• 
• 

Three Part Question

In [suspected scaphoid fractures] is [magnetic resonance imaging] a realistic modality if [plain radiographs do not identify a fracture]

Clinical Scenario

A patient attends the emergency department with pain in keeping with a fractured scaphoid. The standard scaphoid views failed to identify a fracture. Should magnetic resonance imaging be conducted or is it too expensive.

Search Strategy

Medline 1966 until April 2005
(fracture$.af. OR exp Fractures, Comminuted/ OR exp Fractures, Closed/ OR exp Fractures/ OR exp Fractures, Ununited/ OR exp Fractures, Malunited/) AND (exp Magnetic Resonance Imaging? OR (magnet$ ADJ reson$ ADJ imag$).mp. OR mri.af. OR Magnetic Resonance Spectroscopy? OR (magnet$ ADJ reson$ ADJ spect$).mp. OR nmr.af. AND (Scaphoid Bone? OR scaphoid.af. OR scaphoid$).
Limited to humans and english

Search Outcome

143 papers were identified in medline, three of these were relevant to the three part question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Raby N 2001 UK	53 patients late MRI 56 patients early MRI (extremity MRI)	PRCT	Acute injury detected on MRI, Cost effective and changed patient management	early MRI changed management in 89% of patients. Late MRI changed management in 69% of patients. Early MRI more cost effective	Poor follow up of discharged patients Patients not randomly allocated Doesn't describe criteria used to diagnose scaphoid fractures
Brydie A 2003 UK	195 patients with 14 day acute injury	CT	Detected injury to wrist. Cost and change in patient management	51% normal. 38% fracture identified (19% scaphoid). 92% change in patient management. MRI no more expensive than previous protocol.	No follow up of discharged patients with negative MRI scan
Gaebler et al 1996 Austria	32 patients with MRI scan in less than 6 days post injury	PRCT	Cost and detection of injury	MRI detected all fractures earlier than plain x-rays. Saving of $7,200 per 100,000 inhabitants	Small study

Comment(s)

The evidence suggests that MRI scanning is a cost effective alternative to the protocols used currently in the emergency department. More importantly it has demonstrated that it significantly alters patients management. However the limiting factor will probably be the availability of the scanners to conduct such tests.

Clinical Bottom Line

Early MRI scanning is a cost effective procedure when a scaphoid fracture is suspected and plain radiographs fail to identify the injury. It also has a large effect on the subsequent management of the patient.

References

1. Raby N. Magnetic Resonance Imaging of Suspected Scaphoid Fractures Using a Low Field Dedicated Extremity MR System Clinical Radiology (2001) 56:316-320
2. Brydie A. and Raby N. Early MRI in the management of clinical scaphoid fracture The British Journal of Radiology (2003) 76:296-300
3. Gaebler C., Kukla C., Breitenseher M., Trettnig S., Mittboeck M. and Vecsei V. Magnetic Resonance Imaging of Occult Scaphoid Fractures The Journal of Trauma (1996) 41:73-76