Shelf acetabuloplasty in Perthes disease: comparison with nonoperative treatment

Background: The purpose of this study was to compare radiographic results between operatively and nonoperatively treated hips in patients with Perthes disease. Methods: Eighty children (88 hips) treated for Perthes disease were retrospectively reviewed with focus on the radiographic result at a mean follow-up of 6.3 yr (range 2.0 to 12.9 yr). Forty-seven hips had shelf acetabuloplasty, and 41 hips were treated nonoperatively. The radiographs were evaluated at the time of diagnosis, at 4 wk and 3 yr postoperatively (for the shelf group) and finally at latest follow-up for both groups. Results: In the nonoperatively treated group, the prognosis was initially better than in the shelf group: younger age at the time of diagnosis (4.7 vs. 6.1 yr), more Herring type A and fewer Herring type C, fewer “head at risk” signs. Stulberg’s classification at the latest follow-up showed Stulberg 1, 2 or 3 in 85% and Stulberg 4 in 15% in the nonoperative group compared with 89% and 11%, respectively, in the shelf group. Acetabular depth ratio and the migration index were better in the shelf group. Conclusions: Despite initial worse prognostic factors, final radiographic result seemed to be better in the shelf group. The shelf procedure showed radiographic improvement in the hip in Perthes disease.