Osteochondropathies of the bones: types and diagnostics

Osteochondropathies are a group of disorders of bone and cartilage growth and remodeling in children and adolescents, and less commonly in adults, affecting the epiphyses, apophyses, and subchondral bone. Classic examples include osteochondritis dissecans, Osgood-Schlatter disease, Legg-Calve-Perthes disease, Köhler disease, Freiberg disease, Panner disease, and others. A common link is local ischemia or mechanical overload damage to the growth plate and subchondral bone, which causes pain, limited function, and, in some cases, joint deformity. [1]

Terminology has historically been confusing. "Osteochondrosis" and "osteochondropathies" are often used as umbrella terms, while "osteochondritis dissecans" is a specific entity characterized by the formation of an unstable osteochondral fragment. This distinction is important for management, as the prognosis and treatment differ significantly between traction apophysitis and osteochondritis dissecans proper. [2]

Modern approaches emphasize stepwise diagnostics with targeted imaging, stratification by lesion stability and skeletal maturation age, and early load modification. Proper management allows for healing and prevention of early osteoarthritis in most cases. [3]

Epidemiology

The incidence of individual forms varies. For juvenile osteochondritis dissecans of the knee, the estimated prevalence is tens of cases per 100,000, with a peak in schoolchildren and adolescents. Osgood-Schlatter disease is one of the most common causes of anterior knee pain in growing athletes. [4]

Legg-Calvé-Perthes disease occurs in young school-aged children and is characterized by avascular necrosis of the femoral head; in recent years, a possible decrease in its incidence and the influence of lifestyle factors, including excess body weight, have been discussed.[5]

Some forms exhibit sexual dimorphism and activity-dependent patterns. Traction apophysitis is more often found in actively training adolescents, especially those with jumping and running loads, reflecting the role of repeated mechanical stress on open growth plates. [6]

Reasons

The etiology is heterogeneous and combines ischemic, mechanical, and biomechanical factors. For osteochondritis dissecans, the key factor is considered to be impaired subchondral perfusion with subsequent instability of the osteochondral plate, aggravated by stress. For traction apophysitis, the leading factor is repeated tension on tendon attachments during the growth period. [7]

Legg-Calve-Perthes disease is thought to be a transient disruption of the blood supply to the femoral epiphysis due to a combination of constitutional and external factors. The etiologic contribution of individual factors continues to be studied. [8]

Genetic causes for the "classical" juvenile forms are not dominant, but biological variability in bone remodeling and vascular response may determine individual predisposition. [9]

Risk factors

Risk factors include intense cyclical loads in children and adolescents, especially during the active growth phase, shortening of the posterior muscle chain, and imperfect movement technique. For some conditions, the contribution of excess body weight and delay in seeking help is discussed. [10]

Age of skeletal maturation and open growth plates increase vulnerability to traction apophysitis. For osteochondritis dissecans, the risk is higher with repetitive microtrauma, high training exposure, and possibly with certain anatomical variations. [11]

Pathogenesis

Osteochondritis dissecans is characterized by damage to the subchondral bone with subsequent involvement of the articular cartilage, resulting in the formation of a stable or unstable lesion, even a free fragment. Imaging and arthroscopy confirm a continuum from bone swelling to splitting of the osteochondral plate. [12]

In traction apophysitis, repeated tension on the tendon causes microdamage to the apophysis and a reactive response in the growth plate, which clinically manifests as pain and localized swelling at the tendon insertion site. This condition is reversible with load correction and stretching. [13]

In Legg-Calvé-Perthes disease, transient ischemia leads to necrosis and subsequent remodeling of the femoral head. The duration and severity of each stage determine the risk of deformity and outcomes. [14]

Symptoms

Common complaints: joint or apophysial pain with exertion, localized tenderness, swelling, decreased range of motion, and sometimes a sensation of blockage or instability with osteochondritis dissecans. Growing athletes typically experience pain when running, jumping, and squatting. [15]

Night pain and severe morning stiffness are atypical and require the exclusion of alternative pathologies. Signs of hip involvement in a child include lameness, limited abduction, and internal rotation. Traction apophysitis is characterized by a painful bony nodule at the tendon attachment site. [16]

Forms and stages

Key clinical and anatomical forms include osteochondritis dissecans (knee, talus, elbow), traction apophysitis (tibial tuberosity, calcaneal tuberosity, inferior pole of the patella), and epiphyseal osteonecrosis of childhood. Staging is based on the stability of the lesion and the degree of skeletal maturation. [17]

For osteochondritis dissecans, MRI stability classifications and arthroscopic assessment are used. For Legg-Calvé-Perthes disease, radiographic staging scales are used to determine treatment management and prognosis. [18]

Table 1. Common osteochondropathy: age, localization, key signs

Nosology	Typical age	Localization	Key Features
Osteochondritis dissecans	Teenagers	Condyles of the femur, talus, head of the humeral condyle	Load pain, swelling, possible blocks
Osgood-Schlatter disease	10-15	Tibial tuberosity	Pain when jumping and running, painful "bump"
Northern Disease	8-12	calcaneal tuberosity	Heel pain in runners and football players
Legg-Calve-Perthes disease	5-8	Head of the femur	Lameness, limited movement in the hip joint
Panner's disease	7-12	Capitulum of the humerus	Elbow pain in throwers

The source of information and generalizations on forms are modern reviews and manuals. [19]

Complications and consequences

The main risks are chronic pain, decreased athletic performance, contractures, and, in osteochondritis dissecans, the formation of loose bodies and accelerated joint degeneration. Delayed diagnosis increases the likelihood of residual deformity. [20]

For Legg-Calvé-Perthes disease, long-term discrepancy between the sphericity of the head and acetabulum increases the risk of early osteoarthritis in adulthood, especially with late onset and large affected areas. [21]

Diagnostics

Basic algorithm: clinical examination, assessment of stress factors, targeted radiography, magnetic resonance imaging (MRI) if necessary for staging and assessing lesion stability, and ultrasound evaluation of soft tissues in cases of apophysitis. Computed tomography is reserved for complex cases. [22]

For osteochondritis dissecans of the knee, current recommendations of the American Academy of Orthopaedic Surgeons are relevant, which describe criteria for lesion stability and evidence-based approaches to visualization and choice of tactics. [23]

Differential diagnosis

The differential diagnosis includes stress fractures, osteonecrosis of other origins, synovial plica syndromes, osteochondral contusions, tumor-like lesions of the pineal gland, inflammatory arthropathies, and infectious processes. The patient's age, relationship to stress, and X-ray/MRI findings help narrow the range. [24]

For anterior knee pain in an adolescent, it is important to differentiate Osgood-Schlatter disease from patellofemoral pain syndrome and from a free osteochondral fragment in osteochondritis dissecans. For the hip joint in a child, transient synovitis and epiphysiolysis must be ruled out. [25]

Treatment

General principles for stable lesions and traction apophysitis: load modification, temporary restriction of painful activities, graduated physical therapy with an emphasis on stretching and controlled exercise volume, and symptomatic pharmacotherapy. In most cases, this leads to healing in growing patients. [26]

For osteochondritis dissecans, the approach depends on the age and stability of the lesion. In skeletally immature patients with stable lesions, conservative management with monitoring is preferred. In unstable patients and in skeletally mature patients, surgical methods are more often considered, including fragment fixation, bone stimulation, and mosaic osteochondral grafting. Decisions are based on the guidelines of the American Academy of Orthopaedic Surgeons and current reviews. [27]

In Legg-Calvé-Perthes disease, early stage stratification and centralization of the femoral head within the acetabulum guide the choice between observation, brace treatment, and surgery, as reflected in recent systematic reviews and clinical consensus statements.[28]

Table 2. Summary of tactics

Scenario	First line strategy	Indications for surgery
Stable osteochondritis dissecans in a skeletally immature patient	Load limitation, physical therapy, monitoring	Progression, instability
Unstable focus or mature skeleton	Preservation and fixation of the fragment, osteochondral techniques	Large unstable fragment, failure of conservative therapy
Osgood-Schlatter disease	Activity modification, stretching, temporary unloading	Rarely, with persistent symptom complex after closure of growth zones
Legg-Calve-Perthes disease	Observation or retention of centralization	Deformation, advanced age, large affected areas

Summarized from manuals and reviews of recent years. [29]

Prevention

The main measure is managing the training load in children and adolescents: gradually increasing volume and intensity, recovery days, proper technique, and stretching the muscles of the anterior and posterior thighs and lower legs. Early treatment for pain reduces the risk of chronicity. [30]

Sports schools and teams benefit from educational programs for coaches and parents on recognizing symptoms and safely planning their seasons. Individual adjustments to footwear and surfaces can reduce impact stress. [31]

Forecast

In most growing patients, stable lesions heal with proper management, returning to their original activity. The prognosis is worse with late diagnosis, fragment instability, and skeletal maturity. The long-term risk of osteoarthritis increases with unpreserved or poorly fixed lesions. [32]

In Legg-Calvé-Perthes disease, the outcome depends on the age of onset and the degree of preservation of the sphericity of the femoral head. Early stratification and the correct choice of tactics improve functional results. [33]