Experimental anterior lumbar interbody fusion with an osteoinductive bovine bone collagen extract.
METHODS
A randomized experimental porcine anterior lumbar interbody fusion.


OBJECTIVE
To determine the osteoinductive potential of a bovine bone derived collagen lyophilisate for anterior interbody spinal fusion in an animal model.


BACKGROUND
Complications associated with autologous bone graft harvesting are still major concerns when performing spinal fusion surgery. A new formulation of bovine bone collagen-protein extracts (Colloss) has been shown to be effective in animal studies as a bone graft enhancer. The present study further tested its osteogenic potential in the anterior spinal fusion cage in a controlled animal study.


METHODS
Twelve normal Danish landrace pigs of 50 kg each were chosen as experimental animals. Lumbar spine interbody fusion of L3-L4, L4-L5 using titanium alloy cages was performed on each pig with pedicle screws instrumentation. Cages packed with either autograft or Colloss were randomly assigned to the two levels. Pigs were followed up to 3 months. After termination, the spine segments were evaluated by radiograph, micro-CT, and histomorphometry


RESULTS
Ten pigs completed the study. Implant breakage, loosening, or spinal deformity was not observed after 12 weeks on radiograph examination. Micro-CT evaluations demonstrated that cages with Colloss had the same fusion rate (9 of 10) as those with autograft, further evaluation of bone volume (BV/TV), and trabecular thickness (Tb Th) also showed no different between them. Histologically, both autograft and Colloss levels had 80% (8 of 10) fusion rate. Histomorphometric results revealed that the only difference was the Colloss-filled cages had a higher cartilage tissue volume (P < 0.04).


CONCLUSIONS
Colloss was effective as a bone graft substitute. It achieved the same fusion rate and the samepercentage of new bone formation as that of autologous iliac bone graft in this demanding porcine anterior spinal fusion model after 12 weeks.
Li
Haisheng
H
Orthopaedic Research Laboratory, Orthopaedic Department E, Aarhus University Hospital, and the Institute of Experimental Clinical Research, Aarhus University, Aarhus, Denmark. haisheng.li@iekf.au.dk
Zou
Xuenong
X
Woo
Charlotte
C
Ding
Ming
M
Lind
Martin
M
Bünger
Cody
C
D000818:Animals; D001863:Bone Screws; D001842:Bone and Bones / Q000737:chemistry*; D002417:Cattle; D003094:Collagen / Q000302:isolation & purification* / Q000627:therapeutic use*; D005260:Female; D005612:Freeze Drying; D007085:Ilium / Q000637:transplantation; D016268:Internal Fixators; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D010012:Osteogenesis / Q000187:drug effects*; D011859:Radiography; D013123:Spinal Fusion / Q000379:methods*; D013552:Swine; D014020:Tissue Extracts; D014182:Transplantation, Autologous
D014020:Tissue Extracts; D003094:Collagen