Cost-Volume Analysis of Primary Total Knee and Hip Arthroplasty in the United States

Utilization of total knee arthroplasty (TKA) and total hip arthroplasty (THA) arthroplasty is increasing along with associated hospitalization costs. A contemporary analysis of the impact of hospital case volume on the costs of TKA and THA is lacking.

Adults undergoing primary elective TKA or THA who had a diagnosis of osteoarthritis were identified from an inpatient all-payer database from 2012 to 2019. Operative volume was ascertained with restrictive cubic spline analysis. The volume corresponding to the inflection point of the spline was used to stratify hospitals as high volume (HVH) or low volume (LVH). Multivariable regression models were developed to examine the association of volume with hospitalization costs, adverse events, lengths of stay, and nonhome discharges.

Of the 7,781,233 patients undergoing TKA or THA over the study period, 73.1% of primary TKA and 77.1% of primary THA were managed at HVH. On adjustment for patient and hospital covariates, treatment at high-volume TKA or THA hospitals was associated with a cost decrement of $2,200 (95% confidence interval, 2,900 to 2,400, P < 0.001), and $1,900 (95% confidence interval, 2,100 to 1,600), respectively. Notably, the disparity in hospitalization costs between HVH and LVH markedly increased during the study period (P < 0.001).

Greater TKA and THA volume was associated with reduced hospitalization costs. These findings suggest that regionalization of care to experienced hospitals may improve the value of orthopaedic surgical care.