Imaging the scaphoid problem : a diagnostic strategy for suspected scaphoid fractures
Beeres, F.J.P.
Citation
Beeres, F. J. P. (2008, May 14). Imaging the scaphoid problem : a diagnostic strategy for suspected scaphoid fractures. Retrieved from https://hdl.handle.net/1887/12857
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Chapter
4
F.J.P. Beeres1 M. Hogervorst2 P. den Hollander3 S.J. Rhemrev1
1Department of Surgery, Medical Centre Haaglanden, The Hague, the Netherlands
2Department of Surgery, Gelre Hospitals, Apeldoorn, the Netherlands
3Department of Orthopaedics, Medical Centre Haaglanden, The Hague, the Netherlands
Diagnostic strategy for suspected scaphoid fractures in the presence of other
fractures in the carpal region
Based on:
The Journal of Hand Surgery 2006; 31:416-418
Abstract
Bone scintigraphy will identify up to 25% of occult scaphoid bone fractures after negative scaphoid radiographs. Consequently, it deserves a place in the diagnostic process of suspected scaphoid fractures. However, the role of bone scintigraphy is less clear if scaphoid radiographs show other fractures in the carpal region. The objective of the present study was to answer this question.
Methods: We analysed 111 consecutive patients with a suspected scaphoid fracture on physical examination.
Results: Scaphoid radiographs revealed 61 fractures. Fifty-five patients had scaphoid fractures only and 6 patients had other fractures in the carpal region but no scaphoid fracture. In 50 cases, no bone injury was seen on these radiographs. In 3 out of the 6 patients with other fractures in the carpal region, bone scintigraphy revealed 4 occult concomitant fractures: 1 scaphoid, 1 scaphoid and trapezial and 1 capitate fracture.
Conclusion: Bone scintigraphy is required when scaphoid radiographs do not confirm a suspected scaphoid fracture, even in the presence of other fractures in the carpal region.
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Figure 4.1
The algorithm for a suspected scaphoid fracture used in our clinic (the numbers of patients in this study are included between brackets).
Clinically suspected scaphoid fracture (111)
Scaphoid radiographs
No scaphoid fracture (50)
Bone scintigraphy >72 hours Bone scintigraphy >72 hours Scaphoid fracture (55)
Normal (16)
Other fractures in the carpal region (6)
Results
In a period of 24 months, 111 patients presented with a history and symptoms consistent with a scaphoid fracture. Scaphoid radiographs revealed 61 fractures. Fifty-five patients had scaphoid fractures only and 6 patients had other fractures in the carpal region but no scaphoid fracture. In 50 cases, no bone injury was seen on these radiographs.
Additional scaphoid fracture (1)
Additional scaphoid + other fracture (1)
Additional other fracture (1)
No additional fracture (3) Scaphoid
fracture (13)
Other fracture (21)
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Chapter 4Scaphoid fractures with associated injuries
Materials and methods
Retrospectively, we evaluated our protocol of routine bone scintigraphy in 111 consecutive cases of a suspected scaphoid fracture. All patients had attended the Emergency Department with a history of acute trauma and symptoms consistent with a fractured scaphoid, i.e. a swollen and tender anatomic snuffbox and pain when applying axial pressure on the first and second digit. This study included 84 men and 27 women of mean age 33 (range 9-88) years. There were no bilateral injuries.
The diagnostic protocol used to evaluate the scaphoid bone is shown in Figure 4.1.
In cases in which a scaphoid fracture was not seen on scaphoid radiographs a bone scintigraphy was performed.
The 56 patients with no scaphoid fracture on scaphoid radiographs, including the 6 with other fractures in the carpal region, underwent bone scintigraphy, on average 4 days after injury. These included 36 male and 20 female patients of mean age 38 (range 9-88) years.
Bone scintigraphy showed evidence of a scaphoid fracture in 15 of the 56 (27%) of these patients. Thirteen of the 50 patients with no fracture on scaphoid radiographs proved to have a scaphoid fracture. Twenty-one of these 50 had other fractures in the carpal region as shown in Figure 4.1.
Of particular interest were the results of the 6 patients with other fractures in the carpal region on scaphoid radiographs. All of the other fractures in the carpal region seen on the scaphoid radiographs were confirmed. Three out of 6 patients had additional injuries on bone scintigraphy of which 2 were scaphoid fractures (example is shown in Figure 4.2).
One patient with an occult scaphoid fracture also had an occult trapezial fracture. A third patient had an occult capitate fracture. Only 3 patients had no additional injury. The results are summarised in Table 4.1.
Figure 4.2
(a) Scaphoid radiograph showing a triquetral fracture (arrow) and no scaphoid fracture.
(b) Bone scintigraphy showing the triquetral fracture and the scaphoid fracture.
a b
Discussion
Patient history, in combination with physical examination, has a relatively high predictive value for the diagnosis of scaphoid fractures.27Therefore, advanced imaging techniques are required to rule out a suspected scaphoid fracture if it does not show on scaphoid
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radiographs. Bone scintigraphy is often referred to as the gold standard, mainly because of its high sensitivity (95%), but the outcome of this investigation has to be interpreted with care because of varying specificity between 60 and 95%.5,8-10,12-14,57However, nuclear imaging is not a widely used diagnostic modality because it is invasive and expensive.
Thirteen of the 50 patients (26%) with clinical signs of a scaphoid fracture but no evidence of a fracture on scaphoid radiographs in this study proved to have an occult scaphoid fracture on bone scintigraphy, confirming the value of this tool, in accordance with the literature.14
A diagnostic dilemma occurs if the scaphoid radiographs show other fractures in the carpal region. If so, the question arises as to whether history taking and physical examination still have a useful predictive value in the detection of a scaphoid fracture. The algorithm for a suspected scaphoid fracture used in our clinic was designed with emphasis on the detection of occult fractures. The results of bone scintigraphy in the small group of 6 patients with other fractures in the carpal region on scaphoid radiographs are interesting.
These included 4 occult fractures: 2 of which were scaphoid fractures and 1 was a capitate fracture. A further patient with an occult scaphoid fracture also had an occult trapezial fracture. These findings illustrate that there is an obvious therapeutic benefit to bone scintigraphy under these circumstances as an occult scaphoid fracture in conjunction with another fracture in the carpal region can alter therapeutic strategies. This is less evident when scaphoid radiographs show another fracture in the carpal region which mandates treatment anyway.
Fractures shown on scaphoid radiographs
Triquetrum First metacarpal
Lunate Distal radius Distal radius Distal radius
Fractures shown on bone scintigraphy
Triquetrum + scaphoid First metacarpal + scaphoid + trapezium
Lunate + capitate Distal radius Distal radius Distal radius
Chapter 4Scaphoid fractures with associated injuries
Table 4.1
Outcome of bone scintigraphy in 6 patients with a clinically suspected scaphoid fracture, no radiological evidence of a scaphoid fracture but another fracture in the carpal region present on the initial scaphoid radiographs.
