title: Thromboprophylaxis using a low molecular weight heparin delays fracture repair.
abstract: Low molecular weight heparins are significantly superior to unfractionated heparin or warfarin in the prevention of thromboembolic episodes associated with orthopaedic surgery. Therapeutic doses of heparin and warfarin have been shown to delay bone repair in a rabbit model. The current study investigated the effect of prophylactic administration of a low molecular weight heparin, enoxaparin, on the healing of a closed rabbit rib fracture. Fracture healing was assessed using histomorphometric, histologic, and immunohistochemical methods at 3, 7, and 14 days, and biomechanical testing with torsional loading was assessed after 21 days. Bone repair was significantly attenuated at all times in animals receiving subcutaneous enoxaparin compared with that of the control animals. Numerous putative mechanisms for this phenomenon are discussed, and additional studies are proposed to elucidate the effects of this pharmacologically diverse group of compounds on all aspects of bone physiology and repair.
authors: Department of Academic Surgery, Cork University Hospital/University College Cork, Ireland.
authors: J T
authors: JT
authors: Street
authors: M
authors: M
authors: McGrath
authors: K
authors: K
authors: O'Regan
authors: A
authors: A
authors: Wakai
authors: A
authors: A
authors: McGuinness
authors: H P
authors: HP
authors: Redmond
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000009:adverse effects*; D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000187:drug effects; D002146:Bony Callus / Q000473:pathology; D004195:Disease Models, Animal; D017984:Enoxaparin / Q000009:adverse effects*; D017102:Fracture Healing / Q000187:drug effects*; D008297:Male; D011183:Postoperative Complications / Q000517:prevention & control*; D011817:Rabbits; D012253:Rib Fractures / Q000473:pathology / Q000601:surgery; D013927:Thrombosis / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin