Introduction Circumferential fusion has become a common procedure in lumbar spinal fusion, both as a primary and salvage procedure. However, the claimed advantages of circumferential fusion over conventional posterolateral fusion lack scientific documentation. The aim of the present study was to analyse the long-term outcome; functional disability, pain and general health of circumferential lumbar fusion in comparison to instrumented posterolateral lumbar fusion.

Methods From April 1996 to November 1999 a total of 148 patients with severe chronic low back pain were randomly selected for either posterolateral lumbar fusion (titanium Cotrel-Dubousset) or circumferential lumbar fusion (instrumented posterolateral fusion with anterior intervertebral support by a Brantigan cage). The primary outcome measure was the Dallas Pain Questionnaire (DPQ). The secondary outcome measures were, the Oswestry Disability Index, the SF-36 instrument and the Low Back Pain Rating Scale. All measures assessed the end-point outcomes at 5–9 years postoperatively.

Results The available follow-up rate was 93%. The circumferential group showed a significantly better improvement (p< 0.05) in comparison to the posterolateral group with respect to all four DPQ categories: daily activities, work/leisure, anxiety/depression and social interest. The Oswestry Disability Index supported these results (p< 0.01) in the circumferential group where as no significant difference was found with respect to mental health compared to the posterolateral group. The circumferential group showed significantly less back pain (p< 0.05) in comparison to the posterolateral group. No significant difference was found regarding leg pain.

Discussion Circumferential lumbar fusion demands more extensive operative resources compared to posterolateral lumbar fusion. However, 5–9 years after surgery the circumferentially fused patients had a significantly improved outcome compared to posterolateral fusion alone. These new results underline the superiority of circumferential fusion in the complex pathology of the lumbar spine and are strongly supported in all validated questionnaires.