Evaluation of a Short Femoral Stem in Total Hip Arthroplasty

In recent years, short femoral stems have been introduced. Short stems are designed based on traditional stems with good clinical results. The assumed benefit of short stems is that they are easier to use in mini-invasive surgery, and that preservation of proximal periprosthetic bone stock is better. Preservation of periprosthetic bone in the proximal femur is thought to secure long time anchoring of the implant, and reduce the risk of loosening. In addition, a good proximal bone stock makes later revision surgery less technically demanding. However, the short stem design could compromise the stability of the prosthesis, and there has been reported diverging results regarding correct positioning of short stems. This may be due to the lack of inherent aiming provided by the tip of the traditional long stems. We want to clinically evaluate the stability and bone remodelling pattern of a new short femoral stem based on a standard stem with excellent long time results. In addition we will compare the two different stems regarding positioning, when using a newly developed guiding broach for the short stem, and the standard broach for the long stem. Finally, patient reported clinical outcome scores will be evaluated with respect to implant and biomechanical reconstruction. The aim of this study is to evaluate whether this specific short femoral stem is stable, safe to use, and if it provides the expected beneficial effects on bone remodelling.