Patient-specific instrumentation vs. a free-hand technique for glenoid baseplate and peripheral screw placement in reverse total shoulder arthroplasty using the Exactech implant system: a multicenter randomized controlled trial.

Study Summary

106 undergoing primary reverse total shoulder arthroplasty (rTSA) were randomized to patient-specific instrumentation (PSI)-assisted surgery or a free-hand technique. The primary outcome was the proportion of patients with postoperative computed tomography-based deviation errors in glenoid baseplate version, inclination, or positional offset relative to the preoperative plan. Secondary outcomes included continuous baseplate deviation measurements and peripheral screw accuracy based on anteroposterior gap, superoinferior gap, and screw-length gap. Outcomes were assessed using postoperative computed tomography. Overall, the results revealed no significant differences in glenoid baseplate version, inclination, or positional offset between the groups. However, PSI improved selected measures of anterior, superior, and inferior peripheral screw placement, suggesting that PSI may enhance screw trajectory accuracy without improving overall baseplate positioning.