Isthmic Spondylolisthesis in the Adult

Isthmic spondylolisthesis is a common condition and is frequently identified in the adult patient with low back pain. Although the natural history of this condition is not well defined, it is a common indication for nonoperative and operative treatment. The authors outline a systematic approach to the evaluation of the adult patient with isthmic spondylolisthesis. If radiologic studies are required, magnetic resonance imaging has improved the visualization of nerve-root compression in the neural foramen and is now widely used. Nonoperative treatment is the preferred approach in most symptomatic patients and is successful in as many as 60%. If nonoperative treatment fails, surgery may be recommended. Arthrodesis continues to be the mainstay of surgical treatment. Nerve-root decompression can be used in selected patients with radiculopathy. Although the Food and Drug Administration still considers the use of pedicle-screw instrumentation investigational or experimental, it has gained wide acceptance as an adjunct to fusion in the adult. It is important to note, however, that such use has not yet been proved safe and effective. Reduction of the spondylolisthetic segment has increased in acceptance for a small subset of patients with defined indications but carries a significant risk of complications.