[Experimental study on repairing rabbit femoral condyles defect by small intestinal submucosa and HA-TCP compositions at different ratios].
OBJECTIVE
To study an optimal ratio of small intestinal submucosa (SIS) and (hydroxyapatite-tricalcium phosphate, HA-TCP, SIS/HA-TCP) compositions according to the effect of SIS/HA-TCP compositions with different ratios on repairing rabbit femoral condyle defect.


METHODS
Thirty-six rabbits were made into bone defect models of 6 mm in diameter and 10 mm in depth in both sides of femoral condyles. Three different ratios of SIS/HA-TCP compositions (w/w: 1, 0. 5, 0. 25) were implanted into rabbit femoral condyle defect. After 2, 4, 8 and 12 weeks of operation, the repair effect was observed grossly. The histological evaluations were performed by histological scoring system and computer imaging analysis system.


RESULTS
The amount of new bone formation in SIS/HA-TCP(0. 5) group was more than that in SIS/HA-TCP(1) and SIS/HA-TCP(0. 25) groups. Histological observation: In SIS/HA-TCP (1) group, few new bone formation was seen and bone defect was repaired in the 12th week. In SIS/HA-TCP (0.5) group, immature woven bone was found in the defect in the 2nd week; more immature woven bone appeared and formed trabeculae in the 4th week; the regenerated bone was vigorously growing into the interspaces of the implanted materials in the 8th week; the implanted materials was basically replaced by bony structure and the lamellar bone appeared in the 12th week. The results of SIS/HA-TCP (0. 25) group were similar to that of SIS/HA-TCP(0. 5) group. The histological scoring was higher in SIS/HA-TCP (0.5) and SIS/HA-TCP (0.25) groups than that in SIS/HA-TCP (1) group (P<0.05) in the 2nd, 4th, 8th, and 12th weeks. The scoring was higher in SIS/HA-TCP (0.5) group than that in SIS/HA-TCP (0.25) group in the 2nd and 12th weeks (P< 0.05). In new bone formation and the degradation of HA-TCP, SIS/HA-TCP (0.5) and SIS/HA-TCPC (0.25) groups were superior to SIS/HA-TCP (1) group (P<0.05), SIS/HA-TCP (0.5) group was superior to SIS/HA-TCP (0.25) group (P<0.05).


CONCLUSIONS
SIS/ HA-TCP (0.5) has better effects of repairing bone defect and it can be used as a reference ratio in constructing bone scaffolds.
Ma
Xin
X
Department of Orthopedic Surgery, Sixth People's Hospital of Shanghai Jiaotong University, Shanghai, 200233, P. R. China.
Zhang
Changqing
C
Zhang
Kaigang
K
D000818:Animals; D018786:Bone Substitutes; D002130:Calcium Phosphates; D004195:Disease Models, Animal; D005269:Femur / Q000293:injuries; D007421:Intestine, Small / Q000637:transplantation; D011817:Rabbits; D019651:Plastic Surgery Procedures
D018786:Bone Substitutes; D002130:Calcium Phosphates; C018392:tricalcium phosphate