Primary Total Knee Arthroplasty in California 1991 to 2001: Does Hospital Volume Affect Outcomes?

This study reports the relationship between hospital surgical volume and outcomes after total knee arthroplasty. Discharge data from 1991 to 2001 were obtained from California’s Office of Statewide Health Planning and Development and linked to California death records. Multivariate logistic regression models were performed to examine the association between hospital volume and complications. The models were adjusted for patient age, sex, race/ethnicity, insurance type, Charlson comorbidity index, hospital type and size, year of surgery, and whether patients underwent bilateral procedures. A total of 222684 primary total knee arthroplasties were identified during the study period. Patients treated at low volume hospitals had a higher likelihood in the 90 days after discharge of death (rate 0.55% vs 0.49%, odds ratio [OR] 1.50, 95% confidence interval [CI] 1.14-1.98, P = .004), and readmission for infection (1.13% vs 0.65%, OR 1.60, 95% CI 1.21-2.12, P = .001), pulmonary embolism (0.48% vs 0.39%, OR 1.45, 95% CI 1.07-1.97, P = .016), and thrombophlebitis (0.49% vs 0.28%, OR 2.12, 95% CI 1.47-3.05, P ≤ .001). This study confirms the relationship of lower hospital volumes to a higher OR for complications after total knee arthroplasty.