Neurosurgery. 2009 Jul; 65(1): 95-9; discussion 99Kim JS, Lee SH, Moon KH, Lee HYOBJECTIVE: This study was conducted to investigate the efficacy of treating central or paramedian disc herniations of the upper lumbar levels, including the thoracolumbar junction, through the oblique paraspinal approach. We published a technical case report on this subject in 2004. METHODS: Nineteen consecutive patients with intracanalicular disc herniations of the upper lumbar levels underwent the oblique paraspinal approach, which utilizes an operating microscope, from March 2005 through January 2008. Their clinical and radiological data were collected and analyzed. The patients were assessed with standard examinations preoperatively and evaluated with dynamic lumbar x-rays, 3-dimensional computed tomographic scans, magnetic resonance imaging, standard pain and disability measurements, a visual analogue scale, the Oswestry disability index, and a patient satisfaction rate that checked their pain scores postoperatively. RESULTS: The average follow-up period was 28.1 months, with a maximum of 48 months. The visual analogue scale for back and leg pain and the Oswestry disability index, which recorded a preoperative mean of 6.7%, 7.2%, and 64.7% and a postoperative mean of 3.2%, 3.0%, and 21.47%, respectively, showed statistically significant improvement at the time of the last follow-up evaluation, compared with preoperative scores. There have been neither recurrent disc herniations nor spinal instability during the follow-up period. CONCLUSION: In this study, 19 cases of intracanalicular disc herniations at the upper lumbar levels, including the thoracolumbar junction, were successfully excised with the oblique paraspinal approach without recurrence or instability. We found that the oblique paraspinal approach, which resulted in satisfactory clinical outcomes with few complications, could be one of the main surgical procedures used to treat intracanalicular disc herniations at the upper lumbar levels.
