Pelvic osteotomy techniques and comparative effects on biomechanics of the hip: a kinematic study.

Dysplasia of the hip is characterized by malpositioning of the proximal femur in a shallow acetabulum, providing deficient femoral head coverage. This abnormal relationship leads to altered biomechanics of the hip joint, as predicted by measurement of kinematic parameters such as increased load over reduced acetabular weight-bearing area, leading to increased joint contact stresses, which subsequently results in secondary osteoarthrosis, pain, and disability. To prevent these sequelae, particularly in children and younger adults, various osteotomies have been performed with varying degrees of success. The goal of this study was to devise a simple and reproducible laboratory method to perform a kinematic analysis of the individual and comparative effects of 5 commonly performed pelvic osteotomy techniques: Chiari pelvic osteotomy, Salter innominate bone wedge osteotomy, Steel triple pelvic osteotomy, Tönnis triple pelvic osteotomy, and Ganz periacetabular pelvic osteotomy. The aim was to determine which of the osteotomy techniques caused greater correction in most of the kinematic parameters used to estimate changes in the biomechanics of the hip joint. Our hypothesis was that pelvic osteotomies such as Chiari and Salter produced favorable changes and were relatively easily reproducible, but that more biomechanical correction in all planes would be achieved by the relatively more complex triple innominate bone and Ganz osteotomy.