An osteochondral lesion is an injury affecting a joint, specifically involving damage to both the cartilage and the underlying bone. These lesions are a localized defect within the joint’s surface. They can occur in various joints, though most frequently observed in the knee and ankle. This condition can lead to pain and impaired joint function, impacting daily activities and sports.
What an Osteochondral Lesion Is
Joints are covered by articular cartilage, a smooth, slippery tissue that allows bones to glide over each other with minimal friction. Directly beneath this cartilage lies the subchondral bone, which provides support and nourishment.
An osteochondral lesion involves damage to both the articular cartilage and the subchondral bone. This damage can range from softening of the cartilage, to cyst-like formations within the bone, or even a fracture of both layers. Lesions are categorized by whether they involve only cartilage (chondral) or both cartilage and bone (chondral-subchondral), and if they are stable or displaced.
These lesions commonly occur in weight-bearing joints, such as the knee, where they frequently affect the medial femoral condyle. In the ankle, osteochondral lesions most often involve the talus, the bone connecting the leg to the foot. The talus’s limited blood supply can make healing more challenging.
Common Causes and Contributing Factors
Osteochondral lesions frequently arise from direct trauma to a joint, including acute injuries like severe ankle sprains, twisting injuries to the knee, or direct impacts. Approximately 85% of ankle osteochondral lesions are linked to a traumatic ankle injury.
Repetitive stress or overuse is another common cause, especially in athletes. Activities involving repeated impact, such as running or jumping, can cause bones within a joint to make hard contact, leading to damage over time. This repetitive microtrauma can result in microfractures of the subchondral bone.
Other factors can contribute to these lesions, including underlying bone development abnormalities, particularly in children, and a genetic predisposition. Reduced blood supply to the affected bone area can also play a role.
Recognizing Symptoms and Getting a Diagnosis
Individuals with an osteochondral lesion experience localized pain in the affected joint, which worsens with activity. This pain may be a dull ache and can persist for months after an initial injury. Swelling around the joint is also common, sometimes with stiffness.
Patients may also notice mechanical symptoms, such as clicking, popping, or catching sensations. The joint might feel unstable or even lock up, preventing full movement. If these symptoms persist after a joint injury, seek medical attention for diagnosis.
Diagnosis begins with a physical examination to assess the joint for tenderness, instability, and range of motion. Imaging techniques confirm the diagnosis and determine damage extent. X-rays are often the first step to rule out other bone issues, but may not clearly show cartilage damage.
Magnetic Resonance Imaging (MRI) provides detailed views of both cartilage and bone marrow changes. A Computed Tomography (CT) scan may also be used for a closer look at bone structure.
Treatment Options
Treatment for osteochondral lesions varies by size, location, stability, and patient age. Non-surgical approaches are considered first, especially for smaller, stable lesions and in younger patients with greater healing potential. These conservative treatments involve rest, activity modification, and immobilization in a cast or brace for four to six weeks. Physical therapy helps regain strength and range of motion, and pain management, including nonsteroidal anti-inflammatory drugs (NSAIDs), may be used.
If non-surgical methods do not provide improvement after about six months, or for larger, unstable, or displaced lesions, surgical intervention may be recommended. Arthroscopy is a common minimally invasive approach. Surgeons can debride (remove loose or damaged tissue) and perform microfracture, creating small holes in the subchondral bone to stimulate blood flow and encourage new cartilage growth. Microfracture results are good in the short term, though outcomes can decline over time for larger lesions or in older patients.
For more extensive damage, restorative surgical procedures are available. Osteochondral autograft transplantation (OATS), also known as mosaicplasty, transplants healthy cartilage and bone plugs from a non-weight-bearing area of the patient’s own joint to the damaged site. This replaces damaged tissue with the patient’s own healthy tissue.
Another option for larger defects is osteochondral allograft transplantation, which uses bone and cartilage from a cadaver donor. Autologous chondrocyte implantation (ACI) is a technique where a patient’s own cartilage cells are harvested, grown in a lab, and then re-implanted into the lesion.
Recovery and Prognosis
Recovery for an osteochondral lesion varies by size, location, and treatment. Following non-surgical management, reduced weight-bearing, often with crutches or a cast, may be necessary for several weeks. For surgical interventions, weight should be kept off the affected joint for four to six weeks, sometimes with a cast.
Rehabilitation, guided by a physical therapist, is important. This involves a gradual progression from low-impact stretches and exercises to more rigorous strengthening activities, restoring joint function, range of motion, and muscle strength. Patients may avoid high-impact sports for several months post-surgery, with return to full activity depending on symptom resolution and radiographic evidence of healing.
The long-term outlook is generally favorable with appropriate treatment, with many patients experiencing significant pain relief and improved function. However, arthritis may develop later, particularly if the lesion is untreated or healing is incomplete. Continued strength training and periodic medical check-ups can help maintain joint health and prevent recurrence.