What is an osteochondral lesion?
An osteochondral lesion is an injury to a small area of cartilage together with the bone immediately beneath it. In adolescents this often takes the form of osteochondritis dissecans, where a segment of bone loses its blood supply and the cartilage above it can loosen.
Because both the surface and its foundation are involved, the fragment can stay stable and heal — or detach and float freely in the joint as a “loose body.” Which path it takes drives the whole treatment plan.
Signs and symptoms
- checkAching, activity-related pain often poorly localised at first.
- checkSwelling after activity.
- checkCatching, locking or clicking if a fragment has loosened.
- checkA sense of the knee “giving way” or not feeling reliable.
Causes & risk factors
- Repetitive impact and overload in young athletes.
- A single significant injury to the joint surface.
- Interrupted blood supply to a segment of bone.
- Growth-related vulnerability in adolescence.
How it is diagnosed
X-rays can show the bony part of the lesion, but an MRI is essential — it reveals whether the fragment is stable or loosening, the health of the cartilage and bone, and the presence of any loose bodies. This staging determines whether the lesion can be left to heal or needs fixing.
Treatment options
Protected healing
Stable lesions in growing patients can heal with a period of reduced loading and monitoring.
Fixation
A loosening but viable fragment can be pinned or screwed back into place to heal.
Resurfacing
A detached fragment is removed and the defect restored with cartilage transfer or regeneration techniques.
A lesion that is caught while still stable has the best chance of healing in place. Once a fragment detaches, the treatment becomes more involved — so persistent activity-related knee pain in a young athlete is worth assessing promptly.
Recovery & outlook
Recovery is staged and protective, allowing the bone and cartilage to heal before impact is reintroduced — typically over several months. Outcomes are good, especially for stable lesions treated early, with the goal of preserving the joint surface for the long term.