Bone morphogenetic protein (RhBMP-2) as a substitute for iliac crest bone graft in multilevel adult spinal deformity surgery: minimum two-year evaluation of fusion.
METHODS
Prospective, single center, nonblinded radiographic analysis of anterior and posterior adult spinal deformity fusions performed with bone morphogenetic protein (rhBMP-2).


OBJECTIVE
To determine the ability of rhBMP-2 to achieve multilevel spinal fusion in the deformity patient.


BACKGROUND
No previous study has evaluated rhBMP-2 for multilevel adult spinal deformity fusion with 2-year results. We postulated fusion could be achieved without distant autogenous graft harvest.


METHODS
Prospective analysis was performed for 98 patients (308 levels; mean age, 51.4 years) who underwent multilevel anterior or posterior spinal fusion (PSF) with minimum 2-year follow-up (average, 2.6 years). Group 1 (10 mg/level) contained 47 patients (109 levels; 2.33 levels/patient) who underwent anterior spinal fusion (ASF): BMP on an absorbable collagen sponge (ACS) with a titanium mesh cage. Group 2 (20 mg/level) included 43 patients (156 levels; 3.63 levels/patient) with PSF: BMP on an ACS with local bone graft (LBG) and bulking agent [tricalcium phosphate/hydroxyapatite (TCP-HA)]. Group 3 (40 mg/level) contained 8 patients (43 levels; 5.38 levels/patient) with PSF: rhBMP-2 and TCP-HA with no autologous bone. Confounding negative factors were present in the study population: medical comorbidities (26%), tobacco use (17%), revision surgery (34%), previous laminectomy (51%), and preoperative pseudarthrosis (27%). Postoperative films (AP, lateral, oblique) were evaluated by independent observers. Average fusion grade was based on a published scale.


RESULTS
Overall fusion rate was 95%. (group 1 91%, group 2 97%, group 3 100%). No confounding factor demonstrated a detrimental statistical significance to fusion.


CONCLUSIONS
In multilevel ASF, BMP (10 mg/level) generates fusion without autogenous bone. In multilevel PSF, BMP (20 mg/level) with LBG and TCP-HA produced fusion. BMP (40 mg/level) and TCP-HA without LBG achieved fusion. In multilevel spinal fusion, rhBMP-2 eliminated the necessity for iliac crest bone graft and yielded an excellent fusion rate.
Mulconrey
Daniel S
DS
Department of Orthopaedic Surgery, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri, USA.
Bridwell
Keith H
KH
Flynn
Jennifer
J
Cronen
Geoffrey A
GA
Rose
Peter S
PS
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D001861:Bone Regeneration / Q000187:drug effects; D016025:Bone Transplantation; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007085:Ilium / Q000637:transplantation*; D008297:Male; D008875:Middle Aged; D016348:Osseointegration / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D011446:Prospective Studies; D011542:Pseudarthrosis / Q000601:surgery; D011859:Radiography; D011994:Recombinant Proteins / Q000627:therapeutic use*; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*; D016896:Treatment Outcome
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2