Objective: To investigate the effectiveness and significance of percutaneous endoscopic discectomy followed by interbody fusion using B-Twin expandable spinal spacer for degenerative lumbosacral disc
Methods: Between January 2007 and August 2008, 21 patients with degenerative lumbosacral disc disease were treated with endoscopic discectomy followed by interbody fusion using B-Twin expandable spinal spacer. Among them, there were 13 males and 8 females with an average age of 52 years (range, 28-79 years). And the disease duration ranged from 3 months to 40 years (median, 9 months). The affected segments included T11, 12, T12-L1, L1.2, and L2, 3 in 1 case respectively, L4, 5 in 4 cases, and L5, S1 in 13 cases. All patients had intractable low back pain or lower extremity radicular symptoms. The placement methods of B-Twin expandable spinal spacer were double sides in 15 cases and single side in 6 cases. Oswestry Disability Index (ODI) and Macnab grading were used to determine the function recovery after operation. And Suk's standard was used to determine the fusion effects by X-ray.
Results: All 21 patients were followed up 18 months to 3 years (mean, 23.8 months). Sciatica symptoms disappeared after operation in 19 cases, no significant improvement occurred in 2 cases of thoracic disease. The ODI scores were 79% +/- 16% at preoperation, 30% +/- 9% at 1 month, 26% +/- 10% at 3 months, 21% +/- 12% at 6 months, and 20% +/- 10% at 18 months after operation, showing significant differences between pre- and postoperation (P < 0.05). According to Macnab grading at 6 months postoperatively, the results were excellent in 14 cases, good in 5 cases, and fair in 2 cases with an excellent and good rate of 90.5%. According to Suk et al. standard, the results were excellent in 1 case, good in 19 cases, and poor in 1 case with an excellent and good rate of 95.2%. The muscle strength of the lower extremities had no improvement in 1 case of T11, 12 disc protrusion; pedicle screws fixation and decompression laminectomy were given after 6 months, but no improvement was achieved during follow-up. Protrusion recurred after 4 months in 1 case of L4, 5 disc protrusion, then was cured by laminectomy discectomy. The remaining patients achieved postoperative relief.
Conclusion: Endoscope combined with interbody fusion is a good combination to solve lumbar instability. B-Twin expandable spinal spacer is a minimally invasive fusion choice of 4, 5 and L5, S1.