Fractures of the bones of the hand

Scaphoid fracture

Epidemiology

• Most common in young males
• Most commonly occurs in the scaphoid waist

Etiology

• Due to a fall on an outstretched hand – hyper-dorsiflexed, pronated and ulnarly-deviated wrist

Pathophysiology

• Transverse fractures are more stable than vertical/oblique fractures

Classification – Herbert and Fisher Classification

• A – stable, acute fracture
• B – unstable, acute fracture
• C – delayed union, characterised by cyst formation
• D – non union

Clinical features

• Pain and swelling over radial aspect of the wrist
• Pain worsens when patient attempts to move wrist in a circular motion
• Tenderness in the scaphoid fossa (anatomical snuff box)

Diagnosis

• X-ray
• Tc⁹⁹ bone scan
• MRI – for associated soft tissue and vascular injury

Treatment

• Cast immobilisation – for stable nondisplaced fractures
• Percutaneous screw fixation
• ORIF – for significantly displaced or comminuted fractures

Complications

• Avascular necrosis
• Delayed and non union
• Wrist osteoarthritis – as a result of avascular necrosis or non union

Lunate dislocation

Epidemiology

• Young adults
• Commonly missed on initial presentation

Etiology/pathophysiology

• Due to high energy trauma on an extended, ulnarly deviated wrist
• Categories
  • Perilunate dislocation – lunate stays in place while carpus dislocates
  • Lunate dislocation – lunate forced volar or dorsal while carpus remains aligned

Clinical features

• Acute wrist swelling and pain
• Median nerve compression

Diagnosis

• X-ray
  • break in Gilula’s arc
  • ‘piece of pie’ sign – triangular appearance of lunate

Treatment

• Closed reduction and casting – usually poor outcomes
• Open reduction, ligament repair, fixation, carpel tunnel release – for all injuries under 8 weeks
• Proximal row carpectomy – for injuries over 8 weeks

Triquetrum Fracture

Epidemiology

• Second most common carpal bone fracture

Etiology/pathophysiology

• Dorsal cortical fractures (most common) – result from impaction, avulsion, shearing force
• Body fractures – can be sagittal, transverse or comminuted
• Palmar cortical fractures – due to avulsion of a ligament or from shearing force from pisiform
• 25% of triquetrum fractures are associated with perilunate dislocations

Clinical features

• Swelling/deformity of ulnar side of the wrist
• Pain with palpation over triquetrum
• Pain with wrist flexion and extension if dorsal cortical fracture

Diagnosis

• X-ray – ‘pooping duck’ sign
• CT/MRI – for ligament injuries

Treatment

• Immobilisation – for dorsal cortical fractures without evidence of instability
• ORIF – for dorsal cortical fractures with evidence of instability, displaced body fractures

Metacarpal fracture

Epidemiology

• Metacarpal fractures make up 40% of hand injuries
• Most common in young men
• 5^th metacarpal most likely to be injured
• Metacarpal neck is most common site of fracture

Etiology/pathophysiology

• Direct blow to hand or rotational injury – e.g. in contact sports (boxing), manual labour
• High energy injuries can result in multiple fractures
• Associated conditions
  • Tendon laceration
  • Neurovascular injury
  • Compartment syndrome – with crush injuries

Clinical features

• Pain, swelling
• Ecchymosis
• Limitation of movement
• Deformity – knuckle asymmetry; finger misalignment

Diagnosis

• X-ray
• CT – if XR is inconclusive

Treatment

• Immobilisation – stable fracture with no rotational deformity
• Operative – ORIF, MCP arthroplasty, MCP fusion
  • Indications – open fracture, rotational misalignment of digit, significantly displaced/angulated, multiple fractures

Phalanx fractures

Epidemiology

• Most common skeletal injury – accounts for 10% of all fractures
• More common in males
• Location of phalanx affected – distal > middle > proximal
• Small finger most affected

Etiology/pathophysiology

• Sports injury (younger patients)
• Machinery related injury (middle aged)
• Falls (elderly)
• Associated conditions – Seymour fracture (distal phalangeal physeal fracture with an associated nailbed injury)
• Can be intra or extra-articular and can occur at the base, neck, shaft or head of the phalanx

Clinical features

• Tenderness, swelling
• Deformity
• Scissoring of digits – indicates rotational deformity
• Numbness – indicates digital nerve injury

Diagnosis

• X-ray

Treatment

• Non-operative – buddy taping/splinting
  • For non-displaced fractures with no rotational deformity or shortening
• Operative – CRPP/ORIF
  • For fractures with large angulation, shortening or rotational deformity
  • Displaced or unstable fractures

Complications

• Loss of motion
• Malunion – malrotation, angulation, shortening
• Non union

Base of thumb fracture

Epidemiology

• 80% of thumb fractures occur at the base
• Most common fracture pattern – extra-articular epibasal

Etiology/pathophysiology

• Due to axial force applied to the thumb in flexion
• Incomplete reductions can lead to increased joint contact pressures
  • Predisposes to early arthritis
• Types
  • Extra articular – can be oblique or transverse
  •    Bennett fracture – partial intra-articular
  • Rolando fracture – complete intra-articular
  • Severely comminuted fracture

Clinical features

• Acute pain at the base of thumb
• Swelling and ecchymosis
• Tenderness to palpation at carpometacarpal joint
• Pain with motion

Diagnosis

• X- ray
  • Bennett fracture – small fragment of 1^st metacarpal base articulating with trapezium
  • Rolando fracture – ‘Y’ sign, represents splitting of the 1^st metacarpal
• CT – for complex fracture patterns

Treatment

• Closed reduction with thumb spica casting
  • Extra-articular fractures with <30^o angulation; Bennetts fracture with <1mm displacement
• Closed reduction and percutaneous k-wire fixation
  • Extra-articular fractures with >30^o angulation; Rolando fracture with <1mm displacement
• ORIF
  • >1mm displacement in Bennett or Rolando