Posterolateral spinal fusion: a study of 123 cases with a long-term follow-up

A total of 123 patients submitted to posterolateral fusion according to the Wiltse method were followed-up after 2-10 years (mean 6 years and 2 months). The series included: isthmic spondylolisthesis: 80; degenerative spondylolisthesis: 18; failed back syndrome: 25. Good morphological fusion of the arthrodesis evaluated by conventional radiology and CT, was obtained in 87% of the entire series, while in 89% of the cases excellent or good clinical results were obtained according to the Friberg evaluation scale. Extent of the fusion to 1 or 2 intervertebral segments, or association of laminectomy did not influence the results. Clinical and radiographic results were maintained stable in time: in only 3 cases did we observe clinical deterioration due to degeneration of the segment located above the fusion 3-7 years after surgery. The only important complications observed were one cauda equina syndrome due to peridural hematoma after laminectomy-fusion, and one iliocaval venous thrombosis. The results of the series studied and the data reported in the literature show that posterolateral fusion is a method capable of providing a high percentage of good clinical and radiographic results, and it may be favorably compared with methods of interbody fusion and of pedicular fixation, compared to which it has the advantage of involving a minor number of complications. Anterior interbody fusion is however indicated for stabilization of the reduction of severe spondylolisthesis in the adolescent. Fusion with pedicular osteosynthesis is indicated for the treatment of macroscopic instability and in fusions which are extended to more than two intervertebral segments.