Efficacy of calcium sulfate plus decompression bone in lumbar and lumbosacral spinal fusion: preliminary results in 40 patients.

Objective: To compare the efficacy of calcium sulfate pellets plus bone obtained from decompression with fresh autologous iliac crest bone in lumbar and lumbosacral spinal fusion with decompression. Design: A prospective randomized clinical trial. Setting: Four tertiary care centres in Halifax, NS. Patients: All were consenting, skeletally mature and suffering from degenerative disc disease or spondylolisthesis. The first 40 patients from a single test centre are reported; 32 of these had completed 1-year follow-up. Interventions: Posterolateral lumbar or lumbosacral spinal fusion with spinal canal decompression and randomized placement of test material (decompression bone plus an equal volume of calcium sulfate pellets) on one side and control material (autologous posterior iliac crest bone of equal volume to the test material) on the contralateral side, which allowed subjects to act as their own control. Outcome measures: Assessment of bone formation by radiographic evaluation at 6 and 12 months after fusion by an independent musculoskeletal radiologist blinded to the placement of test material. Results: At 6 and 12 months after fusion, 78% and 88% of patients, respectively, showed bone formation at the test site that was 75% to 100% of, equal to or more than that at the control site. Increases in bone formation at 6 and 12 months were almost identical at both sites. Smoking status, patient gender or age, instrumentation used and volume of graft used were not predictive of outcome. Conclusions: Calcium sulfate pellets plus decompression bone provided bone formation equivalent to autologous iliac crest bone in a majority of patients. Calcium sulfate pellets plus decompression bone may provide a viable alternative to autologous iliac crest as a graft material for spinal fusion. Objectif : Comparer l’efficacite des implants de sulfate de calcium associes a un greffon osseux preleve par decompression a l’efficacite d’un greffon d’os autologue frais preleve sur la crete iliaque dans la fusion des vertebres lombaires et lombosacrees avec decompression. Conception : Etude clinique randomisee prospective. Contexte : Quatre centres de soins tertiaires a Halifax (N.-E.). Patients : Tous les sujets etaient a maturite squelettique, souffraient d’une maladie degenerative des disques ou de spondylolisthesis et ont donne leur consentement. On rend compte des 40 premiers patients d’un seul centre d’essai, dont 32 ont termine le suivi d’un an. Interventions : Arthrodese posterolaterale du rachis lombaire ou lombosacre associee a une decompression du canal vertebral, et distribution au hasard du materiau a l’essai (greffon osseux preleve par decompression plus un volume egal d’implants de sulfate de calcium) d’un cote et du materiau temoin (un volume d’os autologue provenant de la crete iliaque posterieure egal a celui du materiau a l’essai) du cote controlateral, methode qui a permis a chaque sujet d’etre son propre temoin. Mesures de resultats : Evaluation de la formation osseuse au moyen d’un examen radiographique effectue a l’insu 6 et 12 mois apres la fusion par un radiologue independant et specialise en evaluation de l’appareil musculosquelettique. Resultats : Lors des evaluations a 6 et a 12 mois apres l’arthrodese, on a constate sur le site du materiau a l’essai de 78 % et 88 % des patients, respectivement, une formation osseuse qui representait de 75 % a 100 % de celle observee sur le