AMIS-K has been developed in collaboration with Dr. L. Kerboull and Professor M. Hamadouche, incorporating their own experience with the Charnley-Kerboull femur implant. The AMIS-K stem is in line with the design of the Charnley-Kerboull implant, featuring a very thin cement mantle, and includes modifications aimed at simplifying its implantation using minimally invasive approaches.
AMIS FRIENDLY DESIGN
AMIS-K is 12% shorter than Charnley-Kerboull type stems.This reduction in length is intended to facilitate insertion of the femoral implant when using a minimally invasive procedure, such as the AMIS approach. An experimental study of the mechanical behavior of the AMIS-K stem has revealed that the shortened length does not affect the in vitro rotational and tilting stability after line-to-line cementation.
THE "FRENCH PARADOX"
A stem matching the femoral canal is implanted line-to-line, resulting in a thin cement mantle. The French technique is intended to maximize the stem size within the medullary canal, removing all cancellous bone and fitting the stem in place with cement as a filler only where the internal geometry of the bone does not match the implant shape. Excellent survival rates have been reported for THAs performed with the French technique, also referred to as the “French Paradox”.
SIMPLIFIED REVISION CASES
The AMIS-K stem is compatible with the “cement-in-cement” technique. In case of revision, the removal procedure is simpler when compared to a stem of regular length: distal cement removal is no longer mandatory, thereby reducing the complexity of the operating procedure.