THE EFFECTS OF ORAL ESTROGEN AND PROGESTERONE ON THE ACL AND AT

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 前交叉韧带（ACL）撕裂是女性运动员的主要健康风险。与未受伤的女性相比，ACL撕裂的女性更容易发生早期膝关节退行性关节炎。ACL撕裂通常在受伤后产生6 - 12个月的残疾。全国大学生体育协会伤害监测调查数据表明，女大学生运动员的ACL撕裂率是男大学生运动员的3 - 8倍。前交叉韧带撕裂会导致女性立即和延迟残疾。 关于预防ACL撕裂的可改变风险因素知之甚少。发现这些因素已被国家关节炎、肌肉骨骼和皮肤病研究所（NIAMS）和妇女健康研究办公室确定为一个主要目标。有许多建议的风险因素，例如ACL撕裂和月经周期之间的建议关联。在月经周期中，ACL测量值会发生变化。雌激素水平的波动被认为是ACL性质变化的原因。包括跟腱（AT）在内的肌肉-肌腱复合体为膝关节提供额外的稳定性。这些辅助约束在膝关节的稳定性中起着重要作用。雌激素和孕激素影响肌腱和韧带（如ACL和AT）的胶原蛋白含量。一些研究人员建议口服避孕药，这可以防止雌激素激增，以防止伤害。这些建议还为时过早，因为ACL风险因素尚未得到彻底研究，并且目前使用口服避孕药的任何建议都来自小样本量的回顾性研究。 此外，还需要前瞻性、充分把握度的研究来确定补充激素（如口服避孕药（OCP））对ACL拉伸和应变特性的影响。以前的研究量化的ACL松弛度测量的变化在整个月经周期，而一个女人是OCP不存在。 拟议研究项目的具体目标是，首先确定在整个月经周期中，单相OCP对ACL测量的影响。拟议研究项目的第二个目的是确定在月经周期中双相OCP对肌腱伸展性的影响。最后，拟定项目将用作交叉研究的初步数据，研究在NIAMS的RO 3或RO 1应用程序中使用和不使用OCP的ACL测量结果的变化，这将对ACL撕裂的风险因素进行更全面的评价。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Anterior cruciate ligament (ACL) tears are a major health risk for female athletes. Early degenerative arthritis of the knee is more likely to develop in women with ACL tears as compared to their uninjured counterparts. ACL tears normally produce 6 - 12 months of disability after the injury. The National Collegiate Athletic Association Injury Surveillance Survey data identifies that female college athletes have a 3 - 8 times higher rate of ACL tears compared to males. ACL tears produce immediate and delayed disability in women. Little is known about modifiable risk factors in the prevention of ACL tears. Discovering these factors has been identified as a major goal by the National Institute of Arthritis Musculoskeletal and Skin Diseases (NIAMS) and the Office of Research on Women's Health. There are a number of proposed risk factors for instance a proposed association between ACL tears and the menstrual cycle. Over the menstrual cycle, changes are seen in the ACL measurements. The fluctuation of estrogen levels are proposed to be the cause of the changes in the ACL properties. Muscle-tendons complexes, including the Achilles tendon (AT), provide additional stability to the knee joint. These secondary restraints play an important role in the stability of the knee. Estrogen and progesterone affect the collagen content of tendons and ligaments (like the ACL and AT). Some investigators have recommended oral contraceptives, which prevents the estrogen spike, in order to prevent injury. These recommendations are premature since ACL risk factors have not been thoroughly studied and any current recommendations for the use of oral contraceptives are from retrospective studies with small sample sizes. Further, prospective, adequately powered, studies are needed to define the affects of supplemental hormones such as oral contraceptives (OCP) on the stretch and strain properties of the ACL. Previous studies quantifying the change in ACL laxity measurements across the menstrual cycle while a woman is on OCPs do not exist. The specific aims of the proposed research project are first, to identify the affects of a monophasic OCPs on ACL measurements across the menstrual cycle. The secondary aim of the proposed research project is to identify the affects of monophasic OCPs on tendon extensibility across the menstrual cycle. Lastly, the proposed project will be used as preliminary data for a cross-over study investigating the change in ACL measurements with and without OCPs in an RO3 or RO1 application to NIAMS, which will carry out a more comprehensive evaluation on the risk factors for ACL tears.