Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective long-term study comparing fusion and pseudarthrosis.

STUDY DESIGN A prospective, randomized study on patients who underwent posterior lumbar decompression with bilateral posterolateral arthrodesis. OBJECTIVE To determine the long-term influence of pseudarthrosis on the clinical outcome of patients with degenerative spondylolisthesis and spinal stenosis. SUMMARY OF BACKGROUND DATA Spinal decompression and posterolateral arthrodesis have been shown to be beneficial in the surgical treatment of symptomatic spinal stenosis with concurrent spondylolisthesis. METHODS Forty-seven patients with single-level symptomatic spinal stenosis and spondylolisthesis were prospectively studied. Patients were treated with posterior decompression and bilateral posterolateral arthrodesis with autogenous bone graft. Radiographic evaluation was used to determine if fusion or pseudarthrosis was present. The solid fusion and pseudarthrosis groups were analyzed clinically, roentgenographically, and with a validated self-administered spinal stenosis questionnaire. RESULTS Forty-seven patients were available for review at a range of follow-up from 5 to 14 years. Average follow-up was 7 years 8 months. Clinical outcome was excellent to good in 86% of patients with a solid arthrodesis and in 56% of patients with a pseudarthrosis (P = 0.01). Significant differences in residual back and lower limb pain was discovered between the two groups using a scale ranging from 0 (no pain) to 5 (severe pain). Preoperative back and lower limb pain scores were statistically similar between the two groups. The solid fusion group performed significantly better in the symptom severity and physical function categories on the self-administered questionnaire. The two groups had similar results in the patient satisfaction category of this questionnaire. CONCLUSIONS In patients undergoing single-level decompression and posterolateral arthrodesis for spinal stenosis and concurrent spondylolisthesis, a solid fusion improves long-term clinical results. Benefits of a successful arthrodesis over pseudarthrosis were demonstrated with respect to back and lower limb symptomatology compared with prior shorter-term studies, which indicated no significant difference in clinical outcome between the two groups.