What is the step-by-step procedure for treating an Intertrochanteric fracture of the femur (ICNF) with bipolar hemiarthroplasty via the posterior approach?

Step-by-Step Procedure for Bipolar Hemiarthroplasty via Posterior Approach for Intertrochanteric Femoral Fractures

Bipolar hemiarthroplasty via posterior approach is an appropriate surgical option for unstable intertrochanteric femoral fractures in elderly patients, allowing for early mobilization and weight-bearing to reduce complications associated with prolonged immobilization.

Pre-operative Considerations

• Timing: Surgery should be performed within 24-48 hours of admission for better outcomes 1
• Anesthesia: Either spinal or general anesthesia is appropriate, with spinal anesthesia potentially reducing postoperative confusion 1
• Tranexamic acid: Should be administered at the start of the procedure to reduce blood loss and need for transfusion 1

Patient Positioning and Preparation

• Position patient in lateral decubitus position with the affected hip facing upward 2
• Prepare and drape the surgical site to above the iliac crest and mid-sacrum 2
• Ensure proper padding of bony prominences to prevent pressure injuries

Surgical Approach (Posterior/Moore's Approach)

• Make a curved incision centered over the greater trochanter, extending proximally and posteriorly 2, 3
• Divide the fascia lata in line with the skin incision
• Identify the gluteus maximus muscle and split its fibers in the direction of the muscle fibers
• Identify and protect the sciatic nerve throughout the procedure
• Identify and detach the short external rotators (piriformis, gemelli, obturator internus) from their insertion on the greater trochanter 2
• Tag the short external rotators with non-absorbable sutures for later repair
• Incise the posterior hip capsule and expose the femoral neck and head

Femoral Neck Osteotomy and Preparation

• For intertrochanteric fractures, perform a two-step osteotomy technique 4:
  • First osteotomy at the base of the femoral neck
  • Second osteotomy to remove the femoral head
• Remove the femoral head and preserve it for templating the implant size 2
• Identify and preserve the greater trochanteric and medial fracture fragments for later reattachment 5

Femoral Canal Preparation

• Expose the femoral canal and remove any fracture debris
• Sequentially broach the femoral canal to the appropriate size 2
• Perform trial reduction with provisional implants to assess stability, leg length, and offset

Implant Selection and Placement

• Use cemented femoral stem as recommended for elderly patients with osteoporosis 1, 6
• Select appropriate bipolar head size based on acetabular dimensions 2
• For cement application:
  • Thoroughly clean and dry the femoral canal
  • Insert cement restrictor at appropriate depth
  • Inject cement in retrograde fashion
  • Insert the final stem with 5-10° of anteversion 2
  • Hold the stem in position until cement hardens

Greater Trochanter and Fracture Fragment Reattachment

• Reattach the greater trochanteric fragment and any medial fracture fragments to the stem 5
• Secure fragments with 2-3 16-gauge cerclage wires 5, 7
• Ensure proper tension of the abductor mechanism

Final Implant Assembly and Reduction

• Attach the appropriate bipolar head to the femoral stem 2
• Reduce the hip by gentle traction and internal rotation
• Test range of motion and stability, ensuring no impingement or dislocation

Closure

• Thoroughly irrigate the wound 2
• Repair the posterior capsule and short external rotators to reduce dislocation risk 2
• Close the fascia lata, subcutaneous tissue, and skin in layers
• Apply sterile dressing

Post-operative Management

• Allow sitting up 3-4 days after surgery 4, 7
• Begin partial weight-bearing 5-7 days postoperatively 4, 7
• Progress to walking with assistive devices around 10 days after surgery 7
• Administer appropriate VTE prophylaxis 1

Potential Complications and Prevention

• Dislocation: Proper repair of posterior capsule and soft tissues is crucial 2
• Periprosthetic fracture: Use cemented stems and careful technique 5
• Venous thromboembolism: Early mobilization and appropriate prophylaxis 5
• Infection: Meticulous sterile technique and appropriate perioperative antibiotics

This procedure allows for early mobilization in elderly patients with unstable intertrochanteric fractures, with studies showing that 76.5% of patients can ambulate independently with or without assistive devices at hospital discharge 5.