Bipolar Hemiarthroplasty via Posterior Approach for Intracapsular Femoral Neck Fracture
The posterior approach for bipolar hemiarthroplasty in intracapsular femoral neck fractures should include enhanced soft tissue repair with locking loop stitches to minimize dislocation risk while providing good functional outcomes. 1
Preoperative Considerations
- Timing: Surgery should be performed within 24-48 hours of admission to reduce complications and mortality 2, 3
- Anesthesia: Either spinal or general anesthesia is appropriate (strong recommendation) 3, 2
- Imaging: Standard AP pelvis and lateral hip radiographs are required for proper assessment 2
Surgical Procedure for Posterior Approach
1. Patient Positioning and Preparation
- Position patient in lateral decubitus position with the affected hip facing upward
- Secure patient with anterior and posterior supports
- Prepare and drape the hip area with sterile technique
2. Incision and Approach
- Make a curved incision centered over the posterior aspect of the greater trochanter, extending 10-12 cm
- Incise the fascia lata in line with the skin incision
- Split the gluteus maximus fibers in the direction of their fibers
3. Deep Dissection
- Identify and protect the sciatic nerve
- Identify and tag the short external rotators (piriformis, superior and inferior gemellus, obturator internus, and quadratus femoris)
- Detach the short external rotators from their insertion on the greater trochanter
- Incise the posterior hip capsule in a T-shaped manner
4. Femoral Head Removal and Preparation
- Dislocate the hip by internal rotation and flexion
- Remove the fractured femoral head
- Measure the femoral head size to determine appropriate prosthesis size
- Prepare the femoral canal with sequential reamers and broaches
5. Prosthesis Implantation
Cemented stem: The American Academy of Orthopaedic Surgeons strongly recommends using cemented femoral stems 2, 3
- Clean the femoral canal
- Insert a cement restrictor
- Mix and inject bone cement
- Insert the femoral stem with proper version (10-15° anteversion)
Bipolar head component:
- Assemble the bipolar head component
- Attach to the femoral stem
- Reduce the hip joint
6. Closure (Critical Step)
- Enhanced soft tissue repair: Use locking loop stitches to repair the posterior capsule and short external rotators 1
- Reattach the short external rotators to their insertion on the greater trochanter
- Repair the posterior capsule to the greater trochanter
- This technique has been shown to significantly reduce dislocation rates from 1.9% to 0% 1
- Close the fascia lata, subcutaneous tissue, and skin in layers
Postoperative Management
- Begin physical therapy on postoperative day 1 2
- Implement interdisciplinary care program to improve outcomes (strong recommendation) 3, 2
- Progress from assisted to independent ambulation based on patient ability 2
- Follow-up at 2-4 weeks, then at 3 months, 6 months, and annually 2
Potential Complications and Prevention
- Dislocation: The main concern with posterior approach (5.3% vs 0.6% with direct lateral) 4
- Prevented by enhanced soft tissue repair with locking loop stitches 1
- Avoid extreme hip flexion, adduction, and internal rotation
- Periprosthetic fracture: More common with uncemented stems 2
- Acetabular erosion: More common with unipolar than bipolar prostheses 5
- Infection: Standard perioperative antibiotics and sterile technique
Advantages of Bipolar vs. Unipolar Hemiarthroplasty
- Better Harris hip scores (86.18 vs 79.79) 5
- Improved range of motion (210.63° vs 181.58°) 5
- Lower incidence of acetabular erosion 5
- Fewer complications including painful hip and dislocation 5
The posterior approach offers superior short-term ambulation compared to the direct lateral approach, but requires meticulous soft tissue repair to minimize dislocation risk 4, 1. When performed with proper technique, bipolar hemiarthroplasty via posterior approach provides excellent outcomes for intracapsular femoral neck fractures in elderly patients.