ABSTRACT
Objective To explore the distribution of the plantar pressure in patients with knee osteoarthritis after knee joint replacement surgery.Methods The plantar pressure of 33 patients with double knee osteoarthritis and single knee replacement was measured using the Belgian footscan plantar pressure test system.The peak pressure,the impulse,the peak time of the peak pressure and the parameters of the foot support period were observed.Results The average peak pressure and average impulse of the 2nd,3rd and 4th foot metatarsal,together with the medial and lateral heel,midfoot and full plantar of the knee replacement side were higher than the other side but without significant differences (P＜0.001,P＜0.05).The duration of the maximum pressure peak of the lst,2nd,3rd,4th and 5th metatarsal area and midfoot of the knee replacement side was significantly longer than the other side (P＜ 0.001,P＜0.05).The time of initial contact phase,the duration of foot flat phase and the duration of all single foot support of knee replacement side were significantly longer than the other side(P＜0.05).Conclusions It shows that the plantar pressure parameters and the knee joint's movement ability have improved significantly after the replacement.The foot pressure analysis can be used to evaluate the function of knee joint,to better understand the biomechanical changes of knee joint,so as to explore the best treatment and rehabilitation after the knee arthroplasty.
ABSTRACT
Objective To investigate the role of hypoxia inducible factor-1α (HIF-1α) and von Hippel-Lindau (VHL) in murine endochondral ossification. Methods The knockout of HIF-1α or VHL gene in murine osteoblasts was accomplished by conditional knockout technique at 4th, 8th and 12th week, and the differences between wild-type group and knock-out group in endochondral ossification were detected by HE staining, micro-CT scanning, trabecular bone area measurement, calcium content measurement, tetracycline fluorescence labeling, Real-time PCR and Western blotting. Results After knockout of HIF-1α gene in osteoblasts, the expression of vascular endothelial growth factor ( VEGF) reduced, the rate of new bone formation stepped down, the content of calcium became less, and the trabecular bone volume decreased (P <0.05) . After knockout of VHL gene in osteoblasts, the expression of VEGF increased, the rate of new bone formation stepped up, the content of calcium became more, and the trabecular bone volume was promoted (P < 0.001). Conclusion During murine endochondral ossification, VHL/HIF-1α signal pathway promotes angiogenesis through the stimulation of VEGF expression, which subsequently accelerates osteogenesis.