The reliability of the anterior pelvic plane for computer navigated acetabular component placement during total hip arthroplasty: Prospective study with the EOS imaging system - 14/08/14

Doi : 10.1016/j.otsr.2014.07.003

O. Barbier ^a,^b,^c,^⁎ , W. Skalli ^b, L. Mainard ^d, D. Mainard ^a
Computer Assisted Orthopedic Surgery–France (CAOS-France)Professeur E. Stindel, service orthopédie traumatologie, CHU de Brest, hôpital de la Cavale-Blanche, boulevard Tanguy-Prigent, 29609 Brest cedex, France
^a Service de chirurgie orthopédique, hôpital central, 29, avenue de Lattre-de-Tassigny, 54000 Nancy, France
^b Laboratoire de biomécanique, école nationale supérieure des arts et métiers Paris tech, boulevard de l’Hôpital, 75013 Paris, France
^c Service de chirurgie orthopédique, hôpital d’instruction des Armées-Bégin, 69, avenue de Paris, 94160 Saint-Mandé, France
^d Service de radiologie, hôpital Brabois, rue du Morvan, 54511 Vandœuvre-lès-Nancy, France

^⁎Corresponding author.

connectez-vous ou créez un compte

Bienvenue sur EM-consulte, la référence des professionnels de santé.
Article gratuit.

Connectez-vous pour en bénéficier!

Sous presse. Épreuves corrigées par l'auteur. Disponible en ligne depuis le Thursday 14 August 2014
Cet article a été publié dans un numéro de la revue, cliquez ici pour y accéder

Abstract

Introduction

Computer navigated total hip arthroplasty is mostly based on the use of the anterior pelvic plane (APP) as a reference. EOS is a new imaging system that provides three-dimensional analysis of the pelvis in a functional position with a low dose of radiation. The aim of this study was to evaluate the reliability of the APP for placement of the cup during computer navigated THA using EOS.

Hypothesis

The reliability of the APP is limited for the placement of the acetabular cup during computer navigated THA.

Materials and methods

This was a prospective monocentric study using the EOS imaging system evaluating 44 patients in the standing position three months after computer navigated THA (Orthopilot™). Reproducibility of EOS measurements were analyzed using SterEOS software and the reliability of the navigation data for the position of the cup were assessed.

Results

Intra and interobserver reproducibility of the measurements of the orientation of the cup by EOS were good with correlation coefficients above 93% and 95% and confidence intervals of less than±5°. Mean cup inclination and anteversion were 41.3° and 20.9° and 44.3° and 29.5° respectively in operatively and post-operatively. The differences between measurements of operative cup inclination using computer assisted navigation and the post-operative EOS measurements were significant (P<0.05) with a correlation coefficient of less than 40%.

Discussion

Our study confirms the lack of precision of the APP as a reference for positioning of the acetabular component, especially in relation to anteversion. Although for many years the APP was considered to be a global reference, in fact, it is subject to significant inter-individual variations and variations during changes in position. These factors, associated with the difficulty of determining the preoperative APP, explain the lack of reliability of this reference. Preoperative evaluation of the orientation of APP by EOS and its integration into the navigation system could help the operator position these components.