Preoperative Interventions and Charges in the 2-Year Period Before Unicompartmental Knee Arthroplasty: What Happens Before Surgery

This study investigated preoperative interventions and their costs in the 2-year period before a patient undergoing a unicompartmental knee arthroplasty (UKA).

A retrospective cohort analysis of patients undergoing UKA between 2009 and 2011 was conducted using the PearlDiver Patient Record Database to track inpatient and outpatient billing records.

One thousand eight hundred forty-one patients from Medicare and 4704 patients from United Healthcare underwent UKA between 2009 and 2011. In the 2 years before UKA, the per patient average charge was $3919.96 for Medicare patients and $5219.14 for United Healthcare patients, with 21.7% of Medicare-associated charges and 28.2% of United Healthcare-associated charges occurring within 3 months of surgery. In the 2-year period before surgery, 65.5% of Medicare patients and 53.6% of United Healthcare patients received an intra-articular injection, with 29.1% (Medicare) and 46.0% (United Healthcare) of these injections occurring within 3 months of surgery. In addition, 15.1% of Medicare patients and 20.7% of United Healthcare patients underwent an arthroscopy, with between 32.4% and 43.8% of these occurring in the final 6 months before UKA.

Preoperative interventions (ie, imaging, procedures, physical therapy, and injections) occur at a high frequency in close proximity to UKA resulting in substantial costs. The development of algorithms to guide management of these patients is critical in reducing costs before UKA.