Hemiarthroplasty for Femoral Neck and Head Fractures

Femoral neck and head fractures accompanied by hip dislocation are complex orthopedic injuries, often requiring surgical intervention. Among the various treatment options, hemiarthroplasty has emerged as a widely practiced procedure, particularly in elderly patients. This blog explores the indications, procedure, advantages, complications, and outcomes associated with hemiarthroplasty for femoral neck fractures with hip dislocation.

Understanding Femoral Neck and Head Fractures

Femoral neck fractures are common in the elderly population due to osteoporosis and falls. These fractures can lead to hip instability, pain, and loss of mobility. When accompanied by hip dislocation, the injury becomes more severe, necessitating prompt surgical management. The goal of treatment is to restore joint function while minimizing complications.

What is Hemiarthroplasty?

Hemiarthroplasty involves replacing the femoral head and neck with a prosthetic implant while preserving the acetabulum. Unlike total hip arthroplasty (THA), which replaces both the femoral and acetabular components, hemiarthroplasty focuses solely on the femoral side. This procedure is particularly suitable for elderly patients with lower functional demands or significant comorbidities.

Indications for Hemiarthroplasty

Hemiarthroplasty is indicated in cases where:

• The femoral neck fracture is displaced.
• The patient has pre-existing acetabular arthrosis or limited mobility.
• Hip dislocation complicates the fracture.
• Osteoporosis or poor bone quality limits internal fixation options.

Patients who are less active or have significant comorbidities are often preferred candidates for hemiarthroplasty over total hip arthroplasty.

Surgical Procedure

The hemiarthroplasty procedure can be technically demanding and involves several critical steps:

• Patient Positioning: The patient is placed in the lateral decubitus position to optimize access to the hip joint.
• Incision and Exposure: A posterior approach is commonly utilized, though lateral approaches may reduce dislocation risks.
• Femoral Neck Osteotomy: A conservative osteotomy is performed to remove the fractured femoral head and neck fragments.
• Prosthesis Selection: The diameter of the femoral head component is selected intraoperatively to ensure proper fit.
• Acetabular Inspection: The acetabulum is inspected for arthrosis or debris. If severe arthrosis is present, conversion to THA may be considered.
• Implant Fixation: Cemented prostheses are preferred for osteoporotic patients as they reduce implant-related complications such as periprosthetic fractures.
• Closure: Adequate closure of the capsule and soft tissue is essential to minimize postoperative complications like dislocation.

Types of Prostheses

Hemiarthroplasty prostheses can be categorized into:

• Unipolar Prostheses: Simpler design but associated with higher acetabular erosion rates in short-term follow-ups.
• Bipolar Prostheses: Feature an additional articulation within the prosthesis, potentially reducing acetabular wear over time. However, they are more expensive without significant long-term outcome differences compared to unipolar implants.

Advantages of Hemiarthroplasty

Hemiarthroplasty offers several benefits:

• Reduced operative time compared to THA.
• Lower blood loss during surgery.
• Ability to convert to THA if needed.
• Improved mobility and pain relief in elderly patients with lower functional demands.

Complications

While hemiarthroplasty is effective, it is not without risks:

1. Periprosthetic Dislocation: More common with posterior approaches; meticulous soft tissue closure can mitigate this risk.
2. Infection: Proper aseptic techniques and postoperative care are essential to prevent infections.
3. Acetabular Erosion: Unipolar implants may accelerate erosion; bipolar implants can reduce this risk but at a higher cost.
4. Periprosthetic Fractures: Cemented prostheses significantly lower this risk compared to uncemented options.
5. Reoperation Risks: Factors like dementia or alcohol abuse increase the likelihood of revision surgeries.

Comparison with Total Hip Arthroplasty

Hemiarthroplasty and THA are both viable options for femoral neck fractures but differ in their applications:

While THA offers better functional outcomes in active patients, hemiarthroplasty remains preferable for elderly individuals with comorbidities due to its lower surgical burden and reduced complications.

Postoperative Care

Effective postoperative management includes:

• Early mobilization to prevent complications like deep vein thrombosis.
• Pain management using analgesics.
• Regular physiotherapy to restore mobility.
• Monitoring for signs of infection or implant failure.

Outcomes

Hemiarthroplasty generally results in favorable outcomes for elderly patients with femoral neck fractures complicated by hip dislocation. Studies show that cemented prostheses improve mobility and reduce residual thigh pain compared to uncemented options. However, long-term follow-up is necessary to monitor potential complications like acetabular erosion or implant failure.

How does the choice of surgical approach impact the outcome of Hemiarthroplasty?

The choice of surgical approach in hemiarthroplasty for femoral neck fractures significantly impacts the outcome of the procedure. Different approaches have distinct benefits and drawbacks, influencing postoperative complications, recovery time, and overall patient satisfaction. The selection of a surgical approach in hemiarthroplasty should be tailored to the patient’s specific needs, considering factors such as age, activity level, and overall health status. While no single approach is universally superior, understanding the benefits and drawbacks of each can help surgeons optimize outcomes and minimize complications.

Surgical Approaches in Hemiarthroplasty

1.      Posterior Approach (PA):

1. • Higher Dislocation Risk: Studies have consistently shown that the posterior approach is associated with a higher risk of dislocation compared to other approaches, such as lateral and anterior.
   • Operative Time and Blood Loss: It often results in shorter operative times and less blood loss compared to some other approaches.
   • Reoperation Risk: The posterior approach is linked to a higher risk of postoperative reoperation, primarily due to dislocation issues.

2.      Lateral Approach (LA):

1. • Lower Dislocation Risk: The lateral approach, particularly the direct lateral approach, is noted for having a lower dislocation rate compared to the posterior approach.
   • Complication Rate: It generally shows a lower overall complication rate than the posterior approach.
   • Operative Time: It may have a longer operative time compared to the posterior approach.

3.      Anterior Approach (AA):

1. • Shorter Hospital Stay: The anterior approach, especially the direct anterior approach, is associated with shorter hospital stays.
   • Dislocation Risk: It has a significantly lower dislocation risk compared to the posterior approach.
   • Pain and Recovery: It often results in less postoperative pain and faster recovery due to minimal muscle damage.

Impact on Outcome

• Complication Rates: The choice of approach affects the overall complication rate, with the posterior approach generally showing higher rates due to dislocation.
• Recovery and Mobility: Approaches like the anterior and lateral may offer better early mobility and less postoperative pain, enhancing recovery.
• Reoperation Needs: Higher dislocation rates with the posterior approach increase the likelihood of reoperation.

Conclusion

Hemiarthroplasty remains a cornerstone treatment for displaced femoral neck fractures with hip dislocation, especially in elderly patients with limited functional demands. By balancing surgical complexity, patient needs, and potential complications, orthopedic surgeons can achieve optimal outcomes while improving quality of life for affected individuals.