Assessing glenoid arthroplasty component positioning for surgeons utilizing surgical planning software

Abstract

BackgroundGlenoid component positioning remains a challenge during total shoulder arthroplasty (TSA). While preoperative three-dimensional (3D) planning software is widely available for most TSA systems today, the degree to which this software affects surgeon preoperative and intraoperative decision-making is unknown. The purpose of the study is to determine if surgeons using 3D planning software adhere to their preoperative plan and whether or not the operative plan follows glenoid component positioning guidelines for anatomic TSA (aTSA) and reverse TSA (rTSA). MethodsA total of 695 consecutive, de-identified, planned surgeries using commercially available software were identified from the case registries of six fellowship-trained shoulder arthroplasty surgeons and reviewed retrospectively. Each preoperative plan was reviewed to assess morbid glenoid version/inclination and glenoid component position. aTSA glenoid plans were evaluated for the final implant position with less than 10° of retroversion, corrective reaming less than 15°, and avoidance of glenoid vault perforation. rTSAs were evaluated for the final implant position with less than 15° of retroversion, glenosphere position in neutral or inferior tilt with at least 3 mm of inferior offset and 3 mm of posterior offset, and backside coverage of at least 50% of the baseplate on the glenoid face. Analyses were performed to determine surgeon adherence to these guidelines and variance with specific deformity patterns. Analysis of variance was performed to determine whether glenoid size resulted in selection of differing implant sizes by surgeons. The rate at which surgeon planned component size correlated with the actual implant size utilized in surgery was also evaluated. Results185 aTSAs and 510 rTSAs preoperatively planned surgeries using commercially available software were analyzed. All planning guidelines were adhered to in 90% of all aTSA cases and 79% of all rTSA cases. The concordance, or matching, between preoperative 3D planning implant selection and final implant selection was 90% for aTSA and 91% and 95% for rTSA baseplate and glenosphere implant selection, respectively. Implant size varied in accordance with glenoid size for both aTSA and rTSA (P < .001). ConclusionSurgeons adhered to known guidelines in most TSA cases when utilizing 3D computed tomography-based shoulder arthroplasty planning software. A high concordance was found between preoperative implant selection and the final glenoid component inserted. Understanding how orthopedic surgeons utilize planning software can help lead to improvements in software design.