Establishing maximal medical improvement following aseptic revision of shoulder arthroplasty.

Abstract

Shoulder arthroplasty surgery volume continues to increase yearly. As the prevalence of shoulder replacement continues to rise, there will be a growing number of revision surgeries performed for a variety of indications. Understanding patient outcomes and recovery time following these procedures is critical, particularly as it relates to revision surgery, which generally has worse outcomes and longevity than primary arthroplasty. The point at which the peak of potential improvement is reached can be defined as the point of maximal medical improvement (MMI). The timing to MMI has previously been reported in the literature following both primary anatomic and reverse total shoulder arthroplasty. However, to our knowledge, timing to MMI following revision shoulder arthroplasty has not been defined. The purpose of the present study, therefore, is to establish the time to MMI following aseptic revision shoulder arthroplasty using validated patient-reported outcome measures. A retrospective cohort study was conducted following patients who underwent aseptic revision shoulder arthroplasty over a defined 3-year period. Multiple fellowship-trained shoulder and elbow surgeons from a single institution performed all operations. Those with at least 24 months of follow-up and multiple time points of postoperative patient-reported outcome scores were included in the analysis. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores and Single Assessment Numeric Evaluation (SANE) scores were prospectively recorded and followed over time. Exclusion criteria included revision surgeries done for infection, staged procedures following infection, and revision for periprosthetic fracture. Twenty-two patients met inclusion criteria. The mean preoperative ASES and SANE scores were 41.8 and 30.5, respectively. There was a trend toward improvement in both the ASES and SANE scores through the 6-9-month postoperative follow-up point, at which point clinically significant improvement was achieved, with mean values of, respectively, 76.9 and 81.2. No further improvement was achieved 9 months after surgery, although scores were generally maintained through an average final follow-up of 30 months, with final ASES and SANE scores of 70.1 and 67.8, respectively. Following aseptic revision shoulder arthroplasty, clinically significant improvements in patient-reported outcome scores are seen up to 9 months postoperatively, the point at which MMI is achieved. These findings serve to guide clinicians in counseling patients regarding their expected postoperative recovery following revision shoulder arthroplasty.