Uncemented Tapered Stems

Uncemented Tapered Stems

Timothy S. Brown

Michael J. Taunton

Key Concepts

  • 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

  • Reamers, broaches, trials specific to the selected cementless tapered implant (Figures 7.2 and 7.3)

Surgical Approaches

  • 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 Planning

  • 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.

Figure 7.1 â–ª Retractors utilized by authors for a primary posterior approach.

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Dec 14, 2019 | Posted by in ORTHOPEDIC | Comments Off on Uncemented Tapered Stems

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