Preoperative predictors for postoperative clinical outcome in lumbar spinal stenosis: systematic review.

Study Design. Systematic review. Objective. To define preoperative factors predicting clinical outcome after lumbar spinal stenosis (LSS) surgery. Summary of Background Data. LSS is the most common reason requiring lumbar spine surgery in adults older than 65 years. There are no published systematic reviews on this topic. Methods. A literature search was done until April 30, 2005. Included were randomized controlled or controlled trials or prospective studies dealing with operated LSS. The preoperative predictors had to be presented. Included articles were assessed as high-quality (HQ) and low-quality studies. The predictors in HQ studies were considered as the main results. Results. A total of 21 articles were included. Depression and walking capacity were predictors according to 2 HQ studies. Predictors reported in 1 HQ study were cardiovascular/overall comorbidity, disorder influencing walking ability, self-rated health, income, severity of central stenosis, and scoliosis. Conclusion. Depression, cardiovascular comorbidity, disorder influencing walking ability, and scoliosis predicted poorer subjective outcome. Better walking ability, self-rated health, higher income, less overall comorbidity, and pronounced central stenosis predicted better subjective outcome. Male gender and younger age predicted better postoperative walking ability. The predictive value may be outcome specific; thus, the use of all relevant outcome measures is recommended when studying predictors of LSS.