Stimulated angiogenesis for fracture healing augmented by low-magnitude, high-frequency vibration in a rat model-evaluation of pulsed-wave doppler, 3-D power Doppler ultrasonography and micro-CT microangiography.
This study aimed to investigate the mechanism of low-magnitude high-frequency vibration (LMHFV) treatment on angiogenesis and blood flow for enhancement of fracture healing. Nine-month-old ovariectomized (OVX) and sham-operated (Sham) rats received closed fractures creation at the femora and were randomized into LMHFV treatment (Sham-V, OVX-V) or control (Sham-C, OVX-C) groups. Pulsed-wave Doppler indicated an increase in blood flow velocity of the femoral artery at weeks 2 (OVX pair: p = 0.030) and 4 (OVX pair: p = 0.012; Sham pair: p = 0.020) post-treatment. Significantly enhanced vascular volume (VV) at the fracture site in the vibration groups was demonstrated by 3-D high-frequency power Doppler at week 2 (Sham pair: p = 0.021) and micro-computed tomography (microCT) microangiography at weeks 2 (OVX pair: p = 0.009) and 4 (OVX pair: p = 0.034), which echoed the osteogenesis findings by radiographic and microCT analysis. VV in the OVX groups was inferior to the Sham groups. However, OVX-V showed higher percentages of angiogenic enhancement than Sham-V. Despite impaired neo-angiogenesis in osteoporotic fractures, LMHFV could increase blood flow and angiogenesis in both normal and osteoporotic fractures, thus enhancing fracture healing.
Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
Wing-Hoi
WH
Cheung
Ming-Hui
MH
Sun
Yong-Ping
YP
Zheng
Winnie Chiu-Wing
WC
Chu
Andraay Hon-Chi
AH
Leung
Ling
L
Qin
Fang-Yuan
FY
Wei
Kwok-Sui
KS
Leung
D000792:Angiography; D000818:Animals; D001842:Bone and Bones / Q000098:blood supply*; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D017102:Fracture Healing; D007150:Immunohistochemistry; D018919:Neovascularization, Physiologic; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018608:Ultrasonography, Doppler; D018617:Ultrasonography, Doppler, Pulsed; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014732:Vibration / Q000627:therapeutic use*; D055114:X-Ray Microtomography
D042461:Vascular Endothelial Growth Factor A