Abstract
Recently, the Centers for Medicare & Medicaid Services announced its decision to review
“potentially misvalued” Current Procedural Terminology (CPT) codes, including those
for primary total knee arthroplasty (TKA). CPT 27447 is being reevaluated to determine
contemporary relative value units for work value, with operative time considered a
primary factor in this revaluation. Despite broader indications for TKA, including
extension of the procedure to more complex patient populations, it is unknown whether
operative times may remain stable in the future. Therefore, the purpose of this study
was to specifically evaluate future trends in TKA operative times across a large sample
from a national database. The American College of Surgeons National Surgical Quality
Improvement Project database was queried from January 1, 2008 to December 31, 2017
to identify 286,816 TKAs using the CPT code 27447. Our final analysis included 140,890
TKAs. Autoregressive integrated moving average forecasting models were built to predict
2- and 10-year operative times. While operative times were significantly different
between American Society of Anesthesiologists (ASA) classes 1 and 2 (p = 0.035), there were not enough patients in ASA class 1 to perform rigorous inference.
Additionally, operative times were not significantly different between ASA classes
3 and the combined ASA classes 4 and 5 cohort (p = 0.95). Therefore, we were only able to perform forecasts for ASA classes 2 and
3. Operative time was found to be nonstationary for both ASA class 2 (p = 0.08269) and class 3 (p = 0.2385). As a whole, the projection models indicated that operative time will remain
within 2 minutes of the present operative time, up to the year 2027. Our projections
indicate that operative times will remain stable over the next decade. This suggests
that there is a lack of evidence for reducing the valuation of CPT code 27477 based
on intraservice time for TKA. Further study should examine operative time trends in
the setting of evolving alternative payment models, increasing patient complexity,
and governmental restrictions.
Keywords
operative time - total knee arthroplasty (TKA) - trends - reimbursement - Current
Procedural Terminology (CPT) - autoregressive integrated moving average (ARIMA)
