Abstract
Introduction We report the two-year clinical outcome of a prospective randomised trial comparing Femoral Ring Allograft (FRA) to a Titanium Cage (TC) in circumferential lumbar spinal fusion.
Methods 83 patients recruited to the study fulfilled strict entry requirements (> 6 months chronic discogenic low back pain, failure of conservative treatment, one or two-level discographically proven discogenic pain source). 38 patients were randomised to receive FRA, 45 patients were randomised to receive TC. Posterior stabilisation was achieved with translaminar or pedicle screws. Patients completed questionnaires including Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) and the Short-Form 36 (SF-36) pre-operatively and 6, 12 and 24 months post-operatively.
Results Results were available for all 83 patients with a mean follow-up of 26.5 months (range 24–75 months). Baseline demographic data (age, sex, smoking history, number of operated levels, pre-operative outcome measures) showed no statistical difference between groups (p< 0.05). For patients receiving the FRA, mean VAS (back pain) improved 2.0 points (p=0.01), mean ODI improved 14 points (p=< 0.01), and mean SF-36 scores improved by > 11 points in all domains (p< 0.03) except general health and emotional role. For patients receiving the TC, mean VAS improved 1.2 points (p=0.002), mean ODI improved 5 points (p=0.02); SF-36 improved significantly in only one of eight domains (bodily pain).
Discussion Clinical outcome following circumferential lumbar fusion with FRA readily achieves the accepted mean clinically important differences (MCID). Fusion with TC does not achieve the MCID. The use of TC for circumferential lumbar fusion appears not to be justified.
Please send correspondance to BASS at the Royal College of Surgeons, 35 - 43 Lincoln’s Inn Fields, London WC2A 3PE, UK.
