How To Address Osteochondral Lesions
An athletic, 35 year-old male presents to the office four months after suffering an ankle sprain while playing soccer. In spite of a period of immobilization and a course of physical therapy, he has had continued pain and stiffness localized to the ankle joint. He has been wearing a lace-up ankle brace, icing the ankle and taking OTC NSAIDs.
A physical examination reveals mild tenderness upon palpation to the ankle joint line but there is no significant pain along the medial or lateral collateral ligaments. He has a negative anterior drawer. Routine X-rays are negative. A subsequent MRI shows an osteochondral lesion on the talar dome. How should one proceed?
Osteochondral lesions of the talus (OLT) are routinely missed in the early workup and treatment of impaction or rotational ankle injuries. Keep in mind that ankle sprains are commonly undertreated and often will not end up in a foot and ankle specialist’s office until the condition has become chronic and persistent. Frequently, a clinician will make the diagnosis of OLT after the patient has already experienced several months of pain.
OLTs involve an injury to the articular cartilage with or without subchondral fracture, and lifting or separation of the fragment from the underlying subchondral structure. These joint injuries can occur throughout the body but occur most commonly in the knee.
Osteochondral lesions are not restricted to a traumatic etiology although this is the case in the majority of patients. In some cases, they are caused by a poorly understood ischemic event. Clinicians commonly see OLTs at the anterolateral or posteromedial talar dome. Anterolateral lesions are usually the result of an inversion injury and dorsiflexion forces, causing a shallow and wafer-shaped lesion. Medial talar dome lesions are usually deeper and cup-shaped. They are usually the result of plantarflexion, inversion and external rotation.
Patients with OLTs will usually have a history of inversion injury but keep in mind that spontaneous necrosis can occur without a history of trauma. These patients will usually describe joint stiffness, pain on range of motion and attempted activity, and catching or locking of the ankle.
A routine ankle examination can reveal pain on range of motion. For an anterolateral joint lesion, plantarflex the foot and palpate at the anterolateral aspect of the ankle. When it comes to posteromedial lesions, one can elicit pain by palpating the posterior medial aspect, just behind the medial malleolus, with the foot in full dorsiflexion.
A Guide To X-Ray Classification Of Osteochondral Fractures
Berndt and Harty classified osteochondral fractures of the talus based upon radiographic findings.
Stage I: normal radiographs with subchondral compression fracture
Stage II: a partially detached osteochondral fragment
Stage III: a completely detached fragment, non-displaced, remaining within its bony crater
Stage IV: detached, loose, displaced osteochondral fragment
Pertinent Pointers On Treating Stage I And Stage II Lesions
The options when dealing with OLT are dependent on the location, size, depth and staging of the lesion. With this in mind, here is a suggested treatment approach to a variety of lesions that we may see.
Stage I lesions. A patient of any age presents with ankle pain after a traumatic injury, has negative X-rays and MRI findings that are consistent with a shallow, compression type lesion of the talar dome with subchondral edema. There is no associated tibial plafond injury.