The impact of testosterone replacement therapy on clinical outcomes after anterior cervical discectomy and fusion: a propensity-matched cohort study.

PURPOSE: The purpose of this study was to characterize the short- and long-term outcomes following anterior cervical discectomy and fusion (ACDF) among patients on testosterone replacement therapy (TRT). METHODS: A multi-institutional, propensity-matched retrospective cohort study was conducted on an electronic medical record database for patients undergoing single-level ACDF. The cohort of interest was TRT exposure one-year prior to surgery. Exclusion criteria included prior cervical spine surgery, < 18 years old, and a history of spine neoplasms, trauma, inflammatory, or infectious bone conditions. Odds ratios with 95% confidence intervals for complications were calculated at thirty-days, one-, two-, and five-years. RESULTS: There were 862 patients included in each single-level ACDF cohort and most were male (88.2%). At thirty days, there were similar rates of medical complications in the TRT and non-TRT cohorts (P > 0.05). At one-year, there were similar rates of dysphagia, dysphonia, and venous thromboembolism between the two cohorts (P > 0.05). At five-years, patients in the TRT cohort had higher odds of pseudoarthrosis (OR: 1.3, 95% CI: 1.0-1.8; P = 0.049) and adjacent segment disease (OR: 1.7, 95% CI: 1.0-2.8, P = 0.037) compared to patients in the non-TRT cohort. Additionally, patients in the TRT cohort had higher rates of cervical spine reoperation (OR: 1.5, 95% CI: 1.1-2.2; P = 0.020) at five-years. CONCLUSION: TRT was associated with higher rates of pseudoarthrosis, adjacent segment disease, and cervical spine reoperation at five years following ACDF. These results can be used to inform patients on TRT regarding long-term risks following ACDF.