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What is osteochondritis dissecans (OCD)? Osteochondritis dissecans may occur in any joint in the body.
Osteochondritis dissecans rarely occurs in the foot or ankle. Although doctors are unsure of the exact cause of osteochondritis dissecans, trauma and stress-related injuries as well as interruptions in the normal flow of blood have been identified as factors. Additional factors include metabolic diseases and genetic disposition.
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OCD Progression
Osteochondritis dissecans (OCD) typically progresses in distinct stages. First, a part of the bone under the cartilage undergoes avascular necrosis (degeneration from a lack of blood supply). When this happens, it is primarily the bone that is affected because the cartilage will usually remain intact for a longer period as it continues to be supplied with fluid from the joint. The body's response to the necrotic development in the bone, which typically depends on the age of the patient, will largely determine the course taken by the disease.
In general, the prognosis is better for younger patients, with adults being less likely to heal spontaneously and more likely to need surgery and develop osteoarthritis in the affected joint.
As the condition develops, the fragment may separate and make its way into the joint space where, in addition to causing pain and sensations of joint blocking or weakness, it can be expected to accelerate the development of osteoarthritis in the ankle joint.
What parts of the upper ankle are affected by OCD?
The upper edges of the talar dome are affected by osteochondritis dissecans, with the inner edge of the dome being more frequently affected than the outer edge.
What are the symptoms of OCD and osteochondral lesions (OCL)?
The symptoms of OCD and OCL in the talus are non-specific and usually do not provide a basis for a diagnosis. Most patients complain simply of pain coming from inside the ankle. It is seldom that a patient will complain about clearly demarcatable pain and blocking or clicking in the talus. Often asymptomatic, many cases of OCD and OCL are detected by chance. Up to the point of fragmentation, the pain tends to be slight and the symptoms non-specific. The inflammation of the synovial membrane that is triggered by the deterioration of the cartilage can lead to swelling and joint effusions. Typical late symptoms include sudden and sporadic sticking and locking of the joint.
OCD and OCL Stages
- Stage I: injury to the cartilage
- Stage II: injury to the cartilage and fragmentation of the underlying bone
- Stage III: bone loosening
- Stadium IV: bone detachment
Who is at risk of OCD?
Osteochondritis dissecans often occurs in younger individuals, with boys and young men more likely to have the condition than girls and young women. Regular physical activity - especially involving repetitive impact movement such as jumping - appears to increase the risk.
OCD Diagnosis
The diagnosis is often made at a late stage because the structural changes do not show up on ankle x-ray until long after the onset of a diminished blood flow. Examinations should be carried out in both ankles because the condition affects both joints in around 40% of all cases.
Examinations using magnetic resonance imaging represent the most reliable means of arriving at a diagnosis. They also allow the physician to determine the particular stage of the disorder.
OCD Treatment
Treatment for OCD in the ankle often depends on the stage of the disorder and the age of the patient. Conservative measures alone are often effective at bringing about rapid healing in patients whose bones are still growing and in patients who show no more than early stage symptoms.
Conservative forms of treatment for adults presenting with an advanced stage of the disease are far less effective. Various surgical procedures, which can be carried out in the context of ankle arthroscopy, are available.
- Retrograde drilling
- Retrograde bone grafting under the cartilage
- Transchondral drilling
- Fragment stabilization
- Micro-fracturing
- Osteochondral autograft transplantation (OAT).
- Chondrocyte implantation (autologous chondrocyte implantation)
OCD Prognosis
The condition may heal entirely in children as their bones continue to grow. The prospects of self-healing diminish with increasing age.
In general, the prognosis is better for younger patients, with adults being less likely to heal spontaneously and more likely to need surgery and develop osteoarthritis in the affected joint.
One of the main problems with OCD is the increased risk of ankle osteoarthritis that goes hand in hand with injuries to the bone and cartilage.