Osteochondritis Dissecans of the Knee Joint

OCD is a rare condition, characterized by a disorder of the subchondral bone, which can involve the overlying articular cartilage. The pathologic condition is mainly, but not exclusively, seen in adolescent, active males. While the most common location is the lateral side of the medial femoral condyle, its exact etiology remains elusive; however, there are indications that OCD might be caused by repetitive (micro)trauma, impaired vascularization, or a hereditary disorder. Non-surgical treatment can be attempted, if the overlying cartilage is still intact and the lesion is considered stable. To reduce symptoms and prevent further loosening, physical activities should be restricted. If non-surgical treatment fails while the cartilage layer remains intact, trans-, or retroarticular drilling can induce intrinsic bone healing. In the setting of an unstable OCD, surgical treatment is indicated, as spontaneous healing is rare and unpredictable. If possible, fixation of the loose fragment should be attempted, preferably using compression metallic or bioabsorbable screws. Postoperative bracing protects the surgical site until hardware removal. Afterward, weightbearing and increased range of motion can be introduced progressively. If fixation is not feasible due to excessive cartilage fragmentation, a salvage procedure is indicated. The surgeon’s armamentarium consists of microfracture, autograft (Osteochondral Autograft Transfer (OAT)), allografts, cell-based treatment (Autologous Chondrocytes Implantation (ACI)), and a bioabsorbable or small focal metallic implant.