EARLY FAILURES OF ELECTIVE PRIMARY TOTAL HIP REPLACEMENT: EFFECT OF SURGEON VOLUME.

Abstract

Hospital and surgeon volume is inversely associated with perioperative mortality, dislocation and infection rates following total hip replacement (THR). This study evaluated the relationship between hospital/surgeon volume on early failures requiring revision in a sample of 6826 Medicare beneficiaries in 1995–1996. The primary outcome for the analysis was the time between the primary THR and the first revision. After adjustment for sociodemographic/clinical variables, patients of low volume surgeons in centers with a caseload less than one hundred THR/year were twice as likely to be revised compared with patients in high volume centers by high volume surgeons.

The purpose of this study was to determine whether hospital/surgeon volume is associated with early failures requiring revision.

Patients of low volume surgeons have considerably higher rates of early failure, especially within the first year following surgery.

This study highlights the importance of including surgeon volume among factors that influence referrals for elective THR.

We analyzed claims data of 6826 Medicare beneficiaries, who underwent elective primary THR in 1995–1996 in OH, PA and CO. Hospitals were stratified into, low (< 12 THR/year), medium (12–100 THR/year) and high (> 100 THR/year) volume groups. Low volume surgeons performed fewer than twelve primary THR/ yr. Associations between rates of revisions/surgeon volume were determined by risk ratios after adjusting for hospital volume, patient age, poverty status, gender and comorbidities. We examined whether the effect of surgeon volume on revision rates differed across yearly time intervals. Of patients who had primary THR in 1995–96, two hundred and seventy-one (4%) had at least one revision by the end of 1999, one hundred and twenty-six (46%) of those occurring within the first year after the surgery. Cumulative rates of revision ranged from 2.3% for primary THR in high volume centers performed by high volume surgeons to 5.9% for patients who had primary THR performed by low volume surgeons in low volume centers. Further analysis revealed that the effect of surgeon volume was striking in the first year after the surgery (RR: 2.34; 95%CI: 1.47– 3.78) and was not evident in the subsequent years (RR: 1.08; 95%CI: 0.73–1.58).