Salem Khaled Hamed, Lindner Norbert, Tingart Markus, Elmoghazy Alyaa Diaa
Department of Orthopaedic Surgery, Faculty of Medicine, Cairo University, Egypt.
Department of Orthopaedic Surgery, Brüderkrankenhaus St. Josef Paderborn, Germany.
J Clin Orthop Trauma. 2020 Jan-Feb;11(1):165-170. doi: 10.1016/j.jcot.2019.04.010. Epub 2019 Apr 18.
Metallosis is a syndrome of metal-induced synovitis caused by friction between two metal surfaces. In contrast to the hip joint after resurfacing arthroplasty or metal-on-metal (MoM) total hip replacement, metallosis of the knee is extremely rare.
We describe 4 patients who underwent revision total knee replacement because of disabling pain and implant loosening after a mean time of 21 (range: 13-30) years of knee replacement surgery. They were all females with a mean age of 79 (range: 75-82) years. Septic loosening was excluded through microbiological examination and synovial fluid analysis.
Direct metal-on-metal contact at the tibiofemoral interface was confirmed intraoperatively in all cases. All knees showed severe metallosis with advanced osteolysis and pseudotumor formation. In one knee there was a complete fracture of the tibial tray. All patients had a one-stage revision surgery with implant removal, profound synovectomy and implantation of a constrained modular revision knee system. Long modular stems with offset adapters, wedges and/or blocks were used in all cases.
Metallosis-associated osteolysis should be suspected in cases with radiologically evident polyethylene wear after knee replacement. Recognizing that revision arthroplasty is very technically demanding in such cases, surgeons should have a back-up with modular revision components and a ready access to reconstructive options at this revision setting.
金属沉着病是一种由两个金属表面之间的摩擦引起的金属诱导性滑膜炎综合征。与表面置换关节成形术或金属对金属（MoM）全髋关节置换术后的髋关节不同，膝关节的金属沉着病极为罕见。
我们描述了4例患者，他们在膝关节置换术后平均21年（范围：13 - 30年）因致残性疼痛和植入物松动而接受了全膝关节翻修手术。她们均为女性，平均年龄79岁（范围：75 - 82岁）。通过微生物学检查和滑液分析排除了感染性松动。
所有病例术中均证实胫股界面存在直接的金属对金属接触。所有膝关节均表现出严重的金属沉着病，伴有严重的骨溶解和假肿瘤形成。其中一个膝关节的胫骨托完全骨折。所有患者均接受了一期翻修手术，包括取出植入物、彻底的滑膜切除术以及植入一个限制性模块化翻修膝关节系统。所有病例均使用了带有偏移适配器、楔形物和/或垫块的长模块化柄。
膝关节置换术后影像学显示聚乙烯磨损明显的病例应怀疑存在金属沉着病相关的骨溶解。认识到在这种情况下翻修关节成形术在技术上要求很高，外科医生应备有模块化翻修组件，并在此翻修情况下随时能够获得重建选择。
