Discrimination of abnormal gait parameters due to increased femoral anteversion from other effects in cerebral palsy.

The effects of increased femoral anteversion (IFA) on gait pattern have a complex relationship with other orthopaedic and neurological abnormalities of cerebral palsy (CP). The aim of this study was to differentiate the effects of IFA from other factors in CP. The four groups in this study included: 15 typically developing children (Group: TDC) (age: 9.7 ± 0.5); 14 TDC with IFA (7.5 ± 1.7) (Group: TDC-IFA); 8 CP participants with IFA (age: 6.3 ± 1.7) (Group: CP IFA); and 10 CP participants with nearly normal femoral anteversion (age: 10.3 ± 4.7) (Group: CP-NFA). Altered peak knee-extension angle and stance-time, increased internal hip-rotation, internal foot-progression (p≤0.05) were influenced by IFA in both groups of CP-NFA and TDC-IFA. For the TDC groups; pelvic-rotation increased and peak knee and hip-extension, knee flexion-moment, peak knee-power generation in late-stance decreased among children with IFA (p≤0.05). For CP children; anterior pelvic-tilt, hip-flexion and peak knee-extension, hip power-absorbsion and generation, and peak knee power-absorsion (K3) increased and peak knee-flexion was delayed by IFA (p≤0.05). Therefore, IFA effects are different in CP and TDC. Peak knee-extension angle increased in TDC and decreased in CP with IFA. Besides the well known gait parameters related to IFA which are increased internal hip-rotation and foot-progression angle, it is recognised that peak knee-extension and stance-time are also influenced. Therefore, before muscle lengthening, femoral derotational osteotomy should be considered in the early stages of growth in CP to improve pelvic stability and the knee extensor mechanism.