Higher Surgeon Volume is Associated With a Lower Rate of Subsequent Revision Procedures After Total Shoulder Arthroplasty: A National Analysis

Abstract

Background Studies assessing the relationship between surgeon volume and outcomes have shown mixed results, depending on the specific procedure analyzed. This volume relationship has not been well studied in patients undergoing total shoulder arthroplasty (TSA), but it should be, because this procedure is common, expensive, and potentially morbid. Questions/purposes We performed this study to assess the association between increasing surgeon volume and decreasing rate of revision at 2 years for (1) anatomic TSA (aTSA) and (2) reverse TSA (rTSA) in the United States. Methods In this retrospective study, we used Centers for Medicare and Medicaid Services (CMS) fee-for-service inpatient and outpatient data from 2015 to 2021 to study the association between annual surgeon aTSA and rTSA volume and 2-year revision shoulder procedures after the initial surgery. The CMS database was chosen for this study because it is a national sample and can be used to follow patients over time. We included patients with Diagnosis-related Group code 483 and Current Procedural Terminology code 23472 for TSA (these codes include both aTSA and rTSA). We used International Classification of Diseases, Tenth Revision, procedural codes. Patients who underwent shoulder arthroplasty for fracture (10% [17,524 of 173,242]) were excluded. We studied the variables associated with the subsequent procedure rate through a generalized linear model, controlling for confounders such as patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, hospital size and teaching status, assuming a binomial distribution with the dependent variable being whether an episode had at least one subsequent procedure within 2 years. The regression was fitted with standard errors clustered at the hospital level, combining all TSAs and within the aTSA and rTSA groups, respectively. Hospital and surgeon yearly volumes were calculated by including all TSAs, primary procedure and subsequent, during the study period. Other hospital-level and surgeon-level characteristics were obtained through public files from the CMS. The CMS Hierarchical Condition Category risk score was controlled because it is a measure reflecting the expected future health costs for each patient based on the patient’s demographics and chronic illnesses. We then converted regression coefficients to the percentage change in the odds of having a subsequent procedure. Results After controlling for confounding variables including patient age, comorbidity risk score, surgeon and hospital volume, surgeon graduation year, and hospital size and teaching status, we found that an annual surgeon volume of ≥ 10 aTSAs was associated with a 27% decreased odds of revision within 2 years (95% confidence interval 13% to 39%; p < 0.001), while surgeon volume of ≥ 29 aTSAs was associated with a 33% decreased odds of revision within 2 years (95% CI 18% to 45%; p < 0.001) compared with a volume of fewer than four aTSAs per year. Annual surgeon volume of ≥ 29 rTSAs was associated with a 26% decreased odds of revision within 2 years (95% CI 9% to 39%; p < 0.001). Conclusion Surgeons should consider modalities such as virtual planning software, templating, or enhanced surgeon training to aid lower-volume surgeons who perform aTSA and rTSA. More research is needed to assess the value of these modalities and their relationship with the rates of subsequent revision. Level of Evidence Level III, therapeutic study.

CORR Insights®: Higher Surgeon Volume is Associated With a Lower Rate of Subsequent Revision Procedures After Total Shoulder Arthroplasty: A National Analysis

“…The study by Best et al [1] in this month’s Clinical Orthopaedics and Related Research ® adds support to the growing body of evidence demonstrating that the outcomes of orthopaedic surgical procedures depend, in part, on the annual volume of the specific procedure performed by the surgeon. It has been well documented and is now widely recognized that higher surgical volume correlates with fewer complications, lower costs, and less-frequent revisions after hip and knee arthroplasty [2-5].…”

“…The relationship between the volume of shoulder arthroplasty performed and the outcomes of the procedure (including revisions) requires continued study to enhance our understanding of the factors involved. Because this study [1] included only Medicare fee-for-service patients, expanding the study to all patients undergoing arthroplasty will be important to confirm the findings of this study.…”

“…The decreased odds of revisions for both procedures are based on a comparison with surgeons who performed fewer than four per year. The authors [1] did not find an association between the hospital volume and odds of a revision procedure.…”

“…This is a rapidly expanding area of orthopaedic surgery, and the goal should be to use the data to improve patient outcomes. Best et al [1] are sending a clear message to our specialty that TSA needs to move into the mainstream of orthopaedic practice and training so it is performed with the same expertise and anticipated outcomes as primary hip and knee arthroplasty. Although Best et al [1] reported a threshold of 10 procedures for anatomic TSA and 29 for reverse TSA, the goal must be to drive those numbers down, and the way to achieve that goal is through training, education, and experience.…”

“…One possible next step based on this study could be to divert shoulder arthroplasties to a smaller number of surgeons whose volumes are high enough to achieve the kinds of reductions in complications observed in this study [1]. The authors suggest that the volume-revision relationship shown may support “programs such as employer healthcare plans that partner with high-volume centers of excellence.” However, this is not practical, nor is it a long-term plan.…”