Radiographic and Clinical Outcomes of Posterior Interbody Fusion for High-Grade Spondylolisthesis

ABSTRACT

STUDY DESIGN: Retrospective study. OBJECTIVES: To evaluate the clinical and radiological outcomes of posterior interbody fusion using pedicle screw fixation after posterior decompression for high-grade spondylolisthesis. SUMMARY OF LITERATURE REVIEW The surgical treatment of high-grade spondylolisthesis has been controversial. However, few reports on the results of reduction and posterior interbody fusion after posterior decompression have been published. MATERIALS AND METHODS: Thirteen patients with L5-S1 high-grade spondylolisthesis (Meyerding grade III, IV) who underwent reduction and posterior interbody fusion were analyzed with at least 2 years of follow-up. The mean age of the patients (male 2, female 11) was 51 years. Classified by the type of spondylolisthesis, 10 cases were isthmic, 2 cases dysplastic, and 1 case degenerative. A visual analogue scale (VAS), the Oswestry Disability Index (ODI) score, bone union, anterior slippage, and slip angle were used in comparing clinical and radiographic outcomes. RESULTS: All cases showed improvement of preoperative symptoms. The VAS and ODI score improved from a mean of 8.9 points and 36.2 points preoperatively to 2.1 points and 10.2 points, respectively, at last follow-up. The degree of anterior slippage measured by Taillard's method was improved from a mean of 57.7% before surgery to mean of 14.6% at last follow-up. The slip angle also changed from a mean of 2.4° kyphosis before surgery to a mean of 7.6°C lordosis at last follow-up. There were two complications infection and new radiating pain. CONCLUSIONS: Reduction and posterior interbody fusion using pedicle screw fixation after posterior decompression was a useful surgical method for high-grade spondylolisthesis that corrected lumbosacral kyphosis, filled the structural space of the anterior column, and acheived fusion of interbody movement.