Paper 90: Clinical Evaluation of Surgical Treatments for Lateral Type Osteochondritis Dissecans of the Humeral Capitellum

Osteochondritis dissecans (OCD) of the humeral capitellum most frequently occurs in adolescent baseball players. The treatment for advanced OCD is controversial, especially, the prognosis of the extended lateral type OCD lesion which destroys the lateral wall of the humeral capitellum is poor. We performed two surgical procedures for these cases; first, osteochondral fragment fixation using autologous osteochondral plug for cases of preservationable osteochondral fragment with sufficient cancellous bone and acceptable congruity with reduction, and, second, replacement of the osteochondral fragment with osteochondral autograft for cases without preserved fragments. The objective of this study was to compare the clinical results between the fixation group and the replacement group. Nine patients were treated with fixation procedure (average age: 12.3 years, average follow-up period: 21.3 months) and 7 patients were treated with replacement procedure (average age: 14.4 years, average follow-up period: 21.2 months). First, arthroscopic evaluation was performed, followed by direct visualization of the OCD lesion by the posterolateral approach. In the fixation procedure, the osteochondral fragment was fixed with one or two osteochondral plugs of 5-6mm diameter obtained from the ipsilateral knee joint, and the elbow joint was immobilized in a long arm cast for 2 weeks after surgery. In the replacement procedure, the osteochondral fragment was resected, and replaced with an osteochondral plug of 9-10mm diameter obtained from the ipsilateral knee joint. All patients were evaluated with range of motion (ROM) of elbow joint, Timmerman's scoring system, and the return to activity level. Postoperative radiographs and magnetic resonance imaging (MRI) were obtained for all patients, radiocapitellar congruity with 45 degree flexion view in radiographs and high signal intensity in the subchondral bone area in T2-weighted MRI were evaluated. No significant difference between pre and post operative ROM was detected in either group. In the scoring system, the postoperative average of 185±18 points was statistically significantly higher than the preoperative average of 156±24 points in fixation group, and the postoperative average of 185±12 points was statistically significantly higher than the preoperative average of 149±35 points in the replacement group. All patients returned to full activity level except for one in the fixation group. No significant difference between the groups was detected in the period to return to full activity level. In the radiocapitellar congruity, the postoperative average of 80±15 % was statistically significantly higher than the preoperative average of 39±7 % in the fixation group, and the postoperative average of 70±17 % was statistically significantly higher than the preoperative average of 33±10 % in the replacement group. In the postoperative MRI evaluation, the high signal intensity in the subchondral bone area that was detected in the preoperative T2-weighted MRI was not detected in 5 cases in the fixation group and 7 cases in the replacement group. This study indicated that both methods were effective for lateral type elbow OCD. It is important to make a choice between the methods based on the condition of the OCD lesion.