Internal fixation devices for the treatment of unstable osteochondritis dissecans and chondral lesions

Abstract

Most commonly seen in the knee, elbow and ankle, osteochondritis dissecans (OCD) represents an underlying bony fragment separation from the subchondral region with or without articular involvement. Osteochondral or chondral injuries are associated with trauma and can occur in any joint. Unstable OCD and traumatic osteochondral or chondral lesions demand operative treatment, particularly if displaced. Principles of treatment include anatomic reduction, rigid fixation, enhancement of blood supply, and restoration of articular congruity. Internal fixation can be achieved through open or arthroscopic approaches with one of many devices including cannulated screws, metal pins, and bioabsorbable pins. Cannulated screws can provide rigid fixation and compression across lesions. AO screws must eventually be removed to avoid articular damage and allow weightbearing. Headless, variable pitch screws, however, can be placed below the articular margin, do not need to be removed, and provide compression because of their differential pitch designs. Metal pins in the form of Kirschner wires (K-wire) can be placed antegrade through the lesion, or retrograde from behind the lesion. K-wires can potentially migrate, bend or break, and they must eventually be removed. Bioabsorbable pins have several advantages including bioresorbable properties obviating the need to remove them, low-profile designs, and a decrease in stress-shielding compared with metal implants. The most common reported complication with bioabsorbable pins is a reactive synovitis. Newer devices recently described for OCD lesions of the capitellum include pull-out wires and dynamic staples. The purpose of this article is to present different options for operative fixation of these lesions.