Prognostic factors in lumbar spinal fusion.

The charts of 234 patients who underwent 260 spinal fusions for degenerative spinal disease were reviewed to determine prognostic factors for predicting successful surgical outcome. All patients were evaluated for fusion success and symptomatic relief. Pseudarthrosis occurred in 26 patients (10%) and 14 others failed to have symptomatic improvement despite successful fusion. Outcome was found to be significantly related to smoking status, diagnosis, use of hardware, insurance status, preoperative SGPT level, prior operations or decompressions, and age. The relative risk associated with smoking was 2.9. The association with smoking was present for both subjective and objective poor outcomes. A predictive function based on smoking status and diagnosis was developed. Ninety-two percent of nonsmokers with favorable diagnoses had a good outcome, compared to 77% of those with unfavorable diagnoses. The percentages for the comparable groups of smokers were 77% and 54%.