Glenoid component implantation accuracy using a novel handheld computer targeting system in total shoulder...

The importance of glenoid component positioning in total shoulder arthroplasty (TSA) is increasingly being recognized. Several technologies have been developed to help surgeons accurately replicate their pre-operative plan; however, adoption of these technologies is limited by cost, implant specificity, lack of intraoperative flexibility, and added operating room time. Herein, we evaluate the accuracy of a novel, implant-agnostic, reusable handheld computer targeting system that assists surgeons in placing a central K-wire during TSA using an in vitro cadaveric model.

A cadaveric study was performed wherein 11 matched pairs of fresh-frozen upper torsos (22 shoulders) underwent either anatomic or reverse TSA by 1 of 4 fellowship-trained surgeons. After pre-operative planning and a standard deltopectoral approach, surgeons registered the Computerized Operating Room Experience (CORE) Shoulder system (LinkBio Corp, NJ, USA) to the patients' glenoid. Surgeons then used the wireless handheld device to place the K-wire guided by on-screen targeting cues. Custom anatomic and reverse TSA glenoid test components with metal trackers were subsequently implanted with the retained K-wire, and specimens underwent computed tomography scanning to enable digital comparison to the pre-operative plan. Per convention, a component was considered malpositioned when version or inclination errors exceeded 10° or component displacement exceeded 4 mm. Time from the start of CORE Shoulder glenoid registration to K-wire drilling was calculated from video recordings.

K-wires were accurately positioned in 91% of cases. The mean displacement from the pre-operative plan was 2.1 ± 1.1 mm, and the mean version and inclination errors were 2.2 ± 1.4° and 4.3 ± 4.1°, respectively. Glenoid components were accurately positioned in 95% of cases. The mean displacement from the pre-operative plan was 1.9 ± 1.0 mm, and the mean version and inclination errors were 2.5 ± 1.9° and 3.9 ± 3.1°, respectively. The mean intraoperative time from registration to start of K-wire drilling was 79 ± 24 seconds (range, 44 seconds to 126 seconds). In 95% of cases, registration of the CORE Shoulder device and drilling took less than 2 minutes.

Use of a novel, implant-agnostic, reusable handheld computer targeting system to guide K-wire drilling during in vitro anatomic and reverse TSA enabled surgeons to accurately replicate their pre-operative plan in 95% of cases. The use of the CORE Shoulder system added an average of 79 seconds to the procedure (<2 minutes in 95% of cases), supporting its promise in improving surgeon accuracy with minimal added cost and preserved operating room efficiency.