Scaphoid and Suspected Scaphoid Fracture

There are a few important things to consider when managing a suspected (i.e. clinical suspicion but no Xray evidence) scaphoid fracture.

  1. Scaphoid fractures can be X-ray negative
  2. Scaphoid fractures can lead to avascular necrosis and chronic wrist immobility and pain
  3. X-ray negative scaphoid fractures might be amongst those that have a bad outcome
  4. Immobilising these in plaster of some sort might make a difference to the rates of those bad outcomes
  5. Wearing plaster for 10 days is a real pain in the neck, especially if you work with you hands, have both of them in plaster or have others to care for.

For these reasons please:

  • Make a proper clinical assessment of the chance of an occult scaphoid fracture

 

This means the patient having a meaningful mechanism of injury (true FOOSH with wrist extended), tenderness in the snuff box and on the tubercle of the scaphoid at the proximal end of the thenar eminence, pain on axial loading of the scaphoid along the 1st metacarpal, and reduction in grip strength or increased pain when gripping. Also the patient should have some hand function to save.

  • Always use a removable thumb spica slab rather than a full cast for the X-ray negative possible scaphoid fracture

 

They didn't manage to displace the fracture with the injury, why would the displace it now? The slab provides a reminder to be sensible and some comfort. Remember that good advice about avoiding further injury is more important than the slab (stay off the skateboard until fracture is ruled out).

  • Consider whether early diagnosis today or tomorrow with CT or MRI is worth the money and resource use.

 

In a publicly funded health care system the question is always, can we justify the cost of advanced imaging for all these patients. This is compounded by the problem of different departments all trying to shift costs to one another. "Why sould ED pay for that test? Let them go to fracture clinic and they can pay for it" and so on and so on. From a community perspective you might like to consider the cost of the clinic appointment, the cost of having a manual labourer or personal carer in plaster for 10 days unable to do their job, the overloading of your fracture clinic and so on. It may help to put together a guideline for advanced imaging that lays out clinical and other indicators for CT/MRI that prevent every sore wrist being sent for an expensive test. In a private setting the you can ask the patient. A self employed builder will much rather pay for a CT/MR today or tomorrow than be off tools for 10 days.

  • If you are opting for traditional management with immobilisation and fracture clinic ensure that follow up X-rays are taken out of plaster.

 

As to which advanced imaging test to employ, bone scan is pretty hopeless and doesn't differentiate between bone oedema, fracture and ligamenous injury. It just tells you something is going on which you could have told by poking the patient. CT and MR are pretty close. MR shows more detail of the non-fracture injuries which may be useful for the high level sportsperson who is going to have some specially tailored physiotherapy intervention for every ligament sprain. CT is often quicker to get (although an MRI wrist is a pretty quick easy scan). They are close enough together in sensitivity and specificity to justify choosing a test based on availability, time of day and patient factors (MRI for kids and pregnant women for example and CT for the others).