The gait function of slipped capital femoral epiphysis in patients after growth arrest and its correlation with the clinical outcome.

Purpose: Slipped capital femoral epiphysis (SCFE) represents the preliminary stage of osteoarthritis. Reliable tools for outcome evaluation should be developed to prevent persisting defects. The functional outcome of SCFE-patients after growth arrest is analysed by instrumented 3D-gait analysis (GA). The results are matched to the clinical examination findings.

Methods: A total of 39 SCFE patients after growth arrest (18.8 years; BMI 26.5 kg/m²) with unilateral affection were included. The clinical results were classified according to Harris hip and clinical Heyman Herndon scores. 3D-GA-parameters were evaluated and compared to the sound side and a group of 40 healthy adults (28.0 years; 21.9 kg/m²). The subgroup analysis was performed according to clinical results.

Results: The clinical examination revealed very good results. GA could detect even small alterations. Some parameters indicated sustained functional impairments: Compared to the control group patients' walking speed (p = 0.022), step frequency (p < 0.001) and single support of the slip side (p < 0.001) decreased, while step width (p = 0.014), double support (p = 0.004) and stance time of sound side increased (p = 0.001). For kinematics patients, the sagittal range of motion (ROM) of pelvis (p < 0.001) and the external rotation of the ankle on both sides increased (p = 0.011) and sagittal ROM of hip (p = 0.002) and knee flexion of slip side (p < 0.001) decreased. The sagittal ROM of the ankle on the slip side decreased compared to the sound side (p = 0.003). Subgroup analysis revealed a positive correlation between clinically unsatisfying results and GA parameters.

Conclusions: Functional impairments in SCFE-patients can be found even after growth arrest. Alterations are explained partly by the disease and partly by patients' constitution. BMI-matched controls and long-term follow-up are needed.