Distal Locking Stem for Femoral Loosening and Peri-Prosthetic Fractures: Conception, Development and Operative Technique

At the end of the eighties, cementless stem with distal interlocking screws was developed by Pierre Vives, to assess proximal femoral deficiency in cases of femoral loosening. Originally, this stem was designed without coating, to allow replacement with a standard stem after bone on-growth. In fact, initially good results led to design a new stem with partial coating, and screws were secondary replaced by pegs in order to achieve reliable fixation. Distal inter-locking screws provided immediate rotational and axial stability of the femoral implant and secured the use of a trans-femoral approach for stem revision. Clinical and radiological early results were good. But Ultime stem, available only into 2 diameters (12 and 14mm) with a too proximal first hole, demonstrated a high rate of breakage. More modern distal locked stem with extensive coating were developed. These stems have shown promising results for femoral revisions in literature without mechanical failure. The advantages are initial stability and consistent bony in growth owing to hydroxyapatite coating. Distal locked stems are mainly indicated to treat complex femoral revision with severe bone loss (type 3 and 4 SOFCOT) and peri-prosthetic fractures.