Novel MRI Methods for Osteochondritis Dissecans (OCD) / Osteochondrosis (OC)

项目总结/摘要 剥脱性骨软骨炎（OsteochondritisDissecans，OCD）/骨软骨病（Osteochondrosis，OC）是儿童骨科的重要疾病。 然而，病因和发病机制仍不清楚。OCD/OC在以下人群中非常普遍（几乎100%受影响）： 猪的生长导致跛行。我们小组以前的工作已经证明， 猪的OCD/OC涉及软骨管血液供应的失败，导致骨骺坏死（生长） 软骨我们假设儿童OC/OCD的发病机制是相似的;然而， 软骨管供血不足和剥脱性骨软骨炎（OCD）之间的关系尚未得到证实。 由于1）缺乏非侵入性成像技术来在体内可视化这些结构和2）有限 获取适当的死后组织我们已经开发了一种独特的合作， 共振成像（MRI）专家和兽医和人类骨科研究人员，将利用 明尼苏达大学磁共振研究中心的特殊资源， 上述知识的差距。我们小组最近开发并验证了MRI方法， 软骨管血管和骺软骨缺血性坏死。我们希望 将这些研究扩展到儿童和青少年，以调查关节的成熟过程， 非侵入性地在人类股骨远端的骺软骨中进行，并将其与猪中发生的进行比较。这 将通过完成四个具体目标来实现。目标1和2侧重于发展/ 实施/验证新的MRI技术，离体，以成像血管供应和软骨基质 正常儿童和年轻猪尸体标本的特征/形态， 将存在骨软骨病的亚临床病变（允许评价正常组织以及区域 软骨坏死）。目标3和4侧重于快速儿科成像协议的开发和测试 用于正常儿童和首次诊断为强迫症的儿童的体内研究。这项研究将有多个 1）证实猪是这种重要的人类疾病的非常合适的动物模型，2） 提供了在疾病发展的早期诊断疾病的方法， 可能是有效的，和3）大大提高了我们对疾病的病理生理学的理解。

Project Summary/Abstract Osteochondritis Dissecans (OCD)/Osteochondrosis (OC) is an important orthopaedic disease in children; however, the etiology and pathogenesis remain unclear. OCD/OC is highly prevalent (nearly 100% affected) in growing pigs causing lameness. Previous work by our group has demonstrated that the pathogenesis of OCD/OC in pigs involves failure of cartilage canal blood supply, with resulting necrosis of epiphyseal (growth) cartilage. We hypothesize that the pathogenesis of OC/OCD in children is similar; however, the relationship between failed cartilage canal blood supply and osteochondritis dissecans (OCD) in people has not been studied due to 1) lack of noninvasive imaging techniques to visualize these structures in vivo and 2) limited access to appropriate post mortem tissues. We have developed a unique collaboration among magnetic resonance imaging (MRI) experts and veterinary and human orthopaedic researchers that will make use of the exceptional resources at the Center for Magnetic Resonance Research at the University of Minnesota to fill in the above mentioned gaps in knowledge. Our group recently developed and validated MRI methods to identify cartilage canal blood vessels and ischemic necrosis of the epiphyseal cartilage in young pigs. We wish to extend these studies to children and adolescents to investigate the maturation process of the articular- epiphyseal cartilage of the distal femur noninvasively in humans and compare it to that occurring in swine. This will be accomplished by the completion of four specific aims. Aims 1 and 2 focus on the development/ implementation/validation of novel MRI techniques, ex vivo, to image the vascular supply and cartilage matrix characteristics/morphology in cadaveric specimens from normal children and from young pigs in which subclinical lesions of osteochondrosis will be present (allowing evaluation of normal tissues as well as of areas of cartilage necrosis). Aims 3 and 4 focus on the development and testing of a rapid pediatric imaging protocol for in vivo studies in normal children and children first diagnosed with OCD. This research will have multiple benefits by 1) validating swine as a highly appropriate animal model of this important human disease, 2) providing a method to diagnose the disease at an early point in its development at which time treatments are likely to be effective, and 3) greatly improving our understanding of the pathophysiology of the disease.