Abstract
Summary
Fractures in post-menopausal osteoporosis cause significant morbidity; however, animal models for post-menopausal fracture healing lack the effect of ageing. Therefore, we developed a model using aged animals with chronic oestrogen deficiency, which demonstrates inferior fracture repair (decreased healing histologically, bone mineral density and content and strength). This novel model may help develop molecular strategies for osteoporotic fracture repair.
Introduction
The femur is susceptible to damage by both systemic conditions such as osteoporosis and locally by traumatic injury. The capacity for fracture repair decreases with age, while the risk of fracture increases. As studies of osteoporotic fracture healing in rats traditionally use a period of 3 months or less of oestrogen deficiency prior to fracturing, we aimed to establish a osteoporosis model in rats with chronic oestrogen deficiency by 12 months to better mimic human female osteoporosis.
Methods
Seventy female Sprague–Dawley rats (10 weeks old) were ovariectomised or sham operated and housed for 12 months. The right femur was fractured by way of an open osteotomy and fixed with an intramedullary Kirschner wire. Animals were sacrificed at 1, 3 and 6 weeks for radiography, dual-energy X-ray absorptiometry, tensile testing and histology.
Results
Bone mineral density and bone mineral content were lower by 60 and 63 %, respectively, (p < 0.05) in the bilaterally ovariectomized (OVX) groups than those in the sham groups at 6 weeks in the right fractured femurs. Maximum breaking force of the OVX group was lower than that of the sham group, with the greatest difference seen at 6 weeks following osteotomy. Histologically, the OVX groups demonstrated a delay in cellular differentiation within the fracture callus and the presence of bone resorption. The sham animals had a superior histological healing pattern with an Allen score of 4 at 6 weeks compared to a score of 1 for the OVX groups (p < 0.01).
Conclusions
Long-term ovariectomy has a deleterious effect on fracture healing in a rodent model.
Similar content being viewed by others
References
Namkung-Matthai H et al (2001) Osteoporosis influences the early period of fracture healing in a rat osteoporotic model. Bone 28(1):80–86
Tuck SP, Francis RM (2002) Osteoporosis. Postgrad Med J 78(923):526–532
Lane JM, Russell L, Khan SN (2000) Osteoporosis. Clin Orthop Relat Res 372:139–150
Chrischilles E, Shireman T, Wallace R (1994) Costs and health effects of osteoporotic fractures. Bone 15(4):377–386
Ohlin A, Johnell O, Lerner UH (1990) The pathogenesis of loosening of total hip arthroplasties. The production of factors by periprosthetic tissues that stimulate in vitro bone resorption. Clin Orthop Relat Res 253:287–296
Poole KE, Compston JE (2006) Osteoporosis and its management. BMJ 333:1251–1256
Cooper GS, Sandler DP (1997) Long-term effects of reproductive-age menstrual cycle patterns on peri- and postmenopausal fracture risk. Am J Epidemiol 145(9):804–809
Xu SW et al (2003) Early period of fracture healing in ovariectomized rats. Chin J Traumatol 6(3):160–166
Walsh WR et al (1997) Fracture healing in a rat osteopenia model. Clin Orthop Relat Res 342:218–227
Meyer RA Jr et al (2001) Age and ovariectomy impair both the normalization of mechanical properties and the accretion of mineral by the fracture callus in rats. J Orthop Res 19(3):428–435
Kubo T et al (1999) Osteoporosis influences the late period of fracture healing in a rat model prepared by ovariectomy and low calcium diet. J Steroid Biochem Mol Biol 68(5–6):197–202
Fu L et al (2009) Effect of 1,25-dihydroxy vitamin D3 on fracture healing and bone remodeling in ovariectomized rat femora. Bone 44(5):893–898
Comelekoglu U et al (2007) Biomechanical evaluation in osteoporosis: ovariectomized rat model. Clin Rheumatol 26(3):380–384
Cao Y et al (2002) Raloxifene, estrogen, and alendronate affect the processes of fracture repair differently in ovariectomized rats. J Bone Miner Res 17(12):2237–2246
Diwan AD et al (2000) Nitric oxide modulates fracture healing. J Bone Miner Res 15(2):342–351
Allen HL, Wase A, Bear WT (1980) Indomethacin and aspirin: effect of nonsteroidal anti-inflammatory agents on the rate of fracture repair in the rat. Acta Orthop Scand 51(4):595–600
Millett PJ et al (2003) Bone mineral density changes during fracture healing: a densitometric study in rats. http://www.uni-duesseldorf.de/WWW/MedFak/Orthopaedie/journal/issue98/tx3-3498.htm
Peng ZQ et al (1997) Long-term effects of ovariectomy on the mechanical properties and chemical composition of rat bone. Bone 20(3):207–212
Wronski TJ et al (1989) Long-term effects of ovariectomy and aging on the rat skeleton. Calcif Tissue Int 45(6):360–366
Kalu DN (1991) The ovariectomized rat model of postmenopausal bone loss. Bone Miner 15(3):175–191
Finkelman RD et al (1992) Ovariectomy selectively reduces the concentration of transforming growth factor beta in rat bone: implications for estrogen deficiency-associated bone loss. Proc Natl Acad Sci U S A 89(24):12190–12193
Syftestad GT, Urist MR (1982) Bone aging. Clin Orthop Relat Res 162:288–297
Cesnjaj M, Stavljenic A, Vukicevic S (1991) Decreased osteoinductive potential of bone matrix from ovariectomized rats. Acta Orthop Scand 62(5):471–475
Blythe JG, Buchsbaum HJ (1976) Fracture healing in estrogen-treated and castrated rats. Obstet Gynecol 48(3):351–352
Langeland N (1975) Effects of oestradiol-17 beta benzoate treatment on fracture healing and bone collagen synthesis in female rats. Acta Endocrinol (Copenh) 80(3):603–612
Wronski TJ et al (1985) Skeletal alterations in ovariectomized rats. Calcif Tissue Int 37(3):324–328
Bolander ME (1992) Regulation of fracture repair by growth factors. Proc Soc Exp Biol Med 200(2):165–170
Hill EL et al (1995) Ovariectomy impairs fracture healing after 21 days in rats. Trans Orthop Res Soc 20:230 (Abstract)
Jackson RW et al (1970) Production of a standard experimental fracture. Can J Surg 13(4):415–420
Bonnarens F, Einhorn TA (1984) Production of a standard closed fracture in laboratory animal bone. J Orthop Res 2(1):97–101
Lu J et al (2008) Posterolateral intertransverse spinal fusion possible in osteoporotic rats with BMP-7 in a higher dose delivered on a composite carrier. Spine (Phila Pa 1976) 33(3):242–249
Acknowledgments
We would like to acknowledge Julia Janssen of St. George Hospital for doing the DEXA scans for this study.
Conflicts of interest
None.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Oliver, R.A., Yu, Y., Yee, G. et al. Poor histological healing of a femoral fracture following 12 months of oestrogen deficiency in rats. Osteoporos Int 24, 2581–2589 (2013). https://doi.org/10.1007/s00198-013-2345-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00198-013-2345-2