Acquired lower limb deformities (excluding the foot): clinical guidelines

List of Abbreviations

EFA – external fixation apparatus

AO – Association for Osteosynthesis

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

TIB – tibia

VTE – venous thromboembolism

DTFS – distal tibiofibular syndesmosis

DLLF – distal lower leg fractures

RTA – road traffic accident

Knee – knee joint

CT – computed tomography

SCT – spiral computed tomography

medicines – medicinal products

PT – physical therapy

MDRT – multidisciplinary rehabilitation team

Ministry of Health of the Russian Federation – Ministry of Health of the Russian Federation

ICD-10 – International Statistical Classification of Diseases and Related Health Problems 10th Revision

MRI – magnetic resonance imaging

LLD – acquired limb length discrepancy

NSAIDs – nonsteroidal anti-inflammatory drugs from the M01A Non-steroidal anti-inflammatory and antirheumatic products group

RF – risk factors

PRM – physical and rehabilitation medicine

FS – functional status

TENS – transcutaneous electrical nerve stimulation

Surgical antibiotic prophylaxis

LCP – Locking Compression Plate

MIPO – Minimally Invasive Plate Osteosynthesis

ORIF – Open Reduction Internal Fixation

ACT – activated clotting time

VTE – venous thromboembolism

MMA – multimodal analgesia

LMWH – low molecular weight heparins

UFH – unfractionated heparin

Terms and Definitions

Osteotomy – a surgical procedure involving the transection of a bone for the purpose of subsequently altering its size and shape.

Consolidation of bone fragments – mutual connection of fragments by living bone tissue as a result of the successful completion of reparative regeneration or distraction osteogenesis.

Bone fragment – a part of a bone separated as a result of damage from trauma, surgical intervention, or a destructive process.

Deformity (orthopedic) – discrepancy between reference lines and angles (RLAs) and accepted normal values, in the absence or presence of relative shortening; wherein "shortening" is considered both as a component of the deformity and as a bone defect.

Reference lines and angles (RLAs) – joint lines, anatomical and mechanical axes, and anatomical and mechanical angles in their interrelation accepted as normal.

Joint line (articular line) – a line drawn on the basis of two reference points that determines the orientation of the articular surface.

Anatomical axis – the mid-diaphyseal line.

Overall mechanical axis of the lower extremity – the line from the center of the femoral head to the center of the distal articular line of the tibia.

Mechanical axis deviation (MAD) – the deviation in the frontal plane from the center of the distal articular line of the femur. The normal range is defined as from the center of the joint line to 12 mm medially.

Mechanical axis of the femur – in the frontal plane, the line from the center of the femoral head to the center of the distal articular line of the femur; in the sagittal plane, the line from the center of the femoral head to the anterior 2/5 of the distal articular line of the femur.

Mechanical axis of the tibia – in the frontal plane, the line between the centers of the proximal and distal articular lines of the tibia; in the sagittal plane, the line from the anterior 1/4 of the proximal articular line of the tibia to the center of the distal articular line of the tibia.

Anatomical angle – the angle of intersection between the joint line and the anatomical axis.

Mechanical angle – the angle of intersection between the joint line and the mechanical axis.

Center of rotation of angulation (CORA) – the point of intersection of the anatomical or mechanical axes of the proximal and distal fragments.

Multiapical deformity – a situation where there is more than one center of rotation of angulation along the length of a bone.

Osteotomy rule #1 – when an osteotomy is performed at the level of the CORA, correction of the angular deformity will not result in lateral displacement ("translation") of the mobile (distal) bone fragment.

Osteotomy rule #2 – when an osteotomy is performed proximal or distal to the CORA, correction of the angular deformity will result in lateral displacement ("translation") of the mobile (distal) bone fragment; the greater the distance from the CORA level to the osteotomy level, the greater the translation required.

Modelling resection – excision of a portion of bone to correct a deformity, remove pathological tissues, ensure maximum contact between bone fragments, or eliminate joint impingement.

Fixation – a condition in which complete immobilization of fragments is achieved or micro-motion is preserved that does not prevent bone fragment union under conditions of relative stability.

Transosseous osteosynthesis – a method of treatment for injuries and diseases of bones, joints, and soft tissues utilizing external structures positioned above the skin surface and connected to the bone via transosseous or extracortical elements. Together, they form an external fixation device (EFD).

Rigidity of osteosynthesis (stiffness of bone fragment fixation) – the ability of an EFD to resist deformation (change in shape and/or dimensions) from an applied force along a selected direction in a given coordinate system; rigidity can be precisely measured.

Stability of osteosynthesis – the ability of the "EFD-bone" system to function without altering its internal structure and to remain in equilibrium; stability cannot be measured directly, and only qualitative terms such as "more stable" or "less stable" may be used, based on rigidity criteria.

Load – mechanical force applied to the limb, bone, and fixator-bone system during treatment, typically recurring at a constant periodicity (cyclically).

Optimal (recommended) positions for transosseous element insertion – locations where major neurovascular structures are absent in projection and there is minimal soft tissue displacement (skin, fascia, muscles) during movements in joints adjacent to the segment.

Orthopedic implant – a device implanted into the human body to connect bone fragments and temporarily compensate for lost bone strength (fixator, graft, their components and combinations, and in some cases, an endoprosthesis).

Internal fixator – an orthopedic implant implanted under the patient's skin that connects bone fragments in the treatment of fractures, pseudoarthrosis, and deformity correction.

Revision surgery – a repeat operation at the same site as the primary operation, aimed at achieving the goal of the primary surgery with the maximum possible restoration of limb function.

Re-osteosynthesis – revision osteosynthesis – repeat osteosynthesis at the same location.

Assisted external fixation – a method of using transosseous osteosynthesis for fracture reduction or acute deformity correction and holding bone fragments in the correct position while an intramedullary nail or plate is inserted, after which the EFD is removed.

Lengthening over nail (along plate) – a technique for lengthening a long bone using an EFD in the presence of an inserted intramedullary (or on-bone) implant, locked proximally or distally, followed by final locking and removal of the apparatus after the distraction period is completed.

Lengthening and then nailing (plating) – a technique for lengthening a long bone using an EFD with insertion of an intramedullary (on-bone) implant at the end of the distraction period and removal of the external fixation apparatus.

Latency period – the period from the performance of the osteotomy to the start of distraction (deformity correction) in the external fixation apparatus.

Distraction period (deformity correction period) – the period during which bone lengthening (distraction) or deformity correction manipulations are performed in the EFD.

Fixation period – the period from the end of lengthening or deformity correction until the removal of the EFD.

Period of transosseous osteosynthesis – the period from the transosseous osteosynthesis surgery until the removal of the EFD.

Anticoagulants – chemical substances and drugs that inhibit the activity of coagulation hemostasis (the blood-clotting system) and prevent thrombus formation, belonging to the group of antithrombotic agents (B01A).

Antibacterial drug, antibiotic – a medicinal product from the group of antibacterials for systemic use (J01).

Beta-lactam antibiotics – a group of antibacterial drugs sharing a common structural element—the beta-lactam ring. They inhibit bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to lysis and death of the microbial cell. According to the Anatomical Therapeutic Chemical classification, beta-lactam antibiotics include the following main groups: penicillins (J01C) and other beta-lactams (J01D), of which first-generation (J01DB), second-generation (J01DC), third-generation (J01DD), and fourth-generation (J01DE) cephalosporins, other cephalosporins and penems (J01DI), carbapenems (J01DH), and monobactams (J01DF) are of greatest clinical significance.

Nonsteroidal anti-inflammatory drugs – nonsteroidal anti-inflammatory drugs belonging to the group "Anti-inflammatory and antirheumatic products, non-steroids" (M01A).

Unfractionated heparin is a parenteral anticoagulant, representing a heterogeneous mixture of sulfated mucopolysaccharides with a molecular weight ranging from 3,000 to 30,000 kDa, with a mean value of 15,000 kDa, which corresponds to approximately 45 monosaccharide residues. It is represented by heparin sodium (or heparin).

Low-molecular-weight heparins are a type of parenteral anticoagulants that are fragments of unfractionated heparin obtained through enzymatic or chemical depolymerization processes, resulting in polysaccharide chains with a mean molecular weight of approximately 5 kDa. They belong to the heparin group (B01AB). a surgical procedure involving the transection of a bone for the subsequent modification of its size and shape.

Consolidation of bone fragments – mutual connection of fragments by living bone tissue as a result of the successful completion of reparative regeneration or distraction osteogenesis.

Bone fragment – a part of a bone separated as a result of damage from trauma, surgical intervention, or a destructive process.

Deformity (orthopedic) – discrepancy between reference lines and angles (RLAs) and accepted normal values, in the absence or presence of relative shortening; wherein "shortening" is considered both as a component of the deformity and as a bone defect.

Reference lines and angles (RLAs) – joint lines, anatomical and mechanical axes, and anatomical and mechanical angles in their interrelation accepted as normal.

Joint line (articular line) – a line drawn on the basis of two reference points that determines the orientation of the articular surface.

Anatomical axis – the mid-diaphyseal line.

Overall mechanical axis of the lower extremity – the line from the center of the femoral head to the center of the distal articular line of the tibia.

Mechanical axis deviation (MAD) – the deviation in the frontal plane from the center of the distal articular line of the femur. The normal range is defined as from the center of the joint line to 12 mm medially.

Mechanical axis of the femur – in the frontal plane, the line from the center of the femoral head to the center of the distal articular line of the femur; in the sagittal plane, the line from the center of the femoral head to the anterior 2/5 of the distal articular line of the femur.

Mechanical axis of the tibia – in the frontal plane, the line between the centers of the proximal and distal articular lines of the tibia; in the sagittal plane, the line from the anterior 1/4 of the proximal articular line of the tibia to the center of the distal articular line of the tibia.

Anatomical angle – the angle of intersection between the joint line and the anatomical axis.

Mechanical angle – the angle of intersection between the joint line and the mechanical axis.

Center of rotation of angulation (CORA) – the point of intersection of the anatomical or mechanical axes of the proximal and distal fragments.

Multiapical deformity – a situation where there is more than one center of rotation of angulation along the length of a bone.

Osteotomy rule #1 – when an osteotomy is performed at the level of the CORA, correction of the angular deformity will not result in lateral displacement ("translation") of the mobile (distal) bone fragment.

Osteotomy rule #2 – when an osteotomy is performed proximal or distal to the CORA, correction of the angular deformity will result in lateral displacement ("translation") of the mobile (distal) bone fragment; the greater the distance from the CORA level to the osteotomy level, the greater the translation required.

Modelling resection – excision of a portion of bone to correct a deformity, remove pathological tissues, ensure maximum contact between bone fragments, or eliminate joint impingement.

Fixation – a condition in which complete immobilization of fragments is achieved or micro-motion is preserved that does not prevent bone fragment union under conditions of relative stability.

Transosseous osteosynthesis – a method of treatment for injuries and diseases of bones, joints, and soft tissues utilizing external structures positioned above the skin surface and connected to the bone via transosseous or extracortical elements. Together, they form an external fixation device (EFD).

Rigidity of osteosynthesis (stiffness of bone fragment fixation) – the ability of an EFD to resist deformation (change in shape and/or dimensions) from an applied force along a selected direction in a given coordinate system; rigidity can be precisely measured.

Stability of osteosynthesis – the ability of the "EFD-bone" system to function without altering its internal structure and to remain in equilibrium; stability cannot be measured directly, and only qualitative terms such as "more stable" or "less stable" may be used, based on rigidity criteria.

Load – mechanical force applied to the limb, bone, and fixator-bone system during treatment, typically recurring at a constant periodicity (cyclically).

Optimal (recommended) positions for transosseous element insertion – locations where major neurovascular structures are absent in projection and there is minimal soft tissue displacement (skin, fascia, muscles) during movements in joints adjacent to the segment.

Orthopedic implant – a device implanted into the human body to connect bone fragments and temporarily compensate for lost bone strength (fixator, graft, their components and combinations, and in some cases, an endoprosthesis).

Internal fixator – an orthopedic implant implanted under the patient's skin that connects bone fragments in the treatment of fractures, pseudoarthrosis, and deformity correction.

Revision surgery – a repeat operation at the same site as the primary operation, aimed at achieving the goal of the primary surgery with the maximum possible restoration of limb function.

Re-osteosynthesis – revision osteosynthesis – repeat osteosynthesis at the same location.

Assisted external fixation – a method of using transosseous osteosynthesis for fracture reduction or acute deformity correction and holding bone fragments in the correct position while an intramedullary nail or plate is inserted, after which the EFD is removed.

Lengthening over nail (along plate) – a technique for lengthening a long bone using an EFD in the presence of an inserted intramedullary (or on-bone) implant, locked proximally or distally, followed by final locking and removal of the apparatus after the distraction period is completed.

Lengthening and then nailing (plating) – a technique for lengthening a long bone using an EFD with insertion of an intramedullary (on-bone) implant at the end of the distraction period and removal of the external fixation apparatus.

Latency period – the period from the performance of the osteotomy to the start of distraction (deformity correction) in the external fixation apparatus.

Distraction period (deformity correction period) – the period during which bone lengthening (distraction) or deformity correction manipulations are performed in the EFD.

Fixation period – the period from the end of lengthening or deformity correction until the removal of the EFD.

Period of transosseous osteosynthesis – the period from the transosseous osteosynthesis surgery until the removal of the EFD.

Anticoagulants – chemical substances and drugs that inhibit the activity of coagulation hemostasis (the blood-clotting system) and prevent thrombus formation, belonging to the group of antithrombotic agents (B01A).

Antibacterial drug, antibiotic – a medicinal product from the group of antibacterials for systemic use (J01).

Beta-lactam antibiotics – a group of antibacterial drugs sharing a common structural element—the beta-lactam ring. They inhibit bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to lysis and death of the microbial cell. According to the Anatomical Therapeutic Chemical classification, beta-lactam antibiotics include the following main groups: penicillins (J01C) and other beta-lactams (J01D), of which first-generation (J01DB), second-generation (J01DC), third-generation (J01DD), and fourth-generation (J01DE) cephalosporins, other cephalosporins and penems (J01DI), carbapenems (J01DH), and monobactams (J01DF) are of greatest clinical significance.

Nonsteroidal anti-inflammatory drugs – nonsteroidal anti-inflammatory drugs belonging to the group "Anti-inflammatory and antirheumatic products, non-steroids" (M01A).

Unfractionated heparin is a parenteral anticoagulant, representing a heterogeneous mixture of sulfated mucopolysaccharides with a molecular weight ranging from 3,000 to 30,000 kDa, with a mean value of 15,000 kDa, which corresponds to approximately 45 monosaccharide residues. It is represented by heparin sodium (or heparin).

Low molecular weight heparins are a type of parenteral anticoagulants that are fragments of unfractionated heparin obtained as a result of enzymatic or chemical depolymerization processes, resulting in polysaccharide chains with an average molecular weight of about 5 kDa. They belong to the heparin group (B01AB).

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Acquired limb deformities represent various acquired pathologies characterized by alterations in the shape, length, and axis of the limbs. These changes are frequently accompanied not only by external deviations but also by varying degrees of functional impairment.

Diagnosis is established using symptoms and medical history data, as well as the results of X-rays, computed tomography (CT), magnetic resonance imaging (MRI), and other diagnostic methods. Depending on the causes of the deformity, its severity, and the degree of limb function impairment, either conservative or surgical treatment is chosen.

Post-traumatic lower limb deformities are a vast and diverse group of pathological conditions accompanied by changes in limb length and shape resulting from malunion of bone fragments. Furthermore, hematogenous osteomyelitis suffered at an early age is one of the primary causes of severe progressive musculoskeletal deformities in children and adolescents, as their growth plates are vulnerable to infection [6, 7]. In addition to external signs of deformity, in most cases, a more or less pronounced impairment of limb function is typically observed [1-4]. The definition of post-traumatic deformity can be formulated as follows: "A bone deformity is a fixed, clinically significant violation of the axes of bone fragments, i.e., establishing a discrepancy in the relationships of reference anatomical axes accepted as normal" [1, 2, 5].

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

Acquired limb length discrepancy (LLD) and deformities are among the most frequent reasons for referral to an orthopedist [3, 4, 8]. Shortening of one of the lower limbs of acquired etiology, even if seemingly insignificant, affects the development of secondary pathology [9]. A length discrepancy of more than 1.5 cm can cause altered movement biomechanics, leading to scoliotic spinal deformity, gait disturbances, and early development of osteoarthritis in large joints [10, 11].

According to V.I. Moskvin (1969), limb function impairments and various deformities following osteomyelitis account for 71.2%. In children, long bones are primarily affected, especially the femur and tibia (27% and 26%, respectively) [6]. The main mechanisms of infection are hematogenous spread and direct inoculation due to trauma or surgical interventions [7].

Post-infectious lower limb deformities occur as a result of a prior infection (osteomyelitis, septic arthritis, bone/joint tuberculosis, deep purulent soft tissue infections, etc.). Joint involvement of the lower limbs as a complication of hematogenous osteomyelitis most frequently occurs in infants under one year of age (80.5%), particularly in the neonatal period [12-14].

The main causative agents of transphyseal hematogenous osteomyelitis are Staphylococcus aureus and Kingella kingae [14]. Subsequently, this leads to joint contractures, pseudoarthrosis, major shortening, multiplanar limb deformities, and the potential formation of fibrous or bony ankylosis [6, 7, 12-14]. Limb deformities following osteomyelitis progress as the child grows. Complex anatomical disproportions and functional changes disrupt statics and kinematics of the musculoskeletal system, impair gait and the function of adjacent joints, cause secondary musculoskeletal deformities, and ultimately lead to disability in 53.7% of cases [6, 7, 12-14]. Patients with the sequelae of hematogenous osteomyelitis account for up to 10% of individuals with disabilities, which highlights the pressing need for the rehabilitation of children with osteomyelitis sequelae [6, 7, 12-14].

Among the causes of primary disability in patients with musculoskeletal trauma sequelae, rehabilitation outcomes resulting in defects, pseudoarthrosis, and malunions with axis and length abnormalities of the injured segments rank third [1-4].

The most frequent causes of acquired limb deformity include errors in management tactics and complications developed during the treatment of a bone fracture [1-4]:

√ conservative treatment errors – inadequate duration and quality of immobilization of the injured limb segment, overdistraction of fragments on skeletal traction;

√ surgical intervention defects – unstable fixation and fracture reduction, devitalization and/or resection of fragments during debridement;

√ postoperative rehabilitation errors – insufficient duration of limb immobilization following a fracture, use of unstable osteosynthesis, premature removal of the bone fixator, untimely weight-bearing on the limb.

Thus, improper fracture healing is influenced by a number of systemic and local factors. The presence of systemic factors must be taken into account when choosing a fracture treatment method. When planning primary osteosynthesis, it is necessary to ensure a sufficient level of fixation stability, considering the severity of the injury and the patient's systemic factors.

1.3 Epidemiology of the Disease or Condition

The incidence of femoral fractures generally exhibits a bimodal age distribution. Most femoral deformities result from a combination of angular and rotational deviation coupled with shortening. A diaphanous tibial fracture is the most common long bone fracture. The reported incidence of femoral shaft fractures is 10 per 100,000 population per year [15]. The incidence of tibial shaft fractures is approximately 26 per 100,000 fractures per year [16]. According to Milner et al., up to 8% of tibial shaft fractures heal with a degree of deformity exceeding the acceptable range [17]. Among the complications of fracture treatment, post-traumatic deformities occupy one of the leading positions, reaching 40–60% [1-4].

The prevalence of hematogenous osteomyelitis is 9.2 cases per 100,000 population [12]. Young children are particularly affected, with 50% of patients under the age of 5 [7]. In children, long bones are predominantly affected, especially the femur and tibia (27% and 26%, respectively) [6]. Depending on the virulence of the pathogen and the body's response to infection, transphyseal hematogenous osteomyelitis can present in an acute or subacute form and develops in 25.7% of hematogenous osteomyelitis cases [13, 14, 18].

1.4 Features of Coding the Disease or Condition

These clinical guidelines provide information on acquired limb deformities (general category M21), and include additional ICD-10 codes that may also be applicable within these guidelines:

• M21.0 Valgus deformity, not elsewhere classified

• M21.1 Varus deformity, not elsewhere classified

• M21.2 Flexion deformity

• M21.7 Unequal limb length (acquired)

• M21.8 Other specified acquired deformities of limbs

• M21.9 Acquired deformity of limb, unspecified

• M95.8 Other specified acquired deformities of musculoskeletal system

• M99.9 Biomechanical lesion, unspecified

1.5 Classification of the disease or condition

1). Depending on the plane of deformity, the following are distinguished:

a. valgus deformities – deviation of the segment axis outward;

b. varus deformities – deviation of the segment axis inward;

c. antecurvation deformities – angular deformity with an angle open posteriorly, i.e., with deviation of the segment (limb) axis posteriorly;

d. recurvation deformities – angular deformity with an angle open anteriorly, i.e., with deviation of the segment (limb) axis anteriorly;

e. multiplanar deformities – deformity present in more than one plane;

f. torsional deformities – alteration of the segment axis along its length resembling a "twisting" pattern.

2). Depending on the level of bone deformity: metaphyseal, diaphyseal, metadiaphyseal, multi-apical.

3). Depending on the involvement of limb segment(s): single-segment, multi-segment.

1.6 Clinical presentation of the disease or condition

Main clinical signs: presence of a visible "curvature" (proper "deformity") of the segment, limb; shortening; pain and limited mobility in the area of adjacent joints, impaired limb function, decreased muscle strength and atrophy, limping. The degree of manifestation of these signs depends on the severity of the deformity and limb shortening.

Clinically significant deformities, including multi-apical ones, can also occur in the absence of deviation of the overall mechanical axis.

Acquired deformity occurs due to the fact that fracture reduction was not ensured ("post-traumatic" deformities), or the growth plate was damaged in childhood during trauma or as a result of a past infectious process.

Deformities can be "simple" (single-component, single-plane), "moderately complex" (one- to three-component and one- to two-plane), and "complex" (multi-component, multi-plane). Deformities with changes in anatomical (mechanical) angles up to 15º can remain asymptomatic for a long time. Against the background of acquired deformity, the weight-bearing capacity of the entire limb often decreases, and a secondary foot deformity develops. Acquired deformities can be extremely diverse: with varus or valgus curvature, antecurvation or recurvation, multi-plane and multi-level, with changes in the torsional profile.

Limb segment shortening in acquired deformity can also vary. Acquired deformity and limb shortening also determine the main functional impairments: impaired weight-bearing, forcing the patient to use additional support aids (crutches, a cane, orthopedic devices), shoe lifts, or custom orthopedic insoles [1–4]. As a result of past trauma or an infectious process that led to acquired deformity of the limb, surgical interventions for a fracture or deformity, possible complications, and changes in statics, physiological and morphological changes occur in all tissues of the altered limb, constituting a pathological symptom complex (scarring of the skin and underlying soft tissues, dystrophic changes in muscles, nerves, circulatory disorders, including persistent edema, spasm of major and small vessels, vegetative-trophic changes, disuse bone atrophy, contractures, and joint ankylosis).

X-ray examination allows for the differential diagnosis of acquired deformity with a pseudoarthrosis, delayed fracture union with incorrect positioning of bone fragments.

Pseudoarthrosis may be accompanied by deformity, the diagnosis and planning of which should also be carried out based on lower limb length and alignment (LLLA) imaging.

The main radiological signs of acquired deformity of the lower limb are: a difference from the reference values of the deviation of the overall mechanical axis, mechanical (anatomical), and "torsional" angles, and bone shortening. With long-standing deformity, there will be signs of arthrosis of adjacent joints, and with shortening, deformity and degenerative changes in the spine.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Criteria for establishing the disease or condition:

The diagnosis is established based on anamnestic data and clinical manifestations (curvature of the limb axis, its shortening, pain in the joint area under load). However, all these symptoms are optional and may be absent in a number of patients. The most informative diagnostic method is X-ray examination, in the absence of conditions requiring coding by other ICD-10 codes (see section 1.4).

Currently accepted definitions of unacceptable femoral alignment include angulation or malrotation > 10° or shortening > 2 cm [19], although the definition of unacceptable tibial alignment remains elusive and is described differently in the literature. Literature describes correction guidelines that include varus/valgus angulation > 5°, anterior/posterior angulation > 10°, internal rotation > 5°, external rotation > 10°, or shortening > 1 cm [20]. Gait changes, including a limp, have been reported with leg length discrepancies of 1.5 cm or greater [21].

Of particular interest in terms of resolving expert issues and determining indications for surgical correction is the set of norms regulating the fitness of conscripts for service in the Armed Forces of the Russian Federation: the provisions on military medical expertise [22]: Article 69 "Acquired and congenital limb deformities causing impaired function and/or making it difficult to wear military uniforms, shoes, or equipment" identifies the following types of deformities and shortening of traumatic origin:

- clause "a": O-shaped leg curvature with a distance between the prominences of the internal femoral condyles of more than 20 cm or X-shaped curvature with a distance between the internal malleoli of the shins of more than 15 cm; axial shortening of an arm or leg of more than 8 cm, as well as its rotational deformity of more than 30 degrees;

- clause "b": O-shaped leg curvature with a distance between the prominences of the internal femoral condyles from 12 to 20 cm or X-shaped curvature with a distance between the internal malleoli of the shins from 12 to 15 cm; axial shortening of an arm or leg from 5 to 8 cm inclusive, as well as its rotational deformity from 15 to 30 degrees;

- clause "v": axial shortening of a leg from 2 to 5 cm inclusive, rotational deformity of the peripheral segment (shin, foot) from 5 to 15 degrees;

- clause "g": axial shortening of an arm up to 5 cm or a leg up to 2 cm, rotational deformity of the peripheral segment (shin, foot) of less than 5 degrees.

The phrasing is important: "In case of leg shortening, for the elimination of angular and rotational deformities of the arm or leg, examinees under columns I, II, III of the Schedule of Diseases, if indicated, are offered treatment using osteosynthesis. In case of refusal of treatment or its unsatisfactory results, the conclusion on fitness for military service is made according to the relevant clauses of this article."

In fact, this is the only official expert document that details the indications for surgical treatment.

2.1 Complaints and Anamnesis

2.2 Physical Examination

• All patients with suspected acquired deformity of the lower extremities are recommended an initial examination (inspection, consultation) by a trauma surgeon-orthopedist or an initial examination (inspection, consultation) by a surgeon/pediatric surgeon in order to establish a diagnosis and determine treatment tactics [2, 4, 24].

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

Comments: visual examination of limb segments to assess the condition of the skin, identify deformity(ies) and limb shortening, muscle hypo- or atrophy, the neurotrophic status of the limb, clarify the localization of the deformity, and determine further diagnostic and treatment tactics [2, 4, 24].

2.3 Laboratory Diagnostics

Comments: blood tests must be repeated according to their validity period (complete blood count 10 days, blood chemistry panel 1 month, etc.), as well as individually based on the patient's clinical condition.

2.4 Instrumental Diagnostics

• For patients with acquired lower limb deformities, it is recommended to perform standing load-bearing anteroposterior and lateral full-length radiographs ("telere radiographs") of the lower extremity [2, 26-31].

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

Comments: as an exception, radiography of individual segments is acceptable, provided that adjacent joints are included (radiography of the femur, tibia and fibula, knee joint, hip joint, ankle joint). Specific projections (oblique view, "functional" radiography, etc.) may also be performed [2, 26-31].

When assessing lower limb deformities, only a hip-to-ankle radiograph ("panoramic" radiography, "teleroentgenography") of the lower extremity allows for a proper evaluation of the overall mechanical axis. It is incorrect to construct a teleroentgenogram by stitching together 3-4 separately acquired radiographs, as this introduces significant distortion. To identify lower limb deformities, reference lines and angles (RLA) are evaluated (Appendix G3): mechanical axis deviation, anatomical (mechanical) angles, and torsional profile angles [31]. Normally, reference lines should intersect at specific angles and points (Fig. 1).

• If a torsional component of the deformity is suspected, or if there is doubt regarding the degree of bone fragment consolidation, it is recommended to perform computed tomography of the lower extremity (limb segment) [2, 29, 32, 33].

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

Comments: the purpose of lower extremity computed tomography is: to determine the shape and dimensions of the bone (medullary canal diameter, cortical wall thickness, transverse and longitudinal dimensions in millimeters) for proper selection of the correct implant type and size, localization of the apex of the bone deformity, osteophytes, ossifications, and bone defects, and assessment of the degree of bone fragment consolidation. Furthermore, computed tomography data allow for estimating the required resection volume and bone graft material, and determining the projection lines for implant fixation elements (if present) to properly plan the surgical approach for implant removal, placement of a new implant, and execution of the reconstructive-plastic component of the procedure [29, 23, 33].

2.5 Other Procedures

• For patients with an acquired limb deformity and a history of infection in the fracture area resulting from an open injury or an infectious complication of a prior surgical intervention, it is recommended to perform a puncture (aspiration of the purulent focus, microbiological (culture) examination of purulent discharge for aerobic and facultative anaerobic microorganisms) with bacteriological culture of the affected area to rule out latent deep infection during the preoperative preparation period [34].

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

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

• For adult patients being treated for acquired lower limb deformity combined with limb shortening, it is recommended to use several approaches:

  The first approach involves single-stage deformity correction and osteosynthesis of bone fragments using internal fixation (e.g., 246140 non-absorbable sterile bone plate for fracture fixation with screws***, or 258670 sterile intramedullary femoral nail***) [35-43] or an external fixator [44, 45] to achieve bone union, followed by planned segment lengthening.

  The second approach involves simultaneous deformity correction and lengthening of the affected limb using an external fixation apparatus (Ilizarov apparatus, orthopedic hexapod) [46-55]. External fixation may be continued until complete consolidation of the distraction regenerate, or it may be converted to internal fixation [43-45, 52].

  The third approach involves single-stage deformity correction via a resection (shortening) osteotomy followed by segment lengthening using an electromagnetic lengthening nail or lengthening "over" a standard intramedullary nail with the assistance of an external fixator [37, 38, 40, 41].

  It is important to note that limb lengthening and deformity correction using external transfixion based on the Ilizarov method principles is the most widespread surgical procedure [46-55].

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

• For patients, it is recommended to perform single-stage correction of acquired deformity; this technique is most commonly used to treat isolated angular and rotational deformities with less than 2 cm of shortening [35-43]. This method is most comfortable for patients, and typically utilizes internal metal implants [35-43]. For instance, correction of an isolated torsional lower limb deformity can be performed in a single stage, followed by internal fixation with an intramedullary nail (111880 sterile tibial intramedullary nail*** and/or 111890 non-sterile tibial intramedullary nail*** and/or 258660 non-sterile femoral intramedullary nail*** and/or 258670 sterile femoral intramedullary nail***) [56].

Level CLevel 3Level of recommendation evidence C (reliability level of evidence – 3).

Comments: a significant portion of publications regarding single-stage correction of acquired single-plane deformities of the femur and tibia focuses on knee valgus or varus deformities. Isolated publications concerning post-traumatic deformities have a very low level of evidence [57-58]. However, single-stage correction has limited corrective capacity. The magnitude of angular deformity that can be corrected in a single stage does not exceed 30°, and the maximum single-stage lengthening for the femur should not exceed 4 cm [60]. Greater single-stage corrections carry the risk of vascular and neurotrophic complications, for the prevention of which additional soft tissue procedures may be required [29]. Deformities combining multiple components require highly precise and complex preoperative planning [41-42] and surgical technique [35]. The feasibility of single-stage correction must be determined on an individual basis, taking into account the anatomical segment, type and magnitude of deformity, location of major blood vessels and nerves, soft tissue condition, and presence of chronic infection. If there is any doubt regarding the safety of single-stage correction and internal fixation, gradual time-dependent correction using an external fixation device (EFD) must be employed.

3.1 Treatment of patients with acquired lower limb deformities using the Ilizarov apparatus and method

• For patients requiring deformity correction and limb lengthening, it is recommended to use the Ilizarov method (application of external fixation devices using a compression-distraction external fixation apparatus, multi-use external orthopedic fixation system, orthopedic bone wire***, non-absorbable orthopedic bone pin***) [53, 62-83], see Appendix A3.1 – A.3.4.

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

Comments: in accordance with current legislation, the patient must be informed not only of the treatment plan, but also of the basics and specific aspects of external fixation to the extent necessary for their conscious cooperation with the physician in the postoperative period. When external fixation is used in children, a similar discussion must be held with the parents. The informed consent is signed by both parties. The patient should be warned about the inconveniences associated with "wearing" a transosseous device, and attention should be drawn to the fact that the fixation elements pass through soft tissues and bone, which imposes special requirements on compliance with aseptic and antiseptic regimens in the postoperative period. The patient must know and understand the manipulations that are planned to be performed in the postoperative period to achieve the goals of osteosynthesis: mutual displacement of external supports, replacement, "re-insertion" of transosseous elements, etc. The patient must receive general information about potential complications and measures for their prevention and treatment.

Two-stage treatment of deformities

• Patients are recommended a two-stage treatment of deformities ("Apparatus followed by nail/plate"): correction of deformity components using transosseous osteosynthesis techniques, followed by stabilization of fragments using an implant [19, 29, 37, 40, 81, 82], see Appendix A3.1 – A.3.4.

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

Comments: with the sequential use of transosseous and internal osteosynthesis, the internal construct must be implanted while the external fixation device (EFD) is retained; at the same time, some transosseous elements may interfere with the insertion of the intramedullary nail and locking screws, as well as the placement of an osteosynthesis plate. In this case, a partial re-assembly of the apparatus will be required, placing transosseous elements outside the zones where the internal construct is to be installed and removing those that may cause a conflict. In this scenario, "accessibility positions" can be used to select sites for transosseous elements, as the apparatus will be dismantled at the end of the operation. In intramedullary osteosynthesis, the use of extracortical fixators is also effective [80].

3.2 Pharmacotherapy

Surgical antibiotic prophylaxis

• In the surgical treatment of patients with acquired lower limb deformities, it is recommended to perform surgical antimicrobial prophylaxis (SAP) of surgical site infections by a single preoperative administration of an antibacterial drug to reduce the risk of infectious complications [112].

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

Comments: in accordance with international clinical guidelines for the prevention of surgical site infections [112, 113], the objective of SAP is to achieve bactericidal concentrations of the antibacterial drug in tissues exposed to microbial contamination during surgery to prevent surgical site infections. The need for SAP is determined by the surgical wound class of the upcoming procedure: SAP is not required for "clean" surgical wounds not associated with the implantation of orthopedic implants and metal hardware. SAP should be performed for: clean-contaminated and contaminated surgical wounds; "clean" surgical wounds involving the implantation of orthopedic implants and metal hardware. For infected ("dirty") wounds, SAP is not indicated; antibiotic therapy is performed instead.

• In patients with acquired lower limb deformities, it is recommended to use first-generation (J01DB) and second-generation (J01DC) cephalosporins (cefazolin**, cefuroxime**) as the primary drugs for surgical antimicrobial prophylaxis during surgical interventions in traumatology and orthopedics, and as an alternative in case of intolerance to beta-lactam antibacterials – glycopeptide antibacterial drugs (vancomycin**), lincosamides (#clindamycin** as a single dose before surgery: 900 mg for adults, 10 mg/kg for children intravenously 30 to 60 minutes before skin incision) [112]. Recommended single doses of the main antibacterial drugs for SAP in traumatology and orthopedics are presented in Table 1.

Table 1. Recommended single doses of the main antibacterial drugs for SAP in traumatology and orthopedics [112, 115, 116]

Notes: † take into account age restrictions in the instructions for medical use.

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

Comments: for patients with an uncomplicated allergy history and no significant risk factors for methicillin-resistant staphylococci carriage, first- (J01DB) and second-generation (J01DC) cephalosporins (cefazolin**, cefuroxime**) are used for SAP, administered intravenously 30 to 60 minutes prior to skin incision. In case of intolerance to beta-lactam antibacterial drugs, vancomycin** should be prescribed, administered over at least 60 minutes starting 2 hours before the incision, or #clindamycin**. In the presence of significant risk factors for methicillin-resistant staphylococci (MRS) carriage, the SAP regimen should include systemic antibacterial drugs (ATC: J01) with anti-MRS activity (vancomycin**). In most cases, a single preoperative dose of a systemic antibacterial drug is sufficient for effective prophylaxis. For prolonged procedures (more than 3 hours) or massive blood loss, an additional intraoperative dose of a systemic antibacterial drug (ATC: J01) should be administered (the approximate timing for intraoperative administration is 2 half-lives after the preoperative dose). Administration of systemic antibacterial drugs (ATC: J01) after wound closure in the operating room is inappropriate even in the presence of established drains.

• In the surgical treatment of patients with acquired lower limb deformities, it is recommended to perform antimicrobial prophylaxis of surgical site infections lasting no more than 24 hours [117].

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

Comments: in accordance with current regulatory documents in the Russian Federation (SanPiN 3.3686-21) and clinical guidelines [117], to achieve an effective concentration of the antibacterial drug in tissues and blood serum at the time of skin incision, antibiotics for the prevention of surgical site infection should be administered intravenously 30 to 60 minutes before the skin incision, or within 2 hours before the incision when using vancomycin**. The maximum duration of prophylactic administration of a systemic antibacterial drug should not exceed 24 hours after the end of surgery. In most cases, a single dose of a systemic antibacterial drug is sufficient for effective prophylaxis. Additional doses should be administered during prolonged surgeries when the half-life of the administered systemic antibacterial drug has elapsed since the preoperative administration, creating a risk that the concentration of the systemic antibacterial drug will drop below the bactericidal level and increase the risk of surgical site infection.

Postoperative analgesia

• To achieve adequate analgesia in patients with acquired lower limb deformities, it is recommended to use multimodal analgesia for adults and children, taking into account age restrictions in the instructions for medical use; if it cannot be prescribed, monomodal analgesia should be used [118, 119, 120, 121].

GoR ALoE 2Grade of Recommendation A (Level of Evidence – 2).

Comments: when providing analgesia in a hospital setting, it is necessary to take into account prescriptions made at the emergency medical care stage. In the acute period of injury, for pain management, it is necessary to ensure proper immobilization of fragments using a vacuum splint, vacuum mattress, or an external fixation device.

Among pharmacological strategies, the currently accepted standard is multimodal analgesia (MMA), which involves the use of several analgesics (opioid and non-opioid) from the N02 Analgesics group with different mechanisms of action, along with non-pharmacological interventions aimed at targeting peripheral and/or central parts of the nervous system [122]. Postoperative MMA may include psychotherapy, physiotherapy, NSAIDs, paracetamol**, gabapentinoids (ATC group code N02BF), regional anesthesia (single injection or peripheral nerve catheter placement), local injections, and opioids [119, 123]. In modern scientific literature, authors emphasize the use of the lowest effective doses of opioids for the shortest possible duration, avoiding extended-release opioids.

When prescribing analgesic therapy for children, a single dose should be chosen taking into account the child's weight and age. Preference should be given to analgesics with oral or rectal administration routes, avoiding intramuscular injections.

• For major musculoskeletal trauma in adult patients, as part of multimodal analgesia, it is recommended to use a combination of opioid analgesics of the N02A group, NSAIDs, and gabapentin, depending on pain intensity and the risk of neuropathic pain [122]. Recommended medications used for postoperative pain relief are presented in Table 2.

Table 2. Recommendations for pain management in major musculoskeletal trauma (surgical interventions for fixation of long bone fractures or complex articular fractures, extensive soft tissue trauma, extensive surgery, etc.) in adults

The table presents analgesic medications and their dosing regimens in accordance with the Clinical Guideline for Pain Management in Acute Musculoskeletal Trauma [122]. The medications listed in the table do not constitute an exhaustive list of permissible analgesics and may be substituted with others within the ATC group codes (N02A, M01A) in accordance with the instructions for medical use.

GRL CLEL 5Grading of Recommendations Assessment, Development and Evaluation (GRADE) Level C (Level of Evidence – 5).

• For musculoskeletal trauma without surgical intervention in adult patients, as part of multimodal analgesia, it is recommended to use a combination of opioid analgesics (N02A group) and NSAIDs, depending on pain intensity and the risk of neuropathic pain [122]. Recommended medications used for postoperative pain relief are presented in Table 3.

Table 3. Recommendations for pain management in musculoskeletal trauma without surgical intervention (closed fractures, superficial wounds, etc.) in adults

The table presents analgesic medications and their dosing regimens in accordance with the Clinical Guideline for Pain Management in Acute Musculoskeletal Trauma [122]. The medications listed in the table do not constitute an exhaustive list of permissible analgesics and may be substituted with others within the ATC group codes (N02A, M01A) in accordance with the instructions for medical use.

GRL CLEL 5Grading of Recommendations Assessment, Development and Evaluation (GRADE) Level C (Level of Evidence – 5).

• For pain management in children in the postoperative period, it is recommended to use multimodal analgesia with combinations of paracetamol**, NSAIDs, opioid and opioid-like analgesics, in accordance with the age restrictions in the instructions for medical use [121]. Recommended medications used for postoperative pain relief in children are presented in Table 4.

Table 4. Dosing regimen of analgesic drugs for children

The medications presented in the table do not constitute an exhaustive list of permissible analgesics and may be substituted with others within the ATC group codes in accordance with the instructions for medical use.

¹ In children under 12 years of age, it is preferable to use morphine** if opioid analgesics need to be prescribed, as the use of tramadol** is associated with a higher risk of adverse reactions [125, 126].

² Trimeperidine** should not be used in children, as its metabolite accumulates in the body and provokes seizures with repeated use [127].

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

Prevention of venous thromboembolic events

• All patients scheduled for surgery are recommended to undergo risk assessment and thromboprophylaxis for venous thromboembolism (VTE) and bleeding, taking into account individual patient characteristics and surgical factors, in order to select the VTE prophylaxis strategy [128, 129, 130, 131]. Recommended doses, frequency, and route of administration of anticoagulants for high-risk VTE prophylaxis in conservative management and the preoperative period for patients over 18 years of age are presented in Table 5.

Table 5. Recommended dosing regimen of unfractionated heparin and low-molecular-weight heparins for high-risk VTE prophylaxis in conservative management and orthopedic surgeries in adult patients at high risk for VTE

Note: spinal or epidural anesthesia should only be performed 12 hours after the administration of a dose of low-molecular-weight heparins and no earlier than 4–6 hours after the administration of unfractionated heparin (meanwhile, aPTT or ACT values must be within the normal range) [139, 140].

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

Comments: to assess the risk of VTE before surgery, it is advisable to use the Caprini VTE risk scoring scale (Appendix G4).

All patients with limited mobility, regardless of the degree of VTE risk, should receive mechanical VTE prophylaxis [129]. All patients with moderate or high VTE risk must receive pharmacological (medical) VTE prophylaxis, typically until normal or expected mobility is restored.

Pharmacological VTE prophylaxis should be considered for elective surgeries in cases where the VTE risk outweighs the bleeding risk.

• All patients undergoing neuraxial procedures are recommended to observe the minimum time interval between the last dose of anticoagulant before the neuraxial procedure and the minimum time for resuming anticoagulant administration after placement or removal of the epidural catheter to prevent hemorrhagic complications (Table 6) [140].

Table 6. Recommended intervals between prophylactic anticoagulant administration and neuraxial procedures

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

• When choosing pharmacological VTE prophylaxis in children, it is recommended to consider the use of #enoxaparin sodium** 0.5 mg/kg SC every 12 hours, but not exceeding 60 (the dosing regimen is indicated for children with normal renal function weighing less than 60 kg), taking into account the child's renal function and weight [138]. The anticoagulant dosing regimen for pharmacological VTE prophylaxis in patients aged 6 months to 18 years at high risk for VTE is presented in Table 7 [130, 132, 133, 134, 135, 136, 137].

Table 7. Anticoagulant dosing regimen for pharmacological VTE prophylaxis in patients aged 6 months to 18 years at high risk for VTE [133, 134, 135, 130, 136, 137, 138, 141, 142]

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

Comments: there is no standardized and validated tool for thromboprophylaxis risk assessment in pediatric practice [138]. VTE prophylaxis in trauma and orthopedic patients is discussed in detail in the 2022 guidelines [128] and the 2023 Russian expert recommendations [129].

3.3 Dietary therapy

Only in the presence of comorbid pathology.

3.4 Other treatment

Comments: modern physical therapy widely uses several dozen physical and natural factors: high- and low-voltage electric currents of direct and alternating directions, electric, magnetic and electromagnetic fields, ultrasonic vibrations, various types of light, air and water ions, oxygen under increased pressure, inhalation of medicinal substances, natural and artificial mineral waters, thermal treatment methods using paraffin, ozocerite and therapeutic mud. The choice of a physical factor and the method of physical therapy depends on the stage of reparative bone tissue regeneration, the level of surgical intervention, the method of fragment fixation, the patient's ability or inability to visit the physiotherapy department, and its equipment [89-90].

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Acquired lower limb deformity is a complex condition that can significantly impact a person's quality of life. By following rehabilitation recommendations, treatment outcomes for these patients can be significantly improved, functional recovery and quality of life restored, allowing them to return to their daily activities [88, 91-92] (Appendices G1 and G2).

The literature presents rehabilitation recommendations proposed by individual authors without evidence of their effectiveness, primarily regarding the use of physical therapy factors. Therefore, the selection of rehabilitation means and methods is based on general knowledge of the negative consequences of prolonged immobilization and general principles of joint function restoration based on the mechanisms of action of various exercise therapy (physical therapy) modalities and physical therapy factors [93].

Further high-quality studies are needed to investigate the effectiveness of various rehabilitation concepts.

Comments: rehabilitation is carried out by a multidisciplinary rehabilitation team and begins within the first 48 hours after hospital admission and surgical treatment according to individual programs, with specific goals and objectives in accordance with the method and stage of orthopedic treatment, the patient's age and health status. Rehabilitation programs are based on the differentiated use of physiotherapeutic factors, methods and means of physical therapy, addressing general tasks of preventing the development of complications and maintaining the patient's motor activity, as well as local tasks of preventing functional disorders in the limb and restoring its function. Treatment and rehabilitation outcomes are improved by proper nutrition with the mandatory inclusion of cottage cheese, dairy products, hard cheese, cod, salmon, beans, liver, and cereals in the diet [91-94].

Comments: The early stage of rehabilitation begins in the hospital and lasts on average up to 2 weeks after surgery. The outpatient stage is carried out after the removal of immobilization in a day hospital or specialized rehabilitation centers. According to indications, in case of pronounced functional changes and due to the duration of the regeneration process, rehabilitation should be continued in specialized restorative treatment hospitals or sanatorium-resort institutions.

Indications and contraindications for prescribing specific medical rehabilitation modalities are determined individually, taking into account the localization of the injury, the method of surgical stabilization of bone fragments or conservative immobilization, as well as the age, general condition of the patient, and the presence of comorbid internal organ pathologies.

Comments: the rehabilitation program is primarily aimed at improving blood circulation in the limb.

4.1 Physiotherapy

• During the immobilization period or the early postoperative period, physiotherapy is recommended (high-frequency electromagnetic field therapy [inductothermy], general magnetotherapy, alternating magnetic field therapy, sinusoidal modulated current therapy [SMT therapy], ultraviolet skin irradiation, interferential current therapy, drug electrophoresis for bone pathology, medical massage of the lower extremity, low-frequency pulsed electrostatic field therapy, therapeutic exercise for joint diseases and injuries, individual therapeutic exercise session for joint diseases and injuries, drainage breathing exercises, therapeutic gymnastics for musculoskeletal disorders in children, mechanotherapy using basic mechanotherapy devices for bone fractures, robotic mechanotherapy, patient training in self-care for moving with additional support) in order to reduce pain, decrease edema, and improve microcirculation and tissue trophism [91-94].

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

• Outpatient rehabilitation is recommended for patients after removal of immobilization or in the late postoperative period, which is carried out by an MDRT to restore limb function, social and domestic adaptation (appointment [examination, consultation] by a physical therapy physician and/or examination [consultation] by a physical therapist, therapeutic exercise for joint diseases and injuries, therapeutic gymnastics for musculoskeletal disorders in children, individual therapeutic exercise session for spinal disorders, medical massage of the lower extremity, massage of the lower extremity and lower back, vacuum therapy, hydrokinesitherapy for bone fractures, electromyographic biofeedback electrical stimulation, interferential current therapy, combined pulsed current and ultrasound therapy, robotic mechanotherapy, biofeedback training based on dynamographic indicators [strength] for joint diseases and injuries) [91-94].

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

Comments: ultrasound therapy (combined pulsed current and ultrasound therapy), the main objective of which is to stimulate blood supply to the tissues around the joints, must be used with extreme caution in the presence of metal structures that may be used for fragment reposition.

Comments: ESWT is a treatment method using acoustic (shock) waves, which, unlike sound waves, are characterized by higher energy amplitudes and short pulse duration. Under the influence of ESWT, remodeling of damaged tissues is triggered through a stimulating effect on fibroblasts and tenocytes, leading to the proliferation of extracellular matrix components, including collagen and glycosaminoglycans. Shock waves enhance microcirculation and angiogenesis, promoting tissue healing, and increase the expression of angiogenic factors, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF), which leads to vessel formation and improved oxygen delivery to damaged tissues [95-98]. When applied over a fracture site, ESWT causes [95-98]:

- osteoblast growth mediated by osteogenic factors (vascular endothelial growth factor A [VEGF-A] and hypoxia-inducible factor 1-alpha,

- regulation and stimulation of chondrogenesis and bone tissue regeneration via the mesenchymal stem cell mechanism,

- periosteal stimulation with a decrease in osteoclast activity,

- osteoblast proliferation through the regulation of nitric oxide, protein kinase B, bone morphogenetic protein, etc.

Thus, based on the studied mechanisms of action and evidence-based literature data, ESWT is a non-invasive, safe, and effective method for treating many musculoskeletal diseases, including cases following reconstructive treatment. It is a valuable and rapidly developing treatment method which, thanks to ongoing research, will possess great potential to increase the efficacy of treatment for many musculoskeletal disorders, and first of all, following reconstructive treatment.

5. Prevention and Dispensary Observation

Comments: prevention of infectious complications involves precise adherence to the technique, correct diagnosis of contraindications to internal fixation (excluding interventions in the presence of unmanaged local inflammation, undiagnosed generalized chronic infections, and laboratory-proven metal allergies), correct execution of the surgery and postoperative period, use of short-term immobilization, early active range-of-motion exercises in the operated joint, timely weight-bearing on the operated limb, strict compliance with asepsis rules, and implementation of perioperative antibiotic prophylaxis. To prevent metallosis, it is advisable to use screws and plates made of homogeneous metal from the same set. The incidental use of screws made of different metals can lead to metallosis and late suppuration due to the electrochemical conflict between contacting elements [99-100].

• Follow-up examination (inspection, consultation) by a trauma surgeon / orthopedic surgeon (follow-up examination (inspection, consultation) by a surgeon / follow-up examination (inspection, consultation) by a pediatric surgeon) is recommended for all patients after inpatient surgical and conservative treatment following correction of acquired deformity combined with limb lengthening, in order to monitor consolidation and the recovery of limb function [2, 94].

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

• The follow-up examination is recommended at 3, 6, and 12 months post-treatment, as well as in the long-term period more than 1 year after surgery [2, 94].

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

Comments: patients need to be followed up at the outpatient clinic (trauma center) by a trauma and orthopedic surgeon until full consolidation is achieved and a decision is made regarding the removal (or retention) of the implant. Once consolidation and functional recovery of the operated segment are achieved, the patient is discharged from follow-up [2, 94].

6. Organization of Medical Care

Stages of medical care for patients with acquired lower limb deformities:

• primary pre-medical health care;

• primary physician-delivered health care;

• primary specialized health care;

• emergency, including specialized emergency, medical care;

• specialized, including high-tech, medical care.

7. Additional Information

To assess treatment outcomes in patients with acquired lower limb deformities, questionnaires have been developed to evaluate (a) the functional result of treatment and (b) the patient's health-related quality of life:

• SF-36 questionnaire [101] – assessment of health-related quality of life in adults.

• PedsQL 4.0 Generic Core Scales questionnaires [102] – assessment of health-related quality of life in children (within the scope of these Clinical Practice Guidelines, ages 13 to 18 years).

These questionnaires have been translated into Russian, and validation studies of the translations have been published (see Appendix G1-GN).

Criteria for Evaluating the Quality of Medical Care

Criteria for assessing the quality of medical care for patients with acquired lower limb deformities (ICD-10 codes M21, M95.8, M99.9, etc.).

References

Appendix A1. Working Group Composition

Aleksandr V. Burtsev – D.Sc. in Medicine, Director of the National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health, Kurgan.

Alena N. Vorobyeva – Orthopedic Trauma Surgeon, Traumatology and Orthopedics Department No. 6, National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health, Kurgan.

Evgeny S. Gorbach – Ph.D. in Medicine, Orthopedic Trauma Surgeon, Traumatology and Orthopedics Department No. 6, National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health, Kurgan.

Shokhbek A. Imomov – Orthopedic Trauma Surgeon, Traumatology and Orthopedics Department No. 6, National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health, Kurgan.

Andrey V. Kaminsky – Ph.D. in Medicine, Honored Doctor of the Russian Federation, Deputy Director for the Implementation of Federal Projects, National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health.

Daria S. Leonchuk – Orthopedic Trauma Surgeon, Purulent Traumatology and Orthopedics Department No. 2, National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health, Kurgan.

Sergey S. Leonchuk – Ph.D. in Medicine, Orthopedic Trauma Surgeon, Head of Traumatology and Orthopedics Department No. 6, National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health, Kurgan, Member of the Presidium of ASAMI Russia.

Oksana V. Nedoboeva – Clinical Pharmacologist, National Ilizarov Medical Research Center for Traumatology and Orthopedics of the Russian Ministry of Health, Kurgan.

Leonid N. Solomin – D.Sc. in Medicine, Professor, Highest Category Orthopedic Trauma Surgeon, Vreden National Medical Research Center of Traumatology and Orthopedics of the Russian Ministry of Health, Honorary Professor of the National Ilizarov Medical Research Center.

Aleksey I. Kokorev – Ph.D. in Medicine, Orthopedic Trauma Surgeon, Traumatology and Orthopedics Department No. 12, Head of the Department for the Organization of Traumatology and Orthopedic Services, Priorov National Medical Research Center of Traumatology and Orthopedics of the Russian Ministry of Health, Moscow.

During the development of these clinical guidelines, the working group had no conflicts of interest regarding acquired lower limb deformities (excluding the foot).

Appendix A2. Methodology for Developing Clinical Guidelines

The clinical guidelines describe the technology for correcting acquired lower limb deformities in children after the completion of their active growth period (girls over 13 years old, boys over 14 years old) and in adults as consequences of trauma and hematogenous osteomyelitis suffered in childhood.

Methods used for evidence collection/selection: searching electronic databases.

The evidence base for writing these clinical guidelines consists of relevant English- and Russian-language publications in the MEDLINE, PubMed, WOS, EMBASE, and RSCI electronic databases. The literature search depth is 25 years.

Methods used to formulate the recommendations:

• expert consensus.

Target audience of the clinical guidelines:

1. Orthopedic trauma surgeons with more than 3 years of clinical experience.

2. Graduate students and doctoral candidates whose scientific work is related to the correction of long bone deformities.

Methods used for evidence analysis:

• reviews of published meta-analyses;

• systematic reviews with evidence tables.

Description of methods used for evidence analysis

When selecting publications as potential sources of evidence, the methodology used in each study is examined to ensure its validity.

The results of this evaluation affect the level of evidence assigned to the publication, which in turn influences the strength of the recommendations.

To minimize potential errors, each study was evaluated independently.

Any discrepancies in evaluations were discussed by the full panel of authors in corpore. If a consensus could not be reached, an independent expert was consulted.

Evidence tables: compiled by the authors of the clinical guidelines.

In these clinical guidelines, all data are ranked by level of reliability (evidence) depending on the quantity and quality of studies on the issue.

The level of scientific evidence supporting the recommendation theses was evaluated according to Tables 1 and 2, and the strength of the recommendation theses was determined according to Table 3 (Appendix No. 2 to the Requirements for the Structure of Clinical Guidelines, Composition and Scientific Validity of Information Included in Clinical Guidelines, approved by Order of the Russian Ministry of Health No. 103n dated February 28, 2019).

Table 1. Scale for assessing levels of evidence (LE) for diagnostic methods (diagnostic interventions)

Table 2. Scale for assessing levels of evidence (LE) for prevention, treatment, and medical rehabilitation methods, including those based on natural therapeutic factors (preventive, therapeutic, and rehabilitative interventions)

Table 3. Grading system for the levels of recommendation conviction (LRC) for methods of prevention, diagnosis, treatment, and medical rehabilitation, including those based on natural therapeutic factors (preventive, diagnostic, therapeutic, and rehabilitative interventions)

Economic analysis. Cost analysis was not performed, and pharmacoeconomic publications were not analyzed.

Method of recommendation validation:

• external expert review,

• internal expert review.

Description of the recommendation validation method

The draft of these recommendations was reviewed by independent experts who were primarily asked to comment on how comprehensible the interpretation of the evidence underlying the recommendations is.

All comments received from the experts were thoroughly systematized and discussed by the members of the working group (authors of the recommendations). Each item was discussed individually.

Consultation and expert evaluation.

The draft recommendations were reviewed by independent experts who were primarily asked to comment on the clarity and accuracy of the interpretation of the evidence base underlying the recommendations.

Working Group

For the final revision and quality control, the recommendations were re-evaluated by the members of the working group, who concluded that all comments and feedback from the experts had been taken into account and the risk of bias in the development of the recommendations was minimized.

Key recommendations

Levels of recommendation conviction (strength) based on the corresponding levels of evidence reliability are provided alongside the text of the recommendations.

Updating of these clinical guidelines will be carried out at least once every three years. The decision to update will be made based on proposals submitted by medical professional non-profit organizations, taking into account the results of comprehensive assessments of medicinal products, medical devices, and clinical trials.

Appendix A3. Reference Materials

Appendix A3.1 Preoperative preparation, technical execution, osteotomy, postoperative patient management, external fixation frame (EFF) disassembly

Preoperative preparation.

Preoperative preparation includes a set of well-established procedures for assessing the patient's orthopedic status, including determination of reference lines and angles (Fig. 1), the apex of the deformity, the magnitude of shortening, selection of the osteotomy/corticotomy variant, and selection of device components [53, 71, 72].

Preoperative preparation of patients for whom transosseous osteosynthesis is indicated includes a comprehensive general clinical examination aimed at assessing their general condition and local status. The complex of diagnostic laboratory methods includes general (clinical) blood and urine tests, determination of main blood groups (AB0 system), and determination of the Rhesus system D antigen (Rh factor).

Pronounced edema, soft tissue tension of the injured limb (an increase in circumference at any level by more than 50–60 mm), skin discoloration, a rheovasographic index asymmetry value exceeding 40%, as well as a shift in hemostatic parameters toward hypercoagulation, are indications for a course of conservative treatment. Pharmacotherapy includes adequate dosages of antispasmodics, anticoagulants, and antiplatelet agents. Physiotherapy and reflexology are advisable. Treatment is carried out for 3–7 days with dynamic monitoring of efficacy and necessary corrections.

To clarify the diagnosis in patients admitted for treatment with concomitant diseases, consultants of various specialties are involved:

Initial appointment (examination, consultation) by a general practitioner/pediatrician,

Initial appointment (examination, consultation) by a surgeon/pediatric surgeon,

Initial appointment (examination, consultation) by a neurosurgeon,

Initial appointment (examination, consultation) by a cardiovascular surgeon,

Initial appointment (examination, consultation) by a urologist/pediatric urologist-andrologist,

Initial appointment (examination, consultation) by an endocrinologist/pediatric endocrinologist, etc.

The time parameters for a specialist consultation examination are determined individually depending on the patient's condition. An obligatory part of the preoperative preparation is the identification and, in the case of orthopedic pathology, sanitization of chronic infection foci.

Patients with lower limb pathology are fitted with crutches (a cane) of the appropriate size well in advance. Preoperative preparation includes preparing at least two cotton covers for the device.

The cotton cover must not cover the fingers of the hand (or toes). In winter, it becomes necessary to use an additional cover with an external moisture-proof layer and an internal insulating layer.

In addition, the patient needs to arrange in advance for special clothing with widened sleeves (trouser legs). Patients who are to undergo transosseous osteosynthesis of the lower leg require a foot support.

The patient and the physician must understand that the risk of infectious complications is higher with transosseous osteosynthesis than with internal fixation implants. However, the damage to the patient's health, time, and effort required to treat an infectious complication arising from transosseous osteosynthesis are incomparably less than those from an infectious complication following implant osteosynthesis.

On the eve of the surgery (if it is not performed for acute trauma), the patient takes a hygienic bath. Immediately before surgery, hair is removed from the future surgical field using special trimmers (razor blades that come into contact with the patient's skin are not allowed), treated with chlorhexidine alcoholic topical solution (D08AC02), and wrapped with a sterile bandage. The patient is transported to the operating room.

Technical execution.

To determine the presence of deformity, the overall mechanical axis of the limb, joint lines, and anatomical (mechanical) axes of the segments are used. If the deviation of the overall mechanical axis exceeds reference values, this confirms the presence of deformity [53, 71, 75, 84–86]. However, an "ideal" passage of the overall mechanical axis in the frontal plane, i.e., through the center of the knee joint, does not rule out the presence of femoral and tibial deformities. Therefore, determining the mechanical (anatomical) angles of the femur and tibia in two planes is crucial (Fig. 1). Additionally, "torsional" reference lines and angles (RLA) and limb (segment) length discrepancies are assessed. Thus, the algorithm for analyzing the presence of deformity in the frontal plane includes:

• Assessment of the torsional component of the deformity;

• Assessment of the magnitude of overall mechanical axis deviation;

• Assessment of ligamentous "competence": whether there is instability (unevenness of the joint space);

• Assessment of the proximal and distal mechanical angles of the femur and tibia;

• Assessment of the difference in limb segment lengths.

Analysis of the presence of deformity in the sagittal plane includes:

• Assessment (confirmation) of the torsional component of the deformity;

• Assessment of the overall mechanical axis;

• Assessment of relationships in the knee joint for subluxation;

• Assessment of the mechanical (anatomical) angles of the femur and tibia;

• Assessment (confirmation) of the difference in limb segment lengths.

Only after confirming the presence of deformity using the method described above does one proceed to planning the deformity correction.

The stages of planning frontal plane deformity corrections (if there is no torsional component of the deformity) include:

• Determination of the mechanical (anatomical) axis of the proximal fragment;

• Determination of the mechanical (anatomical) axis of the distal fragment;

• Determination of the apex of the deformity;

• Determination of the osteotomy level;

• Determination of the osteotomy type ("open wedge", "closed wedge", "neutral wedge", hinged, other);

• Performing a (virtual) osteotomy;

• Virtual correction, including elimination of limb length discrepancy;

• Checking the deviation of the overall mechanical axis and the values of mechanical (anatomical) angles remaining after correction.

The stages of planning sagittal plane deformity corrections (if there is no torsional component of the deformity) include:

• Determination of the anatomical (mechanical) axis of the proximal fragment;

• Determination of the anatomical (mechanical) axis of the distal fragment;

• Determination of the apex of the deformity;

• Determination of the osteotomy level;

• Determination of the osteotomy type ("open wedge", "closed wedge", "neutral wedge", hinged, other);

• Virtual correction, including elimination of limb length discrepancy;

• Checking the deviation of the overall mechanical axis and mechanical (anatomical) angles remaining after correction.

Osteotomy (virtual during planning) is best performed at the level of the deformity apex (Osteotomy Rule No. 1). If, for any reason (e.g., the apex of the deformity is located at the joint level or outside the bone; there are foreign bodies at the apex level, compromised soft tissue state [scars, adhesions to the bone, superficial wounds, etc.]), the osteotomy is performed proximal or distal to the apex level (Osteotomy Rule No. 2).

The general algorithm of the transosseous device assembly method includes [31, 71–75]:

1. Defining the objectives for using the transosseous device;

2. Determining the optimal levels for inserting transosseous elements;

3. Determining, based on "Accessibility Positions" and "Recommended Positions" of transosseous elements, those most significant for the given clinical situation;

4. Determining the optimal locations for external supports;

5. Determining the types and sizes of external supports that match the chosen transosseous elements and allow modular transformation of the EFF (if planned);

6. Marking the selected levels and positions for transosseous elements on the segment;

7. Inserting transosseous elements and assembling the device.

Steps 1–5 are performed during preoperative planning. Steps 6 and 7 pertain directly to the surgical intervention. General issues regarding the execution of each designated stage of the transosseous device assembly method are discussed below.

1. Defining the objectives for using the transosseous device.

Osteosynthesis in traumatology and orthopedics serves to achieve a common goal: the restoration (improvement) of the anatomy, function, and physiology of the injured limb. The most typical tasks for using a transosseous device are:

a) Changing the spatial arrangement of bone fragments.

Changing the position of fragments using specific transosseous osteosynthesis techniques can be either "acute" (during the surgery) or gradual, performed over a certain period in the postoperative period. To accomplish this task alone, it is assumed that the device will be dismantled after achieving the necessary orientation of the bone fragments. This technique is used in assisting external fixation, as well as in sequential external and internal fixation techniques ("correction-then-nail/plate", "lengthening-then-nail/plate").

b) Fixation of bone fragments.

It is assumed that the transosseous device will be used solely as a fixing device, for example, after open reduction of bone fragments, acute deformity correction, ensuring compression arthrodesis, etc.

c) Ensuring (improving) limb function in the postoperative period.

To enable the support and movement functions of the limb, the transosseous device must fix the bone fragments with sufficient rigidity for this purpose. In addition, transosseous elements must be inserted in a way that reduces the risk of transfixation contractures.

In the clinical practice of external fixation, situations predominate where the use of a transosseous device must meet the requirement of solving a combination of any two of the indicated tasks or solving all of them collectively. Therefore, for a specific clinical situation, a compromise solution is often required to ensure the maximum possible efficiency of all components of the transosseous device.

2. Determining the optimal levels for positioning the external supports of the transosseous device.

This stage of implementing the transosseous device assembly method should be based on the biomechanics of bone fragment control and the biomechanics of osteosynthesis rigidity. The Ilizarov circular apparatus and orthopedic hexapods meet the requirements for providing optimal conditions for both position correction and bone fragment fixation. If deformity correction involves changing the spatial arrangement of bone fragments through the mutual movement of transosseous modules fixing each bone fragment, the distance between the base and stabilizing transosseous elements must be maximized to ensure adequate osteosynthesis rigidity. For this purpose, when using single-ring modules, stabilizing transosseous elements should be fixed using a 4-hole extension bracket. When using double-ring modules, the distance between the rings must be as large as possible.

3. Determining, based on "Accessibility Positions" and "Recommended Positions", the transosseous elements most significant for the given clinical situation

The implementation of this item depends on the objectives of osteosynthesis. For safe insertion of transosseous elements with minimal soft tissue tethering, special atlases have been developed for each segment, indicating "Recommended Positions (RP)" for the insertion of K-wires and Schanz screws [71-75, 84-86]. If the RPs are located symmetrically relative to the bone, for example, 2 and 8, 3 and 9, 6 and 12, etc., a K-wire can be inserted in the projection of these positions. A Schanz screw can also be inserted from any of the recommended positions. If there is no contralateral position at the given level, it is advisable to use Schanz screws. Base and stabilizing transosseous elements must provide maximum osteosynthesis rigidity. The distance between them in each module must be as large as possible. Base transosseous elements are inserted in the frontal or sagittal planes and perpendicular to the longitudinal axis of the bone fragment. Efforts should be made to ensure that stabilizing transosseous elements are inserted at a crossing angle of α = 60º (75 + 15º) relative to the base transosseous element. The number of transosseous elements that need to be passed through bone fragments to ensure sufficient osteosynthesis rigidity depends on the segment, patient weight, and bone tissue condition. For lower limb segments, the minimum number of transosseous elements is 4 for the proximal fragment and 3 for the distal fragment. If the patient is overweight and/or has osteoporosis, the number of transosseous elements can be increased to 5 and 4 for the proximal and distal fragments, respectively. It should also be noted that in cases of pronounced osteoporosis, it is preferable to use K-wires rather than Schanz screws.

4. Determining the optimal levels for positioning external supports.

During deformity correction, base supports are also positioned in the immediate vicinity of the base transosseous elements. When using single-ring modules, the distance from the support to the stabilizing Schanz screws should be 4-5 cm (the length of a 4-hole extension bracket). If additional stabilizing transosseous elements at a greater distance from the base support are required to increase osteosynthesis rigidity, a stabilizing support is used, i.e., a double-ring module is applied.

5. Determining the types and sizes of external supports that match the selected transosseous elements and allow for modular transformation of the external fixation device (if intended).

A closed external support provides greater opportunities for increasing the stability of bone fragment fixation and the fixation of correction units. However, situations where the use of rings is impossible are not uncommon. In such cases, 2/3, 4/5, and 1/3 rings are used. The advantages of sector (arched) and monolateral supports are related to the minimal bulkiness of the structure and the relative ease of device assembly. However, when using them, one must consider the limitations associated with lower capabilities in providing reduction and osteosynthesis rigidity. The diameter of the external supports is selected taking into account the circumference of the segment at each level of transosseous element insertion. The choice of size must account for the likelihood of soft tissue edema, which increases the circumference by 4-6 cm, as well as soft tissue displacement associated with bone fragment reduction. Due to anatomical and individual characteristics, the circumference of the segment at each level varies. Consequently, the diameter of the supports at each level may differ.

6. Marking the selected levels and positions for transosseous element insertion and levels for support placement on the segment.

A sterile marker is used to implement this stage.

7. Insertion of transosseous elements and device assembly.

The order of transosseous element insertion and the features of external support assembly depend on the operated segment, the type of pathology, and the objectives of osteosynthesis. For deformity correction, the algorithm for this stage is as follows:

- Insertion of base and stabilizing transosseous elements into the proximal bone fragment;

- Assembly of the proximal transosseous module based on one base support or two (base and stabilizing) supports;

- Similar assembly of the distal module;

- Connection of the proximal and distal transosseous modules using an Ilizarov-standardized or universal (hexapod strut) correction unit;

- Final stage (if necessary) — "bone": osteotomies, corticotomies, bone grafting, etc.

The orientation of the external supports relative to the bone in the horizontal plane (the so-called "centering" of external supports relative to soft tissues) is performed according to the individual characteristics of each segment. In femoral shortening, the question of which axis (anatomical or mechanical) should be used to lengthen the femur (and, consequently, how to assemble the supports) is decided individually. In tibial lengthening, this situation is not considered, as the anatomical and mechanical axes of the tibia run parallel.

After completing the device assembly, movements in adjacent joints are performed with the maximum possible amplitude. If there is soft tissue tension, the skin, and if necessary the fascia, are incised, shifted relative to the transosseous element, and sutured.

Osteotomy. For single-stage correction of an angular deformity through a 5 mm stab incision made on the convex side of the curvature, the adjacent and "lateral" cortical plates are divided using a narrow corticotome. Each pass of the osteotome through the cortical plate is completed with "crushing" (up-and-down) movements of the osteotome. After this, using assembled external supports, flexion or rotational osteoclasis of the remaining cortical plate is performed. In the presence of osteosclerosis or a deformity exceeding 20°, this method of osteotomy is not always suitable, and wedge resection ("closed" or "neutral" wedge osteotomy) should be preferred. In cases where major vessels and nerves are located in the projection of the osteotomy level, or scars are present that may alter the soft tissue topography, this stage of the operation is performed under visual control. Following single-stage restoration of the bone axis, the modules of each bone fragment are connected and a compressive force is applied.

For gradual correction, corticotomy with osteoclasis according to Ilizarov is used [53, 66, 67, 71]. To do this, the proximal and distal modules fixing the proximal and distal bone fragments are first disconnected. Then, through a stab incision, the adjacent and lateral cortical plates are transected using a narrow 5 mm osteotome. The proximal and distal modules of the apparatus are grasped manually, and the remaining part of the cortical plate is osteoclased via counter-rotation and bending.

In sclerotic bone, to avoid splitting, corticotomy must be preceded by the creation of five to six 2-mm fan-shaped channels made from 1-2 approaches. On days 5–7, correction is initiated at a rate of 0.25 mm 3–6 times a day.

Corticotomy with osteoclasis for lengthening the femur (leg) is performed outside the zone of the former fracture and, as a rule, on the longer fragment. It should be taken into account that the closer the lengthening is performed to a joint, the higher the risk of contracture development in it. Lengthening a segment by more than 5 cm is preferably performed using polylocal distraction osteosynthesis. The distraction rates at the level of the proximal corticotomy should average 0.25 mm 3–4 times a day. At the distal lengthening level, to avoid the formation of a hypoplastic distraction regenerate, distraction is performed at a rate of 0.25 mm 2–3 times a day. The rate of distraction may vary depending on the patient's complaints, the state of innervation, limb circulation, and the rate of bone formation.

The skin around the exit sites of transosseous elements is covered with 4–6 cm² pads soaked in a 70% ethyl alcohol solution or an alcoholic chlorhexidine solution. A control X-ray examination in the operating room is mandatory. Using special bedding positioning or attachments to the transosseous apparatus, joints are positioned specifically for each segment and type of pathological condition for which the surgical intervention was performed. For transosseous osteosynthesis of the femur, this is positioning with flexion in the knee joint to a right angle or the maximum angle permitted by the external structures. For transosseous osteosynthesis of the leg, the foot is fixed at a 90° angle to the leg axis using a footplate on elastic traction. The external structure is covered with a cotton cover.

Postoperative management of the external fixation frame (EFF). Distraction period. 7 days after the start of distraction, a control radiography must be performed to determine whether the distraction rate and primary diastasis correspond to the plan. If diastasis is insufficient, the rate may be increased to 0.25 mm 6–8 times a day, followed by a control X-ray examination and a return to the initial rate. In cases of lower limb segment lengthening, distraction may be continued on an outpatient basis if the patient has mastered the independent execution of the manipulations. Control radiographs during the distraction period should be performed every 10–15 days to assess the developing distraction regenerate. As at the initial stage, the distraction rate is reduced if: a) the height of the "growth zone" of the bone regenerate on the radiograph exceeds 10 mm; b) neurotrophic disorders appear in the distal parts of the limb; c) severe traction pain occurs in the operated limb; in the latter two cases, the rate may be reduced down to the complete cessation of distraction. Distraction is resumed after pain relief or elimination of neurotrophic disorders. Upon completion of distraction, panoramic limb radiographs ("teleroentgenograms") must be performed to assess the achieved length correction and rule out any deformity at the regenerate level, which must be corrected. Afterwards, the apparatus is transitioned to the fixation phase. When performing deformity correction without significant segment lengthening, it is advisable to perform the entire procedure in an inpatient setting. When sequentially using standardized modules for correction, radiographs are taken at each module replacement. When using an orthopedic hexapod, a control radiograph is taken upon completion of the calculated correction scheme. After completing the deformity correction, panoramic limb radiographs must also be taken to evaluate the achieved result. Subsequently, the apparatus is transferred to the fixation phase.

Fixation period. The duration of the fixation period corresponds to the time required for organotypic remodeling of the distraction regenerate and depends on the regenerate size, the initial state of the bone tissue, the patient's age, and the presence of concomitant pathology. Ideally, the time of organotypic remodeling with the formation of cortical plates can be estimated at 1 month per 1 cm of lengthening. At the same time, regenerates up to 3–4 cm in length remodel within the timeframes of fracture healing for the corresponding localization. Depending on the state of the bone tissue, segment trophism, patient age, and concomitant pathology, this time interval may be longer. During the fixation period, the patient is monitored on an outpatient basis. Radiographs are performed at 1–2 month intervals; once the radiological picture shows the formation of cortical plates along 3/4 of the regenerate's circumference throughout its length (the "three cortical plates" rule), the removal of the EFF can be discussed. Gradual loading is permitted and is gradually increased as the regenerate remodels. Dressings of transosseous elements are performed at intervals of 10–14 days.

EFF removal. After the formation of cortical plates along ¾ of the regenerate's circumference throughout its length (according to radiographs), a clinical union test must be performed. To do this, the connecting elements between the modules are removed and mobility is checked. If mobility is detected, fixation must be continued. If tight amortization is present, modular transformation or removal of the apparatus followed by plaster immobilization may be performed. In the absence of mobility, a dynamic test is performed. Connecting elements are installed and fixed on one side, while the nuts on the other side are backed off by 2–3 mm, and the patient is required to walk with the previous load. The dynamic test is conducted for 7–14 days, after which the clinical test is repeated. If mobility appears or if pain, edema, or a feeling of instability was noted during the dynamic test, fixation must be continued. In the absence of mobility, EFF removal is performed. Anesthesia for this procedure is chosen depending on the stability of the transosseous elements, the patient's emotional state, and the presence of concomitant neurological pathology: options range from local anesthesia around the transosseous elements to general anesthesia. After apparatus removal, aseptic dressings are applied, and subsequently, the wounds are managed under dry scabs. Limb loading is restricted for 1–2 weeks using crutches, followed by radiological control.

Appendix A3.2 Material and technical support

1. 266550 External orthopedic fixation system, reusable (kit for Ilizarov transosseous osteosynthesis, registration certificate no. FSR 2007/00756 dated September 27, 2007, validity period: unlimited. "Instruments and devices for G.A. Ilizarov osteosynthesis", registered in the State Register of Medical Devices (State Reg. No. 81/823-5)),

2. Implants for traumatology, orthopedics, and neurosurgery (329870 Non-absorbable, non-sterile bone fixation plate with screws***; 332570 Non-adjustable, sterile orthopedic bone staple***; 245510 Non-absorbable, non-sterile orthopedic bone screw***).

Appendix A3.3 Potential errors and complications

According to the time of onset of complications arising from transosseous osteosynthesis, they can be divided into those inherent to the surgical procedure itself and those occurring postoperatively: during the manipulation period, the fixation period, and after apparatus removal. The main ones when using transosseous osteosynthesis are:

- Injury to major vessels and nerves;

- Inflammation of the tissues surrounding the transosseous elements;

- Dermatitis, soft tissue necrosis;

- Cut-through, eruption of transosseous elements, fractures in the area of transosseous elements;

- Neurovascular disorders;

- Joint contractures and subluxations;

- Component failure of the apparatus;

- Secondary displacement of bone fragments during the fixation period;

- Osteogenesis problems;

- Post-fixation fractures, secondary deformities;

- Related to the patient's refusal to continue treatment using an external fixation device.

Prevention and treatment of these complications are covered in detail in specialized literature [77].

Complications inherent to the use of internal fixation:

- deformation and fractures of locking screws,

- secondary deformities due to locking screw fracture,

- fracture of the intramedullary nail,

- deep surgical site infection.

When combining transosseous and internal osteosynthesis, complications characteristic of both external and internal fixation may be observed. The probability of complications typical for transosseous osteosynthesis is lower, as it depends on the duration of the transosseous osteosynthesis period. However, with lengthening "over" an intramedullary nail, the probability of premature union at the regenerate level increases.

Appendix A3.4 Clinical guidelines are protected by RF patents:

Patent No. 42949 "Device for polylocal leg lengthening and deformity correction".

Patent No. 36207 "Device for deformity correction and lengthening of long tubular bones".

Patent No. 2305510 "Method for increasing the longitudinal dimensions of limbs".

Patent No. 2317034 "Method for treating fractures of long tubular bones".

RF Patent No. 2324450 "Wire for intramedullary reinforcement of long tubular bones".

RF Utility Model Patent No. 116763 "Intramedullary wire".

Patent No. 2317034 "Method for treating fractures of long tubular bones".

Patent No. 2324450 "Wire for intramedullary reinforcement of long tubular bones".

Patent No. 116763 "Intramedullary wire".

Patent No. 2246139 "Method for studying the rigidity of transosseous osteosynthesis models and device for its implementation".

Patent No. 2218083 "Method for determining soft tissue displacement relative to bone and device for its implementation".

Patent No. 2299678 "Method for determining soft tissue displacement relative to bone during segment rotation and device for its implementation".

Patent No. 2257866 "Extracortical fixator".

Patent No. 2310408 "Method for modular transosseous osteosynthesis of lower leg bones".

Patent No. 2336842 "Apparatus for transosseous osteosynthesis "SUV-Frame".

Patent No. 2 640 999 "Method for correcting multilevel deformities of long bones".

Patent No. 193832 "Telescopic strut for transosseous osteosynthesis apparatus".

Patent No. 2744655 "Transosseous apparatus, telescopic strut for a transosseous apparatus, computer system and method for modeling bone fragment displacement using a transosseous apparatus".

Patent No. 2584555 "Method for femoral lengthening over an intramedullary nail".

Appendix A3.5 These clinical guidelines were developed taking into account the following regulatory legal documents:

1. Constitution of the Russian Federation.

2. Resolution of the Supreme Soviet of the RSFSR No. 1920-1 dated November 22, 1991, "On the Declaration of Human and Civil Rights and Freedoms".

3. "Criminal Code of the Russian Federation" dated June 13, 1996, No. 63-FZ (as amended on April 9, 2026).

4. Code of Criminal Procedure of the Russian Federation dated December 18, 2001, No. 174-FZ (as amended on April 9, 2026).

5. Federal Law No. 323-FZ dated November 21, 2011 (as amended on December 29, 2025) "On the Fundamentals of Protecting the Health of Citizens in the Russian Federation".

6. Federal Law of the Russian Federation No. 4180-1 dated December 22, 1992 (as amended on May 1, 2022) "On Transplantation of Human Organs and/or Tissues".

7. Federal Law of the Russian Federation No. 91-FZ dated June 20, 2000 "On Amendments to the Law of the Russian Federation 'On Transplantation of Human Organs and/or Tissues'".

8. Federal Law No. 61-FZ dated April 12, 2010 (as amended on December 29, 2025) "On Circulation of Medicines".

9. Federal Law No. 3-FZ dated January 8, 1998 (as amended on October 27, 2025) "On Narcotic Drugs and Psychotropic Substances".

10. Federal Law No. 152-FZ dated July 27, 2006 (as amended on June 24, 2025) "On Personal Data".

11. Order of the Russian Ministry of Health No. 901n dated November 12, 2012 (as amended on February 21, 2020) "On Approval of the Procedure for Providing Medical Care to the Population in the Profile 'Traumatology and Orthopedics'".

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

An acquired limb deformity is a condition characterized by changes in the shape and size of bones, which are confirmed clinically and radiologically. Treatment of acquired deformities is generally surgical. Treatment of an acquired limb deformity is a prolonged process that often lasts longer than the consolidation of a "fresh" fracture of the corresponding localization (up to several months), and therefore requires a lot of patience from the patient and absolute compliance with all medical recommendations.

Complications (impaired bone and soft tissue healing, surgical wound healing, instability (displacement) of the installed construct, inflammation, restriction of joint mobility in the injured limb) that may occur in patients after surgical treatment of acquired deformities of long tubular bones can lead to an increased duration of treatment and the need for repeated hospitalization.

Signs of complications:

• pain in the operated segment, especially if appearing after a pain-free interval;

• appearance of painful mobility, crepitus in the osteotomy area;

• decreased range of motion or pain upon movement;

• radiological findings indicating impaired consolidation or fragment displacement;

• appearance of deformity or painful induration in the operated segment;

• edema of the segment and discoloration (redness or pigmentation), pain after a pain-free interval. The most frequent causes are patient non-compliance with medical recommendations, surgical technique errors, or structural defects of the implants.

It is essential to be aware of the factors that may contribute to the development of complications:

• repeated trauma to the operated segment as a result of a fall;

• overweight/obesity;

• parathyroid gland disorders;

• diabetes mellitus;

• incorrect selection of crutches, immobilization devices, braces, and plaster casts;

• systemic and local osteoporosis, including that associated with systemic diseases (hormonal disorders, prolonged corticosteroid therapy, emaciation, and the use of pathological diets);

• genetic predisposition to impaired consolidation;

• sequelae of polytrauma with impaired limb function, making it difficult to adhere to the therapeutic regimen, restrictions and load dosing, and rational physical and functional therapy.

To prevent and monitor complications, it is necessary to:

• carefully follow the medical recommendations received after orthopedic intervention, especially issues concerning loads, immobilization periods, initiation and intensity of joint mobilization, and training of limb muscles. If uncertain about understanding the instructions, ask the operating surgeon what can and cannot be done and in what sequence in the postoperative period, especially after discharge from the hospital;

• thoroughly study the technique and rules for walking on crutches, the rehabilitation treatment methodology (especially the rules for safe mobilization of movements) and its phasing, i.e., transitioning from low loads and ranges of motion to their gradual increase;

• strictly adhere to the schedule of regular examinations by an orthopedic traumatologist, including the operating surgeon, with follow-up radiological examinations preceding the transition to the next rehabilitation period, which consists of changing loads and determining their optimal intensity;

• apply rehabilitation therapy only after agreeing on its intensity and nature with the operating orthopedic surgeon.

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

Appendix G1. SF-36 Questionnaire

Russian title: SF-36 Questionnaire.

Original title (if any): 36-Item Short Form Health Survey (SF-36). Source: validation publication [87]. https://www.rand.org/health-care/surveys_tools/mos/36-item-short-form.html

Type (underline):

- rating scale

- index

- questionnaire

- other (specify): _________________________________________________

Purpose: assessment of health-related quality of life in adults.

Content (template): Consists of 36 questions with a single-choice answer format. The full validated Russian-language questionnaire template is available at: https://therapy.irkutsk.ru/doc/sf36.pdf

Key (interpretation): evaluation is carried out across 8 health domains: Physical Functioning (PF); Role-Physical Functioning (RP); Bodily Pain (BP); General Health (GH); Vitality (VT); Social Functioning (SF); Role-Emotional (RE); Mental Health (MH). It is also possible to calculate 2 summary components: Mental Component Score (MCS) and Physical Component Score (PCS); the possibility of using a Total/Global/Overall Score is explored. Each of these indicators is defined on a scale from 0 to 100 points (higher scores correspond to higher quality of life). The full Russian-language questionnaire key is available at: https://therapy.irkutsk.ru/doc/sf36a.pdf

Notes: ________________________________________________________________

Appendix G2. PedsQL 4.0 Generic Core Scales Questionnaires

Russian title: PedsQL 4.0 Generic Core Scales Questionnaires.

Original title (if any): Pediatric Quality of Life Inventory Generic Core Scales (PedsQL 4.0 GCS).

Source: validation publication [88].

Type (underline):

- rating scale

- index

- questionnaire

- other (specify): _________________________________________________

Purpose: assessment of health-related quality of life in children (aged 13 to 18 years) [88].

Content (template): questionnaire to be completed by children aged 13-18 years. Versions for completion by parents of children also exist. The full validated Russian-language template of the children's version of the questionnaire for the 13–18 age category is available in Appendix G3 of the clinical guideline "HIV infection in children" (ID 459), approved by the Scientific and Practical Council of the Russian Ministry of Health and approved in 2020: http://cr.rosminzdrav.ru/recomend/459

Key (interpretation): Assessment is performed across 4 health domains: physical functioning, emotional functioning, social functioning, and role-school functioning. Calculation of 3 composite scores is also possible: total score across all questionnaire scales, psychosocial health summary score, and physical health summary score. Each of the 7 specified indicators ranges from 0 to 100 points (higher scores correspond to higher quality of life). The full Russian-language key of the pediatric questionnaire version for the 13–18 age group is available in Appendix G3 of the clinical guideline "HIV Infection in Children" (ID 459), approved by the Scientific and Practical Council of the Russian Ministry of Health and published in 2020: http://cr.rosminzdrav.ru/recomend/459

Notes: ________________________________________________________________

Appendix G3. Main reference lines and angles of the lower limb

Figures

Fig. 1. Main reference lines and angles of the lower extremity in the frontal plane: (a) Mechanical; (b,c) Anatomical; (d,e) Torsional profile [31, **].

Appendix G4. Caprini Venous Thromboembolism Risk Assessment Scale

Russian title: Caprini individual risk assessment scale for venous thromboembolic complications Caprini.

Original name: Caprini Score for Venous Thromboembolism.

Source: Bahl V., Hu H.M., Henke P.K., et al. A Validation Study of a Retrospective Venous Thromboembolism Risk Scoring Method // Annals of Surgery. 2010. Vol. 251, № 2. P. 344–350.

Type: scale.

Purpose: assessment of venous thromboembolism risk.

Content:

1 point

Age 41–60 years

Lower extremity edema

Varicose veins

Body mass index > 25 kg/m²

Minor surgery

Sepsis (< 1 month)

Severe pulmonary disease (including pneumonia < 1 month)

Oral contraceptive use, hormone replacement therapy

Pregnancy and postpartum period (< 1 month)

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

Premature birth with preeclampsia or intrauterine growth restriction

Acute myocardial infarction

Chronic heart failure (< 1 month)

Bed rest in a non-surgical patient

History of inflammatory bowel disease

History of major surgery (< 1 month)

Chronic obstructive pulmonary disease

2 points

Age 61–74 years

Arthroscopic surgery

Malignant neoplasm105

Laparoscopic procedure (duration >45 min.)

Bed rest > 72 h

Limb immobilization (< 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)

Interpretation: Depending on the total score obtained from the patient's history and examination, the patient is assigned to one of the risk groups:

• low risk: 0 - 1 point;

• moderate risk: 2 points;

• high risk: 3 - 4 points;

• very high risk: 5 points or more.