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Three Part Question

In [adult patients with a suspected scaphoid fracture], is [CT scan is better than bone scintigraphy (BS)] in [diagnosing a fracture with an initially negative X-ray result]?

Clinical Scenario

A 25-year-old right-handed carpenter came to the Emergency Department (ED) with a recent history of a fall onto his outstretched hand. He complained of pain in the wrist and some tenderness was reported in the anatomical snuffbox. The subsequent X-ray showed no abnormality. Should the patient undergo another investigation such as a CT scan there and then?

Search Strategy

Ovid MEDLINE(R) 1950 to June Week 4 2010
[exp Scaphoid Bone OR exp Carpal Bones OR scaphoid$.mp. OR exp Fractures, Bone OR fracture$.mp]
Limit to English language AND humans AND all adult (19 plus years).
AND
[exp Tomography, X-Ray Computed OR computed tomography scan$.mp. OR CT scan$.mp]
AND
[exp Radionuclide Imaging OR bone scintigraphy$.mp. OR bone scan$.mp.]

Search Outcome

9 papers were identified in Medline, four papers were identified 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
Jonsson K et al. 1992 Sweden	10 patients (6 male, 4 female) present at ED With suspected scaphoid fracture but normal initial radiograph	Diagnostic cohort studies	BS result	6-scaphoid fracture, 2-increased uptake of scaphoid, 1-trapezium fracture, *1 patient not examined because of pregnancy	Poor data presentation, Publication bias was not stated, Statistical analysis was not included, Small sample size, No sensitivity or specificity of the intervention mentioned.
			CT result (CT in sagittal projection)	7-scaphoid fractures, 3-no scaphoid fracture (including 2 patients with increased uptake on BS)
Breederveld RS, Tuinebreijer WE. 2004 The Netherlands	29 patients-present at ED with suspected scaphoid fracture but normal initial radiograph	Diagnostic cohort studies	CT scan	sensitivity, specificity, positive and negative predictive values= 100%	Publication bias was not stated, Statistical analysis was not included, Small sample size, Results were not compared with previous studies. Only one nuclear diagnostician interpreting the BS result.
			BS	Sensitivity 78%, Specificity 90%, Positive predictive values 78%, Negative predictive values 90%
Groves AM et al. 2005 England	1 patient (male) Presented to ED having fallen on outstretched left hand, tender anatomical snuffbox, negative initial radiograph	Case report	BS vs CT on the day 10 post-injury	scaphoid fracture vs normal	Publication bias was not stated
			MRI (day 14)	probable scaphoid fracture
			Radiograph day 42 post-injury	scaphoid fracture
Groves AM et al. 2005 England	51 patients (17 male, 34 female), mean age: 40.2 years old. Presented to nuclear medicine department with suspected scaphoid fracture at 10–14 days post injury	Prospective study, Diagnostic cohort studies	Scaphoid fractures	10 BS vs 5 CT (7 patients with +ve BS of scaphoid fracture have normal CT and follow-up radiography at 6 weeks)	Publication bias was not stated. No sensitivity or specificity of the intervention mentioned because no universal gold standard for waist fracture diagnosis. Statistical analysis on the result was mentioned but not included.
			Radius fractures	5 BS vs 3 CT
			Other carpal bones fractures	8 BS vs 6CT

Comment(s)

The different sources of evidence conflict with each other as to whether CT scans are better than BS at diagnosing scaphoid fractures. Studies by Breederveld et al showed that CT scans are superior to BS. A case study by Groves et al claimed that BS is better at detecting scaphoid fractures, while Jonsson et al claimed that CT can be used in place of BS if there are no nuclear medicine facilities. Interestingly, a study by Groves et al found that seven scaphoid fractures detected by BS were negative on CT and the follow-up X-ray.

Clinical Bottom Line

CT scans can possibly be used on patients who present at EDs with a suspected scaphoid fracture, particularly in places with no nuclear medicine facilities (BS). However, not enough evidence is available to claim which one is superior to the other, thus comparisons between CT and BS should be studied further, particularly in terms of cost-effectiveness and safety measures.

References

1. Jonsson K, Jonsson A, Sloth M, Kopylov P, Wingstrand H. CT of the wrist in suspected scaphoid fracture. Acta Radiologica 1992; 33(5): 500-1
2. Breederveld RS, Tuinebreijer WE Investigation of Computed Tomographic Scan Concurrent Criterion Validity in Doubtful Scaphoid Fracture of the Wrist. J Trauma 2004; 57: 851-4
3. Groves AM, Cheow HK, Balan KK, Courtney HM, Bearcroft PWP, Dixon AK False negative 16 detector multislice CT for scaphoid fracture. The British Journal of Radiology 2005; 78: 57–9.
4. Groves AM, Heok Cheow H, Balan K, Courtney H, Bearcroft P, Dixon A 16-MDCT in the Detection of Occult Wrist Fractures: A Comparison with Skeletal Scintigraphy AJR 2005; 184: 1470-4.