Biomechanical analysis of hip function after Chiari pelvic osteotomy.

The reasons are discussed for differences in functional results of the pelvic osteotomy after Chiari, regardless of the fact that the CE and AC angles were equal in all patients. When lateralization and distal displacement of the greater trochanter were performed in addition to the pelvic osteotomy, the functional results proved to be better. Biomechanical analysis of the relationship between gluteal force and body weight revealed that these relations change; in all examined cases where lateralization and distal displacement of the greater trochanter were performed, the relationship proved postoperatively to be considerably more favorable. In the same group of patients, the relationship between the force of reaction and body weight was also changed after surgery. Therefore, lateralization and distal displacement of the greater trochanter are important factors for the undisturbed functioning of a hip; in all examined patients the functional results were better when lateralization and distal displacement of the greater trochanter were performed.