Comparison of Lateralized RTSA With and Without Subscapularis Repair

Inclusion Criteria: * Clinical diagnosis of glenohumeral arthritis, rotator cuff arthropathy, or massive irreparable rotator cuff tear with surgeon-patient decision to undergo RTSA * First RTSA implantation * Absence of neoplastic diseases at the treated site * Fatty infiltration of the subscapularis is low-grade (i.e. Goutallier \< Grade 3) based on pre-operative CT performed as standard of care in the patient group Exclusion Criteria: * Previous shoulder arthroplasty (hemi-, total shoulder, or RTSA) * Avascular necrosis * Post-infectious arthritis * Proximal humerus fracture * Inflammatory arthritis * Inability to communicate in English * Unable to return for study visits to 24-months post-operative (e.g. unable to arrange transportation to study appointments, plans to relocate, etc.) Intra-operative Exclusions: * Subscapularis with fatty infiltration (Goutallier ≥ 3) * Subscapularis that is deemed to be irreparable. An irreparable tendon is defined as one that is not of sufficient quality or does not allow adequate excursion to reach the repair site * Any anatomical or patient characteristic that warrants a non-lateralized implant