Five-year outcome of surgical decompression of the lumbar spine without fusion
As the average life expectancy of the population increases, surgical decompression of the lumbar spine is being performed with increasing frequency. It now constitutes the most common type of lumbar spinal surgery in older patients. The present prospective study examined the 5-year outcome of lumbar decompression surgery without fusion. The group comprised 159 patients undergoing decompression for degenerative spinal disorders who had been participants in a randomised controlled trial of post-operative rehabilitation that had shown no between-group differences at 2 years. Leg pain and back pain intensity (0–10 graphic rating scale), self-rated disability (Roland Morris), global outcome of surgery (5-point Likert scale) and re-operation rates were assessed 5 years post-operatively. Ten patients had died before the 5-year follow-up. Of the remaining 149 patients, 143 returned a 5-year follow-up (FU) questionnaire (effective return rate excluding deaths, 96%). Their mean age was 64 (SD 11) years and 92/143 (64%) were men. In the 5-year follow-up period, 34/143 patients (24%) underwent re-operation (17 further decompressions, 17 fusions and 1 intradural drainage/debridement). In patients who were not re-operated, leg pain decreased significantly (p < 0.05) from before surgery to 2 months FU, after which there was no significant change up to 5 years. Low back pain also decreased significantly by 2 months FU, but then showed a slight, but significant (p < 0.05), gradual increase of <1 point by 5-year FU. Disability decreased significantly from pre-operative to 2 months FU and showed a further significant decrease at 5 months FU. Thereafter, it remained stable up to the 5-year FU. Pain and disability scores recorded after 5 years showed a significant correlation with those at earlier follow-ups (r = 0.53–0.82; p < 0.05). Patients who were re-operated at some stage over the 5-year period showed significantly worse final outcomes for leg pain and disability (p < 0.05). In conclusion, pain and disability showed minimal change in the 5-year period after surgery, but the re-operation rate was relatively high. Re-operation resulted in worse final outcomes in terms of leg pain and disability. At the 5-year follow-up, the “average” patient experienced frequent, but relatively low levels of, pain and moderate disability. This knowledge on the long-term outcome should be incorporated into the pre-operative patient information process.