Low-intensity pulsed ultrasound accelerated callus formation, angiogenesis and callus remodeling in osteoporotic fracture healing.
Osteoporotic fracture is a critical medico-social challenge leading to burdens in health care costs and hospital bed stays. Low-intensity pulsed ultrasound (LIPUS) was reported to accelerate normal fracture; however, its effect on osteoporotic fracture has not been previously addressed. We hypothesize that LIPUS can accelerate osteoporotic fracture healing and up-regulate the expression in the osteogenesis-, remodeling- and angiogenesis-related genes. Ovariectomy-induced osteoporotic fracture rat model was used to investigate the effects of LIPUS. Fractured rats were assigned to LIPUS or control group and healing was assessed by gene expression quantification, radiographic callus morphometry and histomorphometry. In the LIPUS group, Col-1 and bone morphogenetic protein-2 were up-regulated at earlier time points of week 2 to week 4 post-fracture; vascular endothelial growth factor was found to be up-regulated at week 4 to week 8; osteoprotegerin was up-regulated at week 2 post-fracture, followed by the surge of RANKL expression. Callus width and area measurements showed higher callus formation at weeks 2-4 in the LIPUS group and more rapid drop at weeks 6-8. Histomorphometry showed enhanced endochondral ossification in the callus at weeks 2-4, and lower at week 8. We conclude that LIPUS can accelerate osteoporotic fracture healing by enhancing callus formation, angiogenesis and callus remodeling.
Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China. louis@ort.cuhk.edu.hk
Wing-Hoi
WH
Cheung
Simon Kwoon-Ho
SK
Chow
Ming-Hui
MH
Sun
Ling
L
Qin
Kwok-Sui
KS
Leung
D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism; D002146:Bony Callus / Q000098:blood supply / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D005260:Female; D017102:Fracture Healing; D005786:Gene Expression Regulation; D010012:Osteogenesis / Q000235:genetics / Q000502:physiology; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging* / Q000628:therapy*; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014463:Ultrasonography
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D053245:RANK Ligand