6 years ago I came off my bike on the way to work for a night shift – a bit embarrassing sure, but apart from the odd scrape nothing to worry about. Thankfully we’d a really quiet night, by 5 in the morning I’d a chance to sit down and noticed I was vaguely tender in my anatomical snuffbox. When I mean vaguely tender, I mean 0.07 out of 10. Partly because I was bored, I registered myself as a patient and had X-rays taken. They’re shown below:
The official report read:
‘Subtle irregularity related to the lateral aspect of the waist of the scaphoid, which may still be a vascular channel but a subtle fracture can certainly appear as this’
In an effort to prove I didn’t have a fractured scaphoid so I could still work the following night shift I had a day 1 isotope bone scan which was reported as
‘Highly suggestive of recent fracture of the right scaphoid.’
I spent 5 weeks in a cast and thankfully have had no issues since and have always maintained a healthy skepticism as to whether I actually had a fracture.
- Occult Fracture rate = 20% (7% Scaphoid).
- ED decision = Wait and see vs Day 1 CT/MRI.
- Simple removable wrist splint appropriate for low-index-of-suspicion cases.
- Simple Colles cast probably as good and less disabling as a Scaphoid cast.
- Consider long arm casting in waist and proximal third fractures.
- Early Surgery becoming more commonplace.
This is all to illustrate a very common Emergency presentation – the patient with tenderness in their anatomical snuffbox and a non-diagnostic X-ray.
Standard practice in most of the places I’ve worked has been to immobilise people for 2 weeks, usually in a plaster (with both simple and scaphoid specific casts) and to reassess tenderness and X-rays in a fortnight and to perform a isotope bone scan if there was still suspicion.
This has always seemed untidy to me. I don’t think very many Orthopods realise how much people hate wearing casts. Is it the right plan of attack? Should I even care about missing an occult Scaphoid fracture?
Having done a pubmed search and focusing mainly on recent reviews it seems there remains much debate as to what the best approach is.
1 – The Traditional Approach:
Occult Scaphoid fracture rate is of the order of 7%. About 12 % of these will develop non-union. Interestingly most of the studies had a rate of occult ‘other wrist fractures’ of double that of true occult Scaphoid fractures, bringing the number of occult fractures up to about 1 in 5. Proponents of the traditional conservative approach would suggest that even if there isn’t an occult fracture, there is likely to be an ill-defined ligamentous injury that would benefit from a period of immobilsation anyway. Isotope bone scanning does appear to be close to 100% sensitive for the detection of Scaphoid fractures, but is only about 90% specific - apparently even less so in the first few days due to the occurrence of traumatic synovitis (what I reckon I had!).
2 – Day 1 MRI:
There seems little doubt that a day 1 MRI of the wrist is the best test we have available at detecting occult fractures. Proponents of this strategy believe this is not only cost effective, but actually saves money in the long-term, if you take into account time off work and leisure activities on top of the cost of follow up medical review for the majority of patients that turn out to have non-diagnostic X-rays.
3 – Day 1 CT:
Pragmatists suggest that a happy medium is a day 1 CT scan if the initial film is equivocal, as even in our ED (The largest academic Emergency Department outside of North America, according to our Prof) we need to offer sexual favours to radiologists to get urgent MRI’s on anything but ?cauda equina syndrome patients.
Indications for Surgery:
All proximal scaphoid fractures? (controversial)
All clearly visible fractues? (controversial)
Fractures associated with any degree of lunar tilt.
Non-union develops during follow-up.
Unwilling or unable to wear cast for 6-12 weeks.
Patients with non-diagnostic X-rays and a low clinical index of suspicion can be treated with a simple wrist splint with the decision on follow-up dependent on the patient, the doctor and their resources.
Patients with a high index of suspicion or proven fracture with no indication for surgery should be immobilised. A Colles plaster has been shown to be at least as effective as a traditional short arm Scaphoid cast.
Some crazy yanks advocate a long arm Scaphoid cast for a mid-body or proximal scaphoid fracture for up to 6 weeks, changing to a short arm for a further 6 weeks. This is not in widespread use in either the UK or Australia.
The more proximal the fracture, the longer the healing time:
- Distal 1/3 - 6-8 weeks.
- Middle 1/3 – 8-12 weeks.
- Proximal 1/3 – 12-23 weeks.
Personally there’s no way on earth I’d wear a cast for 23 weeks. Bring out the Herbert Screw…
- Adams JE, Steinmann SP. Acute scaphoid fractures.Orthop Clin North Am. 2007 Apr;38(2):229-35, vi. PMID: 17560405
- Phillips TG, Reibach AM, Slomiany WP.Diagnosis and management of scaphoid fractures. Am Fam Physician. 2004 Sep 1;70(5):879-84. PMID: 15368727
- Pillai A, Jain M.Management of clinical fractures of the scaphoid: results of an audit and literature review. Eur J Emerg Med. 2005 Apr;12(2):47-51. PMID: 15756078