Uncemented Tapered Stems
Timothy S. Brown
Michael J. Taunton
The starting point for preparation of the femur is key and can differ by implant.
Special attention must be paid to lateralize during the preparation process to keep the final component from being placed in a varus position.
Stable initial fixation with scratch-fit and appropriate stem sizing is critical for long-term ingrowth and implant fixation.
Sterile Instruments and Implants
Retractors specific for the surgeon’s preferred approach (Figure 7.1)
Round high-speed burr
Posterolateral: Care must be taken when reaming to avoid extending the femoral component.
Anterolateral: Care must be taken when reaming to avoid flexing the femoral component.
Direct anterior: Adequate exposure of the femur is necessary for safe preparation. The abdomen may push the reamer into varus and flexion.
Preoperative evaluation of the femoral bone quality and any deformity can help the surgeon decide which type of stem will fit best. A tight canal with a wide metaphysis may be more amenable to a ream and broach system that allows expansion of the diaphysis to allow for a sufficiently large stem to provide good fit in the metaphysis.
Preoperative templating for femoral stem sizing and position is useful for planning stem insertion relative to the greater trochanter (Figure 7.4).
Bone, Implant, and Soft Tissue Techniques
After initial exposure of the proximal femur, a sharp Hohmann retractor is placed on the anterior border of the greater trochanter to move the gluteus medius and minimus away from the path of reaming and broaching.
An entry point posterolaterally near the piriformis fossa is made with the high-speed burr (Figure 7.5).
A T-handled starting reamer is used to define the femoral canal.