Principles of Fractures

Prof. Mamoun Kremli

Objectives

What is a Fracture - the soft tissue part
Fracture types / classification
Relation between fracture and force
History and physical exam. In fractures
Principles of imaging

What is a fracture?

A fracture is a break in the structural continuity of bone

Definition of a Fracture

A fracture is a break in the structural Discontinuity of bone
- Always associated with some soft tissue injury Fibula is always lateral
A fracture is a soft tissue injury in which the underlying bone is broken!

Type of Injury

Mechanism of injury helps expect the
Extent and type of bone injury
- Simple / comminuted / complex
- Associated fractures/injuries
  - Fall from height on feet
    - fractured calcaneus and lumbar spine
  - Car dashboard injuries
    - fractured patella and hip dislocation
Extent of soft tissue injury
Suggested treatment and reduction technique
Prognosis

Types of Injury Mechanisms

Fall: height, point of impact, twist
Sport: type, direction of force
Road traffic accident (RTA):
- Car (MVA), motorcycle, pedestrian
Heavy object fall:
- TV, wall, metal, earthquake
Assault & firearms / blast

Mechanism of Injury

Low energy
High energy
Direction of force
- Inversion
- Eversion
Blunt / Sharp
Closed / Open When the hematoma is exposed to the external environment

Energy Dissipated During Injury

Kinetic Energy = ½ MV²

If a Simple fall = 1
Skiing injury = 3-5
High-velocity gunshot = 20
Car bumper (25 km/hr) = 100

Fracture Classification

According to site of Fracture:
- Diaphyseal
- Metaphyseal
- Articular
- Epiphyseal (in children)

Classification by Fracture Line

According to fracture line:
- Complete (usual)
  - Cortex fractured on both sides
- Incomplete (in children)
  - Green stick / Torus, Buckle /Deformation

Classification by Fracture Pattern

According to fracture pattern:
- Simple
- Wedge comminuted
- Complex comminuted
  - Multi-fragmented

According to fracture pattern:
- Compressed
- Depressed

Classification by Type of Injury (Force)

According to type of injury (force):
- Ordinary fracture
  - Expected from force of injury
- Stress fracture
  - Repetitive loading
- Pathological fracture
  - Force too weak to cause fracture
  - Bone is pathologically weak
- Avulsion fracture
  - Resisted muscle action, or where ligaments and tendons pull a bone fragment off

Stress Fractures

Bone reacts to repeated loading, may become fatigued & a crack develops
Fatigue fractures
- Abnormal stress or torque on a bone that has normal elastic resistance
- Examples:
  - military recruits, athletes, ballet dancers
Insufficiency fractures
- Normal muscular activity stresses a bone that is deficient in mineral or elastic resistance

Stress Fracture Details

Fatigue fractures
- Usually Transvers
  - 2^nd metatarsal
  - Tibia
  - Fibula
Insufficiency fractures
- In osteopenia, osteomalacia
  - Neck of femur
  - Ribs
  - Neck of humerus
  - Scapula

Pathological Fractures

Fractures caused by trivial force on abnormally weak bone. Seen in:
- Local bone disease
  - Osteomyelitis
  - Benign tumors and Bone cysts
  - Malignant tumors and metastasis
- Generalized disease
  - Metabolic: osteoporosis, rickets
  - Congenital: osteogenesis imperfecta
  - Others: Paget’s disease

Force & Fractures

Normal bone:
- Strong force: ordinary fracture
- Repetitive stress: Stress (fatigue) fracture
Weak bone (Pathological fracture)
- Weak (trivial) force: pathological fracture
- Normal daily activity: Insufficiency fracture

Quality of Bone	Type of Force	Type of Fracture
Normal	Strong	Normal
Normal	Repetitive loading	Stress - fatigue
Abnormal - weak	Normal daily activities	Stress - insufficiency
Abnormal - weak	Trivial injury	Pathological

Avulsion Fractures

Part of bone separated by forceful sudden resisted muscle action
- Caused by ligament or tendon pull on bone
- Part of bone avulsed – bone weaker than tendon/ligament

Type of Injury and Fracture Pattern

Direct
- Mild force: transverse / Severe force: comminution
- Soft tissue more injured
Indirect
- Pattern of fracture depends on force direction
- Less soft tissue injury
Penetrating
- Missiles
  - Low velocity < 300 m/s - damage along the tract
    - Comminution
  - High velocity: >300m/s - severe comminution
    - Comminution with wide soft tissue damage

Fracture Pattern and Mechanism of Force

Fracture pattern suggests mechanism of force
- Spiral: (twisting)
- Short oblique: (compression)
- Wedge: (compression + bending)
- Transverse: (angulation) (avulsion)

Displacement

Types of Displacement

Described as: Position of distal in relation to proximal
Un-displaced
Shift
- Sideways
- Shortening
- Distraction
Angulation
- In all planes
Rotation

Fracture Diagnosis

History
Clinical features
Imaging: Radiology (x-Ray)

Trauma History

Mechanism of injury
- Date, time, type, method of impact, …
Consciousness
Function of injured part
Open wound / bleeding
Other injuries
Anti-Tetanus status (if skin breached)

Approach - History

Details of injury
- Mechanism, force, bleeding, consciousness, …
Details of facture
- Deformity, pain, loss of function, ..
Other medical problems
- Shall be discussed separately
Anti-tetanus status if open injuries
Careful:
- Fractures are not always at the site of impact
- Some fractures do not need severe force

Clinical Features

History of Trauma
Symptoms and signs:
1. Pain
2. Swelling
3. Deformity
4. Loss of function
5. Localised bony tenderness
6. Loss of motion
7. Abnormal movement
8. Crepitus

Approach - Clinical Exam

General medical condition
- Should be evaluated to exclude
  - Shock
  - Brain injury
  - Other Principles

Vital signs
- Should be observed and followed up

Look:
- Adequate exposure
- General on patient
- Local:
  - Swelling, deformity, bruises, color, …
  - Special attention is to be paid to wounds
Feel:
- Localized bone Tenderness
- Pulse distal to injury – capillary refill
- Sensory and motor deficits
- Compartment syndrome
- Temperature and crepitus on movement
Move:
- With care
  - make sure not to cause more pain or injury
- Crepitus & abnormal movement indicates a fracture
- Joints distal to the affected area

Examination of Viscera

Examination of the viscera
- Liver and spleen in rib fractures
- Urinary bladder and urethra in pelvic fractures
- Neurological examination in head and spinal injury

Imaging Principles

Plain x-ray: (law of two’s)
Two views: AP and Lateral

Apley’s System of Orthopedics & Fractures

Law of Two’s

Plain x-ray: (law of two s)
- Two views: AP and Lateral
- Two joints: joint above and joint below
  - To show other injuries
  - To assess rotation
- Two limbs: for comparison
  - more in children to compare epiphysis
- Two occasions
  - e.g. stress fractures
  - e.g. scaphoid fracture
- Two injuries
  - e.g. patellar fracture and hip injury
  - e.g. calcaneal fractures & spine injuries
…and two Doctors!!
Special views:
- Ankle mortis
- Calcaneal view
- Scaphoid views
- Shoulder dislocation: axial view
- Acetabular fractures: 45° tilt views
- Stress views
- Traction views
- Functional flexion/extension (spine)