Are there biomechanical differences in repair technique for lesser tuberosity osteotomy with stemless total shoulder arthroplasty?

Background: Total shoulder arthroplasty (TSA) has evolved as a treatment for advanced shoulder osteoarthrosis, with stemless implants gaining popularity due to reduced risks of stress shielding and complications associated with stemmed designs. However, the optimal technique for repairing the subscapularis with lesser tuberosity osteotomy (LTO) during TSA remains under investigation. This study evaluates the biomechanical performance of two repair techniques-bone tunneling and suture anchors-used for LTO in the context of stemless TSA. Methods: Ten shoulders from 6 cadaveric specimens (3 males and 3 females; aged 58-93 years old) were prepared and allocated to bone tunneling or suture anchor repair groups. Cyclic loading tests were performed, followed by incremental load-to-failure protocols. Outcomes included repair gapping during cyclic loading, initial repair stiffness (derived as the average secant stiffness for 10 of the initial 3,000 cycles prior to fatigue), cycles to failure, displacement of repair, and load to failure. Results: The mean age of the cadavers used in this study was 90.2 ± 14.7 years. Mean failure load were alike, and cycles to failure nearly identical, between groups ( Conclusion: This study suggests that both techniques may yield comparable biomechanical outcomes in cadaveric models of LTO repair, which warrants further exploration. As a pilot project, this study lays the groundwork for future research that could expand upon these preliminary results and contribute to a deeper understanding of LTO repair techniques.