Changes in the calcar femoris in relation to cement technology in total hip replacement.

Radiological changes in the calcar femoris after total hip replacement, in 97 hips where an extreme valgus position of the prosthesis had been achieved, were compared with 119 hips where the alignment of the prosthesis ranged from varus to only a moderate degree of valgus. In the series with extreme valgus there was a minimum of 1 cm of cement between the calcar femoris and the prosthesis, whereas in the other series the thickness of cement averaged 4.5 mm. In the series with thick cement destructive changes in the calcar were reduced by a factor of 10 and there were no examples of incipient subsidence of the femoral prosthesis. This comparison was based on a follow-up of only 2 years.