Pelvimetry in Squirrel Monkeys (Saimiri scireus Linnaeus, 1758)

Radiographic study of the axial and appendicular skeleton of Callithrix jacchus and Callithrix penicillata

BACKGROUND

Marmosets are small arboreal primates. Knowledge of normal radiographic parameters and frequent disorders is limited. The objectives of this study were to evaluate possible variations between quantitative analyses and injuries to the appendicular and axial skeleton of Callithrix jacchus and Callithrix penicillata and their relationship with the environment.

METHODS

Radiographic images of 29 marmosets were used. Skeletal lesions were described, long bones were measured, and pelvimetry, vertebrae, and sternebras were counted.

RESULTS

Measurements of long bones and pelvimetry were similar between species. Evaluation of vertebrae and sternebras exhibited variations relative to the literature. Lesions on the skull, spine, thoracic and pelvic limbs were present in 48%, 54%, 44%, and 52% of marmosets, respectively.

CONCLUSION

Skeletal disorders, especially of traumatic and metabolic origin, have a high prevalence in marmosets.

Female squirrel monkeys as models for research on women's pelvic floor disorders

Animal models enable research on biological phenomena with controlled interventions not possible or ethical in patients. Among species used as experimental models, squirrel monkeys (Saimiri genus) are phylogenetically related to humans and are relatively easily managed in captivity. Quadrupedal locomotion of squirrel monkeys resembles most other quadrupedal primates in that they utilize a diagonal sequence/diagonal couplets gait when walking on small branches. However, to assume a bipedal locomotion, the human pelvis has undergone evolutionary changes. Therefore, the pelvic bone morphology is not that similar between the female squirrel monkey and woman, but pelvic floor support structures and impacts of fetal size and malpresentation are similar. Thus, this review explores the pelvic floor support structural characteristics of female squirrel monkeys, especially in relation to childbirth to demonstrate similarities to humans.