The Effect of Surgeon Volume on Complications Following Total Shoulder Arthroplasty: A Nationwide Assessment.

Background: Increased surgeon volume has been demonstrated to correlate with improved outcomes after orthopedic surgery. However, there is a lack of data demonstrating the effect of surgeon volume on outcomes after total shoulder arthroplasty.

Methods: The PearlDiver Mariner database was retrospectively queried from the years 2010-2022. Patients undergoing shoulder arthroplasty were selected using the CPT code 23472 (Total Shoulder Arthroplasty). Patients under 40 years of age, those undergoing revision arthroplasty and cases of bilateral arthroplasty were excluded. Additionally, cases with a history of fracture, infection, or malignancy prior to surgery were excluded. Only surgeons who performed a minimum of 10 cases were selected and PearlDiver was queried using their provider ID codes. Primary outcome measures included 90 day, 1-year, and 2-year rates of complication and reoperation. A Bonferroni correction was utilized in which the significance threshold was set at p≤0.00082 RESULTS: A total of 155,560 patients met inclusion criteria and were retained for analysis. The 90^th percentile for surgeon volume was determined to be 112 cases during the study period. Surgeons above the 90^th percentile (n=340) operated on 68,531 patients whereas surgeons below the 90^th percentile (n=3,038) operated on 87,029 patients. Surgeons in the high-volume group were significantly more likely to have completed a Shoulder and Elbow fellowship (p<0.001) and less likely to have no fellowship training or fellowship training outside of Shoulder and Elbow or Sports Medicine (p<0.001). Low-volume surgeons operated on patients with higher baseline comorbidities (CCI: 2.01 vs 1.85, p<0.001). After adjusting for age, gender, CCI, obesity, and tobacco use, high-volume surgeons experienced lower rates of medical complications including renal failure (p<0.001), anemia (p<0.001), and UTI (p<0.001). All cause readmission (0.90, p<0.001), reoperation at 90 days (OR 0.75, p<0.001) and reoperation at 1 year (OR: 0.86, p<0.001) were significantly lower among high-volume surgeons. High-volume surgeons exhibited lower rates of various complications including prosthetic joint infection (90d: p<0.001; 1yr: p<0.001; 2yr: p<0.001), periprosthetic fracture (90d: p<0.001; 1yr: p<0.001; 2yr: p<0.001) and all complications (90d: p<0.001; 1yr: p<0.001).

Conclusion: Surgeons who perform a high volume of total shoulder arthroplasty are more likely to operate on healthier patients than surgeons who perform a lower volume of cases. When compared to low-volume surgeons, and after adjusting for age, gender, and CCI, high-volume surgeons have a significantly lower overall complication rate. Despite this lower complication rate, high-volume surgeons are responsible for a decreasing portion of shoulder arthroplasty since 2016.