Abstract:

BACKGROUND: Posterior vertebral bone fusion is a very common operation. Artificial bone can promote bone fusion, However, because the soft tissue may present some abnormal reactions to artificial bone, it is rarely used in posterior vertebral operation.
OBJECTIVE: To investigate a way to lower the reaction of soft tissue to artificial bone through a posterior vertebral bone fusion experiment in rabbits.
METHODS: Thirty-six adult male rabbits were randomly divided to absorbable hemostatic gauze group and control group. All rabbits were given a posterior vertebral bone fusion operation. The β-tricalcium phosphate artificial bone was implanted on the surface of L2-3 decorticating vertebral plate, and absorbable hemostatic gauze was laid between back soft tissue and β-tricalcium phosphate artificial bone in the absorbable hemostatic gauze group, while there was nothing between soft tissue and artificial bone in the control group. The C-reaction protein expression was detected at different time points after implantation, the skin healing and subcutaneous tissue healing at 1 and 12 weeks after implantation were recorded. The creeping substitution of artificial bone at different time points was recorded with CT.
RESULTS AND CONCLUSION: At 1 week after implantation, the back subcutaneous fascia of all rabbits in the absorbable hemostatic gauze group was well-healed, while among the nine rabbits in the control group, only seven rabbits were well-healed and two rabbits below the standard. At 12 weeks after implantation, among the nine rabbits in the absorbable hemostatic gauze group, the back subcutaneous fascia of eight rabbits was well-healed and one healed poorly; among the nine rabbits in the control group, the back subcutaneous fascia of six rabbits was well-healed and two was poorly healed, one rabbit suffered slight infection. At 1 week after implantation, there was muscle tissue congestion and inflammatory cell infiltration in two groups, but the inflammatory cell infiltration and local congestion in the absorbable hemostatic gauze group was less than those in the control group. At 12 weeks after implantation, granulation tissue hyperblastosis could be observed in the muscle tissue of two groups, but the inflammatory cell infiltration in the absorbable hemostatic gauze group was less than that in the control group, and necrosis tissues could be found in the control group. There was no significant difference of C-reaction protein expression between two groups immediately, 1 and 4 weeks after implantation. At 12 weeks after implantation, the CT results showed that there was significant absorption in the artificial bone adjacent to grafting interface, and there was almost no absorption in the artificial bone adjacent to soft tissue. There was no significant difference in absorption of artificial bone between two groups. Artificial bones should be put to contact with the grafting interface as much as possible, which can help the absorption of artificial bone and lower the reaction of soft tissue. Diminishing the contact between artificial bone and soft tissue may decrease the reaction of soft tissue to artificial bone. The biological isolation of absorbable hemostatic gauze and the tissue repair may decrease the reaction of soft tissue to artificial bone.

Key words: bone and joint implants, spinal implants, artificial bone, spine, vertebral body, bone graft, biological isolation, soft tissue, absorbable hemostatic gauze, skin healing, C-reaction protein, other grants-supported paper, photographs-containing paper of bone and joint implants