Journal article

Publication year: 2013

Pages: 14-19

Journal: Zeitschrift für Orthopädie und Unfallchirurgie

Volume number: 151

Issue number: 1

ISSN: 1864-6697

eISSN: 1864-6743

DOI Link: https://doi.org/10.1055/s-0032-1327976

Publisher: Thieme

Abstract: 

Background: Osteoporosis is a widespread disease characterised by low bone mass and structural deterioration of bone resulting in an increased susceptibility to fractures. Osteoporosis affects women more frequently than men; every second woman older than 50 years suffers from an osteoporotic fracture, frequently a vertebral fracture. The aim of this study was to induce osteoporosis in rats to establish an osteoporotic small-animal model that simulates the human pathology particularly in the spine. Therefore, bone density parameters, which are routinely determined in the spine of osteoporotic patients, were investigated by Dual-Energy X-ray Absorptiometry (DEXA).

Materials and Methods: Fourteen-week-old female Sprague-Dawley rats (n = 50) were either sham-operated (control group: sham) or ovariectomised (experimental group). Ovariectomised rats were further divided into two groups; one received calcium/vitamin D-2/D-3 deficient diet (OVX + diet), and the other received subcutaneous steroid injections (dexamethasone 0.3 mg/kg body weight) twice a month (OVX + steroid). Rats were scanned by DEXA at three time points (Month = M, 0 M, 1M and 3 M). DEXA measurement of the spine delivered T-value, Z-value, bone mineral content (BMC), and the scanned area. Fifteen female patients at an age of 57-72 years were scanned in 8-10 regions of the spine (150 measurements). T-values and Z-values were pre-calculated based on patient databases. Statistical analysis was performed using two-way ANOVA followed by Bonferroni correction, with significance considered at p < 0.05.

Results: T-value and Z-value of both rat groups were compared with the patient data as well as with each others. Both treated rat groups revealed significantly lower T- and Z-values than controls. Despite the significant difference, the reference line (-2.5 for T-value and -1.5 for Z-value) was only reached by the OVX + diet group. On the other hand, the sham group showed an increase in BMC over time, while no change was seen in OVX + diet or OVX + steroid. Bone area demonstrated a significant increase up to M3. However, the increase in bone area within the OVX + diet group was notably higher than in both sham and OVX + steroid groups. Patients showed significantly lower T-and Z-values than sham and OVX + steroid but insignificant ones when compared with OVX + diet.

Conclusion: A reproducible vertebral osteoporosis can be generated in a rat model by combination of ovariectomy with administration of a calcium/vitamin D-3 deficient diet. T- and Z-values of this experimental group mimicked values obtained from osteoporotic patients, reflecting a simulation of their pathology. Interestingly, the increase in bone area over time with the steady BMC results in lower mineral density (BMD) of the OVX + diet group. Therefore, this rat model presents a reliable experimental set-up that may serve as a tool to better understand and treat osteoporosis.

Harvard Citation style: Schlewitz, G., Govindarajan, P., Schliefke, N., Alt, V., Böcker, W., El Khassawna, T., et al. (2013) Ovarektomie und Kalzium-/Vitamin D2/D3-arme Diät als Osteoporosemodell an der Wirbelsäule von Sprague-Dawley-Ratten, Zeitschrift für Orthopädie und Unfallchirurgie, 151(1), pp. 14-19. https://doi.org/10.1055/s-0032-1327976

APA Citation style: Schlewitz, G., Govindarajan, P., Schliefke, N., Alt, V., Böcker, W., El Khassawna, T., Thormann, U., Lips, K., Hemdan, N., Zahner, D., Schnettler, R., & Heiss, C. (2013). Ovarektomie und Kalzium-/Vitamin D2/D3-arme Diät als Osteoporosemodell an der Wirbelsäule von Sprague-Dawley-Ratten. Zeitschrift für Orthopädie und Unfallchirurgie. 151(1), 14-19. https://doi.org/10.1055/s-0032-1327976