Cementless R.M. isoelastic total hip prosthesis in revision surgery for loose prostheses

Forty-three patients with aseptic mobilization of hip prostheses were submitted to revision surgery using cementless R.M. isoelastic total hip prostheses. The femoral component was substituted in all cases, the acetabular component in 37. Autoplastic bone grafts were required in 27 cases to replace severe bone defects in the acetabulum or femoral diaphysis. All the patients were followed up for an average of 46 months (range 36 to 59 months). The results were good in 38 cases, evaluated both on the Harris scale (average 87 points) and the Charnley method (5.4 points for pain, 5.0 for walking, and 5.2 for movement). There were 2 cases of ankylosis, one case of infection, one paralysis of the peroneal nerve and one proximal migration of the acetabular component. Therefore we believe that the use of cement is contraindicated in revision surgery of the hip, particularly in the presence of severe osteolysis and in younger patients. The isoelastic stem encourages bone reconstruction and cortical thickening in the femoral diaphysis. When there is bone deficiency the cementless acetabulum must always be associated with autoplastic bone grafting.