EP1.62 Arthroscopic Osteochondroplasty versus Open Surgical Dislocation for Femoroacetabular Impingement Secondary to Slipped Capital Femoral Epiphysis: A Proportional Meta-Analysis and Severity-Based Algorithm

Abstract Background Chronic deformity following slipped capital femoral epiphysis (SCFE) predictably causes cam-type femoroacetabular impingement (FAI). While both hip arthroscopy and open surgical dislocation (SHD) correct this deformity, the literature lacks a severity-stratified consensus guiding surgical selection. Objectives To evaluate clinical outcomes, radiographic correction, and complication profiles of arthroscopy versus open SHD procedures, establishing a severity-based treatment algorithm. Methods A PRISMA-compliant meta-analysis was conducted across MEDLINE, Embase, Scopus, and Web of Science (inception to March 2026). Inclusion required ≥10 SCFE hips, ≥12-month follow-up, and reported PROMs or radiographic parameters. Continuous single-arm outcomes were pooled using an inverse-variance random-effects model, with the exception of arthroscopy functional scores, which utilized a sample-size-weighted mean due to ceiling effects. Results Twelve studies met inclusion criteria (seven arthroscopy, four open SHD, one comparative). Arthroscopy, applied predominantly to mild-to-moderate slips, yielded a pooled postoperative HHS/mHHS of 86.2 (N=38) and alpha angle of 42.6° (95% CI 40.75–44.49), with near-zero avascular necrosis (AVN) incidence. Conversely, open SHD, targeting moderate-to-severe deformities, achieved powerful morphological correction (alpha angle 51.8°; 95% CI 51.04–52.73) and functional gains (HHS 92.6; 95% CI 91.58–93.58). However, this extensive open realignment carried higher risks, including AVN rates approaching 10–15% in specific modified Dunn cohorts. Conclusion Arthroscopy delivers excellent outcomes with minimal morbidity for mild-to-moderate SCFE deformities. Open SHD remains necessary for severe slips but demands careful risk-benefit calculus due to elevated AVN risk. We propose a severity-stratified algorithm: prioritising arthroscopic joint preservation for mild-to-moderate FAI, reserving open dislocation strictly for severe anatomical distortion.