Hand radiograph (an approach)

Systematic review

Review the wrist

A hand radiograph contains an PA and oblique view of the distal radius and ulna and the carpus.

• check the wrist as you would for a wrist radiograph (an approach)
  • distal radius
  • carpal alignment
  • carpometacarpal articulation
  • bone cortex

Joint spaces

Assess the carpal and carpometacarpal joint space:

• 1-2 mm joint space should be seen between the carpals and metacarpals
• look specifically at the base of the 4th and 5th metacarpals
• if the joint space is narrowed, think carpometacarpal dislocation

Assess the interphalangeal joint space:

• metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints should be congruent and there should be a visible joint space

Metacarpals

Assess the cortex of each metacarpal in turn:

• pay particular attention to the 1st and 5th metacarpals
• metacarpal injuries or those affecting several phalanges may coexist with injuries to other digits
• if cortical disruption of 5th metacarpal neck, think Boxer fracture
• be wary of fractures involving the joint surface - they are unstable
• if intra-articular cortical disruption of 1st metacarpal base, think Bennett fracture dislocation or Rolando fracture

Alignment

Assess the alignment of the metacarpals and phalanges:

• check each finger from metacarpal to distal phalanx
• malalignment and reduced joint space both point to dislocation
  • carpometacarpal dislocation
  • metacarpophalangeal dislocation
  • interphalangeal dislocation

Phalanges

Assess the cortex of each phalanx in turn, proximal to distal:

• pay particular attention to phalangeal tufts, shafts and ligamentous insertions
• if lateral or medial bony fragment, think collateral ligament avulsion
• if dorsal bony fragment, think extensor ligament avulsion
• if palmar bony fragment, think volar plate avulsion

Common pathology

Interphalangeal joint dislocation

• common upper extremity dislocation
• usually a hyperextension injury
• typically dorsal dislocation of PIP joint +/- bony avulsion
• palmar bony fragment indicates avulsion of volar plate
• more: interphalangeal joint dislocation

Mallet finger

• disruption of extensor mechanism at DIP joint leading to tendon injury +/- bony avulsion
• extended finger struck at the tip or crushed
• dorsal bony fragment indicates avulsion of extensor tendon
• more: Mallet finger

Boxer fracture

• minimally comminuted, transverse fracture of the 5th metacarpal
• 25% of all metacarpal fractures
• usually young male adults
• caused by a direct blow when the fist is clenched
• more: Boxer fracture

Bennett fracture

• unstable intra-articular fracture of the base of 1st metacarpal 
• caused by forceful thumb abduction
• large metacarpal fragment dislocated by pull of abductor pollicis longus
• small metacarpal fragment remains attached to MCP joint
• more: Bennett fracture

Skier/Gamekeeper thumb

• rupture of ulnar collateral ligament of 1st MCP joint
• there may be an associated bony avulsion
• avulsion fracture occurs at the ulnar corner of the proximal phalanx base
• caused by forceful thumb abduction
• more: Gamekeeper's thumb

Don't miss...

Rolando fracture

• base of 1st metacarpal intra-articular fracture - comminuted (3 fragments) and highly unstable
• axial blow to partially flexed metacarpal
• fracture line typically T or Y-shaped
• more: Rolando fracture

Carpometacarpal dislocation

• rare but important injury to dominant hands of younger males
• younger male predominance
• often occur after a punch followed by a fall
• reduction of joint space on the AP
• best seen on an oblique study
• more: carpometacarpal dislocation

Enchondroma

• common benign medullary cartilaginous neoplasm
• tend to be seen in young adults
• 50% lesions found in small tubular bones
• complicated by pathological fracture
• more: enchondroma