Hip replacement implants made with metal-on-metal components have been causing problems for patients worldwide, particularly active individuals, forcing many to undergo further surgery. If you or someone you love has suffered harm as a result of an implant, do not wait to take legal action. A defective hip replacement implants lawyer could help you understand your eligibility for compensation. Contact our office to get started.
髋关节置换手术
髋关节置换手术有两种类型。在髋关节表面置换中，将金属帽安装在股骨头上，并且通常对髋臼（球窝髋关节的窝）进行铰孔并用人造杯重新衬里。在全髋关节置换术中，股骨顶部在股骨头下方被锯掉，股骨柄被挖空，并在其中安装金属柄。然后将人造股骨头放置在新股骨柄上。金属对金属（“MoM”）髋关节具有金属股骨头和金属髋臼杯。近年来，MoM 髋关节在全髋关节置换术中越来越受欢迎。医学界认为，这些现代金属关节表面的磨损可以忽略不计，并且在医学上无关紧要。
金属对金属髋关节的已发现问题
MoM hips appear to be failing and requiring early revision (further surgery to replace one or more components) more often than other types. The most common reasons for revision surgery–which has a lower probability of a successful outcome than the original hip replacement–are pain and recurrent dislocations. Some revision surgeries require well-fixed components to be removed, which can cause bone loss and tissue damage. A New York Times series describes how the failure occurs ( New York Times, The High Cost of Failing Artificial Hips, December 28, 2011; New York Times, Sources of Debris in Artificial Hips, December 27, 2011).
导致 MoM 髋关节衰竭的严重并发症包括无菌性松动、骨质溶解、金属沉积和神经系统问题。当某个部件（通常是髋臼杯）由于感染或其他器质性疾病过程以外的原因而变得松动时，就会发生无菌性松动。骨质溶解（骨质流失）被怀疑是由 MoM 关节表面的磨损以及由此导致的金属离子释放到体内引起的。金属沉积是人体对金属离子或金属碎片堆积的反应；髋关节处积聚浓稠的灰色液体可能是这种情况的信号。金属沉积的进一步反应和并发症包括假瘤的形成、组织死亡和骨退化。 MoM 植入物的接受者可能会接触钴和铬离子，这可能与头痛、口腔中持续的金属味、记忆问题和心脏异常有关。
一些 MoM 髋关节的磨损速度似乎比制造商预期的要快，并产生更多的金属离子和碎片。至少在一些 MoM 髋关节的设计中，植入髋臼杯的倾斜角度的可接受范围（误差幅度）比其他人工髋关节要窄得多。植入到这个狭窄范围之外的杯子更容易受到过度磨损和所谓的“边缘负载”——当球在球窝中铰接时，杯子边缘承受不成比例的重量。多年来，外科医生都没有被告知植入边缘较窄。
MoM 髋关节的接受者可能不会经历疼痛作为装置故障的早期症状，因此建议他们接受骨科医生的监测。现在建议定期检测血液中的钴和铬含量。 2011 年 5 月，FDA 命令 21 家制造商进行上市后监督研究，要求他们提交一份研究方案，解决与这些设备相关的具体安全问题。
有缺陷的金属对金属髋关节的类型
DuPuy ASR – Due to design defects, many patients receiving either the DePuy ASR™ XL Acetabular System or ASR™ Hip Resurfacing Platform found themselves back under the knife within five years of the initial surgery. In the United States, only the ASR XL Acetabular System was approved for use in hip replacement surgeries. The DePuy device came on the market in 2005 after being cleared by the FDA by a process known as 510(k) approval. This process allowed Johnson & Johnson to obtain market approval of this MoM hip replacement device with very little clinical testing–and with no human testing–based upon its claim that the ASR device was “substantially similar” to another product already on the market.
ASR 髋关节表面置换平台未经批准在美国使用或销售。 DePuy 援引从英格兰和威尔士国家联合登记处收到的数据，于 2010 年 8 月 26 日自愿召回 ASR XL 髋臼和 ASR 髋关节表面置换系统。数据显示，需要在最初手术的五年时间高于预期。 2010年国家联合登记数据显示，在使用DePuy ASR髋关节装置的患者中，13%的患者需要进行完全髋关节置换术，12%的患者需要在平均5年内进行矫正手术。
ASR 装置于 2010 年 8 月 24 日正式召回。据估计，全球有 93,000 名患者接受了其中一种有缺陷的髋关节装置。 2009 年，DePuy 停止了两种髋关节植入物的生产，据称是由于需求下降以及开发下一代髋关节置换和表面重修设备的愿望。一名加州建筑工人对该公司提起诉讼，称 DePuy 多年来就知道 ASR 髋关节植入物存在缺陷。截至 2008 年底，大约有 300 份关于使用 ASR 髋关节装置的手术中髋关节植入失败的报告。
据报道，DePuy ASR 髋关节的失败率正在上升。英国骨科协会主席于 2011 年发表的一份声明，总结了该组织年会上有关大直径金属髋关节的演讲，显示 ASR CL 的早期翻修率在 4 年时为 21%，在 6 年时为 49%。
如果您已接受任何一种 ASR 植入物，DePuy 建议您去看外科医生并每年进行一次监测，以确保其正常运行。任何无法解释的髋关节疼痛或感觉髋关节植入物松动可能表明髋关节置换术失败，应立即报告给您的外科医生。
DePuy Pinnacle – DePuy also manufactures the Pinnacle system, which has a modular acetabular cup with a cup liner made of either polyethylene or metal. Metal on metal combinations are used frequently. As with the DePuy ASR, the primary issues in failure appear to be cup loosening and metallosis.
FDA Warnings on Two Other DePuy Products – A warning letter was dated August 19, 2010—seven days before the company issued its recall of both ASR hip implants, the FDA issued a warning claiming that DePuy violated the Federal Food, Drug, and Cosmetic Act by marketing its TruMatch™ Personalized Solutions System and Corail®Hip System without first receiving the required marketing clearance and/or approval.
Wright Conserve – The Wright Medical Conserve® Cup features a similar design to the DePuy ASR™ Cup. The Wright Conserve® Hip Implant System is a metal-on-metal design, which consists of cast cobalt chromium molybdenum that provides the receptacle for the cobalt-chromium molybdenum femoral head. The metal femoral head rotates within the metal monoblock Conserve® Cup, without a liner, resulting in the release of metal particles that can cause metal toxicity in the blood, soft tissue, and bone. This can result in metallosis, tissue necrosis, pseudotumors, and other serious health problems.
自从 FDA 根据相同的 510(k) 上市前批准系统批准 Wright 金属对金属髋关节置换系统以来，患者和医生已向 FDA 提交了数百份不良事件报告。与其他 MoM 植入物一样，该装置的设计本质上会引起股骨头和髋臼杯之间的摩擦，从而在腿部运动过程中产生比其他类似植入物更大的初始摩擦力。升高的摩擦力从髋臼和髋臼杯之间的接合处传递到髋臼。
2011 年 5 月，FDA 要求 Wright Medical 和其他金属对金属髋关节制造商（例如 DePuy、Stryker 和 Zimmer）获取有关髋关节置换术释放的金属颗粒达到危险程度、其中含有多少金属的更多信息。实际释放，并量化金属沉积的潜在副作用。
植入后不久的失败可能与 MoM 更换植入物无关；然而，DePuy 植入物应接受医学监测。
立即联系有缺陷的髋关节置换植入物律师
Our personal injury attorneys are currently evaluating cases concerning the defective hip implants, including the ASR XL Acetabular System used in hip surgeries performed in the United States. If you or a loved one has received a DePuy ASR implant, one of the implants listed above, or a failed MoM implant leading to pain or revision surgery, please contact a defective hip replacement implants lawyer at our office today.
