gms | German Medical Science

Objectives: The best treatment of patients with severe slipped capital femoral epiphysis is still under discussion. Depending on the dislocation and type SCFE different operative procedures with different high potential for avascular necrosis of the femoral head are available. An anatomical restoration at least for severe chronic and acute on chronic SCFE is sought to avoid early onset of osteoarthritis. Using surgical hip dislocation (SDH) enables the surgeon to reconstruct the anatomical deformity. The incidence of AVN with this treatment differs in literature between 0 - 66.7%. To analyze the progress of this technic we evaluated our early cases using an isolated surgical hip dislocation with modified Dunn procedure and later cases with additional extended retinacular soft-tissue flap over the last 10 years in our department.

Methods: From 04/2006 to 07/2017, 20 patients (22 hips) underwent SDH for SCFE. In 16 cases an isolated SDH with modified subcapital correction osteotomy (group 1) and in 6 cases an additional extended retinacular soft-tissue flap (group 2) was performed. The collective consisted out of 10 boys and 10 girls with a mean age of 12.2±1.4 (10-15) years. The mean angle of preoperative posterior displacement was 57.1°±10.1° (50 - 91°). The indications for surgery were acute on chronic SCFE in 11 cases (instable) and chronic SCFE in 11 cases (stable). There was no acute SCFE treated with SHD in this study. The general follow-up time for all cases was 26±30 (4- 123) months, for group 1 33±33 (11 - 123) months and for group 2 7±3 (6 - 12) months (p<0.001).

Results and conclusion: Overall 5 patients (31%) had postoperative complications Analyzing both techniques separately revealed in group I 4 cases (25%) of femoral head necrosis occurring after generally 5±2 (2 - 6) month as well as 1 case (6%) of chrondrolysis whereas no major complications occurred in group II. The risk for complications was heightened, but not significant, using no retinacular soft tissue flap (p=0.133).Analyzing group 1 further showed a higher risk for postoperative AVN after isolated SHD with Dunn procedure for instable acute on chronic SCFE [3/9 AVN (33%)] in comparison to isolated chronic SCFE [1/7 AVN (14%)] (p=0.585).

The treatment of severe SCFE is challenging. Increasing numbers of SDH with modified Dunn procedure lead to more experience with these technique generating less complications. Due to our experiences surgical hip dislocation for SCFE should only performed using an extended retinacular soft-tissue flap to prevent the risk of AVN.