RADIOGRAPHIC EVALUATION OF EARLY OUTCOME AFTER TWO TYPES OF CEMENTLESS HIP ARTHROPLASTY

Abstract

Introduction Total Hip Arthroplasty is one of the most common orthopaedic procedures. Its outcome is assessed by radiographic evaluation. Two principal radiographic parameters are cup inclination and stem position angle. Aim The study aimed to compare radiological outcomes of two total hip arthroplasty techniques: Alloclassic Zweymüller versus Corail Pinnacle endoprostheses. Material and methods Medical histories of 345 patients who had a hip replacement between 2007 and 2017 were reviewed. Patients with primary total hip arthroplasty with both of mentioned systems were included in the research. Seven observers individually evaluated the radiological images of the 67 endoprostheses (39 Alloclassic Zweymüller and 26 Corail Pinnacle). The cup inclination and the stem position angle were measured using MB-Ruler programme. Results There was no statistical difference (p > 0.338) in cup inclination angle between Alloclassic Zweymüller and Pinnacle cups, with the angle ranging from 31.01° to 58.80° (45.20° on average) and from 30.61° to 59.1° (43.60° on average), respectively. Femoral stem position did not differ between both types of endoprosthesis (p > 0.932), ranging from −1.05° to 7.87° (3.09° on average) for Alloclassic Zweymüller and 0.35° to 7.79° (3.06° on average) for Corail Pinnacle stem. ICC (Intraclass Coefficient Correlation) was estimated and their 95% confident intervals were calculated for cup inclination and stem position showing good reliability of cup inclination measurements. Conclusions Both types of endoprostheses presented similar radiological outcomes. Cup inclination can be used by non-experienced medical staff to reliably assess the postoperative radiograms. Keywords: cementless hip replacement, radiological outcomes, imaging.