Hip flexion deformity is an adverse prognostic factor for the evolution of gait in patients with myelomeningocele. In high level lesions (thoracic and upper lumbar), it prevents proper orthotic use. In low level lesions (lower lumbar), hip flexion deformity produces anterior pelvic tilt and hyperlordosis with foward flexion during gait, a eventually low back pain. A series of 14 hips in 8 patients were operated. Hip flexion deformity (Thomas lest): mean 34° (from 20° to 60°). Femorosacral angle (Bleck): mean -30° (from -12° to -45°). Lumbar lordosis (Cobb): mean 87°. The fixator is placed using 4 pins, with the fixatior joints al 0°, a percutaneous osteotomy is performed, complete correction is done at the time of surgery, angulating the fixator''s A-P joint, then the fixator''s joints are fixed. Consolidation occured at (mean) 85 days (from 63 to 87). Follow up: mean 14 months (from 4 to 48). Hip flexion deformity: pre-surgery 34°; post-surgery 8°. Lumbar lordosis: pre-surgery 87°; post-surgery 75°. Minor complications occured such as pin tract infection and one case of pin loosening. Hip extension subtrocanteric osteotomy corrects the deformity without damage of useful hip flexors. The advantages of external fixation vs internal fixation are: minimal surgical invasion, inmediate weight bearing (avoids post-inmovilization osteoporosis). Allows corrections post-surgery if needed, no need of second surgical procedure under general anesthesia for hardware removal.

Hip flexion deformity is an adverse prognostic factor for the evolution of gait in patients with myelomeningocele. In high level lesions (thoracic and upper lumbar), it prevents proper orthotic use. In low level lesions (lower lumbar), hip flexion deformity produces anterior pelvic tilt and hyperlordosis with foward flexion during gait, a eventually low back pain. A series of 14 hips in 8 patients were operated. Hip flexion deformity (Thomas lest): mean 34° (from 20° to 60°). Femorosacral angle (Bleck): mean -30° (from -12° to -45°). Lumbar lordosis (Cobb): mean 87°. The fixator is placed using 4 pins, with the fixatior joints al 0°, a percutaneous osteotomy is performed, complete correction is done at the time of surgery, angulating the fixator''s A-P joint, then the fixator''s joints are fixed. Consolidation occured at (mean) 85 days (from 63 to 87). Follow up: mean 14 months (from 4 to 48). Hip flexion deformity: pre-surgery 34°; post-surgery 8°. Lumbar lordosis: pre-surgery 87°; post-surgery 75°. Minor complications occured such as pin tract infection and one case of pin loosening. Hip extension subtrocanteric osteotomy corrects the deformity without damage of useful hip flexors. The advantages of external fixation vs internal fixation are: minimal surgical invasion, inmediate weight bearing (avoids post-inmovilization osteoporosis). Allows corrections post-surgery if needed, no need of second surgical procedure under general anesthesia for hardware removal.