Anatomic and physiologic rationale for various technologies for primary total hip arthroplasty.

A number of patients have anatomic or physiologic variations that may adversely affect the performance of a primary total hip arthroplasty. Various technologies have been utilized in an attempt to improve the outcomes for these patients; however, some of these potential solutions are controversial. The authors examined the complete body of literature for scientific evidence regarding the use of these new technologies. The anatomic and physiologic anomalies that were studied include extra-articular deformities, developmental dysplasia, Perthes disease, Type C femoral bone, acetabular bone deficiency, femoral rotational abnormalities, variations that increase the risk of hip dislocation, sickle cell anemia, and extremely small or large bone sizes. This article presents the current scientific evidence and imparts an unbiased view of the use of various technologies to provide individualized solutions for patients who have anatomic or physiologic variations.