The role of glenoid version in arthroplasty

Glenoid retroversion is considered a mechanical risk factor for failure of shoulder arthroplasty, often leading to preemptive version correction. However, the necessity of routine retroversion correction in anatomic total shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (rTSA) remains unclear. This review assesses the impact of glenoid retroversion, posterior subluxation, and superior inclination on implant performance, implant survivorship, and patient outcomes. A narrative review of clinical and biomechanical studies was performed, focusing on retroversion correction, subluxation, superior inclination, and their influence on outcomes in aTSA and rTSA. Key studies addressing minimal or noncorrective reaming, augmented implants, and reverse arthroplasty were synthesized. In aTSA, residual retroversion up to 15° does not consistently affect short- or mid-term outcomes when glenoid seating is adequate. Posterior subluxation and poor initial component fixation are stronger predictors of adverse outcomes than retroversion alone. In rTSA, moderate retroversion between 10° and 20° does not compromise stability or functional outcomes, and correction is typically performed only to optimize fixation. In aTSA, excessive superior inclination increases the risk of humeral head migration, rotator cuff strain, and glenoid loosening. Furthermore, unwarranted version correction may introduce complications such as bone loss, graft resorption, or peg perforation without clear clinical benefit. Current evidence suggests that correction of glenoid retroversion to less than 15° is unnecessary in both aTSA and rTSA. Implant stability, component seating, and soft-tissue balance are more critical for successful outcomes. Surgical strategies should be individualized, prioritizing fixation quality and load distribution over strict anatomic restoration. In cases of severe retroversion greater than 30° with contracture or severe posterior subluxation, rTSA may be preferable, while substantial retroversion with preserved kinematics can often be managed with a fully seated anatomic implant.