Outcomes and their predictors in lumbar spinal stenosis: a 12-year follow-up.

PURPOSE

The aim of this prospective observational cohort study was to evaluate long-term outcomes in patients with mild-to-moderate lumbar spinal stenosis (LSS) and to analyse the predictors of clinical outcomes.

METHODS

A group of 53 patients were re-examined after a median period of 139 months. Evaluations were made of subjective clinical outcome, objective clinical outcome and its predictors, any correlation between subjective and objective outcome, and the development of changes in radiological and electrophysiological parameters after 12 years.

RESULTS

Satisfactory objective and subjective clinical outcomes were recorded in 54.7 and 43.4% of patients, respectively. No statistically significant correlation between objective and subjective clinical outcome was found (Spearman coefficient = 0.225, p = 0.132). Patients with isolated unsatisfactory subjective outcome exhibited the highest Functional Comorbidity Index of all subgroups. Electrophysiological and radiological findings did not demonstrate statistically significant changes after 12-year follow-up. Multivariate logistic regression confirmed only the lowest transverse diameter of spinal canal ≦13.6 mm as an independent predictor of unsatisfactory clinical outcome (OR = 5.51).

CONCLUSIONS

Satisfactory objective and subjective clinical outcomes were disclosed in about half of the patients with mild-to-moderate LSS in a 12-year follow-up. The number of comorbid diseases had an unfavourable effect on subjective evaluation of clinical outcome. The lowest transverse diameter of spinal canal proved to be the only independent predictor of deterioration of clinical status in LSS patients.