Hydroxyapatite biocoating improves bone-implant interface and promotes osseointegration / 中国组织工程研究

ABSTRACT

BACKGROUND:We have designed and manufactured a novel artificial cervical vertebra and intervertebral complex (ACVC) which combines the cervical titanium cage with the artificial cervical disc, and also developed the ACVC with a hydroxyapatite biocoating (ACVC-HA). OBJECTIVE:To evaluate biomechanical properties of the joint system, and the role of HA coating in promoting osseointegration and long-term stability. METHODS:Twenty-four goats were randomly divided into three groups and underwent the anterior C2/3 and C3/4 discectomy, and C3 subtotal corpectomy, fol owed by ACVC implantation (group 1) and ACVC-HA implantation (group 2), and given no intervention (black control group), respectively. group. At 12 weeks after surgery, C1-5 samples were col ected to undergo biomechanical tests and histological staining. RESULTS AND CONCLUSION:Prior to the fatigue test, compared with the blank control group, the range of motion and neural zone of groups 1 and 2 in the directions of flexion-extension and lateral bending showed no significant differences, but the above indicators were significantly increased in the direction of rotation (P<0.05). Additional y, the stiffness in al three directions was significantly lower than that in the blank control group (P<0.05). There were no significant differences in the range of motion and neural zone in al directions between groups 1 and 2. Similar results were found after the fatigue test. The histological staining showed that both two implants had good biocompatibility and abradability, but more new bone formed on the ACVC-HA. These results suggest that ACVC can effectively reconstruct the motor function of the cervical spine after decompression. Furthermore, HA coating can markedly improve bone-implant interface to promote osseointegration.