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

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。前交叉韧带（ACL）撕裂是女运动员的主要健康风险。与未受伤的女性相比，前交叉韧带撕裂的女性更容易发生膝关节早期退行性关节炎。前交叉韧带撕裂通常会导致受伤后6 - 12个月的残疾。美国大学体育协会损伤监测调查数据表明，女大学运动员的前交叉韧带撕裂率是男运动员的3 - 8倍。前交叉韧带撕裂在女性中产生即时和延迟的残疾。对于预防前交叉韧带撕裂的可改变的危险因素知之甚少。发现这些因素已被国家关节炎、肌肉骨骼和皮肤疾病研究所（NIAMS）和妇女健康研究办公室确定为一个主要目标。有许多被提出的危险因素，例如前交叉韧带撕裂和月经周期之间的联系。在月经周期中，ACL测量值发生变化。雌激素水平的波动可能是导致前交叉韧带特性改变的原因。肌肉-肌腱复合物，包括跟腱（AT），为膝关节提供额外的稳定性。这些二级约束对膝关节的稳定起着重要的作用。雌激素和黄体酮影响肌腱和韧带（如前交叉韧带和AT）的胶原蛋白含量。一些研究人员推荐口服避孕药，以防止雌激素飙升，以防止受伤。这些建议还为时过早，因为ACL的危险因素尚未得到彻底的研究，目前任何关于口服避孕药使用的建议都是来自小样本量的回顾性研究。此外，需要前瞻性、充分有力的研究来确定口服避孕药（OCP）等补充激素对前交叉韧带拉伸和应变特性的影响。先前的研究量化了女性服用ocp后整个月经周期中ACL松弛度的变化，目前还不存在。提出的研究项目的具体目的是首先，确定单相OCPs对月经周期内ACL测量的影响。提出的研究项目的第二个目的是确定单相ocp对整个月经周期的肌腱延伸性的影响。最后，该项目将作为交叉研究的初步数据，研究在NIAMS应用RO3或RO1时，使用和不使用ocp时ACL测量的变化，这将对ACL撕裂的危险因素进行更全面的评估。

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.