Low Surgeon and Hospital Volume Increase Risk of Early Conversion to Total Knee Arthroplasty After Tibial Plateau Fixation

BACKGROUND Some orthopaedic procedures exhibit volume-outcome relationships that suggest benefits associated with a triage and treatment by higher volume surgeons and hospitals. The purpose of this study was to determine whether this association is present for open reduction internal fixation (ORIF) of tibial plateau fractures regarding the outcome of conversion to total knee arthroplasty (TKA). METHODS The Florida State Inpatient Database was queried to identify patients who underwent ORIF of a tibial plateau fracture between 2006 and 2009. The annual volumes of surgeons and hospitals were determined. The outcome of interest was any subsequent hospitalization for TKA within 5 years. Comparing the rates of this outcome, cut points were established to define high and low volume. Survival analysis, including Cox proportional hazards modeling, was used to estimate the effect of volume on rates of TKA while controlling for patient factors and injury characteristics. RESULTS In this cohort of 3,921 patients, 172 patients (4.4%) underwent TKA within 5 years of ORIF of the tibial plateau. This included 5.0% of patients treated by low-volume surgeons versus 2.1% treated by high-volume surgeons and 4.8% treated at low-volume hospitals versus 2.0% treated at high-volume hospitals. High-volume surgeons and hospitals were defined by annual volumes greater than or equal to 7 and 29, respectively. After adjustment, treatment at a low-volume hospital was associated with a larger hazard of conversion to TKA (hazard ratio = 2.05; 95% confidence interval = 1.11 to 3.80). Treatment by a low-volume surgeon was also associated with a larger hazard of conversion to TKA (hazard ratio = 2.17; 95% confidence interval = 1.31 to 3.59). DISCUSSION High-volume treatment of tibial plateau fractures is associated with a lower rate of conversion to TKA, suggesting that the regionalization of care for these injuries may improve outcomes. LEVEL OF EVIDENCE Level III.