Magnetic Resonance Imaging Assessment of Cartilage Appearance Following Marrow Stimulation of Osteochondritis Dissecans of the Humeral Capitellum

Abstract

Osteochondritis dissecans (OCD) of the capitellum is often treated by marrow stimulation techniques with good long-term outcomes. Magnetic resonance imaging (MRI) can be used to characterize the healing of cartilage repair tissue. However, no formal system exists for assessment of cartilage healing after marrow stimulation in capitellar OCD. The aims of this study were to describe the postoperative MRI appearance of capitellar repair cartilage after debridement and marrow stimulation for capitellar OCD and assess differences between symptomatic and asymptomatic patients. This was a retrospective study of patients with capitellar OCD who underwent arthroscopic debridement and marrow stimulation and had a postoperative MRI to assess healing. The classification system developed by Marlovits and colleagues (Magnetic Resonance Observation of Cartilage Repair Tissue) was used to quantitatively profile the cartilage repair tissue in comparison to adjacent "normal" cartilage. Study participants completed an online survey to correlate outcomes with cartilage appearance. Eleven patients who underwent MRI for routine evaluation (asymptomatic), and 18 who underwent MRI for symptoms were identified. Overall, 59% of defects were completely filled, and in 83%, the cartilage surface had ulcerations or fibrillations. The cartilage variables were similar between symptomatic and asymptomatic patients. Capitellar subchondral bone edema was observed on the MRI of every patient who underwent a reoperation and was present in only 62% of those who did not. Clinical scores did not correlate with MRI cartilage findings, but the small sample size limited conclusions regarding clinical outcomes related to postoperative cartilage features seen on MRI. This detailed assessment of cartilage appearance by MRI after marrow stimulation for capitellar OCD demonstrated that incomplete cartilage fill was common in both symptomatic and asymptomatic patients. Those requiring a second surgery were more likely to demonstrate subchondral bone edema. Diagnostic IV.