Isthmic Lumbar Spondylolisthesis.

Lumbar isthmic spondylolisthesis is the anterior translation of one lumbar vertebra relative to the next caudal segment as a result of an abnormality in the pars interarticularis. Although it is most often an asymptomatic radiographic finding, symptomatic patients may present with low back and/or radicular leg pain. In the setting of persistent symptoms, despite nonoperative treatment, surgery can be considered. Successful arthrodesis and neurologic decompression, when necessary, are the chief goals of surgical treatment, which has demonstrated reasonable long-term outcomes. A variety of surgical treatment options are available and the relative efficacy of them based on patient-specific factors continue to be investigated.