Periprosthetic Femur Fracture

Key Concepts

The key to fracture management is accurately determining if the femoral component is well-fixed or loose because most well-fixed implants are treated with internal fixation and most loose implants are treated with revision.
Careful analysis of preinjury and injury radiographs to assess for femoral component fixation helps with accurate classification of the fracture.
Open reduction and internal fixation (ORIF) of periprosthetic femoral fractures with stable femoral components (Vancouver B₁ and C fractures) should be performed using rigid constructs that include locking plates/screws and cables/wires.
Revision total hip arthroplasty (THA) of periprosthetic fractures with loose femoral components (Vancouver B₂ and B₃) usually is accomplished with modular fluted tapered femoral stems bypassing the fracture and 2 to 3 cerclage wires proximally to wrap the remaining fracture fragments around the revision femoral component in a biologically friendly manner.
The focus of this chapter will be on Vancouver B and C fractures.

Sterile Instruments and Implants

Instruments

ORIF

Pointed reduction clamps
Lobster claw reduction clamps
Two ball spikes
Intraoperative fluoroscopy or imaging
Revision THA instrumentation available (not open) if conversion needed

Revision THA

Routine revision hip retractors
Sagittal and reciprocating saws
Short and long pencil-tip burrs
6.5-mm round burr
Multiple wide osteotomes
Intraoperative fluoroscopy or imaging readily available

Implants

ORIF

Variable-angle locking plates with a radius of curvature similar to that of the femur
Locking and nonlocking screws
Cerclage cables and/or Luque wires

Revision THA

Uncemented modular fluted tapered stem and corresponding instrumentation
Cerclage cables and/or Luque wires
Consider femoral head and polyethylene liner exchange if the femoral head diameter can be increased to minimize the risk of instability—in these circumstances have available compatible polyethylene liners and modular femoral heads.

Positioning

ORIF

We prefer a lateral decubitus position to access the entire femur on a flat radiolucent table with fluoroscopy access to the lower limb; this facilitates fracture reduction, stabilization, and imaging and allows ease of conversion to a revision THA if required intraoperatively.

Revision THA

Lateral decubitus position to access the entire femur as necessary for fracture fixation and access for fluoroscopy.

Surgical Approaches

ORIF

In noncomminuted fractures, rigid internal fixation and direct bone healing is the goal.
- Therefore, a lateral exposure of the femur and direct visualization and reduction of the fracture is needed on a fracture table.
- Take care not to strip the soft tissues and periosteum circumferentially.
- A lateral exposure at the knee is required for insertion of the lateral distal femoral locking plate.
- Screws and cables are placed proximally via a percutaneous approach.
In comminuted fractures, the goal is to bridge and stabilize the fracture in appropriate alignment.
- Therefore, indirect reduction techniques with minimal soft-tissue stripping and minimal exposure at the fracture site are ideal.
- A lateral exposure at the knee is required for insertion of the lateral distal femoral locking plate.
- Screws and cables are placed proximally via a percutaneous approach.

Revision THA

In revision THAs, a lateral incision directly over the lateral proximal femur is required.
- Oftentimes, an extended trochanteric osteotomy (ETO) or transfemoral osteotomy is used to minimize soft-tissue stripping of the proximal fracture fragments.

Preoperative Planning

For both ORIF and revision THA, the most important factor in treating periprosthetic femur fractures is the stability and fixation of the femoral component. As such, a thorough history and radiographic evaluation are essential.

Careful Clinical History

Timing of the injury with respect to the primary THA
- Implants should be considered loose if the fracture occurs within 6 to 8 weeks of the index primary THA.
Antecedent hip/thigh pain
- If there is significant prior groin or thigh pain, procurement of preinjury radiographs to assess for subsidence, progressive radiolucent lines, and/or component migration is helpful.

Radiographic Evaluation

Careful analysis of orthogonal injury radiographs (anteroposterior [AP] and lateral) to assess the location and nature of the fracture is essential.
Evaluation of the stability of the implant is key. In particular, the surgeon should evaluate for:
- Subsidence
- Radiolucent lines around the implant
- Change in implant positioning
- Fractured cement mantle
Comparison with preinjury radiographs is imperative if there is any uncertainty about implant stability.
Computerized tomography (CT) scans are warranted in highly comminuted fractures, distal spiral femoral fractures where the distal extent of the fracture is not clear, and in situations in which the femoral component stability is in question.

Fracture Classification

Fractures should be classified via the Vancouver classification given the fact that it guides treatment decisions:
- Vancouver A_G (Figure 38.1A and B): A fracture of the greater trochanter
- Vancouver A_L (Figure 38.2A and B): A fracture of the lesser trochanter
  - Uncommon fracture pattern, most often related to osteolysis from one source or another.
  - Consider a CT scan to assess for occult spiral fractures around the femoral component or oncologic lesions.
- Vancouver B₁: Periprosthetic femur fracture near the stem tip of a well-fixed femoral component (Figure 38.3A and B)
- Vancouver B₂: Periprosthetic femur fracture around a loose femoral component (Figure 38.4A and B)
- Vancouver B₃: Periprosthetic femur fracture around a loose femoral component with significant bone loss or extremely poor bone quality (Figure 38.5A and B)
- Vancouver C: Periprosthetic femur fracture far distal to a well-fixed femoral component (Figure 38.6A and B)
In general, loose femoral components (Vancouver B₂ and B₃) are best treated with revision THA, whereas well-fixed femoral components (Vancouver B₁ and C) are best treated with ORIF.

Figure 38.1 ▪ Illustration (A) and AP radiograph (B) of a Vancouver A_G periprosthetic femur fracture. (Used with permission of Mayo Foundation for Medical Education and Research. All rights reserved.)

Figure 38.2 ▪ Illustration (A) and AP radiograph (B) of a Vancouver A_L periprosthetic femur fracture. (Used with permission of Mayo Foundation for Medical Education and Research. All rights reserved.)

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