Vol.:(0123456789) 1 3 European Journal of Orthopaedic Surgery & Traumatology https://doi.org/10.1007/s00590-018-2133-y ORIGINAL ARTICLE • HIP - NAVIGATION A new system of computer‑assisted navigation leading to reduction in operating time in uncemented total hip replacement in a matched population Fouad A. Chaudhry 1  · Sanaa Z. Ismail 1  · Edward T. Davis 1 Received: 26 September 2017 / Accepted: 7 January 2018 © Springer-Verlag France SAS, part of Springer Nature 2018 Abstract Computer-assisted navigation techniques are used to optimise component placement and alignment in total hip replacement. It has developed in the last 10 years but despite its advantages only 0.3% of all total hip replacements in England and Wales are done using computer navigation. One of the reasons for this is that computer-assisted technology increases operative time. A new method of pelvic registration has been developed without the need to register the anterior pelvic plane (BrainLab hip 6.0) which has shown to improve the accuracy of THR. The purpose of this study was to fnd out if the new method reduces the operating time. This was a retrospective analysis of comparing operating time in computer navigated primary uncemented total hip replacement using two methods of registration. Group 1 included 128 cases that were performed using BrainLab versions 2.1-5.1. This version relied on the acquisition of the anterior pelvic plane for registration. Group 2 included 128 cases that were performed using the newest navigation software, BrainLab hip 6.0 (registration possible with the patient in the lateral decubitus position). The operating time was 65.79 (40–98) minutes using the old method of registration and was 50.87 (33–74) minutes using the new method of registration. This diference was statistically signifcant. The body mass index (BMI) was comparable in both groups. The study supports the use of new method of registration in improving the operating time in computer navigated primary uncemented total hip replacements. Keywords Computer-assisted navigation · Uncemented total hip replacement · Operating time Introduction Computer-assisted navigation techniques are used to opti- mise component placement and alignment in total hip replacement (THR) [1]. It has been shown that poor cup positioning is associated with increased rate of dislocation, impingement, pelvic osteolysis, accelerated polyethylene wear, component loosening and migration [2–5]. Ran- domised controlled studies and meta-analysis have shown that computer navigation improves component positioning in hip replacement [6–10] and reduces dislocation rates [7]. It has developed in the last 10 years to improve compo- nent positioning, but despite this only 0.3% of all total hip replacements in England and Wales are done using computer navigation [11]. One of the reasons for this is that computer-assisted tech- nology for THR increases operative time [8]. However, as the technology is advancing, new systems of navigation are being used which can potentially improve upon this. The development of a new registration methodology that elimi- nates the need for the acquisition of the anterior pelvic plane has recently been shown to improve the accuracy of compo- nent orientation [12]. The aim of this study was to determine whether there is a signifcant diference in operative time between the old and new navigation registration techniques. The null hypothesis was that there is no diference in the operating time in pri- mary uncemented hip replacement using the new computer navigated registration technique. * Fouad A. Chaudhry fouad.chaudhry@doctors.org.uk 1 Department of Trauma and Orthopaedics Surgery, Russells Hall Hospital, Dudley, UK