Comparing Short-Term Radiographic Outcomes of Cementless Primary Reverse Total Shoulder Arthroplasty Implantation With and Without Augmentation by Humeral Matchstick Autograft: A Retrospective Cohort Study

Reverse Total Shoulder Arthroplasty (RTSA) is an arthroplasty procedure that is increasing in incidence in the United States (26). As the incidence of the procedure increases, the gross number of RTSA complications is also expected to increase. Humeral-sided complications, accounting for up to 21% of RTSA complications requiring revision surgery, are associated with progressive humeral bone loss (10, 28). This bone loss can be explained by Wolff's law, which states that bone will adapt according to the amount of stress placed upon it (6, 27). Per Wolff's law, having a large, stiff humeral construct will lead to humeral adaptations and implant-induced osteopenia, a phenomenon called stress shielding (5, 6). Studies by Raiss et al., have suggested that lowering the size of the humeral implant in relation to the humeral metaphysis of patients can lower the incidence of stress shielding (7-9). Surgeons at The Shoulder Center at Baylor University Medical Center in Dallas, Texas, inspired by Raiss et al., have developed and implemented a new matchstick autografting procedure to reduce the size of humeral implants and combat the risk of stress shielding. This study seeks to evaluate whether the recommendations and results of Raiss et al. hold true with regards to the new matchstick RTSA procedures as well as traditional RTSA procedures performed by surgeons at The Shoulder Center (9).