Early failures of total hip replacement: effect of surgeon volume.

OBJECTIVE

To determine whether provider volume is associated with early failures following total hip replacement (THR) requiring revision.

METHODS

Claims data were analyzed to follow a cohort of 57,488 Medicare beneficiaries who underwent elective primary THR in 1995-1996 in 3,044 hospitals in the US. Patients were followed through the end of 1999. Failure of primary THR was defined as a subsequent revision THR, as determined by International Classification of Diseases, Ninth Revision codes in hospital claims. Hospitals were stratified into 4 volume groups: low (<25 THRs/year), medium (26-50, 51-100 THRs/year), and high (>100 THRs/year). Low-volume surgeons were defined as those surgeons performing <12 elective primary THRs annually in the Medicare population. Associations between the rates of revision and surgeon volume were determined by hazard ratios from a proportional hazard model, with adjustment for hospital volume, patient age, poverty status, sex, and comorbidities. We also examined whether the effect of surgeon volume on revision rates differed between the first 18 months postoperatively and later time periods.

RESULTS

Among 57,488 patients who had elective primary THR in 1995-1996, 2,537 (4.4%) had at least 1 revision THR by the end of 1999, with 1,437 (56.6%) of these revisions occurring within the first 18 months after the index primary THR. Median followup time was 47 months (range 0-54). Patients of high-volume surgeons were less likely to have revision THRs than patients of low-volume surgeons, regardless of hospital volume stratum. Further analysis revealed that the effect of surgeon volume on revisions was striking in the first 18 months after surgery but was not evident in the subsequent years.

CONCLUSION

Patients of low-volume surgeons have higher rates of revision THR than patients of high-volume surgeons, particularly within the first 18 months postoperatively. Referring clinicians should consider including surgeon volume among the factors influencing their choice of surgeon for elective THR.