Functional evaluation of flail hip joint after periacetabular resection of the pelvis.

Five patients subjected to flail hip joint after resection of primary bone tumor of the pelvis involving acetabular region were examined with respect to function. When a thick portion of the supraacetabular pelvic neck was left in place, the operated legs functioned well regardless of whether the head of the femur was placed anterior or posterior to the iliac wing. In a patient who had only a thin portion of the iliac wing left in place and in those who underwent total excision of the ilium or hemiresection of the pelvis, the function of operated legs was poorer than with a thick portion of the supraacetabular pelvic neck left in place, but still more than 50% of leg function remained. Although flail hip joint results in a larger leg-length discrepancy than do other techniques, it enables favorable healing of the operative wound. Therefore, this method should be considered for women or sedentary patients with primary bone tumor of the pelvis involving acetabular region.