Normalization of Subchondral Bone Density Patterns After Surgical Treatment for Capitellar Osteochondritis Dissecans:...

Capitellar osteochondritis dissecans (OCD) is common in adolescent throwing athletes. Surgical treatment yields favorable clinical outcomes. However, the relationship between bone density and clinical outcomes following OCD treatment is not well understood. We hypothesized that surgery normalizes subchondral bone density distribution and that clinical outcome improvements correlate with the bone density changes. This study quantitatively analyzed these changes and compared different surgical techniques.

Fifty-one male ethnic Japanese patients with capitellar OCD treated surgically (mean age at surgery: 14.0 ± 1.6 years) were enrolled, with a mean follow-up of 6.7 ± 3.1 years (mean age at final evaluation: 20.7 ± 3.5 years). Subchondral bone density was measured in Hounsfield units using computed tomography preoperatively and postoperatively, as well as in the contralateral elbow. Relative bone densities, expressed as proportions, in the distal humerus, radial head, and proximal ulna were compared among the preoperative, postoperative, and contralateral elbows within their respective anatomical subregions. Subgroups with reconstruction procedures and with preservation procedures were also analyzed separately. Functional outcome changes using Timmerman-Andrews scores were correlated with bone density changes.

In the distal humerus, subchondral bone density at the OCD lesion was significantly lower preoperatively (0.99 ± 0.17) than postoperatively (1.19 ± 0.17, p < 0.001) and in the contralateral elbow (1.17 ± 0.13, p < 0.001), whereas the density of the surrounding sclerotic bone was higher preoperatively (1.24 ± 0.10) than postoperatively (1.14 ± 0.10, p < 0.001) and in the contralateral elbow (1.07 ± 0.08, p < 0.001). The regions within and outside the site of the OCD lesion exhibited similar density distribution patterns postoperatively and in the contralateral elbow. In the radial head, the highest density was in the radial-volar quadrant preoperatively (1.14 ± 0.14) but shifted to the ulnar-volar quadrant postoperatively (1.06 ± 0.12, p = 0.020) and matched the contralateral value (1.02 ± 0.10, p < 0.001). Patterns in subchondral bone density in the regions were comparable between the reconstruction and preservation groups across all conditions. Improvements in Timmerman-Andrews scores correlated moderately with bone density normalization at the lesion site (R = 0.49, p = 0.003) and surrounding sclerotic bone (R = 0.43, p = 0.010).

Surgical treatment of capitellar OCD effectively restored the subchondral bone density distribution to normal patterns, regardless of the surgical technique. These bone density changes moderately correlated with improvements in functional outcome, providing quantitative evidence supporting the efficacy of surgical intervention for advanced lesions.

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.