d="sp0010">This was a retrospective study of patients seen at our institution between 2000 and 2009. Antero–posterior and frog lateral X-rays were reviewed to measure: Southwick's lateral slip angle, the alpha angle of Notzli and Klein's line offset. Quantitative 3D gait data was collected using a state of the art motion capture system. Kinematic waveforms were compared using a functional data analysis version of the t-test.
d="sp0020">There were 30 patients with an average age at pinning of 13 y (10–17 y). Mean gait profile scores were significantly abnormal for slipped side (10.8°) versus sound side (6.8°), slipped side versus normal (5.6°) and sound side versus normal. There was little statistically significant correlation between severity of radiographic deformity and degree of gait disturbance.
d="sp0030">Major kinematic pattern deviations could be associated with (a) morphology of the proximal femur and potential femoral acetabular impingement problems and (b) leg length discrepancy. Gait analysis was able to quantify the kinematic deviations due to the anatomical deformities.