Comment: Scaphoid fractures. Thumbing through the research

The following is a comment to the online article “Scaphoid fractures. Thumbing through the research“, written by Dr Robin Park on the FOAM4GP website.  This was a very readable summary of some of the evidence behind the management of scaphoid fracture assessment in the general practice context.

Dear Rob,

Another fantastic post and summary!

Before I give my 2c on this clinical scenario, I like to reflect on the Dave Sackett vision of EBM – that it is the combination of best external evidence, patient values and expectations, and clinical expertise. The research evidence (of which the majority in this scenario has not been in the primary care setting) needs to be applied in a critical manner, appropriate to the context and setting in which care is provided.

Even in my context (Inner Sydney suburb), MRIs are not that easy to obtain within a narrow time window (i.e., 1-2 days). There is the upfront financial cost, not to mention the time cost – MRIs take longer to do than plain radiographs or CTs.

I think my approach in the context of the above evidence would be very similar to yours. Assuming clinical features suggestive of a scaphoid fracture, x-ray first, which can probably be done on the day. A 70% pick up rate may not be “great”, but it is still the majority of them. If the film is normal, then I think that a discussion for the options needs to be made with the patient.

(1) Cast + wait and see for a fortnight seems like a pretty reasonable approach for individuals where the loss of function of a hand for the short-term is not a major issue. If the individual is substantially better symptom-wise at the end of 2 weeks, then we’ve avoided the costs involved in further investigations.

I wasn’t aware of the rather limited diagnostic utility of a follow up film, so thanks for looking that up! I think that if the patient still has symptoms at this point, a CT would be reasonable for most patients. MRI might be better, but it appears that the practical difference between the two at this point is marginal.

(2) Early (ASAP) CT of the wrist would appear to be a very pragmatic approach for individuals who want to avoid wrist immobilisation. According to the ED observational study, the normal CT has a very high NPV – effectively excluding a fracture (in the context of young adult patients with clinical features of scaphoid # and a normal initial x-ray). Given the primary care population is likely to have a lower prevalence rate of fractures compared to an ED one, the NPV will probably even be higher.

What is less clear is what an abnormal CT finding means… Given that study had smallish numbers and no gold standard comparison, it is difficult to know what proportion of patients with positive CTs actually have clinically important abnormalities.

(3) Early MRI of the wrist is a possible strategy but I doubt that it is particularly pragmatic in most contexts at present.

[rant]
Philosophically, I think that we also have an opportunity in Australia to avoid some of the poor referral patterns for MRI that perhaps occur for CT. At present, I’m really appreciative of the fact that urgent (on day/next day) MRIs are available in the private community sector for important/time sensitive indications (e.g., stroke, intracranial masses, spinal lesions). I’ve had patients who have presented a day or two after a probable minor CVA/TIA at home, gotten them an MRI/A of the head, made the diagnosis, and packaged them to receive definitive inpatient care without the diagnostic fluffing around in the public system. We won’t have access to this if private MRI services are flooded with low acuity and inappropriate requests.
[/rant]

Cheers,
Michael