [121].

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

Comments. For patients with an unburdened allergy history and no significant risk factors for methicillin-resistant Staphylococcus aureus carriage, first- and second-generation cephalosporins (cefazolin**, cefuroxime**) are used for SAP, administered intravenously 30 to 60 minutes before skin incision. In case of hypersensitivity to beta-lactam antibacterial drugs, a combination of vancomycin** with one of the fluoroquinolones (ciprofloxacin**, #levofloxacin**) administered as an intravenous infusion over at least 60 minutes starting 2 hours before the incision, or #clindamycin**, should be prescribed. In the presence of significant risk factors for methicillin-resistant Staphylococcus aureus (MRS) carriage, the SAP regimen must include a systemic antibacterial agent with anti-MRS activity (vancomycin**). In most cases, a single preoperative dose of a systemic antibacterial agent is sufficient for effective prophylaxis.

Single doses of the main antibacterial drugs for SAP in trauma and orthopedic surgeries in adults: cefazolin** 2 g (for patients weighing ≥120 kg – 3 g), cefuroxime** 1.5 g, #clindamycin** 900 mg, vancomycin** 15 mg/kg as a slow IV infusion, ciprofloxacin** 400 mg, #levofloxacin** 500 mg [121]. Single doses for children should be calculated based on actual weight: cefazolin** 30 mg/kg, cefuroxime** 50 mg/kg, #clindamycin** 10 mg/kg, vancomycin** 15 mg/kg; the use of fluoroquinolones during the period of musculoskeletal system development is contraindicated due to the risk of arthropathy [121].

3.4.2 Prevention of venous thromboembolic complications

Comments: To assess the risk of VTE before surgery, it is advisable to use a formal scale – Caprini score (Appendix G1).

Non-pharmacological means of VTE prophylaxis include:

- elastic and/or intermittent sequential pneumatic compression of the lower extremities;

- early mobilization and activation of the patient;

- therapeutic exercises.

All patients with additional thrombosis risk factors are recommended to receive mechanical VTE prophylaxis, as well as pharmacological VTE prophylaxis, typically in the absence of a high bleeding risk, until motor activity is restored.

Pharmacological VTE prophylaxis in adults includes the use of enoxaparin sodium** 40 mg subcutaneously 12 hours after surgery, then once daily. The standard duration of pharmacoprophylaxis is 7–10 days, and longer if the risk of thrombosis persists; or parnaparin sodium** 0.4 ml (4,250 anti-Xa IU) subcutaneously 12 hours before and after surgery, then once daily throughout the postoperative period for at least 10 days; or nadroparin calcium 0.4 ml (3,800 anti-Xa IU) subcutaneously 12 hours after surgery and then once daily until the 3rd postoperative day, and 0.6 ml (5,700 anti-Xa IU) starting from the 4th postoperative day for patients with a body weight of 70 kg or more throughout the period of thrombosis risk (but not less than 7 days).

• During arthroscopic procedures, it is routine VTE prophylaxis is not recommended in the absence of additional VTE risk factors and if tourniquet time is less than 45 minutes and anesthesia time is less than 90 minutes [122].

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

• When performing arthroscopy with a tourniquet time of 45 minutes or more, general anesthesia lasting longer than 90 minutes, or in adults at high risk for VTE, it is advisable to consider prescribing low molecular weight heparins from the heparin group (ATC: B01AB Heparin group) 6–12 hours postoperatively, followed by a transition to DOACs (dabigatran etexilate** or rivaroxaban**) extending the course of thromboprophylaxis to 10–14 days [122].

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

Comments: A high risk of VTE may be indicated by, for example, a history of VTE and/or pulmonary embolism, obesity with a BMI ≥40 kg/m2, etc. Recommended doses, frequency, and routes of administration of anticoagulant drugs from the antithrombotic group for thromboprophylaxis in high-risk VTE are provided in Appendix A3.3.

3.4.3 Pain management

Postoperative pain management

• To achieve adequate postoperative analgesia, it is recommended to use multimodal analgesia, which may include nonsteroidal anti-inflammatory and antirheumatic drugs (NSAIDs), paracetamol**, gabapentinoids, and immediate-release opioids, or monomodal analgesia if multimodal is not feasible [102–104, 125].

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

Comments: Adequate postoperative analgesia must be ensured prior to any manipulations and throughout the entire treatment period, the duration of which varies significantly depending on the chosen patient management strategy. When administering analgesia in a hospital setting, prescriptions made at the emergency medical care stage must be taken into account.

Among pharmacological strategies, the current consensus is to use multimodal analgesia (MMA), which involves the administration of multiple analgesics (opioids and other analgesics and antipyretics) with different mechanisms of action, along with non-pharmacological interventions targeting the peripheral and/or central nervous system [105]. This combination provides more effective pain relief by enhancing the effects of various drugs, which in most cases leads to a reduced frequency of prescriptions and/or lower doses of opioid analgesics. Thus, MMA lowers the risk profile of each drug while ensuring synergistic pain control through different drug classes. Postoperative MMA may include psychotherapy, physical therapy, NSAIDs, paracetamol**, gabapentinoids, regional anesthesia (single-shot or peripheral nerve catheter placement), local injections, and opioids [103].

In modern scientific literature, authors emphasize using the lowest effective doses of opioids for the shortest possible period, avoiding extended-release opioids. As an adjuvant to MMA in adults, a single dose of #dexamethasone** 1.25–20 mg IV can be administered prior to surgery (60 minutes before the incision), which provides a significant reduction in pain [102].

It is essential to remember that the parenteral administration of most NSAIDs used in adults (ketorolac**, ketoprofen**, diclofenac**) is limited to a duration of two days, which requires timely switching of the patient to oral administration, changing the drug, or approving further use with the medical commission. The specific choice of local anesthesia method and medicinal products is made by the attending physician individually in accordance with the patient's characteristics, local protocols, and the medical organization's equipment.

Recommended analgesic drugs are listed in Appendices A3.1 and A3.2.

3.6 Nutritional Therapy

Specific diet therapy has not been developed.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

There are many treatment options for knee cartilage injury, but there is no "gold standard" rehabilitation protocol for either conservative or surgical treatment.

Postoperative rehabilitation has been shown to be a critical component of the cartilage recovery process, providing the optimal mechanical load required for local adaptation and remodeling of cartilage tissue and returning the patient to an optimal level of motor activity [107, 108, 111, 120].

Modern concepts of rehabilitation after cartilage repair are based on a combination of fundamental scientific data, currently available surgical techniques, empirical information, and a limited number of clinical studies. Due to the complex nature of cartilage repair, varying defect characteristics, and concomitant conditions, an individualized rehabilitation approach should be developed for each patient following articular cartilage repair [107, 108, 115, 117, 120].

Because surgeons use different techniques in treating articular cartilage lesions in the knee, rehabilitation protocols should be designed in collaboration with the surgeon and take into account the specifics of the surgical intervention [108, 110, 113].

Comments: At the first stage of the articular cartilage recovery program, the primary focus should be on reducing pain and effusion, monitoring weight-bearing restrictions, and eliminating impairments in joint mobility, muscle performance, and neuromuscular control.

Following the initial consultation with a PRM (physical and rehabilitation medicine) physician / exercise therapy doctor, an individualized rehabilitation program for the first period is drawn up, prescribing: local cryotherapy, postural correction, isometric exercises to reduce pain and effusion in the knee joint, which is the main goal at the initial stage of cartilage recovery.

Electrostatic field massage has been shown to be clinically effective.

Upon a follow-up consultation with the PRM / exercise therapy physician after acute symptoms of the injury have subsided, a rehabilitation program is prescribed, including [109, 110, 114, 118]:

- passive exercises and passive mechanotherapy for the knee joint, positioning therapy

- patellar mobilization (manual therapy)

- manual massage of the knee joint and thigh area,

- laser therapy (exposure to low-intensity laser radiation for joint diseases, low-intensity laser skin irradiation), interference current therapy, and ultrasound therapy (ultrasound exposure for joint diseases) applied to the knee area.

- isometric exercises and free dynamic exercises to strengthen the thigh and lower leg muscle groups.

Continuous passive motion (passive mechanotherapy) is a standard inclusion in rehabilitation during articular cartilage repair [109, 111]:

As physical loads are adapted to, in the absence of pain and joint effusion, with full extension and flexion up to 90 degrees in the knee joint, upon a follow-up consultation with the PRM / exercise therapy physician, the rehabilitation program includes [109, 110, 116, 118]:

- dynamic exercises with additional load and resistance, and static exercises

- active mechanotherapy on stationary bikes (mechanotherapy for joint diseases and injuries);

- proprioception and balance training with biofeedback (balance therapy, exercise therapy with biofeedback for joint diseases and injuries);

- electromyostimulation of the quadriceps femoris muscle.

The leg is immobilized in an orthosis for three weeks, and gait training without weight-bearing on the leg is performed. Graded weight-bearing on the leg is permitted after 3–4 weeks [110, 120].

Comments: regardless of the cartilage repair method, the rehabilitation process is based on the biological healing phases of cartilage: an initial load-shielding phase during joint movement, followed by a progressive joint-loading phase and a functional recovery phase [109, 111, 113, 115].

In some cases, the knee is immobilized in an orthosis, which is removed during procedures. On the day of surgery, the PRM / exercise therapy physician draws up an individualized rehabilitation program prescribing the following for the early postoperative period [109, 110, 112, 113, 115, 116, 118]:

local cryotherapy, magnetic field therapy, barotherapy/limb pressotherapy, pneumatic compression, and electrostatic field massage to reduce joint effusion;

- isometric exercises for the thigh and gluteal muscles, and free dynamic exercises for the ankle joint to improve blood flow and normalize muscle tone;

- passive patellar mobilization;

- continuous passive mechanotherapy;

- gait training with additional crutch support without weight-bearing on the operated leg (starting from the second day).

Continuous passive motion (passive mechanotherapy) is recommended immediately after surgery and is a standard inclusion in rehabilitation for articular cartilage repair [107, 113, 114].

Comments: the main objective of postoperative rehabilitation is the adequate selection of rehabilitation methods and means that simultaneously promote cartilage healing and maturation while preventing the risk of further chondrocyte death or damage due to inappropriate loads [109, 113].

Although there is currently no evidence-based consensus regarding the use of a postoperative brace after articular cartilage repair of the knee, a full-extension brace is generally recommended in certain cases for the first 4–6 weeks, especially if the cartilage defects are large or kissing, or if there is an active quadriceps extension lag [109, 110].

After brace removal, the PM&R/physical therapy specialist develops an individualized rehabilitation program prescribing [110, 112, 114, 118, 120]:

- passive knee exercises and passive continuous passive motion (CPM) with an increasing range of motion;

- low-level laser therapy for joint diseases, high-intensity pulsed electromagnetic field therapy;

- after suture removal, aquatic physical exercises, electrotherapy, ultrasound therapy;

- dynamic exercises for the ankle and hip joints.

During the follow-up examination, if there is no pain or joint effusion, and 90⁰ of flexion and full extension of the knee have been achieved, the PM&R/physical therapy specialist includes the following in the rehabilitation program [108, 109, 115, 119]:

- dynamic exercises with load and resistance to strengthen the thigh and gluteal muscles;

- quadriceps neuromuscular electrical stimulation;

- manual massage of the thigh muscles and knee joint;

- active mechanotherapy on a stationary bicycle;

- mechanotherapy for joint diseases and injuries;

- biofeedback physical therapy for joint diseases and injuries;

- balance training;

Graduated weight-bearing on the leg is recommended to begin at 4 weeks, and full weight-bearing at 8–10 weeks after surgery. For 2–3 months, patients are advised to use a cane and a soft knee sleeve when walking.

Comments: adherence to these recommendations promotes cartilage regeneration, which occurs slowly due to the lack of blood supply in cartilage tissue. Pain and swelling (recurrent synovitis) are the primary indicators that rehabilitation is progressing too intensively and overloading the reparative cartilage.

Failure to follow these recommendations will lead to recurrent pain, resulting in the development of osteoarthritis [107, 109, 110].

5. Prevention and Dispensary Observation

Preventive measures against knee cartilage injuries include the elimination of risk factors (improving exercise and training methodology) and the avoidance of potential trauma and microtrauma to the knee joint.

6. Organization of Medical Care

Indications for scheduled hospitalization in a medical organization:

1 conservative treatment failure;

2) presence of indications for surgical correction.

Indications for emergency hospitalization in a medical organization:

1) levels 1–4 – pain syndrome;

2) risk of complications;

3) pronounced limb function impairment.

Indications for discharging a patient from a medical organization:

1) completion of the rehabilitation course;

2) absence of surgical complications;

3) achieved clinically significant improvement in the treatment of knee joint conditions.

7. Additional Information

Patients after surgical treatment for cartilage injuries are advised to follow an orthopedic regimen that excludes prolonged standing, running, jumping, deep squats, and contact sports, as these contribute to the early onset and rapid progression of knee osteoarthritis.

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Butkova L.L., Cand. Sci. (Med.), National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov of the Russian Ministry of Health, Moscow, member of ATOR.

2. Vasiliev D.O., Cand. Sci. (Med.), National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov of the Russian Ministry of Health, Moscow, member of ATOR.

3. Geroeva I.B., MD, DSc, Professor, National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov of the Russian Ministry of Health, Moscow.

4. Gorbatyuk D.S., Cand. Sci. (Med.), National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov of the Russian Ministry of Health, Moscow, member of ATOR.

5. Yeltsin A.G., Cand. Sci. (Med.), National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov of the Russian Ministry of Health, Moscow.

6. Kleimenova E.B., MD, DSc, Professor, National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov of the Russian Ministry of Health, Moscow.

7. Kornilov N.N., Dr. Sci. (Med.), National Medical Research Center of Traumatology and Orthopedics named after R.R. Vreden of the Russian Ministry of Health, St. Petersburg, member of ATOR.

8. Kulyaba T.A., MD, PhD, DSc, R.R. Vreden National Medical Research Center of Traumatology and Orthopedics of the Russian Ministry of Health; St. Petersburg, member of ATOR.

9. Nazarenko A.G., MD, Professor of RAS, Director of the Priorov National Medical Research Center of Traumatology and Orthopedics of the Ministry of Health of Russia, Moscow, Vice President of ATOR.

10. Orletsky A.K., MD, PhD, DSc, Professor, N.N. Priorov National Medical Research Center of Traumatology and Orthopedics of the Russian Ministry of Health, Moscow, member of ATOR.

11. Otdelenov V.A., PhD, National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov of the Russian Ministry of Health, Moscow.

Conflict of interest: the members of the working group declare no conflict of interest in the development of this clinical guideline.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. Trauma and orthopedic surgeons

2. Surgeons

3. Pediatric surgeons

4. General practitioners (family physicians)

5. Medical rehabilitation physicians

Stages of evaluating the levels of evidence and grades of recommendation:

1. Definition of search and selection criteria for publications on clinical trials (CT) regarding the efficacy and/or safety of the medical intervention described in the recommendation statement.

2. Systematic search and selection of CT publications in accordance with the previously defined criteria.

Systematic search and selection of clinical trial publications:

The evidence base for the recommendations consisted of publications retrieved via information retrieval in the following databases: Central Scientific Medical Library (CSML) "Russian Medicine", MEDLINE (US NLM), and COCHRANE Library; scientific electronic libraries eLibrary.ru and "CyberLeninka"; as well as on the Internet using Yandex, Google, and Google Scholar search engines, by reviewing leading specialized peer-reviewed domestic medical journals on the subject and treatment guidelines for fractures from the international Association for Osteosynthesis AO/ASIF.

Table 1. Levels of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)

Table 2. Scale for grading levels of evidence certainty (LEC) for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitative interventions)

Table 3. Scale for grading grades of recommendation (GR) for prevention, diagnostic, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitative interventions)

Procedure for updating clinical guidelines

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

Appendix A3.1 Recommendations for analgesia in major musculoskeletal trauma (surgical interventions for long bone fracture fixation or complex articular fracture, extensive soft tissue trauma, extensive surgical intervention, etc.) for adults

The table presents analgesic medications and dosing regimens in accordance with the Clinical Guidelines for Analgesia in Acute Musculoskeletal Trauma [105].

Appendix A3.2 Pain management recommendations for non-surgical musculoskeletal trauma (closed fractures, superficial wounds, etc.) in adults

The table presents analgesic medications and dosing regimens in accordance with the Clinical Guidelines for Analgesia in Acute Musculoskeletal Trauma [105].

Appendix A3.3 Recommended doses, frequency, and route of administration of anticoagulants from the antithrombotic drug group for thromboprophylaxis in high-risk venous thromboembolism (VTE) during conservative treatment and the preoperative period for adults

It should be noted that spinal or epidural anesthesia is possible only 12 hours after the administration of a low-molecular-weight heparin dose and no earlier than 4–6 hours after the administration of unfractionated heparin (meanwhile, aPTT or ACT values must be within the normal range) [129, 130].

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

A patient suffering from chronic hip pathology must strictly follow the doctor's prescriptions, adhere to the basic principles of rehabilitation in the postoperative period, and follow recommendations in the long-term period after surgical treatment:

- walk with crutch support for 6 weeks;

- on days 6–12, arrive at the medical facility for suture removal according to the attending physician's instructions;

- after suture removal, undergo a course of restorative treatment (exercise therapy, massage, physiotherapy);

- perform a follow-up CT scan of the joint 8 weeks after surgery to determine the further axial load regimen on the limb according to the attending physician's instructions;

- perform a follow-up MRI of the joint 6 months after surgery according to the attending physician's instructions;

- subsequently exclude heavy impact and static loads on the joint;

- in case of osteoarthritis development and periodic joint pain, undergo courses of conservative rehabilitation treatment.

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

Appendix G1. Caprini Risk Assessment Scale for Venous Thromboembolism (Caprini J.)

Russian title: Caprini Individual Risk Assessment Scale for Venous Thromboembolism

Original title: Caprini Score for Venous Thromboembolism

Source: Lobastov K.V., Barinov V.E., Schastlivtsev I.V., Laberko L.A. Caprini scale as a tool for individual risk stratification of postoperative venous thromboembolism in the high-risk group. Pirogov Russian Journal of Surgery. 2014; (12):16-23.

Type: scale

Purpose: assessment of venous thromboembolism risk

Content (template):

1 point

Age 41-60 years

Lower extremity edema

Varicose veins

Body mass index over 25 kg/m2

Minor surgery

Sepsis (within 1 month)

Serious pulmonary disease (including pneumonia within 1 month)

Oral contraceptive use, hormone replacement therapy

Pregnancy and postpartum period (up to 1 month)

History of unexplained stillbirths, spontaneous abortions (≥3),

Premature birth with preeclampsia or intrauterine growth restriction

Acute myocardial infarction

Chronic heart failure (within 1 month)

Bed rest in a non-surgical patient

History of inflammatory bowel disease

Major surgery within the past 1 month

Chronic obstructive pulmonary disease

2 points

Age 61-74 years

Arthroscopic surgery

Malignant neoplasm105

Laparoscopic surgery (duration > 45 min)

Bed rest > 72 h

Limb immobilization (within 1 month)

Central venous catheterization

Major surgery (duration > 45 min)

3 points

Age > 75 years

Personal history of VTE

Family history of VTE

Factor V Leiden mutation

Prothrombin G20210A mutation

Hyperhomocysteinemia

Heparin-induced thrombocytopenia

Elevated anticardiolipin antibodies

Lupus anticoagulant

5 points

Stroke (< 1 month)

Multiple trauma (< 1 month)

Major joint arthroplasty

Femur and lower leg fractures (< 1 month)

Spinal cord injury/paralysis (< 1 month)

Key: Depending on the score obtained from history taking and patient examination, the patient is assigned to a specific risk group:

• low risk: 0–1 point;

• moderate risk: 2 points;

• high risk: 3–4 points;

• very high risk: 5 points or more