title: Trunnion Corrosion in Metal-on-Polyethylene Total Hip Arthroplasty: A Case Series.
abstract: BACKGROUND
  Modular total hip arthroplasty implants can help the operating surgeon reproduce the optimum limb length and offset; however, the modularity can lead to fretting and corrosion with associated metal-related problems. Although metal-on-metal bearings are often reported to have problems, recent case reports suggest that the problems can occur with any articulation, usually as a result of problems at the head/neck junction.
  
  
  METHODS
  We retrospectively reviewed three cases of a specific implant combination with nontraumatic trunnion failure, with two cases presenting as acute complete dissociation of the femoral head from the neck.
  
  
  RESULTS
  All three cases had failure of the Accolade TMZF plus stem and trunnion (Stryker) that progressed rapidly from the onset of symptoms. The most likely contributing factors to failure were large femoral head size, high horizontal offset, a low angled neck, and a β titanium alloy taper with a cobalt-chromium head.
  
  
  CONCLUSIONS
  We recommend regular follow-up of all patients with Accolade TMZF stems, and patients should be advised to seek immediate medical attention if they have any new mechanical symptoms in a metal-on-polyethylene total hip arthroplasty. Providers should specifically look for any alteration of alignment between the femoral head and neck in follow-up radiographs.
authors.affiliation: From Wake Forest University School of Medicine, Winston Salem, NC (Dr. Raju), Shri Sathya Sai Medical College and Research Institute, Ammapettai, India (Dr. Chinnakkannu), IORI Clinic, Bangalore, India (Dr. Puttaswamy), and Buffalo Medical Center, Buffalo, NY (Dr. Philips).
authors.forename: Sivashanmugam
authors.initials: S
authors.lastname: Raju
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Chinnakkannu
authors.forename: Mohan K
authors.initials: MK
authors.lastname: Puttaswamy
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Phillips
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D061825:Metal-on-Metal Joint Prostheses; D011475:Prosthesis Failure