Preprint version. Journal of Orthopaedic Research, Volume 24, Issue 4, April 1, 2006, pages 645-652. This is the pre-peer reviewed version of the following article: Effect of Low Molecular Weight Heparin on Fracture Healing in a Stabilized Rat Femur Fracture Model, David J. Hak, Rena L. Stewart, Scott J. Hazelwood, Journal of Orthopaedic Research, 24:4, Copyright © 2006 Wiley-Blackwell., which has been published in final form at http://dx.doi.org/10.1002/jor.20090.
NOTE: At the time of publication, the author Scott J. Hazelwood was not yet affiliated with Cal Poly.
The purpose of this studywas to evaluate the effect of low molecular weight heparin (LMWH) on fracture healing in a standard stabilized rat femur fracture model. A closed, mid-diaphyseal transverse fracture was created in the right femur of Long-Evans rats after insertion of a 0.8-mm K-wire into the medullarycanal. Animals were randomized to receive either LMWH (70 units/kg dalteparin) oraninjection of normal saline daily for 2 weeks. Animals were sacrificed at 2, 3, and 6 weeks. Fracture healing was assessedbyradiographs, histology, and mechanical testing. There were no significant differences between the control and LMWH groups in the percentage of animalswith radiographic bridging callus at each time point. Histologicappearance of fracture healing was similar between the control and LMWH groups. There were no significant differences in the normalized mechanical properties of the control and LMWH groups at 2 and 3 weeks. At 6 weeks, the percent torque of the LMWH group was significantly greater thanthe control group (p = 0.00 72), however, there was no significant difference in the stiffness and energy absorption. Dalteparin, at the dosage used in this study, did not impair fracture healing in this standard stabilized rat femur fracture model.
Biomedical Engineering and Bioengineering