Soft stabilization with interspinous artificial ligament for mildly unstable lumbar spinal stenosis: a multicenter comparison. 
In an attempt to fill a gap between simple decompression alone and fusion in the spectrum of surgical treatment for degenerative lumbar spinal stenosis (DLSS), the authors sought to demonstrate the efficacy and reproducibility of soft stabilization with interspinous artificial ligament after microsurgical fenestration to prevent post-decompression segmental instability for mildly unstable DLSS.  Clinical outcomes from 556 patients treated with soft stabilization with artificial ligament following microdecompression for mildly unstable DLSS from March 1998 to June 2006 were retrospectively obtained from three institutions in three countries.  Outcomes were measured at a mean of 48.9 months after surgery using MacNab criteria.  Peri- and postoperative complications and revision surgery cases were also analyzed.  Follow-up was achieved in 391 (70.3%) of the 556 patients.  Clinical outcomes were excellent in 43.7%, good in 36.7%, fair in 12.2%, and poor in 7.4% of the patients.  The overall clinical success rate was 80.4%.  No major complications except postoperative hematoma and wound infection (6/391 cases, 1.5%) were observed, and few revision surgeries (2.3%) were done during follow-up.  We found favorable and reproducible results with soft stabilization with artificial ligament after microdecompression for mildly unstable DLSS from three institutions in three countries.  Soft stabilization with artificial ligament may be concluded to represent an effective prevention of increased post-decompression instability with reliable reproducibility for mildly unstable DLSS in carefully selected patients.