Conversion THA should be risk-adjusted in alternative payment models due to complications

William G. Hamilton, MD

The authors of this study, which includes several of the foremost experts in bundled payments and health economics, explore the differences in complication rates between primary and conversion hip arthroplasty. As expected, this study demonstrates what surgeons already inherently knew, that conversion procedures are more difficult, require more resources and have higher complication rates. Without risk adjustment, more complex procedures like conversion hip replacement will be costlier, creating a disincentive to providers that participate in bundled payments to take care of these patients.

One of the more impressive statistics from the study is the increased rate of infection in the conversion cohort, which had more than four times the likelihood for deep infection. The greater likelihood of discharge to a skilled nursing facility in the conversion group is also compelling. It is well recognized that both these factors are substantial “bundle busters” and increased rates can derail an otherwise productive bundle.

Bundled payments should ultimately result in improved efficiency, better patient care and reduced costs. However, as the target is slowly ratcheted down by CMS (the dollar value providers must beat to realize a reward from bundled payments), surgeons will ration care, implementing cut-offs and barriers to surgery. Although this may provide short-term returns for surgeons, our neediest patients will pay by losing access to valuable services.