The Press-Fit Concept: Practical Application

Abstract

• A proximal press-fit, most often in the metaphyseo-diaphyseal region, must be aimed for (or discussed) whenever the femur is straight in the frontal plane and when there are no or only small bone defects in Gruen zone(s) 2 and/or 6. An endofemoral approach is the rule, with a wide lateral and posterior opening of the greater trochanter.

• When the press-fit zone needs to be situated in the diaphyseal region (isthmic zone), a trochantero-diaphyseal flap is the rule. The preparation of the isthmic anchorage zone is performed with a reamer whose sole function is the reshaping of the medullary cavity to give it, in most cases, a tapered configuration. To be efficient, it is necessary to be near the anchorage zone and to ream a straight segment of the femur over a short distance.

Selection of the implant with a trial prosthesis. The objective is to keep a “conical reserve”, which is a guarantee for a perfect wedging while making re-wedging possible.