Contrasts in gait mechanics of individuals with proximal femoral focal deficiency: Syme amputation versus Van Nes rotational osteotomy

Lower-limb kinematics and kinetics during preferred and fast speeds of walk ing were measured in persons with proximal femoral focal deficiency to comp are outcomes after Syme amputation (nine subjects) with those after Van Nes rotational osteotomy (10 subjects). Subjects with a Van Nes rotational ost eotomy and full tibial rotation (seven subjects) demonstrated prosthetic kn ee function during stance as they were able to support a flexed-knee postur e at both speeds and produced greater knee-extensor moments at preferred sp eeds as compared with the Syme group (p < 0.05). Nonprosthetic limb compens atory mechanics were significantly exacerbated in subjects with a Syme ampu tation compared with the Van Nea group: (a) stance-phase vaulting, resultin g in greater inappropriate ankle-power generation at both walking speeds, ( b) excessive hip-extensor moments at fast speeds, (c) excessive hip-power a bsorption and generation at both speeds, and (d) excessive knee-joint power generation at bath speeds (p < 0.05). The improved gait after Van Nes rota tional osteotomy is one factor that should be considered when making clinic al decisions for children with proximal femoral focal deficiency.