Partial Lumbosacral Kyphosis Reduction, Decompression, and Posterior Lumbosacral Transfixation in High-Grade Isthmic Spondylolisthesis Clinical and Radiographic Results in Six Patients

Background. In an attempt to increase fusion while decreasing the neurologic risk associated with complete reduction of high-grade spondylolisthesis, the authors have used a technique of partial lumbosacral kyphosis reduction, posterior decompression, and pedicle screw transfixation of the lumbosacral junction. Objective. To determine if this technique is effective in treatment of high-grade spondylolisthesis. Study Design. A retrospective review of six patients with high-grade spondylolisthesis treated by this technique was performed. There were four female patients (ages 16 years [n = 2], 23 years [n = 1], and 29 years [n = 1]) and two male patients (both 13 years of age) with spondylolisthesis ranging from Grade IV to Grade V. All patients presented with pain and radiculopathy. After surgery the patients were evaluated for resolution of symptoms, sagittal alignment, fusion, and satisfaction. The radiographic measurements included the slip angle, the percentage slip, and the sacral inclination. An SRS outcome score was also obtained on all six patients to evaluate postoperative outcome, in terms of pain control, self-image perception, and return to function. Results. The average length of follow-up was 42.6 months (range 24-60 months). All patients evidenced solid fusion by the 6-month follow-up (based on oblique radiographs showing lateral bridging bone masses). The slip angle was improved from 62 degrees to 28 degrees (P < 0.5), whereas there was no significant improvement in the percentage slip or the sacral inclination (89-80% and 28-37 degrees, respectively). No progression of the slip angle or percentage slip was noted on the follow-up radiographs. Complications included two intraoperative dural tears that were identified and repaired. There were no neurologic complications. The SRS outcome instrument demonstrated good postoperative pain control, function, self-image, and satisfaction in all patients. Conclusion. In high-grade spondylolisthesis, this posterior approach is safe and effective in obtaining a solid arthrodesis, restoring sagittal balance, and improving function. These results reinforce the impression that it is the partial reduction of the slip angle, not the percentage slip, in high-grade spondylolisthesis that is important in obtaining optimal results.