[Loosening of total hip prosthesis]

The problem of total hip prosthesis is an immediate and long-term stability. An insufficient bone anchorage of the prosthesis produces a tissue reaction around the implant that causes a loosening. The hight incidence of loosening of cemented total prosthesis has spurred the research into uncemented implants. The experience at the Busto Arsizio Hip Center (Director Prof. R. Bombelli) with more than 2,800 R.M. uncemented isoelastic total hip prostheses was favorable and the study with the cooperation of Pathology Department (Director Prof. P. Lampertico) of the 82 loosening hips has shown: 1) the importance of the elasticity for a stress transmission to the surrounding bone; 2) the pursuit of the most suitable stem calibre and length; 3) the necessity of a stable primary mechanical fixation, waiting for a biological reaction.