Age as a Risk Factor for Complications Following Anterior Cervical Discectomy and Fusion

Analysis From the Michigan Spine Surgery Improvement Collaborative (MSSIC)

Michael H. Lawless, DO; Doris Tong, MD; Chad F. Claus, DO; Connor Hanson, PSM; Chenxi Li, PhD; Clifford M. Houseman, DO; Peter Bono, DO; Boyd F. Richards, DO; Prashant S. Kelkar, DO; Muwaffak M. Abdulhak, MD; Victor Chang, MD; Daniel A. Carr, DO; Paul Park, MD; Teck M. Soo, MD


Spine. 2022;47(4):343-351. 

In This Article

Abstract and Introduction


Study Design: Retrospective analysis of prospectively collected registry data using multivariable analyses of imputed data

Objective: We sought to demonstrate that age would not be associated with complications in patients undergoing anterior cervical discectomy and fusion (ACDF).

Summary of Background Data: Elderly patients (≥70 yrs) undergoing ACDF are considered a higher risk for complications. However, conclusive evidence is lacking. The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a quality improvement collaborative with 30 hospitals across Michigan.

Methods: The study included all patients who had 1 to 4 level ACDF (September 2015–August 2019) for 90-day complications. Major and minor complications were defined using a validated classification. Multiple imputations were used to generate complete covariate datasets. Generalized estimating equation model was used to identify associations with complications using the whole cohort and elderly subgroup analyses. Bonferroni correction was used.

Results: Nine thousand one hundred thirty five patients (11.1% ≥ 70 yrs and 88.9% <70 yrs) with 2266 complications were analyzed. Comparing elderly versus non-elderly, the elderly had a significantly higher rate of any complications (31.5% vs. 24.0%, P < 0.001) and major complications (14.1% vs. 7.0%, P < 0.001). On multivariable analysis, age was not independently associated with any complication. POD#0 ambulation and preop independent ambulation were independently associated with significantly decreased odds of any complication. In the elderly, independent preoperative ambulation was protective for any complication (odds ratio [OR] 0.53, 0.39–0.73 95% confidence interval [CI]), especially major complications (OR 0.41, 0.27–0.61 95% CI).

Conclusion: Age was not an independent risk factor for complications in patients that underwent ACDF. In the elderly, independent preoperative ambulation was especially protective for major complications.

Level of Evidence: 3


Anterior cervical discectomy and fusion (ACDF) is one of the most frequently performed spine surgeries to treat degenerative cervical spine conditions.[1] As the incidence of these conditions increases with age, the number of elderly patients undergoing ACDF procedures continues to grow.[1–5] The assessment of safety and actual risk in this population becomes increasingly essential. Prior cervical fusion studies in the elderly reported an increased risk for complications and mortality when compared with younger cohorts.[5–11] Several of these early studies were limited by sample sizes or the absence of post-discharge complications data.[5,6,8,9,11] More recently, larger studies utilizing the American College of Surgeons National Surgery Quality Improvement Program (ACS-NSQIP) database found older age to be a risk factor for complications and mortality following ACDF.[7] Despite a large number of patients, many have questioned the use of large databases such as these, which depend heavily on administrative or billing data.[12,13] Lack of institutional standardization and data collection differences have resulted in gross discrepancies in incidence and risk factors of various adverse events and comorbidities within the ACS-NSQIP.[14,15] Further, ACS-NSQIP does not collect spine surgery-specific outcomes such as neurologic status and collects outcomes only up to 30 days postoperatively.[10] Therefore, further investigation into the effect of age on complications and clinical outcomes in patients undergoing ACDF is necessary.