Published in:
01-12-2009 | Symposium: Tribute to Dr. Marshall Urist: Musculoskeletal Growth Factors
OP-1 Augments Glucocorticoid-inhibited Fracture Healing in a Rat Fracture Model
Authors:
Robert S. Gilley, DVM, PhD, DACVS, Larry J. Wallace, DVM, MS, DACVS, Craig A. Bourgeault, BS, Louis S. Kidder, PhD, Joan E. Bechtold, PhD
Published in:
Clinical Orthopaedics and Related Research®
|
Issue 12/2009
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Abstract
Glucocorticoids inhibit bone remodeling and fracture healing. We sought to determine whether osteogenic protein 1 (OP-1) can overcome this inhibition in a closed fracture model in the rat. Time-released prednisolone or placebo pellets were implanted subcutaneously; closed femoral fractures were created 2 weeks later in rats. Fractures received sham, OP-1 and collagen, or collagen-only implants. Femurs were harvested at 3, 10, 21, 28, and 42 days postfracture. Fractures were examined radiographically for amount of hard callus; mechanically for torque and stiffness (also expressed as a percentage of the contralateral intact femur); and histomorphometrically for amount of cartilaginous and noncartilaginous soft callus, hard callus, and total callus. Glucocorticoid administration inhibited fracture healing. The application of a devitalized Type I collagen matrix mitigated the inhibitory effects of prednisolone on fracture healing However, further increases in indices of fracture healing were observed when OP-1 was added to the collagen matrix compared with collagen alone. OP-1 and collagen was more effective than collagen alone.