RADIOGRAPHIC COMPARISON OF CEMENTED AND UNCEMENTED TOTAL HIP ARTHROPLASTY AND HIP RESURFACING

Abstract

Introduction: The technology available for replacing/resurfacing the hip is constantly evolving. The surgeon can now choose from a wide array of componenets to perform a cemented, hybrid, uncemented total hip arthroplasty (THA) or resurfacing arthroplasty (RSA). The aim of our study was to evaluate and compare the restoration of hip biomechanics following insertion of three different, commonly used constructs.

Methods: We compared the pre and postoperative radiographs from 40 patients who underwent cemented THA, 45 patients who underwent uncemented THA and 40 who underwent RSA. The femoral offset and limb length differences were measured, with reference to the normal contralateral hip.

Results: Resurfacing resulted in a significant reduction in femoral offset, with accurate restoration of limb length. Both cemented and uncemented THA resulted in a significant increase in femoral offset and leg length. Uncemented THA resulted in the greatest degree of leg lengthening.

Discusssion: Restoration of normal hip anatomy optimises biomechanical function and reduces wear of components. The RSA group had the most accurate restoration compared to the two other groups. The reduced femoral offset associated with the RSA group may reduce the lever arm of the abductor muscles however this is unlikely to be clinically important.