ABSTRACT
Objective To investigate the clinical outcomes of interbody fusion with transpedicular screw fixation in the reoperation for lumbar spinal instability secondary to lumbar discectomy.Methods From May 1997 to Aug 2002, 23 patients underwent reoperation with posterior lumbar spinal decompression, removal of residual disc, transpedicular screw instrumentation and interbody fusion because of lumbar spinal instability after previous lumbar discectomy. There were 14 males and 9 females. The age of patients ranged from 28 to 64 years with an average age of 48.5 years. The time between the onset of the symptoms and the diagnosis was 18 months on average (range, 6 months to 36 years). The mean interval between the primary and revision surgery was 68 months (range, 24 months to 10 years). Lumbar discectomy had been performed in all patients as the primary surgery. All patients were evaluated by the conventional radiography, and CT or MRI if necessary. The low back pain was predominant in 8, and associated with radicular leg pain in 15. The instability of one segment was found in 17, and two segments in 6. The average follow-up was 3.6 years (range, 1 to 6.4 years). Results The lateral, AP, flexion and extension X-ray films were taken at 1, 3, 6 months and 1 year to evaluate the fusion, sliding between two vertebral bodies and internal fixation, and McGill pain questionnaire was adopted to determine the satisfaction of the patients. The intraoperative blood loss ranged from 550 to 800 ml (mean, 650 ml), and the total operative time ranged from 120 to 210 min (mean, 180 min). Based on Oswestry low back pain and disability scores, the clinical successful rate was 86.9%. The rate of patient satisfaction was 82.6%. 20 patients showed radiographic bony fusion. Pedicle screw breakage and loosening were found in 3 out of the 102 screws. 5 patients had nerve root irritation and recovered within 2 to 3 weeks. 5 patients had dural laceration. Bony nonunion was found in 3 patients. Conclusion Transpedicular screw instrumentation and interbody fusion is proved helpful in management of spinal instability secondary to decompression surgery, providing successful interbody fusion and restoration of the intervertebral stability.