Comparison between anterior cuneiform osteotomy and Dunn procedure in the surgical management of unstable severe slipped femoral epiphysis: A case-control study of 41 patients.

ABSTRACT

BACKGROUND: There is little consensus on the best treatment algorithm for unstable severe slipped capital femoral epiphysis (SCFE). Subcapital osteotomy, which is one of the surgical options, is performed either anteriorly (anterior cuneiform osteotomy, CO) or laterally with trochanteric osteotomy (Dunn procedure, DP). The CO is technically easier and decreases operating time. Moreover, because the DP was the standard in our department before it was replaced by the CO, we had a series of consecutive patients. Therefore, we did a retrospective case-control study in unstable, severe SCFEs treated by CO versus DP, which is to our knowledge the first one aiming to compare (1) postoperative complications and in particular avascular necrosis, (2) functional outcome, (3) radiologic findings. HYPOTHESIS: CO is less or just as likely to cause avascular necrosis and has the same clinical and radiologic findings as DP. METHODS: A total of 41 patients (24 girls, i.e. 58.5%) were included between 2005 and 2018 23 in the CO group and 18 in the DP group. The median age was 12.9 years (range, 11.5-14.9) and the median slip angle 70̊ (range, 62.5̊-80̊) with a median follow-up of 3 years (range, 2-4). Preoperative, intraoperative, and postoperative clinical and radiologic parameters (Southwick and alpha angles, and femoral head-neck offset) were analyzed, and all complications were documented. RESULTS: Two (8.7%) cases of avascular necrosis were reported in the CO group and 6 (33.3%) in the DP group (p=.11), with an overall rate of avascular necrosis of 19.5% (8/41). Five out of the 41 patients (12.2%) underwent a total hip arthroplasty 1/23 (4.3%) in the CO group and 4/18 (22.2%) in the DP group (p=.16). Two (9.5%) patients in the CO group and 7 (38.9%) in the DP group developed postoperative limping before any arthroplasty was performed (p=.055). The alpha angle at follow-up (54±6.1̊ vs. 59.1±7.2̊; p=.027), Oxford hip score at follow-up (17/60 [range, 14-20] vs. 23.5 [range, 19-27]) (p=.021), operating time (132 min [range, 103-166] vs. 199.5 min [range, 142-215]) (p=.011) and intraoperative bleeding (250 mL [range, 100-350] vs. 300 mL [range, 197-450]) (p=.088) were more favorable in the CO group than in the DP group. CONCLUSIONS: The CO has similar results to DP in the surgical management of unstable severe SCFE. LEVEL OF EVIDENCE III; retrospective comparative study.