| Objective To investigate the effect of parathyroid hormone (1-34) on implant osseointegration of strontium- containing hydroxyapatite coating in ovariectomized rats. Methods Twelve weeks after bilateral ovariectomy, the rats were randomly divided into control group, PTH group, Sr group, and PTH + Sr group. The HA-coated implants or Sr-HA implants were bilaterally inserted in all OVX rats. Subsequently, rats of PTH and PTH + Sr groups were given the treatment of PTH. In 12 weeks after therapy, all OVX rats were sacrificed and their femurs with implants were harvested and evaluated by micro-CT，histology, and biomechanical tests. Results Three dimensional reconstruction of Micro-CT showed that rats in PTH + Sr group had the largest bone tissue formation around implants. Compared to control group, the bone volume ratio of PTH + Sr group increased by 45 times, the trabecular number ( Tb. N) increased by 2. 94 times, the connectivity density (Conn. D) increased by 2. 31 times, the trabecular thickness (Tb. Th) increased by 1. 56 times, but the trabecular separation (Tb. Sp) decreased by 1. 65 times (P < 0.05). Bone biomechanical results indicate that, compared with that in the control group, Sr group, PTH group and PTH + Sr group, the maximum push-out force were increased by 1.27 times, 1. 36 times, and 1. 61 times ( P < 0. 05 ), respectively. Histological evaluation revealed that the bone area ratio (BAR) of Sr group, PTH group, and PTH + Sr group increased by 1. 52 times, 1. 73 times, and 2. 30 times (P <0.05)，respectively. Bone implant contact ratio (BIC) increased by 1. 35 times, 1.56 times, and 2. 21 times (P <0.05)，respectively, when compared with the control group. Conclusion Strontium-containing hydroxyapatite coating combined with PTH (1-34) enhances implant osseointegration in osteoporotic bone. |