Clinical results after percutaneous automated lumbar nucleotomy. A follow-up study.

This study was carried out in order to assess the clinical results after percutaneous automated nucleotomy with regard to predictive factors for the outcome. Selection criteria included patients with predominance of low-back pain, diffuse posterior disk bulges and concomitant spinal stenosis who are not normally accepted for nucleotomy. In all, 142 patients were treated. The overall success rate after an average observation time of 21 months was 56%. The results were not influenced by whether a diffuse posterior bulge or a focal hernia had been treated or not (p = 0.449). Spinal stenosis (p = 0.043) and disk space narrowing exceeding 25% of the expected width (p = 0.017) were associated with a poor outcome. By excluding these categories and patients with symptoms from more than one disk level, the success rate rose to 70%. With this selection, the results were equally good in patients with predominantly low-back pain compared to those with predominantly sciatica (p = 0.490).