| Popis: |
We have to face the fact that the prosthetic replacement of a hip joint using cement is still considered a standard procedure for the stem. Some authors even hold the opinion — whether right or wrong - that this system is still unsurpassable. The tendency for human beings to search for improvements and innovations has induced numerous researchers to investigate the so called biological anchorage. We were and still are protagonists of this idea. The search for a cementless anchorage began in 1976. Around 2000 stems of various manufacture were implanted before the CLS stem, which is still in clinical service, began to be used in December 1983. It is obvious that the stability of a cemented system is assured by the extensive bone cement surface and, in particular, because the cement with its very fine proturbances can claw into the cancellous bone structures. It is thus self-evident that with an uncemented prosthesis the reverse of this phenomenon was considered as the primum movens. Consequently, it is a question of trying to promote the growth of new bone formations of the trabecular structure onto the rough or macrostructured surfaces of the implant. From the very beginning, the idea of the porous coating was a popular solution and it is still widely supported today [8]. |
