Klontz Karl C, Smith William I, Jonathan C Klontz
Epidemiologist with the U.S. Food and Drug Administration, College Park, Maryland, USA.
Department of Pathology, Suburban Hospital, 8600 Old Georgetown Rd, Bethesda, Maryland 20814 USA.
J Orthop Case Rep. 2014 Jan-Mar;4(1):21-3. doi: 10.13107/jocr.2250-0685.142.
Metallosis involving the knee joint most often results from metal-on-metal contact late in the life of a failing implant following polyethylene wear. We report a case of acute metallosis following knee arthroplasty in a previously healthy 59-year old male.
In June 2011, the patient underwent left knee arthroplasty for severe osteoarthritis with necrosis and bone edema in the medial femoral condyle and tibial plateau. Nine months later, because of persistent pain and swelling in the joint, revision arthroplasty was undertaken along with partial synovectomy. Examination revealed pristine prosthetic implants in the absence of loose fragments of bone or glue. Synovial pathology exhibited marked chronic inflammation and hyperplasia with extensive finely granular foreign material resembling metallic debris. Laboratory analysis of synovium revealed a predominance of iron, the principal component of the saw blades.
We hypothesize the patient experienced acute metallosis resulting from deposition of metallic fragments from three saw blades used during arthroplasty. We believe the increased density of the patient's bone that required use of multiple blades may have resulted, in part, from heavy lifting the patient partook in during the two years preceding arthroplasty.
膝关节金属中毒最常见于聚乙烯磨损导致植入物失效后期的金属对金属接触。我们报告一例59岁既往健康男性膝关节置换术后急性金属中毒病例。
2011年6月，该患者因严重骨关节炎伴股骨内侧髁和胫骨平台坏死及骨水肿接受左膝关节置换术。九个月后，由于关节持续疼痛和肿胀，进行了翻修关节置换术并同时行部分滑膜切除术。检查发现假体植入物完好，无骨或胶水松动碎片。滑膜病理显示明显的慢性炎症和增生，有大量类似金属碎片的细颗粒状异物。滑膜的实验室分析显示铁含量占主导，铁是锯片的主要成分。
我们推测该患者经历的急性金属中毒是由于关节置换术中使用的三个锯片的金属碎片沉积所致。我们认为患者骨密度增加需要使用多个锯片，这可能部分是由于患者在关节置换术前两年从事重物搬运工作所致。
