Patients at Risk for Exceeding CJR Cost Targets After Total Ankle Arthroplasty

The Comprehensive Care for Joint Replacement (CJR) model includes total ankle arthroplasty (TAA), under which a target reimbursement is established. Whether this reimbursement is sufficient to cover average cost remains unknown. We hypothesized that a substantial number of TAAs still exceed cost targets, and that risk factors associated with exceeding the target cost could be identified preoperatively.

Two hundred two primary TAAs performed at a single tertiary referral center under the CJR model from June 2013 to May 2017 were retrospectively reviewed. Patient demographics, comorbidities, outcomes, and costs were extracted from the electronic medical record using a validated structured query language (SQL) algorithm. A comparison cohort of 2084 CJR total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases performed during the same period was also reviewed.

Twenty TAAs (10%) exceeded the target cost of care, significantly fewer than CJR THAs/TKAs (29%) performed during the same period (P < .0001). These patients did not differ significantly in age, sex, body mass index, number of Elixhauser comorbidities, or the American Society of Anesthesiologists score. The average cost for these patients was $17 338 higher than those who did not exceed the target cost, and they were less likely to be married or have a partner (45% vs 79%, P = .001). Non-Caucasian status also reached significance (P < .0001). Those exceeding the target cost had a significantly longer length of stay (2.6 vs 1.5 days, P < .0001) and were more likely to be discharged to either skilled nursing or a rehabilitation facility (60% vs 1%, P < .0001).

Even high-volume TAA centers still exceed target costs in up to 10% of cases, with length of stay, discharge location, and readmissions driving many of these events. Potential risk factors for excess cost include marital/partner status and non-Caucasian ethnicity, but further work is needed to clarify their effects and whether other risk factors exist.

Level III, comparative study.