Carpal fractures
Background
- Scaphoid fractures account for 70% of all carpal fractures
- Ulnar nerve damage associated with fractures of hamate or pisiform
- 50% of pisiform fx associated with injury to distal radius or other carpal bone
- If bone fragment seen posterior to carpus on lateral, very likely triquetrum fx
Diagnosis
- Mechamism of injury
- Hyperextension (FOOSH)
- Scaphoid, lunate, triquetrum, or pisiform fractures
- Consider oblique views
- Hyperflexion
- Triquetrum fracture
- Axial loading
- of the wrist: scaphoid fx, scapholunate dissociation
- thumb: trapezium fx
- index: trapezoid fx
- Direct blow to palmar surface
- Pisiform or hamate fractures
- Specific Bone Fx
- Scaphoid
- Pain in the snuffbox (especially with ulnar deviation)
- Grip strength reduced
- Often associated with perilunate dislocation
- Lunate
- Pain aggravated by wrist motion or gripping
- Pain with axial loading of the 3rd digit
- Often associated with other injuries
- Triquetrum
- TTP just distal to the ulnar styloidPain on the ulnar aspect of the wrist
- Pisiform
- Pain/swelling at the palmar and ulnar aspects of the wrist
- TTP over the hypothenar eminence
- Hamate
- Sudden wrist pain when a swinging motion has been interrupted
- TTP over hypothenar eminence
- 4th, 5th digit paresthesia if fx involves ulnar nerve
- Capitate
- Pain/swelling on dorsum of hand
- Rarely fractured in isolation
- Trapezoid
- Point tenderness just proximal to 2nd metacarpal base
- Trapezium
- Pain/weakness with making "OK" sign or touching thumb to tip of 5th digit
- Significant discomfort
- Minimal swelling
Imaging
- Checklist
- Palmar tilt of the radius is present on the lateral view
- Radial articular surface lies distal to the ulna
- Dorsal surface of the distal radius is smooth
- Waist of the scaphoid is intact
- Capitate sits in the concavity of the lunate
- Intercarpal joints are no more than 2mm wide; adjacent surfaces are parallel
- PA
- EvaluateZone of vulnerability.pdf
- Lateral
- Evaluate scapholunate angle (should be between 40o and 60o)
- Oblique
- Also consider:
- PA with maximal ulnar deviation ("Scaphoid View")
- Scaphoid fx
- Carpal tunnel view
- Hamate hook fx
- Trapezium fx
- Pisiform Fx
- PA clenched fist view
- Consider for scapholunate instability (space >2mm suggests ligamentous disruption)
- CT
- Trapezoid fx
Treatment
- Scaphoid Fx
- Thumb-spica spint (or preferably a cast) until repeat xrays performed at 10 days
- Lunate Fx
- Double sugar tong or long-arm thumb spica splint
- May lead to osteonecrosis if not recognized and treated
- Triquetrum Fx
- Volar splint w/ wrist in slight dorsiflexion and the MCP free
- Pisiform Fx
- Volar or dorsal splint
- Hamate Fx
- Volar splint
- Capitate Fx
- Sugar-tong or short arm thumb spica splint
- Trapezoid Fx
- Volar splint
- Trapezium Fx
- Short arm thumb-spica
- Dislocations
- Scapholunate
- Volar splint, referral within 1 week
- Lunate/perilunate
- Volar spint, immediate reduction
==Disposition==
- Scaphoid Fx
- Always refer to a hand surgeon b/c may lead to osteonecrosis if not recognized/treated
- Lunate Fx
- Always refer to a hand surgeon b/c may lead to osteonecrosis if not recognized/treated
- Triquetrum Fx
- Refer for displacment >1mm
- Pisiform Fx
- Tend to do well with casting; refer for casting if unable to obtain in the ED
- Hamate Fx
- Refer for dislocation, pts who need to return to actvitiy ASAP
- Capitate Fx
- Always refer to a hand surgeon b/c may lead to osteonecrosis if not recognized/treated
- Trapezoid Fx
- Refer for comminution or dislocation
- Trapezium Fx
- Refer for displacement >2mm, intraarticular fx w/ >1mm incongruity, comminuted fx
- Lunate/perilunate dislocation
- Consult hand surgeon for immediate reduction(very difficult to reduce)
Source
UpToDate, Accident & Emergency Radiology, Harwood-Nuss