The outcome of decompression alone for lumbar spinal stenosis with degenerative spondylolisthesis.

PURPOSE: Lumbar spinal stenosis in the presence of degenerative spondylolisthesis is generally treated by means of surgery. The role of lumbar decompression without fusion is not clear. Therefore, the aim of this study was to assess whether patients who undergo decompression alone have a favourable outcome without the need for a subsequent fusion. METHODS: This is a prospective cohort study with single blinding of 83 consecutive patients with lumbar stenosis and degenerative spondylolisthesis treated by decompression, without fusion, using a spinous process osteotomy. Blinded observers collected pre- and post-operative Oswestry Disability Index (ODI), EuroQol Five Dimensions (EQ-5D), and visual analogue scale (VAS) for back and leg pain scores prospectively. Failures for this study were those patients who required a subsequent lumbar fusion procedure at the decompressed levels. Statistical analysis was performed using paired t test and Mann-Whitney test. RESULTS: There were 36 males and 47 females with a mean age of 66 years (range 35-82). The mean follow-up was 36 months (range 19-48 months). The mean pre-operative ODI, EQ-5D, and VAS scores were 52 [standard deviation (SD) 18], 0.25 (SD 0.30), and 61 (SD 22), respectively. All mean scores improved post-operatively to 38 (SD 23), 0.54 (SD 0.34) and 36 (SD 27), respectively. There was a statistically significant improvement in all scores (p ≤ 0.0001). Nine patients (11 %) required a subsequent fusion procedure and five patients (6 %) required revision decompression surgery alone. CONCLUSION: Our study's results show that a lumbar decompression procedure without arthrodesis in a consecutive cohort of patients with lumbar spinal stenosis with degenerative spondylolisthesis had a significant post-operative improvement in ODI, EQ-5D, and VAS. The rate of post-operative instability and subsequent fusion is not high. Only one in 10 patients in this group ended up needing a subsequent fusion at a mean follow-up of 36 months, indicating that fusion is not always necessary in these patients.