Background: Although unilateral laminectomy and bilateral decompression (ULBD) is effective in the treatment of degenerative spondylolisthesis (DSPL), few reports have compared the outcomes of ULBD and instrumented fusion for the treatment of DSPL. We describe here the clinical and radiological outcomes of ULBD and instrumented fusion surgery for the treatment of DSPL after a minimum 3-year follow-up.
Methods: We retrospectively analyzed the outcomes of 47 DSPL patients with radicular pain who underwent ULBD or instrumented fusion between January 2005 and December 2007. Clinical outcomes were assessed using the numeric rating scale (NRS) for back and leg pain, the Oswestry Disability Index (ODI), and Short Form-36 Health Survey (SF-36). Radiological outcomes of ULBD were analyzed by determining changes in slippage, disc height translation, and angular difference on simple and dynamic X-rays.
Results: The mean NRS of back pain showed a significantly greater decrease in the fusion than the ULBD group, whereas the mean NRS of leg pain, mean ODI, and mean physical component summary and mental component summary of the SF-36 decreased similarly in the ULBD and fusion groups. Radiologically, the ULBD group showed a 2.1 ± 3.10% change in mean slippage, a 0.15 ± 1.58 mm change in mean translation, a -0.91 ± 4.48° change in mean angular difference, and a -1.83 ± 1.69 mm change in mean disc height. In the ULBD group, three patients had residual pain and three had recurrent pain. In comparison, no patient in the fusion group reported residual pain, whereas five patients experienced recurrent radicular pain caused by adjacent segmental disease.
Conclusions: Our findings suggest that ULBD is the recommendable procedure for the treatment of patients with grade I DSPL who have mainly radicular pain. Although the two groups showed similar clinical outcomes overall, radiological degeneration was not as serious after ULBD treatment. In our analysis, foraminal stenosis is a contraindication for ULBD in the treatment of grade I DSPL.