Femoral Neck fracture classification

Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA

 

Overview

• Femoral neck fractures commonly occur following low-energy trauma in elderly patients, often related to osteoporosis.

  • These patients require thorough medical evaluation and optimization.

• Femoral neck fractures can also occur following high-energy trauma, such as falls from height or motor vehicle accidents.

  • These injuries may affect both younger and older patients.

  • In such cases, management should follow Advanced Trauma Life Support protocols.

• Femoral neck fractures may also result from:

  • Insufficiency fractures, caused by weakened bone due to osteoporosis or osteopenia

  • Stress fractures, caused by repetitive loading and overuse

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Insufficiency Fractures of the Femoral Neck

• Occur in patients with poor bone quality.

• Present with:

  • Groin pain

  • Pain with axial loading

• Initial radiographs may be normal.

• Magnetic resonance imaging is helpful for diagnosis.

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Stress Fractures of the Femoral Neck

• Occur due to repetitive loading and overuse.

• Commonly seen in:

  • Athletes

  • Ballet dancers

  • Military recruits

• More frequent in females due to the female athletic triad:

  1. Amenorrhea

  2. Eating disorders

  3. Osteoporosis or osteopenia

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Anatomic Classification of Femoral Neck Fractures

Femoral neck fractures are classified anatomically as:

1. Subcapital fractures (most common)

2. Transcervical fractures

3. Basicervical fractures

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Subcapital Fracture Classifications

Subcapital fractures are further classified using:

1. Garden classification

2. Pauwels classification

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Garden Classification

Principle

• Based on the degree of fracture displacement.

• Correlates displacement with the risk of vascular disruption to the femoral head.

• Most applicable to geriatric and insufficiency fractures.

Groups

• Non-displaced fractures: Type I and Type II

• Displaced fractures: Type III and Type IV

Description

• Type I

  • Incomplete fracture

  • Impacted in valgus

• Type II

  • Complete fracture

  • Non-displaced on both anteroposterior and lateral views

• Type III

  • Complete fracture with partial displacement

  • Trabecular pattern of the femoral head does not align with the acetabular trabeculae

• Type IV

  • Complete fracture with full displacement

  • No continuity between proximal and distal fragments

  • Trabecular pattern of the femoral head remains parallel to the acetabular trabeculae

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Pauwels Classification

Principle

• Based on the orientation of the fracture line relative to the horizontal.

• Reflects biomechanical stability.

• As fracture obliquity increases, shear forces increase, leading to higher instability and complication rates.

Types

• Type I

  • Obliquity of 0 to 30 degrees

  • Stable fracture

• Type II

  • Obliquity of 30 to 50 degrees

  • Moderately unstable fracture

• Type III

  • Obliquity of 50 to 70 degrees or more

  • Highly unstable fracture

Key Concepts

• Horizontal fracture lines are more stable.

• Vertical fracture lines are more unstable.

• Increasing displacement increases:

  • Risk of vascular disruption

  • Risk of avascular necrosis

  • Risk of nonunion

• Nonunion occurs in approximately 25 percent of displaced femoral neck fractures.

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Management of Nonunion in Younger Patients

• In young patients with nonunion:

  • A subtrochanteric valgus osteotomy may be performed

  • This reorients the fracture line from vertical to horizontal

  • Improves biomechanical stability and fracture healing

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Femoral Neck Fractures Associated with Femoral Shaft Fractures

• Commonly vertical and non-displaced.

• May be missed on standard radiographs.

• Internal rotation views of the hip are often required.

• Treatment priority:

  1. Fixation of the femoral neck fracture

  2. Followed by fixation of the femoral shaft fracture

• Typical fixation construct:

  • Parallel screws for the femoral neck

  • Retrograde intramedullary nail for the femoral shaft

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Pipkin Type III Injury

• Consists of:

  • Fracture of the femoral head

  • Hip dislocation

  • Fracture of the femoral neck

• Closed reduction of the hip dislocation should be avoided when possible.

• Open reduction of the hip dislocation is preferred, especially when the femoral neck fracture is not displaced.

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Classification of Femoral Neck Stress Fractures

A. Tension-Side Stress Fractures

• Located on the superior aspect of the femoral neck.

• Adult bone is weak in tension.

• These fractures are unstable and require surgical fixation.

• Should be treated as an emergency to prevent displacement.

• Magnetic resonance imaging is essential for diagnosis.

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B. Compression-Side Stress Fractures

• Located on the inferior aspect of the femoral neck.

Management depends on fracture extent:

• Less than 50 percent of neck width:

  • Considered stable

  • Managed with protected weight bearing using crutches

• Greater than 50 percent of neck width:

  • Considered unstable

  • Requires open reduction and internal fixation