CLINICAL STUDY ON MODIFIED LAMINOPLASTY WITH POSTERIOR COLUMN RESERVATION FOR TREATMENT OF LUMBAR SPINAL STENOSIS

Abstract

To investigate the technique and effectiveness of modified laminoplasty for lumbar spinal stenosis (LSS) and to explore the application value of modified laminoplasty in maintaining the stability of the spine by comparing with the conventional laminectomy. Fifty-six patients with LSS were included between June 2012 and July 2013, and they were divided into 2 groups: 27 patients underwent modified laminoplasty in group A, and 29 patients received conventional laminectomy in group B. There was no significant difference in sex, age, disease duration, narrow segment, visual analogue scale (VAS) score of low back pain and leg pain, Japanese Orthopaedic Association (JOA) score, and walking tolerance between 2 groups (P > 0.05). The postoperative VAS score of low back pain and leg pain, JOA score, walking tolerance, X-ray film, and CT were used to evaluate the clinical results. Dural tear occurred in 2?cases of group A and 1 case of group B and were repaired during operation. All incisions primarily healed without infection. The patients were followed up 24-31 months (mean, 24.7 months) in group A, and 24-37 months (mean, 26.2 months) in group B. The bone healing time was 6-12 months (mean, 9 months) in group A. CT showed healing at the junction of spinous process and vertebral plate in group A at 12 months after operation; new scar in varying degre es was observed in group B. At last follow-up, lumbar spondylolisthesis and instability occurred in 4?and 2 cases of group B respectively, and received re-operation. The change value of slip distance was (0.27±0.23) mm in group A and was (0.83±1.22) mm in group B, showing significant difference (t=-2.405, P=0.023). The postoperative JOA score, VAS score, and walking tolerance were significantly improved when compared with preoperative ones in 2 groups (P < 0.05).?At?last follow-up, group A was better than group B in VAS score of low back pain (P < 0.05), but no significant?difference?was?found in the other indexes between 2 groups (P > 0.05). The modified laminoplasty?is better than the conventional laminectomy in relieving low back pain and maintaining the stability of the lumbar spine.