Two-year 3D gait outcomes following in-situ pinning or modified Dunn procedure in children with slipped capital femoral epiphysis

Background: Slipped Capital Femoral Epiphysis (SCFE) is femoral head slippage off the femoral neck through the physis occurring in children aged 8-16 years. Surgical intervention is required in all paediatric cases and there is no universal agreement on choice of surgical procedure.

Research question: What are the two-year 3D gait outcomes in children with SCFE who have undergone in-situ pinning (PIN) or modified Dunn procedure (MDP) compared with normative reference values?

Methods: 17 children with SCFE who had undergone PIN (n=7, slip severity mild to moderate) or MDP (n=10, slip severity moderate to severe) surgical procedures prospectively underwent a 3D gait analysis post-surgery (2∙0 ± 0∙5 years). Ten age-matched children were also recruited to provide normative reference values. The conventional gait model was modified to incorporate Hara hip equations and Lerner pelvic tracking methods. Gait Profile Scores, Gait Variable Scores, kinematics, kinetics and spatiotemporal data were calculated for each group.

Results: Overall gait pattern, determined by the Gait Profile Score, indicated that both SCFE groups differed from the normative reference group (PIN 6∙6 ± 2∙5⁰, MDP 6∙2 ± 2∙0⁰ vs. 4∙0 ± 1∙3⁰ norm, p<0∙05). Normalised walking speed was reduced in the MDP group (0∙40 ± 0∙04) compared to the normative reference group (0∙46 ± 0∙06; p=0∙032).

Significance: Gait patterns of children with SCFE treated with PIN was more markedly altered than that of children with SCFE treated with MDP, despite having lower SCFE severity. Increased external hip rotation observed in the PIN group may be a pre-cursor for osteoarthritis in adulthood. Therefore the use of the corrective MDP which normalises hip rotation may be beneficial for reducing functional impairments.