Abstract and Introduction
Abstract
The indications and use of reverse total shoulder arthroplasty (rTSA) have expanded because of the significantly predictable outcomes compared with other operative procedures for similar conditions. While relatively new in the United States with long-term outcome data not yet available, the use of rTSA in Europe over the past 2 decades has resulted in better overall function and pain relief in patients with difficult to treat disorders of the shoulder that result in chronic pain and dysfunction. Originally indicated for rotator cuff arthropathy, rTSA is proving to be a viable option for other disorders, including failed total shoulder arthroplasty, proximal humeral fracture (either complicated or sequelae from), tumor resection, and other bone-loss related pathologies. The following review article discusses the biomechanics, current implant design features, surgical technique, and possible complications related to rTSA.
Introduction
Early attempts to provide pain relief and restore function to rotator cuff deficient shoulders relied on an incomplete understanding of its biomechanical functions. Neer et al. described the pathology in depth during the 1980s as cuff tear arthropathy (CTA).
Primary surgical interventions for CTA were debridement and hemiarthroplasty. These interventions did not result in restoration of normal shoulder biomechanics and were unreliable for symptom relief or improved function. The results of hemiarthroplasty were unpredictable at best given the continued superior migration and acromial acetabularization, leading to continued dysfunction and pain. Total shoulder arthroplasty (TSA) in patients with CTA also resulted in clinical failures that were caused by glenoid component loosening secondary to humeral head elevation (rocking horse phenomenon). The lack of rotator cuff function and resultant anterior or superior migration, the unpredictability of outcomes and resultant clinical failures eventually led to the first designs in reverse total shoulder arthroplasty (rTSA).