Influence of Pelvic Tilt on Polyethylene Wear after Total Hip Arthroplasty.

Taro Tezuka,Naomi Kobayashi,So Kubota,Masaki Kawamura,Tomoyuki Saito,Yutaka Inaba,Hiroyuki Ike

doi:10.1155/2015/327217

Abstract

We aimed to evaluate the effects of pelvic tilt on polyethylene wear after total hip arthroplasty (THA). A total of 105 joints treated with primary THA were included; conventional polyethylene (CPE) liners were used in 43 hips and highly cross-linked polyethylene (HXLPE) liners were used in the remaining 62 hips. The pelvis was tilted 6° posteriorly in the standing position as compared to the supine position, which resulted in significant increases of 1.7° and 2.8° in cup inclination in the CPE and HXLPE groups, respectively. Moreover, the change in pelvic tilt resulted in significant increases of 3.6° and 4.9° in cup anteversion in the CPE and HXLPE groups, respectively. For the CPE group, multiple regression analysis showed a significant association between the angle of pelvic tilt (PTA) and cup inclination and the polyethylene wear ratio. The adjusted R 2 of the regression model was larger for measures obtained in the standing position as compared to the supine position. For the HXLPE group, there was no significant relationship between radiographic parameters and polyethylene wear. Close observation of polyethylene wear is recommended for patients with severe posterior pelvic tilt who have undergone THA with conventional polyethylene.

Highlights

Inclination and anteversion of the cup in total hip arthroplasty (THA) affect clinical outcomes, including postoperative hip joint range of motion, risk of postoperative dislocation, and increased polyethylene wear, which can lead to osteolysis around the implant and cause loosening [1,2,3].An increase in the posterior tilt position of the pelvis after THA has recently been reported [4, 5]
From the supine to standing positions, the cup inclination changed from 40.2 ± 6.7∘ to 41.9 ± 7.1∘ (p < 0.01), and cup anteversion changed from 14.6 ± 5.5∘ to 18.2 ± 6.3∘ (p < 0.01)
From the supine to standing positions, the cup inclination increased from 41.6 ± 6.6∘ to 44.4 ± 6.5∘, and cup anteversion increased from 20.0 ± 8.8∘ to 24.9 ± 9.7∘, indicating a significant increase in the values from the standing position to the supine position (p < 0.01, p < 0.01) (Table 1)

Summary

Introduction

An increase in the posterior tilt position of the pelvis after THA has recently been reported [4, 5]. A number of studies have investigated the relationship between pelvic tilt and the angle of the cup of the THA [6,7,8]. The specific relationship between pelvic tilt and polyethylene wear has not been investigated. The first was to quantify pelvic tilt after THA in the supine and standing positions and to evaluate the relationship of postural change in pelvic tilt with the angle of the cup.

Objectives

Methods

Results

Conclusion