Staging of osteochondritis dissecans of the elbow based on pathologic progression in the partially detached articular fragment

Our results confirmed that the proposed pathological staging of OCD corresponds to the observed clinical progression of OCD, thus validating the staging system. Our findings revealed that OCD begins with separation beneath the epiphyseal cartilage which is programmed to be replaced with bone. When a stage IA articular fragment has remained partially detached for a prolonged period, the epiphyseal cartilage may be deteriorated and become degenerated, and subsequent ossification may not occur, as is evident in OCD-IB. In contrast, stage IA with a vascular supply through the fibrocartilaginous connection can progress to stage IIA. During the prolonged period in which the osteochondral articular fragment remains un-united, microtrauma can cause to disturb the blood supply to the bony fragment, resulting in osteonecrosis (stage IIB).