Radiographic evaluation of posterolateral lumbar fusion for degenerative spondylolisthesis: long-term follow-up of more than 10 years vs. midterm follow-up of 2-5 years.

Although posterolateral fusion of the lumbar spine without instrumentation has been widely performed for spinal instability caused by degenerative spondylolisthesis in the lumbar spine, few long-term follow-up studies have been reported. We studied ten patients who underwent posterolateral fusion for degenerative spondylolisthesis in the lumbar spine without instrumentation in our hospital, five of whom were followed up for more than 10 years and the other five for 2-5 years. We used radiography to examine their fusion status, instability and degenerative changes at the fusion level, change in the slip, change in lumbar lordosis, and instability and degenerative changes one level above and one level below the fusion. In most of the ten patients, radiographic evaluation demonstrated solid fusion, minimal degenerative changes, and preservation of lumbar lordosis and spinal mobility. Posterolateral lumbar fusion for degenerative spondylolisthesis in the lumbar spine seems promising for obtaining not only good radiographic features but also good clinical results lasting over more than 10 years.