Comparative analysis of CT-based and 2D digital templating in robotic hip arthroplasty.

Abstract

Preoperative templating in Total Hip Arthroplasty (THA) is an essential tool in arthroplasty surgery. This study investigates the efficacy of CT-based templating in robotic total hip arthroplasty (rTHA) compared to traditional 2D digital x-ray templating and evaluates intra-observer variability among 3 arthroplasty consultants. A total of 37 patients scheduled for primary hybrid rTHA using the Mako robot (Stryker) were included in the study. Independent, 2D digital templating (Materialise Orthoview) was performed by 3 experienced orthopaedic arthroplasty consultants, and the results were compared with a CT templating system (Stryker) and the postoperative implant size after CT based rTHA. Intra-observer reliability among the surgeons was determined using Fleiss' Kappa, individual surgeons were compared to the CT-templating system and the postoperative implant using Cohen's Kappa. Intra-observer reliability among surgeons was low, with significant variability and no variable showing strong agreement. 2D digital templating demonstrated poor predictive value for the post-operative implant size. There was considerable variance between surgeons and their agreement with the CT demonstrated superior predictive values for the postoperative implants as compared to the 2D digital templating technique. This study suggests that the predictive value of the CT templating system was superior to that of surgeon based 2D digital templating for CT templating based rTHA.