Post Zachary D, Orozco Fabio R, Ong Alvin C
Department of Orthopaedic Surgery, Thomas Jefferson University, Rothman Institute, Egg Harbor Township, NJ 08234, USA.
Orthopedics. 2013 Apr;36(4):e525-8. doi: 10.3928/01477447-20130327-35.
Recent problems with metal-on-metal bearings in total hip arthroplasty have highlighted a connection between metal particles and allergic responses. Metal sensitivity associated with total knee arthroplasty (TKA) is less understood and poorly characterized. However, metal sensitivity can lead to TKA failure. Accurate and reliable testing for this phenomenon is elusive; therefore, the diagnosis of metal sensitivity remains one of exclusion. Only skin testing and lymphocyte transformation testing are commonly available to assess hypersensitivity, and neither test is reliable.This article describes a woman who presented with severe whole-body dermatitis and hair loss. After prolonged pain and progressive stiffness, including failed manipulation while under anesthesia and open synovectomy, the patient had a positive skin test, but the lymphocyte transformation test was negative. She was treated for metal sensitivity with TKA revision to nonallergenic components, and all symptoms resolved. One year after revision, she had good range of motion, complete dermatitis resolution, and hair loss restoration.To the authors' knowledge, this is the only report that describes hair loss as a symptom of metal sensitivity secondary to TKA and hair regrowth after revision. The authors now include metal sensitivity in a differential of causes of pain and other unusual symptoms after TKA that are otherwise unexplained.
近期全髋关节置换术中金属对金属轴承出现的问题凸显了金属颗粒与过敏反应之间的联系。与全膝关节置换术（TKA）相关的金属敏感性了解较少且特征描述不足。然而，金属敏感性可导致TKA失败。针对这一现象的准确可靠检测难以实现；因此，金属敏感性的诊断仍然是排除性诊断之一。目前通常仅有皮肤试验和淋巴细胞转化试验可用于评估超敏反应，但这两种试验都不可靠。本文描述了一名出现严重全身性皮炎和脱发的女性患者。在经历长期疼痛和进行性僵硬，包括麻醉下手法松解失败及开放性滑膜切除术后，该患者皮肤试验呈阳性，但淋巴细胞转化试验为阴性。她接受了TKA翻修术，更换为无过敏反应的部件以治疗金属敏感性，所有症状均得到缓解。翻修术后一年，她的关节活动范围良好，皮炎完全消退，脱发也得以恢复。据作者所知，这是唯一一篇将脱发描述为TKA继发金属敏感性的症状以及翻修术后毛发再生的报告。作者现在将金属敏感性纳入TKA后疼痛及其他无法解释的异常症状的鉴别诊断病因之中。
