Summary

Posterior or large osteochondral defects of the humeral capitellum on preoperative reconstructed CT sagittal images were associated with poor outcomes of arthroscopic debridement for capitellar OCD in adolescent baseball players.

Abstract

Objectives: To investigate the relationship between size and location of osteochondral defects in capitellar osteochondritis dissecans (OCD) measured on coronal and sagittal reconstructed computed tomography (CT) images and the clinical outcomes of arthroscopic debridement in adolescent baseball players.

Methods

This retrospective study investigated the clinical outcomes of arthroscopic debridement for capitellar OCD in adolescent baseball players with at least 24 months of follow-up after surgery between 2008 and 2020. Outcome measures were determined using the Timmerman–Andrews score at the latest follow-up. On a preoperative reconstructed CT coronal image, defect size (%) was described as the length of the defect relative to the length of the capitellum. On a preoperative reconstructed CT sagittal image, the superior and inferior angles (degrees) were used to describe the location of the defect. Defect angle (degrees) was used to describe the size of the defect on the sagittal plane. Spearman’s rank correlation coefficient was used to examine relationships between the Timmerman–Andrews score and each of the parameters of defect size, superior and inferior angles, and defect angle as well as between each Timmerman–Andrews sub-score and these parameters. Significance was established at p < 0.05.

Results

Thirty players (mean age, 14 [range, 11-16] years) underwent arthroscopic debridement: 6 were pitchers, 6 were catchers, 13 were infielders, and 5 were outfielders. Mean follow-up duration was 26 (range, 24-66) months. Timmerman–Andrews score at the latest follow-up was 188 (range, 165-200) points. Mean defect size was 50.29% (range, 24.43%-69.80%). Mean superior angle was 91.82 (range, 69.80-110.90) degrees, mean inferior angle was 23.03 (range, -32.53-55.33) degrees, and mean defect angle was 68.79 (range, 42.31-135.04) degrees. Timmerman–Andrews score was positively correlated with the inferior angle (r=0.520, p<0.01) and negatively correlated with the defect angle (r= -0.462, p=0.010). For each sub-score considered, pain and sagittal arc of motion were positively correlated with the inferior angle (r=0.478, p=0.007, r=0.409, p=0.025), and flexion contracture was negatively correlated with the defect angle (r=-0.424, p=0.020).

Conclusion

Posterior or large osteochondral defects of the humeral capitellum on preoperative reconstructed CT sagittal images were associated with poor outcomes of arthroscopic debridement for capitellar OCD in adolescent baseball players.