Metal on metal surface replacement of the hip. Experience of the McMinn prothesis

Clin Orthop Relat Res. 1996 Aug:(329 Suppl):S89-98. doi: 10.1097/00003086-199608001-00009.

Abstract

The historical failure of surface replacement has been due to the production of wear debris with subsequent bone resorption, loosening, and failure. To avoid these problems, a surface replacement using a metal on metal bearing allowing thin components and femoral design and instrumentation to avoid varus alignment has been designed. Two hundred thirty-five joints have been resurfaced with this prosthesis in almost 5 years. There have been no femoral neck fractures and no dislocations. There have been 4 designs differing in the method of fixation. In the press fit group, 6 of 70 hips had to be revised for aseptic loosening. In the cemented group, debonding of the cup occurred in 3 of 43 cases. Six patients had hydroxyapatite coated components and have had excellent clinical outcomes. The current design uses a peripherally expanded hydroxyapatite coated cup and a cemented metal head; 116 of this design have been implanted during a 19-month period with excellent outcome. Despite short followup the authors are hopeful that the combination of a polar metal on metal bearing with appropriate fixation will yield a method of preserving bone stock in the younger patient requiring arthroplasty.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Female
  • Gait
  • Hip Joint / diagnostic imaging
  • Hip Joint / physiology
  • Hip Prosthesis* / methods
  • Humans
  • Male
  • Metals*
  • Middle Aged
  • Ossification, Heterotopic / etiology
  • Pain
  • Pilot Projects
  • Prosthesis Design
  • Radiography
  • Range of Motion, Articular
  • Reoperation

Substances

  • Metals