fracture_scaphoid
Table of Contents
scaphoid fractures
see also:
introduction
- fracture of the scaphoid is a critical diagnosis to be made early as missed diagnoses or occult fractures result in non-union in ~12% and risk of avascular necrosis (particularly for proximal fractures)
- it is very rare under age 8 years
diagnosis of scaphoid fracture
clinical tests
- anatomical snuff box (ASB) tenderness
- sens. ~100% spec variable
- axial loading on thumb (hold thumb and push proximally)
- scaphoid tubercle tenderness (palpate base of thenar eminence)
- when combined with ASB and axial loading: sens ~100%, spec high
initial plain Xray with scaphoid views
- sens. ~70%
repeat Xray in 10-14 days looking for signs of fracture healing
- poor inter-operator reliability coefficient
ultrasound
- unreliable
initial CT scan
- sens. > 72%, spec. > 80% (may not be as good in children aged under 14yrs)
- radiation dose = ~25 CXRs
initial MRI scan
- negative predictive value, sensitivity and specificity, approaching 100%
nuclear med scan
- early scans in the 1st few days have false positive rates due to traumatic synovitis
- very good sens/spec if after 5 days but expensive, and higher radition doses1)
general Mx of suspected scaphoid fractures in the ED
- NB. the scaphoid bone is not usually fully visible on Xrays in children under 8 years of age, and in this group, scaphoid fracture is exceedingly rare and thus the information below primarily applies to adolescents and adults.
- All cases of suspected scaphoid fractures require scaphoid x-ray views in addition to Anterior/Posterior (AP) and lateral films.
- If x-ray shows fracture:
- place in scaphoid plaster, arrange POP check 24 hours post-application in the Emergency Department, and review at 1 - 2 weeks - usually in a fracture clinic.
- all patients should be given plaster instructions eg. Vic DHS - Fractures and plaster care (pdf)
- If x-ray shows no fracture:
- if there is swelling and/or severe tenderness in the anatomical snuff box, immobilise in scaphoid plaster and arrange repeat x-ray and review in 10 days.
- if tenderness is mild, apply supportive bandage (eg. Tubigrip) and arrange repeat x-ray and review in 7- 10 days.
- If at 10 days there is improvement in symptoms and no evidence of fracture on the review X-ray, then it is unlikely that there is a scaphoid fracture.
- If the diagnosis needs to be known earlier then a bone scan or CT may be performed 2 days after the injury.
Mx of proven fracture
- potential indications for surgery:
- displacement > 1mm
- proximal fractures given that the alternative may be 6 months in plaster?
- clearly visible fractures?
- fractures with lunar tilt
- non-union
- not willing to wear a cast for 6-12 weeks
- POP cast immobilisation (most advise including the thumb):
- 6-8 weeks for distal 1/3rd fracture
- 8-12 weeks for middle 1/3rd fracture
- 12-23 weeks for proximal 1/3rd fractures
fracture_scaphoid.txt · Last modified: 2015/12/17 22:51 by 127.0.0.1