Aims. The aim of this study was to investigate the clinical and radiographic
outcomes of microendoscopic laminotomy in patients with lumbar stenosis
and concurrent degenerative spondylolisthesis (DS), and to determine
the effect of this procedure on spinal stability. Patients and Methods. A total of 304 consecutive patients with single-level lumbar
DS with concomitant stenosis underwent microendoscopic laminotomy
without fusion between January 2004 and December 2010. Patients
were divided into two groups, those with and without advanced DS
based on the degree of spondylolisthesis and dynamic instability. A
total of 242 patients met the inclusion criteria. There were 101
men and 141 women. Their mean age was 68.1 years (46 to 85). Outcome
was assessed using the Japanese Orthopaedic Association and Roland
Morris Disability Questionnaire scores, a visual analogue score
for pain and the Short Form Health-36 score. The radiographic outcome
was assessed by measuring the slip and the disc height. The clinical
and radiographic parameters were evaluated at a mean follow-up of
4.6 years (3 to 7.5). Results. There were no significant differences in the preoperative measurements
between the group and no significant differences between the clinical
parameters at the final follow-up. The mean percentage slip was
17.1% preoperatively and 17.7% at the final follow-up (p = 0.35).
Progressive instability was noted in 13 patients (8.2%) with DS
and 6 patients (7.0%) with advanced DS, respectively (p = 0.81).
There was radiological evidence of restabilization of the spine
in 30 patients (35%) with preoperative instability. The success
rate of microendoscopic laminotomy was good/excellent in 166 (69%),
fair in 49 (20%) and poor in 27 patients (11%) in both groups. Conclusion. Microendoscopic laminotomy is an effective form of surgical treatment
for patients with DS and stenosis. Preservation of the stabilizing
structures using this technique prevents
We describe a modified technique of micro-decompression of the lumbar spine involving the use of an operating microscope, a malleable retractor and a high-speed burr, which allows decompression to be performed on both sides of the spine through a unilateral, hemi-laminectomy approach. The first 100 patients to be treated with this technique have been evaluated prospectively using a visual analogue score for sciatica and back pain, the MacNab criteria for patient satisfaction, and functional assessment with the Oswestry Disability Index. After a period of follow-up from 12 months to six years and four months, sciatica had improved in 90 patients and back pain in 84 patients. Their result was graded as good or excellent by 82 patients according to the MacNab criteria, and 75 patients had subjective improvement in their walking distance. Late instability developed in four patients. Lumbar micro-decompression has proved to be safe, with few complications.
