Variation in stress distribution patterns across the radial head fovea in osteochondritis dissecans: predictive factors in radiographic findings

Background: Predictive factors for the development of osteoarthritis in adolescent osteochondritis dissecans (OCD) of the humeral capitellum remain unclear. The objectives of this study were to assess subchondral bone density in the radial head fovea of patients with OCD and to evaluate stress distribution in the radiocapitellar joint. The relationship between radiologic classification and stress distribution, according to multivariate ordinal regression analysis, was also investigated. Methods: Computed tomography (CT) imaging data from 54 male patients with OCD (mean age, 13.1 years) were collected. Stress in the radial head fovea was measured using CT osteoabsorptiometry. A stress map was constructed and divided into 4 sections, and percentages of high-density regions in each section were quantitatively analyzed. Multivariate ordinal regression analyses were performed of bone density, incorporating the stage, location, and size of the OCD lesion and the presence of medial elbow disturbance in the radiographic images. Results: The percentage of high-density area in the anteromedial, posteromedial, and the anterolateral sections of the radial head fovea were significantly increased compared with the posterolateral section. Multivariate ordinal regression analysis revealed that the location and size of the lesion and a history of excessive valgus stress were associated with imbalances in the radial head fovea. Conclusions: When the OCD lesion is large and located laterally and a medial epicondyle disturbance is apparent on radiographs, the risk for developing advanced radiocapitellar osteoarthritis should be considered. These findings can be useful in the decision-making process for treating OCD. (C) 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.