%0 Journal Article
%T Titanium Alloy Stem as a Cause for Adverse Reaction to Metal Debris after Bipolar Hemiarthroplasty
%A Masaaki Sakamoto
%A Hitoshi Watanabe
%A Hidetaka Higashi
%A Hitoshi Kubosawa
%J Case Reports in Orthopedics
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/209461
%X A 68-year-old male with failure of bipolar hemiarthroplasty consistent with adverse reaction to metal debris (ARMD) who presented with a painful cystic lesion and lower extremity swelling was encountered. However, revision surgical findings showed no apparent cause of ARMD previously described in the literature, such as corrosion at the head-neck junction and articular abrasion. Therefore, it was difficult to make a definite diagnosis of failure secondary to ARMD, which consequently led to the decision to perform two-stage revision procedure, though the stem was firmly fixed. Postoperative analysis in the retrieval tissues showed that the metal debris mainly originated from the titanium alloy stem itself. Although this is a very rare case, one should be aware that even the well-fixed femoral components themselves have the potential to be the cause of ARMD. 1. Introduction Numerous reports have described failures in hip arthroplasty secondary to adverse reaction to metal debris (ARMD), including osteolysis, metallosis, hypersensitivity reactions, aseptic lymphocyte-dominated vasculitis-associated lesions, cystic lesions, effusions, and pseudotumors [1, 2]. Additionally, there have been various literatures concerning the causes of ARMD. Metallosis has been suggested to occur as a result of either excessive liner wear up to the metal shell, liner breakage, impingement between the femoral neck and the acetabular component, or a combination of these elements [3¨C5]. Furthermore, numerous reports suggest corrosion at the head-neck junction or neck-stem junction as a cause [6¨C8]. Concerning the specific causes after hemiarthroplasty (HA), several case reports have been published describing massive metallosis caused by the abraded outer shell or trunnion corrosion in unipolar HA [9¨C11]. However, in this case, there was no apparent source of metal release previously described in the literature. Quantitative analysis of the metal in the specimens particularly played an important role in identifying the source of metal debris, which gave us new knowledge concerning ARMD. 2. Case Presentation A 68-year-old male with a right femoral neck fracture during bicycle touring underwent bipolar HA (VECTOR-Titan, Peter Brehm, Weisendorf, Germany) elsewhere. The early postoperative course had been excellent, and he was even able to go mountain climbing. Approximately 4 years later, he noticed severe pain especially in the anterior aspect of the right thigh with the onset of swelling in the right lower extremity, and he was referred to our institution for suspicion of
%U http://www.hindawi.com/journals/crior/2014/209461/