No Difference in Functional Outcome but Higher Revision Rate Among Smokers Undergoing Cervical Artificial Disc Replacement: Analysis of a Spine Registry

Background Smoking is a known predictor of negative outcomes in spinal surgery. However, its effect on the functional outcomes and revision rates after ADR is not well-documented. This study is a retrospective analysis of prospectively collected data at a major tertiary center. The objective was to elucidate the impact of smoking on functional outcomes in cervical artificial disc replacement (ADR).

Methods Patients who underwent cervical ADR for myelopathy or radiculopathy from 2004 to 2015 with a minimum of 2 years of follow-up were included in the study. Patient function was assessed using Short Form-36 (SF-36), American Association of Orthopaedic Surgery (AAOS) cervical spine, and Japanese Orthopaedic Association (JOA) scoring systems preoperatively and at 2 years postoperatively. Incidence of further surgery on affected and adjacent segments was analyzed as well.

Results A total of 137 patients were included in the study, consisting of 117 nonsmokers and 20 smokers. There were 60 patients who presented with myelopathy and 77 with radiculopathy. The mean age of smokers was 42.6 years, compared with 46.4 years in the nonsmoker group (P < .01). Statistical improvement was noted in postoperative range of motion, as well as AAOS, SF-36, and JOA scores in both groups, with no difference between groups at 2 years of follow-up. A total of 84.2% of nonsmokers and 87.5% of smokers reported as surgery having met their expectations. A total of 5 of 117 nonsmokers (5.1%) and 4 of 20 smokers (20%) needed revision surgery (P = .018). Three of the 4 smokers who required surgery for adjacent or multisegment disease, whereas only 2 of the nonsmokers needed an operation for adjacent segment disease.

Conclusions Our analysis indicates that there is no difference in functional outcome or patient satisfaction between smokers and nonsmokers. Smokers have a higher chance of revision surgery after an artificial disc replacement compared with nonsmokers at 2 years.

Level of Evidence 3.