Effect of Hormone Therapy on Tensile Strain of the Macaque Inferior Glenohumeral Ligament

The effect of hormone treatment on the material properties of ligaments has been extensively studied for the anterior cruciate ligament (ACL). However, there have been few studies on the effects of hormones on the material properties of the shoulder. Shoulder ligaments contribute to overall shoulder stability, and a change in ligament properties could contribute to a change in overall shoulder laxity. Cynomolgus monkeys have served as nonhuman primate models in studies examining the effects of hormone replacement therapy on the cardiovascular system, as well as serving as a model for menopause, reproductive support structures, the knee joint and shoulder joint. The cynomolgus macaques are commonly used for studies involving hormone replacement therapy because they have 28-day menstrual cycles with very similar hormonal patterns to that of women. This study uses female cynomologus macaque (Macaca fascicularis) monkeys as an animal model of the human shoulder to determine if estrogen has an effect on the strain distribution of the inferior glenohumeral ligament (IGHL).