title: Nationwide investigation into adverse tissue reactions to metal debris after metal-on-metal total hip arthroplasty in Japan.
abstract: BACKGROUND
  Adverse reactions to metal debris (ARMD) after receiving metal-on-metal (MoM) hip implants is a recent concern. However, no epidemiologic study has examined ARMD for MoM hip implants in Japan. The purposes of this study were to research the incidence of ARMD and to identify poorly performing MoM hip implants in Japan.
  
  
  METHODS
  From 2000 to 2011, 7 companies provided 23,226 MoM implants in Japan. A questionnaire regarding ARMD was sent to 101 hospitals at which 62% of the 23,226 MoM implants had been used.
  
  
  RESULTS
  Replies to the questionnaire were received from 82 hospitals. In these hospitals, surface hip replacement types (SRs) were used in 606 hips and stemmed types were used in 12,961 hips. ARMD were reported in 3 hips (0.5%) with SRs and 160 hips (1.2%) with stemmed types. ARMD in the 3 hips with SRs were asymptomatic and no revisions were performed. Among AMRD with stemmed implants, revision was performed in 83 hips and excision of an ARMD lesion was performed in 3 hips. The remaining 74 hips were asymptomatic and careful follow-up was continued. A significant difference in reoperation rate was evident between SRs (0%) and stemmed types (0.7%). Incidences of ARMD were significantly higher with Ultamet (P = 0.005), Conserve (P < 0.001), and Cormet (P < 0.001) MoM bearing couples than with Metasul bearings.
  
  
  CONCLUSIONS
  The incidence of ARMD in large surgical volume hospitals in Japan from 2000 to 2011 was estimated to be 0.5% with SRs and 1.2% with stemmed types. The reoperation rate was significantly higher with stemmed types than with SRs. Three brands of MoM stemmed implants were identified as showing a higher incidence of ARMD.
authors: Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, Yamadaoka 2-2 Suita, Osaka, 565-0871, Japan, n-sugano@umin.net.
authors: Nobuhiko
authors: N
authors: Sugano
authors: Hirokazu
authors: H
authors: Iida
authors: Haruhiko
authors: H
authors: Akiyama
authors: Yoshio
authors: Y
authors: Takatori
authors: Satoshi
authors: S
authors: Nagoya
authors: Masahiro
authors: M
authors: Hasegawa
authors: Tamon
authors: T
authors: Kabata
authors: Yudo
authors: Y
authors: Hachiya
authors: Yuji
authors: Y
authors: Yasunaga
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation; D005500:Follow-Up Studies; D005549:Foreign-Body Reaction / Q000139:chemically induced / Q000453:epidemiology*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008670:Metals / Q000009:adverse effects*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D008670:Metals