Evaluating Surgeon-influenced Factors for Total Knee Arthroplasty Value-based Reimbursement

Clinical outcome measures used under value-based reimbursement models require risk stratification of patient demographics and medical history. Only certain perioperative patient factors may be influenced by the surgeon. The study evaluated surgeon-influenced modifiable factors associated with achieving literature-defined KOOS score thresholds to serve as the foundation of the newly established alternative payment models for total knee arthroplasties (TKA).

We retrospectively reviewed a consecutive cohort of 4,324 patients undergoing TKA. Surgeon-influenced modifiable risk factors included thromboprophylaxis with aspirin, tourniquet use, tranexamic acid (TXA), body mass index, smoking, alcohol or illicit drug use, surgical time, length of stay (LOS), and bilateral TKA. Outcomes included complications, 90-day readmissions, discharge disposition, knee injury and osteoarthritis outcome score (KOOS) minimal clinically important difference (MCID), KOOS patient acceptable symptom state (PASS), and short form-12 (SF-12) MCID achievement. A bivariate analysis and regression were built to determine the likelihood of primary outcomes based on modifiable factors.

Bilateral TKA was associated with a higher odds ratio (OR) for home discharge (OR = 5.40, P < 0.001), KOOS MCID (OR = 2.60, P < 0.001), PASS (OR = 2.4, P ≤ 0.001), and SF-12 PCS MCID achievement (OR = 3.21, P < 0.001). Similarly, LOS was inversely associated with KOOS MCID (OR = 0.88, P = 0.002) and PASS (OR = 0.81, P < 0.001) but directly associated with home discharge (OR = 2.5, P ≤ 0.001) in-hospital complications (OR = 1.50, P < 0.001) and 90-day readmissions (OR = 1.23, P = 0.005). The KOOS MCID and PASS achievement was positively influenced by TXA (OR = 1.33, P = 0.008; OR = 1.29, P = 0.020) use and negatively influenced by aspirin use (OR = 0.68, P = 0.013; OR = 0.73, P = 0.040). In-hospital opioid use was an independent risk factor for not achieving SF-12 MCS MCID (OR = 0.56, P = 0.006).

In this study, modifiable perioperative variables, such as TXA, aspirin use, opioid use, LOS, and bilateral TKA, were found to markedly increase quality metrics threshold achievement and should be considered as risk variables in the current value-based care models. Future studies should investigate the effect of modifiable risk factors on quality metrics to build new risk adjustment tools that incentivize patient perioperative optimization.