Basics
Description
- The scaphoid is the most commonly fractured carpal bone.
- This bone is the stabilizer between the distal and proximal carpal rows.
- Injury may result in arthritis, avascular necrosis, or malunion.
- Classified as:
- Proximal 3rd (10 " 20%)
- Middle 3rd (the waist, 70 " 80%)
- Distal 3rd (the tuberosity)
- Tubercle fractures
- Fractures are missed on initial radiographs 10 " 15% of the time, and delayed diagnosis greatly increases risk of complications.
- The blood supply to the scaphoid enters distally
- The more proximal the fracture, the higher the likelihood for avascular necrosis
- As the wrist is forcibly hyperextended, the volar aspect of the scaphoid fails in tension and the dorsal aspect fails in compression resulting in a fracture.
Etiology
Generally results from a fall on an outstretched (dorsiflexed) hand (FOOSH injury).
Diagnosis
Signs and Symptoms
History
FOOSH injury
Physical Exam
- Maximal pain and tenderness in the anatomic snuffbox (may be elicited with direct palpation or axial loading of the thumb); 90% sensitive, 40% specificity.
- Dorsal wrist pain distal to the radial styloid and decreased range of motion of the wrist and thumb
- Rarely, incidental damage to the superficial branches of the radial nerve results in sensory changes.
- Palpate the scaphoid tubercle for tenderness by radially deviating the wrist and palpating over the palmar aspect of the scaphoid; 87% sensitivity, 57% specificity.
- Carpal fractures are rare in children (and the elderly), as the distal radius usually fails 1st.
- If present, carefully evaluate mechanism.
Diagnosis Tests & Interpretation
Imaging
- Radiographic imaging should include 3 views of the wrist: PA, lateral, oblique, and scaphoid views (wrist prone and in ulnar deviation).
- Pay special attention to the middle 3rd, or waist, of the bone: 70% of injuries occur here.
- Fracture may be identified by subtle findings such as a displaced fat pad.
- 10 " 15% of all fractures are not visible on radiographs at the time of injury.
- Bone scintigraphy or MRI as early as 3 days postinjury can rule out fracture and allow for earlier rehabilitation:
Diagnostic Procedures/Surgery
- If fracture is open or associated injuries are identified, urgent surgical intervention may be indicated.
- Associated injuries with scaphoid fracture:
- Scapholunate dissociation
- Distal radial fracture
- Lunate fracture/dislocation
- Bennett fracture of thumb
- Radiocarpal joint dislocation
- Proximal and distal carpal bone joint dislocations
Differential Diagnosis
- Bennett fracture
- Rolando fracture
- Extra-articular fracture at the base of the thumb metacarpal
- Gamekeeper thumb
- De Quervain tenosynovitis
- Perilunate dislocation
- Scapholunate dissociation
- Lunate fracture or dislocation
Treatment
Pre-Hospital
Splint or immobilize as appropriate.
Initial Stabilization/Therapy
- Evaluate patient for other injuries.
- Dress open wounds.
- Immobilize with thumb in neutral position, ice, and elevate.
Ed Treatment/Procedures
- Assess mechanism of injury and point of maximal tenderness.
- Exam with special attention to skin integrity and neurovascular status.
- If snuffbox tenderness is present, place in thumb spica splint.
- Counsel patient regarding risk of malunion (10%) and avascular necrosis.
- Clinically suspected scaphoid fractures without radiographic evidence:
- Should be treated as a nondisplaced scaphoid fracture
- Spica splint thumb in a position as if the patient was embracing a wine glass.
- Repeat physical/radiographic exam in 7 " 10 days.
- Nondisplaced scaphoid fractures:
- Displaced scaphoid fractures:
- Nonunion rate of 50%
- Often an indication for internal fixation
Medication
Pain control with NSAIDs or narcotics as needed
Follow-Up
Disposition
Admission Criteria
Open fracture or presence of other more serious injuries
Discharge Criteria
- Closed injuries, with 72-hr orthopedic follow-up
- Patients with splints for nondisplaced fractures may be allowed to return to full work or activity of work/sport if the cast does not interfere with the exercises of work or specific sport activities.
Issues for Referral
- If fracture is angulated or displaced >1 mm, immediate orthopedic referral is indicated.
- All scaphoid or suspected scaphoid injuries must be referred to orthopedics.
- If no radiographic abnormalities found on initial radiograph, after placing in thumb spica splint, refer to orthopedics or primary care in 7 " 10 days with repeat radiographs at that time.
Pearls and Pitfalls
- Perfusion enters scaphoid bone distally.
- Avascular necrosis (especially with proximal 3rd fractures), occurs with inadequately reduced or immobilized fractures.
- Patients presenting with symptoms of a sprained wrist must have the diagnosis of acute scaphoid fracture ruled out.
Additional Reading
- Chudnofsky CR, Byers SE. Clinical Procedures in Emergency Medicine: Splinting Techniques. 5th ed. Philadelphia, PA: Saunders Elsevier; 2010.
- Kumar S, O 'Connor A, Despois M, et al. Use of early magnetic resonance imaging in the diagnosis of occult scaphoid fractures: The CAST study (Canberra Area Scaphoid Trial). N Z Med J. 2005;118(1209):U1296.
- Pillai A, Jain M. Management of clinical fractures of the scaphoid: Results of an audit and literature review. Eur J Emerg Med. 2005;12(2):47 " 51.
- Plancher KD. Methods of imaging the scaphoid. Hand Clin. 2001;17(4):703 " 721.
- Simon RR, Sherman SC, Koenignecht SJ. Emergency Orthopedics: The Extremities. 5th ed. New York, NY: McGraw-Hill; 2007:189 " 193.
See Also (Topic, Algorithm, Electronic Media Element)
Lunate Fracture and Dislocations
Codes
ICD9
814.01 Closed fracture of navicular [scaphoid] bone of wrist
ICD10
- S62.009A Unsp fracture of navicular bone of unsp wrist, init
- S62.026A Nondisp fx of middle third of navic bone of unsp wrist, init
- S62.036A Nondisp fx of prox third of navic bone of unsp wrist, init
- S62.016A Nondisp fx of distal pole of navic bone of unsp wrist, init
- S62.013A Disp fx of distal pole of navicular bone of unsp wrist, init
- S62.023A Disp fx of middle third of navic bone of unsp wrist, init
- S62.033A Disp fx of proximal third of navic bone of unsp wrist, init
SNOMED
- 31975004 Fracture of navicular bone of wrist (disorder)
- 42818005 Closed fracture of navicular bone of wrist (disorder)
- 208373008 Closed fracture scaphoid, waist, comminuted (disorder)
- 208374002 Closed fracture scaphoid, tuberosity (disorder)
- 208370006 Closed fracture scaphoid, proximal pole (disorder)
- 209271003 Closed fracture dislocation perilunate transscaphoid (disorder)