Anterolateral compared to posterior approach in total hip arthroplasty: differences in component positioning, hip strength, and hip motion.

In order to identify the functional advantages or disadvantages between the anterolateral and the posterior approaches to total hip arthroplasty, measurements of prosthetic position, hip-muscle strength, and hip joint mobility were made after Müller total hip arthroplasty without osteotomy in 52 patents operated through a posterior approach and 41 patients operated through an anterolateral approach. Men and women who had the posterior approach had less prosthetic component anteversion and longer neck lengths, with resultant more lateral and distal placement of the greater trochanter than groups with the anterolateral approach. Groups with the posterior approach had more normal hip abductor-muscle strength and more inward rotation on the operated side than group with the anterolateral approach. Groups with the anterolateral approach had more outward rotation on the operated side than groups with the posterior approach. These differences in function were related to the surgical approach rather than to differences in component position. An understanding of these observations should be used for selection of the surgical approach for the patient on an individual basis.