Résumé
STUDY DESIGN: This is a prospective study. OBJECTIVES: We wanted to analyze the radiographic and clinical results of the three posterior element saving decompression techniques for treating lumbar degenerative spinal stenosis. SUMMARY OF THE LITERATURE REVIEW: Minimal invasive decompression reduces patient morbidity and the hospital stay. MATERIALS AND METHODS: We evaluated 30 patients, who were treated with posterior element saving microscopic decompression for their lumbar spinal stenosis (without instability), during the period from March, 2002 and February, 2004. The procedures were bilateral laminotomy (10 cases), spinous process osteotomy (8 cases) and laminoplasty (12 cases). We evaluated the estimated blood loss, the amount of transfusion, the complications and the radiographic instability at the last follow-up. The clinical results were evaluated with using the Oswestry disability index (ODI) and the visual analogue scale (VAS) for buttock and leg pain both preoperatively and at postoperative 1, 3, 6 and 12 months, respectively. RESULTS: There was no radiographic instability noted for any of the patients at the last follow up. The mean ODI and VAS scores were substantially improved at postoperative 1 month and then they were marginally improved afterwards. However, there were no statistically significant differences among three procedures (p>0.05). The mean blood loss and the amount of transfusion for each spinal level were 290 ml and 0.5 U for bilateral laminotomy, 370 ml and 0.9 U for spinous process osteotomy and 180 ml and 0.1 U for laminoplasty, respectively. CONCLUSION: There were no significant differences in the radiograhic and clinical results among bilateral laminotomy, spinous process osteotomy and laminoplasty. Yet in terms of blood loss and transfusion, laminoplasty was better than the other techniques. We believe that laminoplasty is a useful and safe technique for treating degenerative lumbar spinal stenosis.