Femoral Neck Fractures

Blood Supply and Healing of the Femoral Head

Blood Supply

  • In adults, blood supply is derived from 3 sources:
    1. Retinacular (capsular) vessels
    2. Intraosseous vessels
    3. Ligamentum teres – branch of obturator or medial circumflex femoral artery (MCFA).
  • Most Important: Ascending retinacular vessels.
  • Circumflex Vessels:
    • Derived from profunda femoris in 79%.
    • Partly from femoral artery in 20%, completely from femoral artery in 1%.
    • MFC and LFC form an anastomosis at the base of the neck.
  • Sub-synovial Ring Anastomosis:
    • Formed at the base of the head, where vessels enter the head.
    • Main blood supply enters the head postero-superiorly, supplying the weight-bearing area.

Healing

  • Occurs via primary endosteal healing (no callus formation due to the absence of a cambial layer over the femoral neck).
  • Prolonged healing time due to this mechanism.

Sensory Supply

  • Provided by femoral, sciatic, and obturator nerves, explaining pain in the groin and thigh.

Classification

Garden Classification

  1. Type 1: Valgus impacted fracture. Trabeculae misaligned with neck or acetabulum.
  2. Type 2: Undisplaced complete fracture. Trabeculae are co-linear.
  3. Type 3: Partially displaced into varus. Trabeculae misaligned with neck or acetabulum.
  4. Type 4: Completely displaced. Trabeculae re-align with acetabulum but not the neck.

Pauwels Classification

  • Based on the angle of the fracture line relative to the horizontal plane:
    1. Type 1: <30° (most common).
    2. Type 2: 30–50°.
    3. Type 3: >50° (higher shear forces; greater risk of non-union and fixation failure).

Management

Undisplaced Fractures

  • Non-Operative Management:
    • 50% displace if treated non-surgically.
    • Higher rates of non-union.
    • 30% 1-year mortality with non-operative treatment.
  • Operative Management:
    • Internal fixation preferred (5% non-union rate).
    • Greater morbidity with hemiarthroplasty.
    • Outcomes worse with increasing age, poor walking ability, lateral displacement, or less impaction.
    • Revision rate: 7%.

Displaced Fractures

  • Non-Operative Management:
    • No role (90% 1-year mortality).
  • Operative Management Considerations:
    • Age: Preserve femoral head in patients <60–70 years.
    • Gender: 50% higher non-union risk in females.
    • THR preferred for rheumatoid arthritis, metabolic bone disease, symptomatic OA, or delayed presentation.

Surgical Options

  1. Internal Fixation:
    • Higher reoperation rate compared to hemiarthroplasty.
  2. THR vs Hemiarthroplasty:
    • THR: Better functional outcomes but higher dislocation rate.
    • Hemi: Similar outcomes to internal fixation.
  3. Cemented vs Non-Cemented Arthroplasty:
    • Cemented: Better pain scores and functional outcomes.
    • Non-cemented: Greater thigh pain, higher fracture rates, and worse functional outcomes.

Closed Reduction Techniques

Leadbetter Technique

  1. Flex and adduct the hip slightly.
  2. Apply traction in line with the femur.
  3. Fully flex and adduct, then slowly abduct and extend while maintaining internal rotation.

Traction Table

  • Minimal traction and internal rotation, with X-ray guidance.
  • Avoid excessive traction to prevent valgus malreduction.
  • Limit repeated attempts to preserve blood supply.

Surgical Approach for Open Reduction

Preferred Approach: Watson Jones

  • Between tensor fascia lata and gluteus medius (no internervous plane).
  • Curved incision toward ASIS, centered on GT.
  • Incision of anterior gluteus medius (similar to Hardinge approach).
  • Capsule incised with an inverted T for exposure.
  • Reduction facilitated by joysticks, hooks, and muscle relaxation via hip flexion/adduction.

Department of Health Best Practice Tariffs for Fractured Neck of Femur

  1. Surgery within 36 hours of casualty arrival.
  2. Admission via agreed protocol.
  3. Joint care by orthopaedic surgeon and ortho-geriatrician.
  4. Pre-surgical ortho-geriatric assessment.
  5. MDT rehabilitation post-surgery.
  6. Falls risk and bone health assessment.
  7. Audit collection and submission for analysis.
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