Cumulative surgeon volume is associated with improved outcomes following hip arthroscopy: A national registry study

PURPOSE: This study assessed the association between (1) annual and (2) cumulative surgeon volume and patient-reported outcome measures (PROMS) after hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) using data from the UK Nonarthroplasty hip registry (NAHR). METHODS: All hip arthroscopies (HAs) recorded in the UK NAHR between January 2012 and May 2023 were identified. Annual and cumulative consultant HA volume were derived for each case. International Hip Outcome Tool (iHOT)-12 and EuroQol-5 Dimensions (EQ-5D) index scores were captured preoperatively and at 6 and 12 months postoperatively. Multivariable linear regression models with restricted cubic splines were used to define associations between consultant annual and cumulative volume and outcome. The null hypothesis was that neither annual nor cumulative volume would be significantly associated with postoperative iHOT-12 or EQ-5D score change. RESULTS: A total of 3531 HAs were identified (median age 36 years [IQR: 28-44], 62.4% female) from 76 contributing consultant surgeons. Median annual consultant HA volume was 51 (IQR: 22-102), and median cumulative volume was 163 (IQR: 57-404). Cumulative consultant volume of 170 HA cases demonstrated the lowest 12-month postoperative iHOT-12 score gain (29.6 [95%CI: 27.0-32.1]) compared to a cumulative consultant HA volume of 972 cases (35.2 [95%CI 32.1-38.3]), where the score difference became significant but remained below the minimal clinically important difference (MCID). No statistically significant relationship between consultant volume and EQ-5D Index were observed. Cases where the consultant had the highest cumulative volumes were younger (35.7 vs. 37.0 years, p = 0.03) and a greater proportion underwent excision of isolated cam impingement lesions (62.2% vs. 49.3% p = 0.001), compared to cases performed by the lowest volume consultants. CONCLUSION: This study found a small but statistically significant association (below the MCID) between higher cumulative case volume and improved early functional outcome following HA. Highest-volume surgeons consistently treated younger patients with less-severe chondral damage. LEVEL OF EVIDENCE: Level III.