Cementless or Uncemented hip replacement
Cementless hip replacements refer to the fixation method of the prosthesis in bone without the interposition of bone cement. The implant gains initial fixation by a tight fit and subsequently is fixed by bony ingrowth.
Indications for uncemented hip replacement
Bearings for uncemented hips -Ceramic on poly, ceramic on metal, ceramic on ceramic, metal on poly are the common bearings. Ceramic and metal are hard bearings with advantage of durability. Cross-linking of polyethylene makes it last longer.
Uncemented femoral stems are of two types, conventional and short stem. The METHA hip, BMHR, Silent hip and Nannos Hip are examples of a short stem uncemented hip replacement.
Head diameter ranges from 22mm for poly cups to 36 for ceramic cups. Large diameter head is possible with Delta Ceramic bearings surfaces. Risk of dislocation is less with large diameter bearings.