Anterior Interbody Fusion Versus Posterolateral Fusion With Transpedicular Fixation for Isthmic Spondylolisthesis in Adults

Abstract

Clinical and radiographic results were assessed in adult patients who had undergone operation for isthmic spondylolisthesis. To compare the results between anterior interbody fusion and posterolateral fusion with those of transpedicular fixation for the treatment of isthmic spondylolisthesis in adults. Successful clinical results after fusion can be expected in adolescents, but the adult type differs in that stability through fusion alone fails to ensure satisfactory outcomes. The role of decompression in the surgical treatment of adult isthmic spondylolisthesis remains controversial. Anterior interbody fusion has an indirect effect of nerve root decompression through widening of the intervertebral space, whereas posterolateral fusion with transpedicular fixation provides direct decompression. The clinical data of 40 adult patients who had undergone operations for isthmic spondylolithesis from June 1977 through June 1994 were reviewed. Anterior interbody fusion was performed in 20 patients (Group I) and posterolateral fusion with transpedicular fixation in 20 patients (Group II). The mean age of Group I was 44.1 years (range, 21-62 years), and that of Group II was 41.3 years (range, 21-57 years). Group I contained B men and 12 women, Group II contained 5 men and 15 women. The symptoms and signs in Groups I and II were similar. The duration of follow-up averaged 3.6 years (range, 1.1-16 years) in Group I and 2.3 years (range, 1.1-6 years) in Group II. The anterior slippage in Group I, assessed by the Taillard method, was 16.1% and was corrected to 10.4% after surgery. Anterior slippage in Group II was 15.2% and was corrected to 9.8% after surgery. The fusion rate 12 months after surgery was 90% in Group I and 95% in Group II. The clinical results were analyzed by Kim's criteria, according to variables on the improvement of clinical symptoms. Satisfactory results were obtained in 85% of Group I and 90% of Group II. There was no statistically significant difference in clinical results between anterior interbody fusion and posterolateral fusion with transpedicular fixation for the treatment of isthmic spondylolisthesis in adults (P < 0.05).