7:58 Adjacent segment failure above lumbosacral fusions instrumented to L1 or L2

Abstract

Purpose of study: Adjacent segment degeneration has been recognized as a problem in lumbar fusion surgery. Several studies have evaluated the radiographic changes adjacent to fusions, but very little has been reported on adjacent segment degeneration as it relates to the level of lumbar fusion. During routine follow-up of adult patients with long instrumented lumbar fusions, we noticed an unexpectedly high number of complications at the cephalad end of the fusion construct. This review was designed to evaluate the rate of adjacent segment problems in patients with instrumented lumbar fusions from the sacrum to L1 or L2.Methods used: From 1994 to 2000, 20 adult patients, with an average age of 56 years, who underwent lumbosacral fusions from the sacrum to L1 or L2 for a variety of spinal pathologies, including degenerative spinal stenosis, scoliosis, postlaminectomy syndrome, pseudarthrosis and spondylolisthesis, were retrospectively reviewed from a prospectively gathered computerized database. Clinical outcomes, pain scores, Short Form (SF)-36 scores, satisfaction scores, reoperation rates and radiographic analysis were performed for all patients at a minimum 2-year follow-up.of findings: Overall, the clinical results for these patients after their index surgery were poor with only two patients having a good or excellent clinical result. Nine patients had adjacent segment failure, usually within the first 2 years postoperatively. Reoperations were required in seven patients, four for fracture at or above the most superior instrumented vertebra, two for adjacent segment degeneration and spinal stenosis and one for infection. One other patient had a pedicle fracture above his fusion treated nonperatively, and two more patients have developed symptomatic adjacent segment degeneration requiring further nonoperative care and are being considered for reoperation.Relationship between findings and existing knowledge: Although the effects of fusion on the acceleration of degenerative changes at levels adjacent to lumbar fusions have been recognized, little has been published about the need for reoperations for symptomatic degeneration, and very few publications have evaluated the effects of number of fusion levels on adjacent segment failure. This study supported the initial clinical observation that instrumented lumbosacral fusions in the adult degenerative population that included the L1 or L2 vertebra resulted in high incidence of adjacent segment failure.Overall significance of findings: Fractures or rapid disc degeneration with subsequent stenosis occurred in half of the patients within the first 2 years of surgery. Because of this unacceptably high rate of early adjacent segment failure, we cannot recommend to L1 or L2 in the adult degenerative population.Disclosures: Device or drug: lumbar pedicle screws. Status: approved.Conflict of interest: No conflicts.