Severe Metallosis Leading to Femoral Head Perforation
ABSTRACT This article describes a case of severe metallosis in a 67-year-old woman who initially underwent primary total hip arthroplasty with a ceramic-on-ceramic articular bearing. This was subsequently revised to a metal-on-polyethylene articulation due to ceramic liner fracture. She presented with severe hip pain and a pelvic mass. Infective workup was negative. Perforation of the cobalt-chrome femoral head was observed intraoperatively. In addition, signs of extensive metallosis, including embedded ceramic debris from the primary procedure, were observed. To the authors' knowledge, this is the first report of a ceramic fracture that led to cobalt-chrome femoral head perforation after subsequent revision total hip arthroplasty. The patient underwent successful revision surgery with a ceramic-on-ceramic coupling.Ceramic materials are increasingly being used in total hip arthroplasty in younger patients. They have excellent tribological properties. However, they also have a lower elasticity and plasticity, which makes them susceptible to sudden material failure. Ceramic fracture is an uncommon yet problematic complication of total hip arthroplasty. Previous authors have reported the importance of performing thorough synovectomy following ceramic liner fracture. Revision surgery using couplings that have a lower hardness, such as metal-on-polyethylene, are best avoided due to their susceptibility to undergo abrasive wear from remaining ceramic particles. The authors advocate revision with ceramic-on-ceramic couplings after ceramic liner fracture.
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ABSTRACT: Retrieval analysis of total joint arthroplasty components has primarily focused on assessing wear or other damage to polyethylene components. As damage to the opposing bearing surface can accelerate polyethylene wear and damage, and especially with the use of hard-on-hard articulations, retrieval analysis benefits from incorporating evaluation of hard bearing surfaces as well. The purpose of this study is to report six case studies of metal bearing surfaces with distinctive damage patterns, to interpret them in the context of adverse events plausibly responsible for their creation, and to suggest their likely clinical or scientific significance. The specific damage patterns reported here are 1) extensive scraping, 2) circumferential discoloration, 3) a long chain of periodic micro-indentations, 4) pitting with deposits, 5) scratches with small-radius directional changes, and 6) indentation with scraping.The Iowa orthopaedic journal 01/2014; 34:84-93.