Terminology

• The femoral shaft or diaphysis runs from just below the lesser trochanter to the beginning of the distal femoral metaphysis above the condyles.
• This text will focus on open femur shaft fractures in adults. For pediatric femur shaft fracture considerations further reading is advised at the AO surgery reference website. 

^{Femoral shaft zone} 

Trauma mechanism

Open femoral shaft fractures are often the result of high-energy trauma and affect young, otherwise healthy patients.¹ Typical mechanisms include road traffic accidents or falls from height.

The classic mechanism involves high-energy forces acting on the femur, such as direct impact, bending, or rotational stress. These forces disrupt the shaft and often produce transverse or comminuted fracture patterns.

Associated injuries should always be considered in patients with femoral shaft fractures.

Management in the ER

General initial management principles apply.

Initial evaluation and management in open fractures in the ER

In open femoral fractures, where blood loss can exceed 1000–1500 mL, there is a risk of hemodynamic instability or shock.

Realignment and temporary stabilization is important to reduce this risk. Temporary stabilization techniques include femoral traction splint or skeletal pin traction or damage control surgery external fixation.² Often the fracture is too proximal for casting.

Fracture management plan

In most cases, especially in high resources settings, internal fixation is feasible at the first surgery as soon as the patient is stabilized.

Alternatively a two stage approach can be chosen when soft tissues do not allow direct definitive internal fixation or when the patient is hemodynamically unstable in a damage control setting. Apply a fracture spanning external fixator for temporary stabilization. In some settings traction is an alternatieve treatment option, preferably temporarily, if resources allow. Take into account soft-tissue treatment options and possible future definitive fixation when applying the pins. If a plastic surgeon is available, early consultation and collaborative surgery is recommended.

Open reduction and internal fixation

In acute open femur shaft fractures definitive fixation with intramedullary nailing, either antegrade or retrograde depending on fracture location, is the gold standard treatment. When timely adequate debridement and soft-tissue management are performed, early weight bearing and high union rates can be achieved.³ In specific fracture types, especially when the fractures extends towards the joint, plate fixation is recommended. Further reading on ORIF is advised at the AO surgery reference website. 

Open reduction and internal fixation should only be performed:

1 Once the fracture has been debrided and cleansed,

2 When soft tissue coverage in the same early setting is achieved,

3 When the environment is sufficiently sterile,

4 When resources and knowledge are available.

External fixation

When resources for internal fixation are unavailable (and referral not possible), external fixation can serve as a definitive treatment modality. Follow the advises for definitive fixation with an external fixator.

External fixator for a femur shaft fracture

When applying a definitive external fixator for a femur shaft fracture, follow some specific considerations:

• Open reduction - Often the wound of an open fracture leads to the fracture and debridement all the way to the fracture is needed. Open reduction of the fracture through this wound is facilitated. Your approach is preferably from lateral. If a fresh fracture has no wound leading directly to the fracture site, closed reduction in femur fractures is preferred, but depends on the availability of intra-operative fluoroscopy.
• Stability - The femur is exposed to large deforming forces, so the construct must be sufficiently stable. Use large pins (preferably 6 mm) for diaphyseal fixation. Place the pins on each side of the fracture as far apart as possible (near–far principle) but still in strong cortical bone.
• Safe zones - Insert pins within the recognized femoral safe zones to avoid injury to surrounding structures. Even when using the recommended safe zones, care must be taken when drilling through the second cortex, as important neurovascular structures, such as the sciatic nerve, lie directly posterior to it.

^{Femoral shaft safe zone}

Adding stability
For the femur, the standard temporarily bar to bar external fixation is not always stable enough for definitive fixation. Depending on the direction of the dislocating forces, consider to:

1 Add an extra bar:

2 Add more pins at the lateral side or

3 If needed, additional pins can be placed medially on each side of the fracture and connected with bars to counteract valgus forces. This should only be done through an open approach, with great attention to the femoral artery and other nearby neurovascular structures.

Technical considerations

• Posterior pin placement - If the pins are placed too far posteriorly in the femur, the external fixation construct may interfere with the bed when the patient is lying down.
• Anterior pin placement - If the external fixator is expected to remain in place for an extended period, the pins should be inserted laterally or anterolaterally in the femur. Pins placed too far anteriorly may restrict knee motion and may result in persistent knee stiffness, even after pin removal.
• Drill guide - Due to the thick layer of soft tissue around the femur the use of a tissue protector is important. Both to guide the drill and pin in the right direction but also to avoid damaging surrounding soft tissues. The best is to have a long drill guide (6mm diameter) with an insert with the right diameter for a drill bit (3.5-4.5mm).
• Rotational alignment - There are various ways to control rotational alignment. Intraoperative x-rays can be helpful. A practical method to control rotation is: The anterior superior iliac spine (ASIS), patella, and the second toe web space into a straight line, and compare this with the uninjured leg.

Soft tissue management

The reconstructive ladder is helpful in deciding your strategy. Start with the simplest effective option, but do not oversimplify.

Soft tissue management in open fractures

For small to medium-sized defects with exposed bone, local transposition or rotation flaps may provide reliable coverage. For larger defects of the distal femur some locoregional options include:

Aftercare

Postoperative rehabilitation

1 Early mobilization – Early mobilization and physiotherapy are crucial for functional recovery and prevention of complications such as joint stiffness or thrombosis. Particularly after external fixation of femoral shaft fractures, knee stiffness (especially loss of flexion or extension) can develop if movement is delayed. Thrombosis profylaxis is commonly recommended until the patient is mobilizing.

2 Pin placement and knee motion – Pin position can influence postoperative mobility. Restrict knee motion could be caused by pins placed too anteriorly. In open fractures, however, pin placement is often dictated by the wound location and fracture configuration and must be balanced with the need for adequate stability.

3 Weight-bearing - Gradual progression to weight-bearing depends on depends on the fracture pattern and the stability of the external fixation construct. More stable frames and simple fracture configurations may allow earlier weight-bearing, whereas complex fractures or less stable constructs require a more cautious approach.

Complications

The femoral shaft is well protected by its surrounding muscles and subcutaneous tissues, which often reduces the risk of soft tissue complications compared to fractures in less muscular regions. However, the substantial forces acting on the femur can lead to secondary displacement if the external fixation construct is not sufficiently stable.

If rotational malalignment is suspected, intra-operative correction should be performed immediately.

Complications of fracture management in open fractures