Surgical management of isthmic spondylolisthesis with radicular pain.

Forty-six patients with low-grade isthmic spondylolisthesis (27 grade I and 19 grade II) and radicular pain underwent surgery after failure of conservative treatment for 6 months. Fusion and decompression was carried out in 23 patients (group 1) and fusion without decompression in the other 23 patients (group 2). Instrumentation was used in 16 patients who had instability and hypermobility as seen by dynamic radiography. Results were assessed functionally and radiographically and graded according to Stauffer and Coventry. The follow-up was an average of 20 (12-36) months. In group 1 there were 17 patients with excellent to good results, and in group 2, 21 patients. There was no significant statistical difference between the fusion rate in the two groups. Decompression in addition to fusion in adults with low-grade isthmic spondylolisthesis and radicular pain does not appear to improve the functional outcome.