Study design

Economic evaluation alongside a prospective, randomised, controlled trial from a two-year National Health Service (NHS) perspective.

Introduction: A prospective randomised controlled trial of circumferantial spinal fusion has shown superior clinical outcome when a femoral ring allograft (FRA) is used compared to when a titanium cage (TC) is used. The implant cost of the TC is nearly ten fold that of the FRA. However the additional costs of surgery and related costs also need to be considered to determine if there is a real cost advantage of FRA over TC. We can find no previously reported studies which economically evaluate the TC and the FRA in circumferential lumbar spinal fusion. The aim of this study was to investigate cost-effectiveness of TCs in comparison to FRAs for circumferential lumbar spinal fusion over a two year National Health Service (NHS) perspective using a cost-utility evaluation

Methods: This randomised study had the approval of the local ethical committee and the institutional research and development board (Reference OR059844) prior to its commencement. Eighty-three patients were randomly allocated to receive either the TC or FRA as part of a circumferential lumbar fusion between 1998 and 2002. NHS costs related to the surgery and revision surgery needed during the trial period were monitored and adjusted to the base year (2005/6 pounds sterling). The Short Form-6D (SF-6D) was administered preoperatively and at 6, 12 and 24 months in order to elicit patient utility and subsequently Quality-Adjusted Life Years (QALYs) for the trial period. Return to paid employment was also monitored. Bootstrapped mean differences in discounted costs and benefits were generated in order to explore cost-effectiveness.

Results: Baseline demographic data including age, sex, smoking history, previous surgery history and number of operated levels did not differ between the two groups. A significant cost difference of £1,942 (AUD4,255), (95% CI £849 (AUD1,860) to £3,145 (AUD6,891)) in favour of FRA was found. Mean QALYs per patient over the 24 month trial period were 0.0522 (SD 0.0326) in the TC group and 0.1914 (SD 0.0398) in the FRA group, producing a significant difference of −0.1392 (95% CI 0.2349 to 0.0436). With regard to employment, incremental productivity costs were estimated at £185,171 (AUD 405,745) in favour of FRA.

Discussion: From an NHS perspective, the trial data show that TC is not cost-effective in circumferential lumbar fusion. The use of FRA was found to dominate (generating greater QALY gains and less cost). In addition FRA patients reported a greater return to work rate and hence, productivity costs were also in favour of FRA.

Study Design: Economic evaluation alongside a prospective, randomized, controlled trial from a 2-year NHS perspective.

Objective: To determine the cost-effectiveness of Titanium Cages (TC) compared to Femoral Ring Allografts (FRA) in circumferential lumbar fusion.

Summary of background data: A randomised controlled trial has shown the use of TC to be clinically inferior to the established practice of using FRA in circumferential lumbar fusion. Health economic evaluation is urgently needed to justify the continued use of TC, given that this treatment is less effective and, all things being equal, more costly than FRA.

Methods: Eighty-three patients were randomly allocated to receive either the TC or FRA as part of a circumferential lumbar fusion between 1998 and 2002. NHS costs related to the surgery and revision surgery needed during the trial period were monitored and adjusted to the base year (2005/6 pounds sterling). The Short Form-6D (SF- 6D) was administered preoperatively and at 6, 12 and 24 months in order to elicit patient utility and subsequently Quality-Adjusted Life Years (QALYs). Return to paid employment was also monitored. Bootstrapped mean differences in discounted costs and benefits were generated in order to explore cost-effectiveness.

Results: A significant cost difference of £1,942 (95% CI £849 to £3,145) in favour of FRA was found. Mean QALYs per patient over the 24 month trial period were 0.0522 (SD 0.0326) in the TC group and 0.1914 (SD 0.0398) in the FRA group, producing a significant difference of 0.1392 (95% CI 0.2349 to 0.0436). With regard to employment, incremental productivity costs were estimated at £185,171 in favour of FRA.

Conclusion: From an NHS perspective, the trial data show that TC is not cost-effective in circumferential lumbar fusion. The use of FRA was both cheaper and generated greater QALY gains. FRA patients reported a greater return to work rate.

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.