Animal models of osteoporosis - necessity and limitations

Abstract

There is a great need to further characterise the available animal models for postmenopausal osteoporosis, for the understanding of the pathogenesis of the disease, investigation of new therapies (e.g. selective estrogen receptor modulators (SERMs)) and evaluation of prosthetic devices in osteoporotic bone. Animal models that have been used in the past include non-human primates, dogs, cats, rodents, rabbits, guinea pigs and minipigs, all of which have advantages and disadvantages. Sheep are a promising model for various reasons: they are docile, easy to handle and house, relatively inexpensive, available in large numbers, spontaneously ovulate, and the sheep's bones are large enough to evaluate orthopaedic implants. Most animal models have used females and osteoporosis in the male has been largely ignored. Recently, interest in development of appropriate prosthetic devices which would stimulate osseointegration into osteoporotic, appendicular, axial and mandibular bone has intensified. Augmentation of osteopenic lumbar vertebrae with bioactive ceramics (vertebroplasty) is another area that will require testing in the appropriate animal model. Using experimental animal models for the study of these different facets of osteoporosis minimizes some of the difficulties associated with studying the disease in humans, namely time and behavioral variability among test subjects. New experimental drug therapies and orthopaedic implants can potentially be tested on large numbers of animals subjected to a level of experimental control impossible in human clinical research.

Effect of stem cells combined with a polymer/ceramic membrane on osteoporotic bone repair

“…20 In the present study, the analyses were limited to the trabecular bone microarchitecture of the distal epiphysis of the femurs as it is a region that is particularly sensitive to the effects of OVX and recognized as a key component of quality and bone strength (resistance), comparable to osteoporosis in humans and detectable by microtomography. 18,21,22,23,24 The results revealed low bone quality of the femurs of OVX rats compared with SHAM rats. However, the lack of a statistically significant difference between the groups in terms of trabecular thickness may be associated with trabecular thickening in osteoporotic rats as an attempt to compensate for the decrease in bone resistance produced by trabecular resorption.…”

Effects of Systemic or Local Administration of Zoledronate on Implant Osseointegration: A Preclinical Meta-Analysis

“…By contrast, rabbits do have some inherent advantages as the osteoporosis animal model. For example, they achieve skeletal maturity shortly after reaching complete sexual development and show significant intracortical remodeling [43]. Thus, some researchers prefer rabbits as their ideal model.…”

Effect of Zirconia Dental Implant Surfaces on Bone Integration: A Systematic Review and Meta-Analysis

“…The characteristics of human bone are best approximated by dog models; but substantial differences exist in the bone anatomy, microstructure, and remodeling between rabbit and humane [42]. Rat is unsuitable due to significant dissimilarities in bone structure [43]. …”