Metal-on-metal hip replacement Q and A

这answers here are provided by John Skinner, consultant orthopaedic surgeon at Royal National Orthopaedic Hospital, Stanmore, UK, and Alister Hart, professor of orthopaedic surgery at UCL and Royal National Orthopaedic Hospital, London, UK.

当它们运行良好时，金属对金属的髋关节重铺和总髋关节置换可提供多年的无故障使用，并且磨损水平非常低。但是，某些金属植入物可能会失败，增加磨损量并产生少量碎屑。这种碎片是构成植入物的钴和铬的颗粒（离子）。这种碎片会触发您体内的反应，这会导致骨骼侵蚀和植入物松动。国家联合注册表指出，9年后，有3％的植入物松开。但是，植入物也因其他原因而失败，因此总体失败率每年约为1％。

In most people the metal ions are absorbed into the bloodstream, then filtered by the kidneys and passed out in the urine. By measuring the concentration of these ions in the blood we can discover how the hip is wearing. These levels are very low and are measured in parts per billion (ppb). However, the concentration of metal ions in the fluid around the hip joint can be much higher. It's these high local concentrations of metal ions that cause damage to the tissues, either by local toxicity or by your body's response as it tries to get rid of them.

While all hip debris causes some reaction in the nearby tissues, often with no major problems, in some people it can cause extensive tissue damage and in some rare cases death of tissue cells, including those of the muscles, tendons, nerves and bones.

In 2010, the UK Medicines and Healthcare Regulatory Agency (MHRA) issued three safety alerts, one for all metal-on-metal hips and two for ASR (Articular Surface Replacement) hips. The Australian and UK National Joint Registries also reported high failure rates for ASR hip replacements and all large diameter metal-on-metal bearing total hip replacements. DePuy International then recalled all their ASR hip resurfacings and ASR XL total hip replacements.

MHRA建议所有金属对金属的臀部都进行了5年的跟踪，并且所有ASR / ASR XL臀部都会在植入物的寿命中进行跟踪。这是要定期检查发生了多少磨损，因此您需要修订手术的可能性。自2004年以来，全球植入了大约100,000个ASR臀部，在英国大约有10,000个。

Anyone who has had an DePuy ASR or ASR XL hip replacement and has any outstanding questions should contact the ASR helpline on 0800 2794865 or 01908 303 195.

这适用于髋关节式围栏和总髋关节置换吗？

是的，它适用于两种类型的金属金属髋关节。但是，最近的证据表明，对于大型金属金属总髋关节置换量可能会更大。

髋关节重露将球的一部分保持在球窝臀部接头的一部分，并将金属盖放在其表面上。骨盆一侧还有一个金属杯。在总髋关节置换中，除去大腿骨头上的球（股骨头），并使用骨水泥或未元素的技术固定茎，并将茎固定在大腿骨的轴上（这意味着假体是固定的，无需使用水泥即可固定将植入物“粘合”）。然后将球固定在该茎上的柱头上。两种类型都涉及金属球在金属杯上摩擦。

所有髋关节重外面操作都使用金属对轴承髋关节。大多数髋关节置换量是not金属对金属轴承并使用其他材料，包括陶瓷和高密度聚乙烯。您的医院将始终记录您的手术以及使用的植入物。您可以直接与医院联系，如果您的手术最近完成，并且仍在外科医生的照顾下。如果您有金属对线的臀部，大多数医院都会尝试与您联系。否则，您可以联系您的全科医生，他们可以帮助您重新接触。

If you signed a consent form for details of your operation to be sent to the国家联合注册表, you can contact them directly and they can tell you details of your implant. Tel: 0845-3459991 or Email:health_servicedesk@northgate-is.com

Most hospitals that have put in a number of metal-on-metal hips will have a system to advise patients. You can try contacting them directly, or your GP can help you and refer you to your orthopaedic surgeon.

Yes, since the safety alerts and recalls the MHRA are advising that all patients with metal-on-metal hips should be followed up annually for 5 years and that all ASR or ASR XL hips (those models that have been withdrawn) should be followed up for the life of the implant. Patients with hip replacements with head diameter of 36 millimetres or more need to be monitored every year for the life of the hip replacement. Even if you don't need to be formally followed up, if you develop pain or start to limp you should tell your doctor straight away, who will arrange for referral or investigations.

这些可以采用多种形式，如果您没有任何问题，那么可能需要的每年电话交谈或问卷。这通常会由您的外科医生或其他从业者进行手术。如果您感到疼痛，如果您有ASR组件或X射线显示植入物已引起问题的迹象，则需要更详细的评估。该评估可能包括体格检查，血液检查以测量血液中金属浓度以及可能的超声检查或MRI检查。

Not all pains and problems are due to your body's reaction to metal debris. Other causes of pain that can affect all types of hip replacement include loosening, wear and infection. If there's damage to your hip then you’ll need revision surgery in which the metal-on-metal implants will be removed and new ones inserted. This may also involve fitting a femoral stem to fix the ball onto (in a total hip replacement). If you already have a stem in place and it’s well fixed and undamaged, then this can often be saved. Your surgeon will discuss this with you.

A national regulator called the Medicines and Healthcare Products Regulatory Agency (MHRA) is in charge of classifying medical devices in the UK.

Medical Device Alerts are the MHRA's way of communicating safety information, including recalls. Alerts are sent out to healthcare professionals and are also published in print and online.

访问www.gov.uk在密苏里州re information.

Anyone can submit a problem with a medical device (such as a hip implant) to the MHRA. This includes clinicians, healthcare workers, carers, patients and members of the public. By law, manufacturers do have to inform the MHRA when they know of failures that have been revised. This, along with NJR data, ensures that the MHRA can keep abreast of problems.

您首先需要看医生检查是否存在临床问题。如果有问题，您的健康必须首先出现。借助ASR和ASR XL植入物，制造商在大多数情况下为所有调查和治疗付费以使事情正确。但是，这些臀部是全球法律程序的主题，因此您应该获得法律建议，以查看您是否有权获得赔偿。

这些臀部对髋关节周围的组织或体内其他部门的组织的长期影响并没有进行太多研究。

人们担心血液中的高金属（钴和铬）。但是，很少有关于实际临床问题的报道。

Yes. It's the only way to perform a resurfacing operation where the thigh bone is simply capped. There’s some clinical evidence that in younger men (under 55 years) or men who are very active, some metal-on-metal hip resurfacing replacements give equal or slightly better results than total hip replacements. However, overall the use of metal-on-metal hips has reduced very sharply in the last two years.

It allows hip resurfacing and can allow much larger diameter femoral heads to be used in total hip replacement. Larger heads can also allow a greater range of movement of the hip and give greater stability, making dislocation less likely.

When they're designed and made well, working well, positioned well and lubricated well by joint fluid, metal-on-metal implants show some of the lowest wear rates of any materials used in hip replacement. This is what made them so popular. However, if any of these factors aren't right, then the wear can be extremely high and this leads to the problems caused by metal debris.

大多数外科医生发现他们满意的两种类型的髋关节替代品。这通常是针对年轻和活跃的患者的一个，而对于更大的老年患者（更可能需要手术的患者）来说，这通常是一个。有许多良好的髋关节替代选项，可以进行良好的跟进，并在医学文献中发表了出色的结果。

Research is constantly being carried out to try to answer this question. All materials have advantages and disadvantages, but most modern materials are showing excellent results and it’s likely that more than one type may be equally effective for you.

您的全科医生可能会看到其他需要在您所在地区进行髋关节手术的患者，因此他们会非常了解向您推荐谁。如果您有朋友，家人或其他接受过髋关节手术的患者，他们也可以为您提供“客户视野”。

您的医生和外科医生尤其能够与您讨论与您的髋关节和髋关节手术有关的所有问题。这英国时尚协会and the英国骨科协会can also be helpful.