Lumbar spinal fusion using recombinant human bone morphogenetic protein in the canine. A comparison of three dosages and two carriers.
METHODS
A randomized, prospective and controlled animal study.


OBJECTIVE
To evaluate lumbar spinal fusion using recombinant human bone morphogenetic protein 2 in a canine model.


BACKGROUND
Spinal fusion using autogenous bone grafting is associated with donor site morbidity and a nonunion rate of 5% to 35%. The use of recombinant human bone morphogenetic protein 2 as a bone graft substitute would eliminate donor site morbidity and perhaps augment the rate of successful fusion.


METHODS
Mature beagles underwent bilateral paraspinal exposure at L4-L5, followed by transverse process decortication and randomization into one of six groups using differing doses of recombinant human bone morphogenetic protein 2 implanted using either a Type I collagen carrier or a polylactic acid carrier. Two control groups were used: one group without recombinant human bone morphogenetic protein 2 and another group using autogenous rib graft alone.


RESULTS
Groups treated with recombinant human bone morphogenetic protein 2 demonstrated complete fusion in all animals. Animals treated with collagen carrier alone (no recombinant human bone morphogenetic protein 2) demonstrated complete absence of fusion. Successful fusion occurred in one of three canines in the autogenous bone graft group. Fusion masses in the recombinant human bone morphogenetic protein 2 treatment groups were significantly larger in size at 3 months than in the autogenous bone graft group. The collagen carrier was more biocompatible and biodegradable because residual polylactic acid carrier was seen with adjacent multinucleated giant cells. There was no evidence of spinal canal or nerve root encroachment in the recombinant human bone morphogenetic protein 2 treatment groups.


CONCLUSIONS
The use of recombinant human bone morphogenetic protein 2 implanted using a Type I collagen carrier resulted in 100% fusion without adverse effects.
David
S M
SM
Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, North Carolina, USA.
Gruber
H E
HE
Meyer
R A
RA
Murakami
T
T
Tabor
O B
OB
Howard
B A
BA
Wozney
J M
JM
Hanley
E N
EN
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D001861:Bone Regeneration / Q000187:drug effects*; D016025:Bone Transplantation / Q000000981:diagnostic imaging; D002417:Cattle; D003094:Collagen / Q000008:administration & dosage; D004195:Disease Models, Animal; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers / Q000008:administration & dosage; D016503:Drug Delivery Systems; D006801:Humans; D019344:Lactic Acid / Q000008:administration & dosage; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology / Q000601:surgery; D011091:Polyesters; D011108:Polymers / Q000008:administration & dosage; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000627:therapeutic use; D013123:Spinal Fusion / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016212:Transforming Growth Factor beta; D016896:Treatment Outcome
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D004337:Drug Carriers; D011091:Polyesters; D011108:Polymers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D019344:Lactic Acid; C033616:poly(lactide); D003094:Collagen