Comparison of survivorship and performance of a platform shoulder system in anatomic and reverse total shoulder arthroplasty

BACKGROUND: Contemporary studies note sustained clinical benefit and decreasing complications after reverse total shoulder arthroplasty (RTSA), which warrant a comparison with the standard anatomic total shoulder arthroplasty (ATSA). The purpose of this study is to evaluate and compare differences in midterm survivorship between ATSA and RTSA patients treated with a single platform shoulder prosthesis. Secondary objectives include a comparison of the clinical outcomes and complication profile for each procedure. METHODS: A prospective analysis of all primary ATSA and RTSA performed by 3 surgeons between 2007 and 2012 was conducted. Selection of the ATSA or RTSA implant configuration was determined by the surgeons per their clinical understanding of each individual patient's glenoid morphology, rotator cuff, and patient expectations. All 778 procedures were performed using a single platform shoulder system. RESULTS: Survivorship for ATSA was similar to that for RTSA at all time points; ATSA at 2 and 8 years was 98.5% and 96.0%, whereas RTSA at 2 and 8 years was 98.7% and 96.0%, respectively ( P= .392). All postoperative range of motion scores for ATSA patients were greater than those for RTSA patients. The overall rate of complications between the ATSA and RTSA groups was similar (6.3% vs. 4.9%, P= .414). CONCLUSIONS: On the basis of this cohort comparison, both ATSA and RTSA demonstrated similar survivorship at 8 years after surgery with multiple surgeons practicing in different countries. Our results demonstrate that the RTSA and ATSA implants have comparable results and can be expected to provide similar implant longevity over the midterm with excellent functional outcomes.