Glenoid vault perforation in total shoulder arthroplasty: Do we need computer guidance?

The proliferation of computer 3D simulation and computer-generated guides is aimed at minimizing perforation of the glenoid vault by glenoid pegs in shoulder arthroplasty, based on assumptions that perforation leads to worse outcomes by component loosening and potential failure. We evaluated outcomes of glenoid peg perforation testing the assumption that perforation produces worse results. Eighty-three shoulders underwent shoulder arthroplasty with pegged hybrid fixation (bone-ingrowth flanged central glenoid peg and peripheral cemented pegs) without precision signal injector guides or use of 3D planning software. Outcomes were determined by American Shoulder and Elbow Score and Oxford Shoulder Score. Fine slice CT determined the presence of vault perforation and the extent of lucent lines at the prosthesis-bone interface and bony morphology of the vault perforation. Follow-up was 46.7 months (24-99). Seven shoulders (8%) demonstrated perforation of glenoid vault. Bony ingrowth and cortical overgrowth occurred despite perforation, with no clinically significant differences in clinical or radiological outcomes in shoulders with and without glenoid vault perforation. None of these patients underwent revision surgery. Despite not utilizing computer planning and/or guides, 92% of implants did not perforate the glenoid vault. However, glenoid vault perforation in our series produced excellent outcomes with no increased risk of revision as a result of glenoid vault perforation.