Hip Arthroplasty in Fracture Neck of Femur

Courtesy: Dr Harish Bhende, Dr Ashok Shyam, Ortho TV

Overview

• Intracapsular fractures of the femoral neck are common in elderly individuals.
• Management options include internal fixation or joint replacement.
• When joint replacement is chosen, two main procedures are considered:
  • Hemiarthroplasty
  • Total hip arthroplasty
• Clinical studies in patients older than sixty years with displaced femoral neck fractures show that internal fixation often produces less reliable outcomes compared with joint replacement.
• In very elderly individuals, especially those older than eighty years, fixation may fail even in fractures that are not significantly displaced.
• For these reasons, hip arthroplasty is frequently recommended as it provides better functional recovery and fewer complications in this age group.

Options for Hip Replacement

Hemiarthroplasty

Hemiarthroplasty involves replacing only the femoral head while the natural acetabulum is retained.

Advantages

• Shorter and technically simpler surgical procedure
• Lower operative stress and medical risk in frail patients
• Reduced blood loss
• Lower risk of postoperative dislocation due to the large head size
• Often lower cost in certain healthcare settings

Limitations

• Reduced long term durability compared with total hip replacement
• Risk of acetabular cartilage wear caused by the metal femoral head
• Possibility of acetabular protrusion over time
• Some patients may require revision surgery in the future
• Functional outcomes may be inferior in active individuals

Total Hip Arthroplasty

Total hip arthroplasty replaces both the femoral head and the acetabular surface.

Advantages

• Improved functional outcomes in many studies
• Longer implant survival
• Eliminates the risk of acetabular cartilage wear
• Lower likelihood of acetabular protrusion

Limitations

• More complex surgical procedure
• Greater operative time and blood loss
• Increased soft tissue dissection
• Potentially higher risk of dislocation compared with hemiarthroplasty
• Slightly increased risk of postoperative complications such as deep vein thrombosis

Evidence from Clinical Studies

• Many comparative studies have evaluated outcomes of hemiarthroplasty and total hip arthroplasty in elderly patients with displaced femoral neck fractures.
• Results generally show that total hip arthroplasty provides:
  • Better long term functional outcomes
  • Longer implant survival
  • Reduced need for later revision surgery
• Some randomized studies involving patients older than eighty years have demonstrated that:
  • Total hip arthroplasty did not significantly increase the risk of dislocation
  • Postoperative mortality rates were similar between procedures
  • Functional scores and mobility outcomes were better with total hip replacement

Challenges in Total Hip Arthroplasty for Acute Fractures

• In patients with acute femoral neck fractures, the soft tissues around the hip are often lax.
• Unlike arthritic hips, there is minimal capsular fibrosis or soft tissue tightening.
• This situation creates two important challenges:
  • Increased risk of postoperative dislocation
  • Difficulty in achieving appropriate soft tissue tension during surgery
• To improve stability, surgeons may occasionally use a longer femoral neck component.
• This adjustment can sometimes lead to mild limb length increase.

Managing Limb Length and Soft Tissue Tension

• Slight limb length increase may be necessary to maintain stability and proper muscle tension.
• Patients should be informed about this possibility before surgery.

Strategies to reduce limb length discrepancy include:

• Use of implants with higher femoral offset
• Careful restoration of hip biomechanics during surgery
• Appropriate selection of femoral neck length

Role of High Offset Implants

• High offset implants increase the lateral distance between the femoral shaft and the center of the hip joint.
• Benefits include:
  • Improved abductor muscle tension
  • Greater range of impingement free movement
  • Reduced risk of dislocation
• Increasing the offset can restore hip stability without excessively increasing limb length.

Alternative Technique When High Offset Implants Are Not Available

• In some settings, high offset implant designs may not be available.
• In cemented hip replacements, a modified technique can be used:
  • A longer femoral neck component may be selected
  • The stem may be positioned slightly deeper within the cement mantle
• This approach can help improve offset while maintaining acceptable limb length.

Dual Mobility and Larger Femoral Heads

• Modern implant designs such as dual mobility systems are increasingly used.
• These designs provide a larger effective head size and increased stability.
• Dual mobility implants are particularly useful in fracture cases where the risk of dislocation is higher.

Clinical Guidelines for Procedure Selection

Clinical recommendations suggest choosing total hip arthroplasty in patients who meet certain criteria.

Key considerations include:

• The patient was able to walk independently outdoors before the fracture, with no more than minimal walking aid support.
• The patient does not have severe medical conditions that would significantly increase surgical risk.
• The patient is expected to have an active life expectancy exceeding approximately two years.

When these conditions are met, total hip replacement is often recommended because it provides better long term functional outcomes.

Additional Consideration: Surgical Experience

• The surgeon’s experience plays an important role in procedure selection.
• Total hip arthroplasty requires greater technical expertise compared with hemiarthroplasty.
• Surgeons who are less experienced with total hip replacement may prefer hemiarthroplasty to minimize complications.

Choice of Implant Type

• When hemiarthroplasty is selected, both unipolar and bipolar prostheses have shown similar outcomes in many studies.
• Cemented femoral stems are generally recommended for elderly patients with osteoporotic bone.
• Cementless stems may carry a higher risk of complications such as periprosthetic fractures in this group.

Variations in Clinical Practice

• Studies evaluating national healthcare systems have demonstrated significant differences in treatment choices between hospitals.
• Some institutions perform hemiarthroplasty in the majority of cases, while others more frequently use total hip replacement for similar patient groups.
• These differences reflect variations in surgeon experience, institutional protocols, and patient selection.

Key Factors in Decision Making

The choice between hemiarthroplasty and total hip arthroplasty should consider:

• Patient activity level before injury
• Degree of osteoporosis
• Associated medical conditions
• Functional expectations
• Surgeon experience and familiarity with the procedure

Summary

• Hip arthroplasty is commonly recommended for elderly patients with displaced intracapsular femoral neck fractures.
• Both hemiarthroplasty and total hip arthroplasty are effective treatment options.
• Total hip arthroplasty often provides better long term function in active patients.
• Hemiarthroplasty may be preferable in frail patients or when surgical risk must be minimized.
• Careful patient selection and proper surgical technique are essential for successful outcomes.