Osteochondritis Dissecans – Causes, Symptoms, Diagnosis, Treatment and Ongoing care

Basics

Description

Separation of a portion of cartilage and underlying subchondral bone from a joint surfaceKnee is the most commonly affected joint; however, it can occur in any diarthrodial joint, including, in decreasing order of frequency, the elbow (capitellum), ankle (talar dome or tibial plafond), tarsal navicular, hip (femoral capital epiphysis), shoulder (humeral head or glenoid), and wrist (scaphoid).The loose piece of bone and cartilage may stay in place or migrate into the joint, making the joint unstable or seeming to lock up.Osteochondritis dissecans (OCD) is the most common cause of an intraarticular loose body in adolescents.System(s) affected: Musculoskeletal

Epidemiology

Incidence

Unknown: Estimated 2–5/10,000 personsPredominant age: Young adults between 10 and 40 years of ageJuvenile type (JOCD) in children and adolescents prior to physeal closurePredominant sex: Male > Female (5:3).

Risk Factors

TraumaSeen in active children and adultsMultisport athletics, especially gymnastics and overhead sports participationAbnormal mechanical axis of the leg can be a risk factor (1)[C]. Varus axis and medial condyle OCDValgus axis and lateral condyle OCD

Pediatric Considerations

Although still idiopathic, the mean age in JOCD is decreasing, and the prevalence in girls is increasing with changes in athletic participation by children (2)[C].

Genetics

No distinct genetic pattern known, but bilateral lesions have been noted in up to 30% of patients.

General Prevention

No clear way to avoid its development

Pathophysiology

Primary change happens in the bone.Necrosis occurs in a focal area.Overlying cartilage changes are secondary to the bony changes.Loss of subchondral bone support leads to degenerative cartilage changes: softening and fibromatous fissuring.Fragment may detach and become a loose body within the affected joint.Cartilage itself is without a vascular supply.Healing occurs by vascular supply to bone, which stimulates inflammation, repair, and remodeling.It is difficult to predict which lesions will go on to heal and remodel.

Etiology

Controversial and unclearTheories include trauma or repetitive microtrauma, ischemia, familial predisposition, fragile blood supply of the physeal line, and endocrine imbalance.Most commonly affected joints are the knee, ankle, and elbow. Knee: Overuse and with patellar dislocation and injury to the anterior cruciate ligament; bilateral involvement noted in up to 30% of patientsElbow: Overuse injury in overhead throwers and in female gymnastsAnkle: Frequently associated with history of previous ankle sprainRelationship between adult and juvenile forms of OCD remains unclear.

Diagnosis

History

Insidious or posttraumatic onset of pain, which improves with restPain usually defined as a deep and vague achePain may be associated with clicking, swelling, locking (usually with loose body), and stiffness.

Physical Exam

May be associated with secondary muscle atrophy, mild effusion, decreased range of motion (ROM), joint-line tenderness, or tenderness over the lesionThe Wilson test may be positive (i.e., pain with knee extension and tibial internal rotation) in some patients with knee involvement.

Diagnostic Tests & Interpretation

Lab

Initial lab tests

No specific tests

Imaging

Initial approach

The diagnosis usually is made by standard radiographs. Typical findings include small articular surface radiolucency or irregularity and bony fragmentation with partial or complete separation. Knee: Anteroposterior (AP), lateral, sunrise, and tunnel views (most likely location for abnormality in the lateral portion of the medial condyle)Elbow: Routine AP and lateral elbow series (common involvement of the humeral capitellum)Ankle: AP, lateral, and mortise views (lesions most commonly involve the posteromedial or anterolateral talar dome)MRI can delineate the bony lesion, involvement of cartilage, and any fluid behind the fragment and helps to stage the lesion. Stage I: Thickening of the articular cartilage and low signal change (stable)Stage II: Articular cartilage breached, low signal rim behind fragment indicating fibrous attachment (stable)Stage III: Articular cartilage breached, high signal changes behind fragment and underlying subchondral bone (unstable)Stage IV: Loose body (unstable)CT scan provides architectural description of bone lesion, but there is less information than with MRI.Bone scan may be useful in evaluation of healing potential, but this is controversial.

Differential Diagnosis

In the knee: Meniscal tearPatellofemoral pain syndromeStress fractureTendinopathyAvascular necrosisAcute fractureNeoplasm

Treatment

Medication

Acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) for symptomatic pain relief

Additional Treatment

General Measures

Goals of treatment: Maintain smooth, congruous joint surface.Alleviate pain.Prevent degenerative joint disease.Promote revascularization of necrotic fragment and regeneration of affected cartilage.There are no randomized, controlled trials, but in JOCD, nonsurgical treatment initially is the standard of care.Treatment options include periods of immobilization, activity modification, and non–weight bearing. Type and duration of immobilization remain controversial.If non-weight-bearing immobilization is used, add intermittent maintenance of ROM.Follow closely for 12 weeks for healing.Casting is used for 6-week intervals, especially with JOCD, owing to issues of compliance.

Issues for Referral

Adult patients in whom surgery may be considered as an early treatment optionUnstable lesions on MRI including intraarticular loose bodyFailure of symptomatic treatment

Surgery/Other Procedures

Surgical treatment is used when Conservative measures have failed.Physeal closure, which carries a worse prognosis for healing (adult form)Unstable lesions on MRI including intraarticular loose bodyLarger lesions (>1 cm)Arthroscopic surgery is the preferred method. In addition, arthroscopy is a valuable tool to evaluate the stability of the lesion and visualize the overlying cartilage.Surgical treatment includes fragment excision, microfracture technique (drilling) to increase blood supply, screw fixation of fragment, and/or allograft insertion and requires an orthopedic consultation (3)[B],(4)[C].

Ongoing Care

Follow-Up Recommendations

Outpatient care usuallyInpatient for surgery

Patient Monitoring

Initially should be followed every 6 weeks with serial radiographs to check for healing and possible displacementExpect healing in 4–6 months.In JOCD, radiographs at 1 year may show no residual abnormality.

Diet

No specific recommendations

Patient Education

Critical importance of compliance with treatment plan

Prognosis

Factors associated with good prognosis: Younger ageOpen growth plateSmaller lesions (<160 mm2)Stable lesionsNon-weight-bearing location of the lesionThe absence of a sclerotic rim on the X-rays at the time diagnosis can be an indication for spontaneous recovery with conservative treatment for OCD of the knee (5)[C].An incongruous joint surface may lead to degenerative changes in the future.Clinical improvement may proceed radiologic healing.

Complications

Failure to revascularize and healDisplacement of fragment becoming loose body within a joint

References

1. Jacobi M, Wahl P, Bouaicha S, et al. Association Between Mechanical Axis of the Leg and Osteochondritis Dissecans of the Knee: Radiographic Study on 103 Knees. The American journal of sports medicine. 2010

2. Kocher MS, Tucker R, Ganley TJ, et al. Management of osteochondritis dissecans of the knee: current concepts review. Am J Sports Med. 2006;34:1181–91.

3. Vasiliadis HS, Danielson B, Ljungberg M, et al. Autologous chondrocyte implantation in cartilage lesions of the knee: long-term evaluation with magnetic resonance imaging and delayed gadolinium-enhanced magnetic resonance imaging technique. Am J Sports Med. 2010;38:943–9.

4. Bruce EJ, Hamby T, Jones DG, et al. Sports-related osteochondral injuries: clinical presentation, diagnosis, and treatment. Prim Care. 2005;32:253–76.

5. Ramirez A, Abril JC, Chaparro M, et al. Juvenile osteochondritis dissecans of the knee: perifocal sclerotic rim as a prognostic factor of healing. J Pediatr Orthop. 2010;30:180–5.

Additional Reading

Cahill BR, Ahten SM, et al. The three critical components in the conservative treatment of juvenile osteochondritis dissecans (JOCD). Physician, parent, and child. Clin Sports Med. 2001;20:287–98, vi.

Crawford DC, Safran MR, et al. Osteochondritis dissecans of the knee. J Am Acad Orthop Surg. 2006;14:90–100.

Wall EJ, Vourazeris J, Myer GD, et al. The healing potential of stable juvenile osteochondritis dissecans knee lesions. J Bone Joint Surg Am. 2008;90:2655–64.

Codes

ICD9

732.7 Osteochondritis dissecans

Snomed

82562007 osteochondritis dissecans (disorder)

Clinical Pearls

Frequent follow-up every 6 weeksCompliance with immobilization and possibility of further trauma should be emphasized, especially with younger athletes.Many lesions heal without surgical intervention with compliance.