Quando e perché utilizzare lo stelo endomidollare nelle revisioni di protesi di ginocchio

Abstract

The number of knee replacement revisions is increasing over the years due to the raising number of first implants performed annually worldwide. It is therefore necessary to recognise the need for a revision and to know how to perform it, in order to choose the best solution that can be adopted depending on the problems encountered.

Manufacturers, in fact, offer a great variety of products and among them intramedullary stems are the most important, made to increase the prosthetic fixation to the bone in revision surgeries. They may have different lengths, they can be fixed at the metaphysis or diaphysis and they can be cemented or not cemented. There are also offset stems that allow a good adaptation to the femoral and tibial metaphyseal and diaphyseal curvature. The stems are often associated with systems such as sleeves and augments to compensate for the loss of bone stock. Despite of the wide variety of proposed solutions there aren’t specific indications in literature. The purpose of this study is to revise the literature to identify when and how the use of intramedullary stems is recommended.

The comparable results observed in the literature by cemented and uncemented stems show how both solutions are effective stabilisation systems in the knee arthroplasty revisions. The choice of the correct implant technique must be carried out case-by-case analysing advantages and disadvantages of each fixation. In particular, cemented stems have a better seal in osteoporotic bone and allow for a better adaptability in the presence of post-traumatic deformations. Press-fit stems are rather more suitable in case of periprosthetic fractures and in case of necessity of lower limb alignment correction, in presence of good bone quality.

From what we analysed, we suggest the use of the intramedullary stems in all knee arthroplasty revisions, trying to use non-cemented stems of the shortest length able to offer a good stability.