Topographic Analysis of 2 Alternative Donor Sites of the Ipsilateral Elbow in the Treatment of Capitellar Osteochondritis Dissecans

Purpose: To find the best topographic subchondral bone match between the capitellum and 2 proposed alternative donor sites of the ipsilateral elbow for capitellar osteochondral autologous transplantation: the non-articulating part of the radial head and the lateral olecranon tip. Methods: In our retrospective database, 20 patients with an unremarkable computed tomography scan of the elbow despite clinical suspicion were identified for analysis. Included were patients aged 11 to 20 years with intact osseous structures and a computed tomography slice thickness of 1.25 mm or less. Three-dimensional polygon models were created using a standard predefined threshold, after which 4 articular surface lesions on the capitellum were created: central 40°, central 60°, lateral 40°, and lateral 60°. In addition, 3 donor locations on the non-articulating part of the radial head (diameter, 5 mm) and the lateral olecranon tip (diameter, 3.5 mm) were created. For each of 24 donor-recipient combinations, the donor graft surface was virtually placed on the recipient surface to quantify the mean distance between surfaces. Results: The group of 20 patients consisted of 16 male and 4 female patients with a mean age of 15.9 years (range, 12-18 years). For a central 40° lesion, the mean distance across all 6 donor-recipient combinations ranged from 0.085 ± 0.023 to 0.118 ± 0.036 mm; for a central 60° lesion, the mean distance ranged from 0.075 ± 0.018 to 0.117 ± 0.062 mm; for a lateral 40° lesion, the mean distance ranged from 0.087 ± 0.030 to 0.182 ± 0.226 mm; and for a lateral 60° lesion, the mean distance ranged from 0.084 ± 0.048 to 0.115 ± 0.045 mm. There were no differences in topographic matching between donor-recipient combinations. Conclusions: The findings of this study show a less than 0.2-mm difference in the topographic subchondral bone match between 4 common lesion locations on the capitellum and 2 alternative donor sites of the ipsilateral elbow for capitellar osteochondral autologous transplantation: the non-articulating part of the radial head and the lateral olecranon tip. Clinical Relevance: These findings suggest that the non-articulating part of the radial head and the lateral olecranon tip may potentially be used as a donor source when treating capitellar osteochondritis dissecans