Trends of single-level anterior cervical discectomy and fusion documentation after the 2015 Centers for Medicare & Medicaid Services coding audit

OBJECTIVE: With the use of anterior cervical discectomy and fusion (ACDF) expected to rise by 13.3% from 2020 to 2040, the increased usage of interbody cages with integral anterior fixation prompted a Centers for Medicare & Medicaid Services (CMS) review, which resulted in coding changes affecting anterior instrumentation documentation. CMS determined that Current Procedural Terminology (CPT) code 22845 should not be used to report integrated instrumentation (plate) with an interbody device, and if additional anterior instrumentation (e.g., plates and screws) is placed with an integrated interbody device, then a 59 modifier should be used. There is sparse literature examining the trends of ACDF without and with additional anterior instrumentation after the 2015 CMS audit. Therefore, this study aimed to evaluate the trends of single-level subaxial ACDF utilization from 2011 to 2019 to determine whether the 2015 CMS audit influenced the documented usage of additional anterior instrumentation. METHODS: A retrospective cohort study was performed using the commercially available database PearlDiver. Patient records were queried from 2011 to 2019 for single-level subaxial ACDF without (CPT code 22551) and with (CPT codes 22551 + 22845) instrumentation. Cochran-Armitage trend analyses were performed to evaluate the hypothesis that ACDF with additional anterior instrumentation decreased over the given time period. RESULTS: Between 2011 and 2019, the total number of single-level ACDFs decreased from 6202 to 4402. From 2011 to 2015, an average of 6240 patients per year underwent single-level subaxial ACDF; of those, 950 patients (15.2%) had ACDF without instrumentation and 5290 patients (84.8%) had ACDF with instrumentation. In 2016, the total number of single-level subaxial ACDFs decreased to 5525, with 1006 patients (18.2%) receiving no instrumentation and 4519 patients (81.8%) receiving instrumentation. From 2017 to 2019, an average of 4283 patients per year underwent a single-level subaxial ACDF; of these, 1280 (29.9%) had no instrumentation and 3003 (70.1%) had instrumentation (all p < 0.0001). CONCLUSIONS: From 2015 to 2019, single-level ACDF without instrumentation significantly increased by 91.5% and ACDF with anterior instrumentation significantly decreased by 18.1%. The 2015 CMS audit of interbody cages and anterior instrumentation coding (CPT code 22845) may account for the decreased documentation of anterior instrumentation in the 9-year period. Understanding CMS auditing could help surgeons perceive changes in practice patterns that may lead to a more thorough evaluation of patient outcomes, cost, and overall value.