The Association of Radial Head Enlargement with Osteochondritis Dissecans of the Humeral Capitellum

Abstract

Abstract Radial head enlargement is a secondary change when capitellar osteochondritis dissecans (OCD) lesions progress. This study was performed to clarify geometric differences between the radial head of the OCD side and the contralateral side in patients with capitellar OCD, and to investigate the correlation between radial head enlargement and elbow range of motion. Eighteen patients with capitellar OCD were underwent computed tomography (CT) images of bilateral elbow joints. Five patients underwent conservative treatment (Nonoperative group) and 13 patients underwent operative treatment (Operative group). Three-dimensional (3D) CT models of the proximal radius were created and exported into polygon and point-cloud models. The radial head geometry of the OCD side was compared with that of the mirror-imaged model of the contralateral side by using a 3D–3D registration technique. The surface-to-surface least distance was calculated. Mean least distance was 1.08 mm (SD 0.55 mm.) The radial head in the Operative group was significantly larger than that in the Nonoperative group (p = 0.02). Elbow flexion correlated negatively with radial head enlargement (P = 0.02 and r = 0.552). Our results clarified that the radial head enlargement increases with disease progression and correlated negatively with elbow flexion in capitellar OCD.