The clinical, functional, and occupational outcomes of smokers vs. non-smokers undergoing spinal arthrodesis: Diagnosis related results
Clinical, functional, and occupational data on 956 consecutive adults who underwent primary or revision spinal fusion were reviewed comparing 133 smokers vs. 823 nonsmokers. Diagnoses were evenly divided between deformity, degenerative, and spondylolisthesis. 47% had undergone prior lumbar surgery. Both smokers and nonsmokers improved VAS and ODI scores and returned to work in similar numbers. Primary vs. revision surgery was a more reliable predictor of outcomes after spinal arthrodesis than smoking.
Smoking has been linked with nonunions after spinal fusion and inferior clinical results after laminectomy. Bone morphogenic protein (BMP) has been shown to overcome the negative effect of smoking on fusion. Little is known about the clinical, functional, and occupational outcomes after spine fusion in smokers vs. nonsmokers, by diagnosis.
Retrospective review of 956 consecutive adults who underwent primary or revision spinal fusion, 133 smokers vs. 823 nonsmokers; 47% had undergone prior lumbar surgery. Diagnoses: Deformity-304, spondylolisthesis-332, degenerative-320. Age: 60.5 (age range 18-90); All had posterior fusion- 5.1 levels (range 2-17); ALIF in 137 patients- 4.2 levels (range 1-13), TLIF in 712 patients- 1.7 levels (range 1-4). BMP was used in 756 patients. Work status was divided into light/medium/heavy by lifting requirements. Clinical, occupational, and radiographic results recorded preop, 1 year, 2 years, and latest.
At 5 years follow-up (range 2-9 years): Nonunions: Smokers- 8 (6.0%), Nonsmokers- 28 (3.4%); Infections: Smokers-6 (4.5%), Nonsmokers- 21 (2.6%). Significant clinical improvement (p<0.05) was noted for both smokers and nonsmokers for all diagnoses, primary and revision surgery, but no difference in smokers vs. nonsmokers. Visual Analog Scores: smokers preop- 7.0, 2 years- 4.0; nonsmokers preop- 6.2, 2 years- 3.5. ODI: smokers preop- 54.2, 2 years- 35.8; nonsmokers preop- 48.5, 2 years- 30.4. Returned to work was similar: primary surgery: smokers-26/31 (84%), nonsmokers-128/175 (73%); revision surgery: smokers-16/29 (55%), nonsmokers-72/118 (61%). Patients undergoing primary surgery had lower preop and 2 year visual analog scores and ODI scores than patients undergoing revision surgery, regardless of smoking status.
Whether a patient undergoes primary or revision spine surgery is more important in predicting clinical, functional, and occupational outcomes than smoking. Fusion rates are still better in nonsmokers, though not significantly.