title: Comparison between component designs with different femoral head size in metal-on-metal total hip arthroplasty; multicenter randomized prospective study.
abstract: OBJECTIVE
  We prospectively studied 78 prostheses with conventional femoral head and 86 prostheses with large head (Magnum) of metal-on-metal total hip arthroplasty (MoM THA) with two years follow-up.
  
  
  METHODS
  Clinical outcomes and blood metal ion were evaluated.
  
  
  RESULTS
  There were no significant differences of clinical outcomes between groups. 1.17 ± 1.01 μg/L of blood cobalt ion in Magnum was significantly lower than 1.99 ± 2.34 μg/L in conventional group. No dislocation was observed in Magnum while one dislocation in conventional group. MoM THA with large head is useful if the implants are positioned in appropriate alignment, however longer follow-up will be necessary.
  
  
  BACKGROUND
  NCT01010763 (registered on ClinicalTrials.gov).
authors.affiliation: Department of Orthopaedic Surgery, Kansai Rosai Hospital, Amagasaki, Hyogo, 660-8511, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Ando
authors.affiliation: Department of Orthopaedic Surgery, Kansai Rosai Hospital, Amagasaki, Hyogo, 660-8511, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Department of Orthopaedic Surgery, Showa University, Fujigaoka Hospital, Yokohama, Kanagawa, 227-8501, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Atsumi
authors.affiliation: Department of Orthopaedic Surgery, Showa University, Fujigaoka Hospital, Yokohama, Kanagawa, 227-8501, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tamaoki
authors.affiliation: Funabashi Orthopaedic Hospital, Funabashi, Chiba, 274-0822, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Oinuma
authors.affiliation: Funabashi Orthopaedic Hospital, Funabashi, Chiba, 274-0822, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shiratsuchi
authors.affiliation: Department of Orthopaedic Surgery, Kansai Medical University Takii Hospital, Moriguchi, Osaka, 570-8507, Japan.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Tokunaga
authors.affiliation: Department of Orthopaedic Surgery, Yokohama City University, Yokohama, Kanagawa, 236-0004, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Inaba
authors.affiliation: Department of Orthopaedic Surgery, Yokohama City University, Yokohama, Kanagawa, 236-0004, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Kobayashi
authors.affiliation: Department of Orthopaedic Surgery, Aihara Hospital, Mino, Osaka, 562-0004, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Aihara
authors.affiliation: Department of Orthopaedic Surgery, Kansai Rosai Hospital, Amagasaki, Hyogo, 660-8511, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohzono
keywords: Large head; Metal ion; Metal on metal total hip arthroplasty