Influence of Preoperative Smoking Status on Clinical Outcomes of Laminoplasty in Patients With Degenerative Cervical Myelopathy: a Prospective Study

Abstract

Background: Smoking is considered to be a risk factor for poor clinical outcomes after anterior cervical decompression and fusion surgery. However, it is unclear whether the preoperative smoking status has similar effects on clinical outcomes after laminoplasty. The current research is carried out to determine whether smoking status before laminoplasty affects clinical outcomes in patients with degenerative cervical myelopathy (DCM). Methods: A series of consecutive patients undergoing laminoplasty to treat DCM at a single institution between April 2017 and April 2020 were included. The patients were divided into the following 3 groups: active smoking (AS), passive smoking (PS), and non-smoking (NS). The primary outcome was the recovery rate of JOA at the last follow-up. Secondary outcomes included JOACMEQ score and the NRS (Numerical rating scale) for neck and arm pain. Statistical analysis of among the three groups differences were performed with ANOVA, and multivariable regression analysis was undertaken to explore predictor variables.Result: A total of 158 consecutive patients completed at least 6 months of follow-up. There were 108 men and 50 women. The mean (±standard deviation) age of this series was 57.7 ± 11.6 years. The average recovery rate of JOA, the improvement in the NRS for neck and arm pain, and in each domain of JOACMEQ did not differ significantly among the three groups (P＞0.05). When used 52.8% as the minimal clinically important difference (MCID) of the JOA recovery rate, active smokers (RR=0.950, 95%CI=0.740-1.220) and passive smokers (RR=0.830, 95%CI=0.540-1.277) had similar likelihoods of reaching MCID compared with non-smokers. Logistic regression revealed that age (OR=0.95, 95%CI=0.92-0.98, P=0.001) and preoperative JOA (OR=0.85, 95%CI=0.75-0.95, P=0.004) were risk factors of the recovery rate that did not reach MCID, but smoking status: AS (OR=0.56, 95%CI=0.21-1.47,P=0.24), PS (OR=.087, 95%CI=0.43-1.76, P=0.70), did not affect the clinical outcomes.Conclusion: Over a follow-up period of at least 6 months, active smokers, passive smokers, and non-smokers had similar improvements in clinical outcomes after laminoplasty. Thus, smoking status was not found to be an independent predictor of clinical outcomes after laminoplasty.