Evaluation of early tissue reactions after lumbar intertransverse process fusion using CT in a rabbit.
OBJECTIVE
The objective of the study was to evaluate tissue reactions such as bone genesis, cartilage genesis and graft materials in the early phase of lumbar intertransverse process fusion in a rabbit model using computed tomography (CT) imaging with CT intensity (Hounsfield units) measurement, and to compare these data with histological results.


METHODS
Lumbar intertransverse process fusion was performed on 18 rabbits. Four graft materials were used: autograft bone (n = 3); collagen membrane soaked with recombinant human bone morphogenetic protein-2 (rhBMP-2) (n = 5); granular calcium phosphate (n = 5); and granular calcium phosphate coated with rhBMP-2 (n = 5). All rabbits were euthanized 3 weeks post-operatively and lumbar spines were removed for CT imaging and histological examination.


RESULTS
Computed tomography imaging demonstrated that each fusion mass component had the appropriate CT intensity range. CT also showed the different distributions and intensities of bone genesis in the fusion masses between the groups. Each component of tissue reactions was identified successfully on CT images using the CT intensity difference. Using CT color mapping, these observations could be easily visualized, and the results correlated well with histological findings.


CONCLUSIONS
The use of CT intensity is an effective approach for observing and comparing early tissue reactions such as newly synthesized bone, newly synthesized cartilage, and graft materials after lumbar intertransverse process fusion in a rabbit model.
Shinbo
Jun
J
Tissue Engineering & Osteoarticular Research Unit, Institute of Pathology, University of Bern, Bern, Switzerland. sbj6725-@ka2.so-net.ne.jp
Mainil-Varlet
Pierre
P
Watanabe
Atsuya
A
Pippig
Suzanne
S
Koener
Jens
J
Anderson
Suzanne E
SE
D000818:Animals; D018786:Bone Substitutes / Q000008:administration & dosage*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000601:surgery*; D011379:Prognosis; D011817:Rabbits; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
D018786:Bone Substitutes