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Fusion Surgery for Lumbar Spinal Stenosis.

To the Editor: Försth et al. (April 14 issue)1 found that in patients with lumbar stenosis, even in patients with degenerative spondylolisthesis, decompression surgery plus fusion surgery does not result in better clinical outcomes than those of decompression alone. Although the authors are to be commended for their work, it is essential to examine the clinical limitations of their results. The primary conclusion of the study is that postoperative functional outcomes are independent of fusion. Although this conclusion may be true, in practice, the patient-specific anatomy should be studied to determine whether a biomechanical predisposition for instability exists. For example, biomechanical studies have shown that in patients with facet-joint edema, joints are likely to be unstable, even if they appear stable on dynamic imaging.2,3 Surgeons should have a low threshold for performing fusion in patients who have such biomechanical predispositions for instability. The authors also conclude that fusion leads to increased operating time, blood loss, and length of hospital stay. Although these results hold true for the open surgical techniques used in the trial, a major shift toward minimally invasive procedures has already substantially improved these variables,4,5 which should call into question the relevance of the findings by Försth et al.