Outcomes of Total Hip Arthroplasty Based on Surgeon Fellowship and Case Volume.

Abstract

Total hip arthroplasty (THA) is a highly successful procedure performed by orthopaedic surgeons of various fellowship training, case volumes, and practice types. This study aimed to compare postoperative outcomes between fellowship-trained (FT) arthroplasty and non-arthroplasty surgeons, stratified by low, intermediate, and high case volume. Outcomes were collected for up to two years postoperatively: 1) mechanical complications (dislocation, aseptic loosening, and periprosthetic fracture (PPFX)), 2) infectious complications (periprosthetic joint infection (PJI) and surgical site infection (SSI)), 3) aseptic revision, and 4) venous thromboembolism (VTE). We retrospectively queried a national all-payer database to identify 457,372 patients who had primary THA between 2010 and 2021. Using National Provider Identifiers, the number of surgeons was categorized by fellowship training (arthroplasty versus non-arthroplasty) and stratified by total case volume during the study period (high, intermediate, and low). Propensity score matching was performed with the respective FT group as the basis of comparison. High-volume FT surgeons demonstrated lower hip dislocation rates compared with all NFT cohorts at 90 days (0.8 versus 0.9 to 1.2%), one year (1.1 versus 1.2 to 1.5%), and two years (1.2 versus 1.3 to 1.7%) (all P < 0.001). High-volume FT surgeons also had lower aseptic revision rates up to two years (all P < 0.05) and lower PJI rates at two years (P = 0.008). There were no differences observed in PPFX, SSI, VTE, or aseptic loosening. Intermediate- and low-volume FT surgeons similarly demonstrated reduced dislocation rates compared with NFT surgeons, though other complications were comparable (all P > 0.05). There were no NFT surgeon volume threshold achieved outcomes equivalent to high volume FT surgeons. Postoperative THA outcomes were optimized by the combined effects of fellowship training and high surgical volume, underscoring the importance of experience in addition to formal subspecialty training.