Severe Metallosis Leading to Femoral Head Perforation

Full article available online at Healio.com/Orthopedics. Search: 20130122-29 Severe Metallosis Leading to Femoral Head Perforation Om Prakash sharma, mBBs, ms(OrthO), FrCs(C); JasJit LOChaB, BsC(hOns), mBBs; YarOn BerkOviCh, mD; OLeg a. saFir, mD, meD, FrCs(C); aLLan e. grOss, mD, FrCs(C), O.Ont 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. The authors are from the Department of Orthopaedics, Mount Sinai Hospital, Toronto, Ontario, Canada. Dr Gross is a paid consultant for Zimmer. The other authors have no relevant financial relationships to disclose. Correspondence should be addressed to: Om Prakash Sharma, MBBS, MS(Ortho), FRCS(C), Department of Orthopaedics, Mount Sinai Hospital, 600 University Ave, Ste 476A, M5G lX5 Toronto, Ontario, Canada (opsharma90@gmail.com). doi: 10.3928/01477447-20130122-29 Figure: Preoperative anteroposterior radiograph showing eccentric deformation of the femoral head (black arrow) with heterotopic ossification (white arrow) and radiodensity around the cup, ischium, and proximal femur.