Navigated augmented reality through a head-mounted display leads to low deviation between planned, intra- and postoperative parameters during glenoid component placement of reverse shoulder arthroplasty: a proof-of-concept case series

Abstract

BackgroundNavigated augmented reality (AR) through a head-mounted display (HMD) has led to accurate glenoid component placement in reverse shoulder arthroplasty (RSA) in an in-vitro setting. The purpose of this study is to evaluate the deviation between planned, intra-, and postoperative inclination, retroversion, entry point and depth of the glenoid component placement during RSA, assisted by navigated AR through a HMD, in a surgical setting. MethodsA prospective, multicenter study was conducted. All consecutive patients undergoing RSA in two institutions, between August 2021 and January 2023, were considered potentially eligible for inclusion in the study. Inclusion criteria were: age >18 years, surgery assisted by AR through a HMD, and postoperative computed tomography (CT) scans at six weeks. All participants agreed to participate in the study and an informed consent was provided in all cases. Preoperative CT scans were undertaken for all cases and used for three-dimensional (3D) planning. Intra-operatively, glenoid preparation and component placement were assisted by a navigated AR system through a HMD in all patients. Intraoperative parameters were recorded by the system. A postoperative CT scan was undertaken at 6 weeks, and 3D reconstruction was used for obtaining postoperative parameters. The deviation between planned, intra-, and postoperative inclination, retroversion, entry point, and depth of the glenoid component placement was calculated. Outliers were defined as >5° for inclination and retroversion and >5 mm for entry point. Results17 patients (9 females, 12 right shoulders) with a mean age of 72.8±9.1 years old (range, 47.0 to 82.0) met inclusion criteria. The mean deviation between intra- and postoperative measurements was 1.5°±1.0° (range, 0.0° to 3.0°) for inclination, 2.8°±1.5° (range, 1.0° to 4.5°) for retroversion, 1.8±1.0 mm (range, 0.7mm to 3.0mm) for entry point, and 1.9±1.9 mm (range, 0.0mm to 4.5mm) for depth. The mean deviation between planned and postoperative values was 2.5°±3.2° (range, 0.0° to 11.0°) for inclination, 3.4°±4.6° (range, 0.0° to 18.0°) for retroversion, 2.0±2.5 mm (range, 0.0° to 9.7°) for entry point, and 1.3±1.6 mm (range, 1.3mm to 4.5mm) for depth. There were no outliers between intra- and postoperative values and there were three outliers between planned and postoperative values. The mean time (minutes:seconds) for the tracker unit placement and the scapula registration was 03:02 (range, 01:48 to 04:26) and 08:16 (range, 02:09 to 17:58), respectively. ConclusionThe use of a navigated AR system through a HMD in RSA led to low deviations between planned, intra-operative and postoperative parameters for glenoid component placement.