UNDERSTANDING FEMORAL NECK FRACTURES (PART 2)

Treatment methods for femoral neck fractures

1. CONSERVATIVE TREATMENT

The goal of femoral neck fracture treatment is to restore hip function, achieve anatomical reduction, and provide stable internal fixation or hip arthroplasty to enable early mobilization of the patient.

Conservative treatment is indicated solely for patients with severe underlying medical conditions and high contraindications for surgery.

The patient rests in bed for 3-4 weeks, then ambulates with a brace to avoid weight-bearing on the fracture site. Patients should be instructed not to bear weight on the fracture site. If relative fracture healing is achieved, partial weight-bearing is allowed within 6 weeks post-injury, and full weight-bearing is permitted upon complete healing.

Note the combination with analgesics, deep vein thrombosis prophylaxis, and mobilization to prevent pressure ulcers.

2. SURGICAL TREATMENT

2.1. Minimally invasive internal fixation

Indication: For young patients with high-energy fractures and normal bone quality, open or closed reduction and internal fixation is an emergency indication. Reduction of the femoral neck fracture should be performed as early as possible to reduce the risk of subsequent femoral head necrosis. Furthermore, the quality of fracture reduction (anatomically) is the decisive prognostic factor.

For elderly patients with good bone quality and high functional demands, internal fixation can be considered; however, the reoperation rate due to avascular necrosis of the femoral head can be up to 40%.

Positioning and anesthesia: The patient is placed on a fracture table with traction devices. General anesthesia or spinal anesthesia is used.

Figure 1. Patient positioned on a fracture table

Reduction technique: Flex the hip, apply gentle traction, and externally rotate to dislodge any fracture fragments (if present), then gently extend the hip and internally rotate to restore the fracture to its anatomical position. If there is no incarcerated fragment, only hip extension, traction, and internal rotation are required. Reduction must be controlled under anteroposterior (AP) and lateral fluoroscopy.

Criteria for successful reduction: On the AP view, the femoral neck and shaft should form an anatomical alignment or valgus. On the lateral view, the anteversion angle must be restored, and posterior displacement of the fracture should be avoided. The posterior fragment must be reduced anatomically.

Internal fixation:

1. Cancellous screws: This is the most commonly used internal fixation method for femoral neck fractures, allowing compression of the fracture site. Typically, 3 parallel screws are used. Inserting fewer than 3 screws does not provide adequate stability for the femoral neck and increases the risk of joint penetration. The screws should be placed in a triangular configuration with one screw directed toward the inferior cortex and one toward the posterior cortex of the femoral neck.

Figure 2. Cancellous screws in the femoral neck.

2. DHS plate-screw, Gamma nail, or proximal femoral locking nail: Rarely used for femoral neck fractures, predominantly utilized for intertrochanteric fractures.

Figure 3. Internal fixation with a dynamic hip screw (DHS) plate

2.2. Open reduction surgery

 Rarely used due to an increased risk of femoral head resorption.

2.3. Hip arthroplasty

Indication: For elderly patients.

• Total hip arthroplasty is indicated for patients with good bone quality and high functional demands.
• Hemiarthroplasty is indicated for patients with poor bone quality and low functional demands. Cemented prostheses may be considered for patients with severe osteoporosis.

Figures 4-5. Cementless total right hip arthroplasty for femoral neck fracture

3. COMPLICATIONS AND SEQUELAE

The most common complications of femoral neck fractures are secondary displacement after reduction and internal fixation, nonunion, and avascular necrosis of the femoral head. Avascular necrosis and femoral head collapse occur in 15-35% of patients due to the disruption of the blood supply to the femoral neck at the time of injury, typically manifesting after 2 years.

Post-traumatic osteoarthritis usually appears later and may be associated with any of the aforementioned sequelae.

The most severe complication of any surgery, particularly in patients undergoing hip arthroplasty, is infection.

Source: Medical University Training Materials - Vietnam National University

Author: Dr. Do Vu Anh

References

1. Human Anatomy, Trinh Van Minh, Hanoi Medical University.

2. Handbook of Fractures, 4th Edition, Kenneth A. Egol, Kenneth J. Koval, Joseph D. Zuckerman, Lippincott Williams and Wilkins.

3. Trauma Manual, 2nd Edition. 2002 Lippincott Williams & Wilkins.

4. Rockwood & Green's Fractures in Adults, 6th Edition. 2006 Lippincott Williams & Wilkins.

5. Campbell’s Operative Orthopaedics (Eleventh Edition) - Edited by S. Terry Canale & James H. Beaty, 2007