At the beginning of the 80’s Professor Mario Cremonese, supervisor of the orthopaedic department clinic of Cittadella (Padua) had an intuition about the basic principle that would allow for improvement in the primary fi xation of the cementless stem and would avoid overcharges on the femoral diaphysis.

In 1985 LimaLto implemented that idea, producing a wedge-shaped rectangular section stem equipped with a proximal collar. The CRM stem.

In the same years Karl Zweymüller experimented a femoral stem that would become the forerunner of one of the most widespread philosophies of cementless hip arthroprosthesis fixation: the proximal stability obtained through the oblique positioning of a straight stem with rectangular section and double-conicity within the curved femoral canal, with extensive cortical contact.

The necessity of having ample fitting hosting implant/bone interfaces was not adequately satisfied by the manufacturing technologies of the period, which still did not allow for the realization of instrument sets of such precision in profiles.

It was only at the end of the 80’s that the first broaches replaced the imprecise chamfered rim rasps.

The subsequent stem modifi cations, with the elimination of the proximal collar, which had proved ineffective, as well as some bio-mechanical techniques in 1996 led to the current prosthesis design.

In 2006 the lateralized version has been introduced, offering an advantageous alternative in terms of intraoperative surgical support. The choice of a suitable implant allows always an optimized functional result overtaking high degrees of morphological case limitation.

Presently C2 can count more than 20,000 implants in Europe, Asia and Australia and is greatly appreciated for its precision, simplicity and reliability.

The C2 stem is the product of Professor Mario Cremonese’s thoughts and experience.

Parallel evolution of the Zweymüller principle with some particular differences.