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
Version: Corrected Publisher’s Version
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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
Outcome of routine bone scintigraphy in suspected scaphoid fractures
Based on:
Outcome of routine bone scintigraphy in suspected scaphoid fractures Injury 2005; 36:1233-1236
Abstract
Undisplaced scaphoid fractures are easily missed on conventional scaphoid radiographs but these occult fractures may seriously impair hand function. Routine bone scintigraphy is often advocated if there are clinical signs of a scaphoid fracture without radiological evidence. However, the results require careful therapeutic management. The objective of the present study was to determine the diagnostic value of bone scintigraphy in daily practice for clinically suspected scaphoid fractures.
Methods: We evaluated our protocol of routine bone scintigraphy in suspected scaphoid fractures. In a retrospective study we analysed 111 consecutive cases with signs of a scaphoid fracture on physical examination. Radiographs revealed 55 fractures, the remaining 56 patients all underwent bone scintigraphy.
Results: On average the bone scintigraphy was performed after 4 days. It showed a fracture in 38/56 (68%) of the patients. The distribution of fractures was: scaphoid bone 15, distal radius 11, other carpal bones 9 and metacarpal bones 3.
Conclusion: If there is a strong clinical suspicion of a scaphoid fracture, which cannot be confirmed by conventional radiology, bone scintigraphy is a valuable diagnostic tool.
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Materials and methods
We reviewed all patients attending the Emergency Department over a period of 24 months with clinical signs of a scaphoid fracture, i.e. a swollen and tender anatomic snuffbox.
Protocol
The diagnostic protocol used is shown in Figure 3.1. All patients attending the Emergency Department with a clinically suspected scaphoid fracture have immediate scaphoid radiographs. Patients with no radiological evidence of a scaphoid fracture undergo bone scintigraphy at least 72 hours after injury. Meanwhile, they are treated with a scaphoid fore arm cast. Final treatment is based on the result of the bone scintigraphy. If a scaphoid fracture is identified, patients will have a scaphoid cast for at least 6 weeks. Other fractures are treated with the appropriate therapy. Patients with no evidence of a fracture on scinti- grams are treated symptomatically with a support dressing.
Follow-up of the fractures consists of at least 3 outpatient clinical reviews, the first 1 week after injury, further reviews at 6 weeks and 3 months.
Figure 3.1
Flow chart of the protocol used for clinically suspected scaphoid fractures. Between brackets are the number of patients included in the study.
Clinically suspected scaphoid fractures (111)
Scaphoid radiographs
Positive (55) Negative (56)
Functional Surgery (3) Scaphoid plaster (52)
Scaphoid fracture (15) Another fracture (23)
Scaphoid plaster Appropriate therapy
Normal (18) Bone scintigraphy
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Chapter 3Outcome of bone scintigraphy
Follow-up
The outpatient trauma department reviews all patients after the trauma. The final assessment consists of a thorough physical examination and patients are questioned regarding pain, restriction of movement, loss of strength in the wrist and any subsequent change in their lifestyle or professional activities following injury.
Results
During the period of this study, 111 patients attended the Emergency Department with a history and signs consistent with a fractured scaphoid. There were 55 patients with radiologically confirmed fractures of which 3 underwent direct surgical treatment. In 56 patients, the conventional scaphoid radiographs showed no fracture. There were 36 male and 20 female, the age range was 9-88 years, mean 38 years.
All these patients underwent bone scintigraphy, on average 4 days (range 1-9 days) after the trauma.
The results of the bone scintigraphy, are shown in Table 3.1: In 15/56 (27%) patients, there was a fracture of the scaphoid bone (Figure 3.2). Even more surprising was the distribution of other fractures: 11/56 (20%) distal radius (Figure 3.3), 9/56 (16%) other carpal bones and even 3/56 (5%) metacarpal bones. In addition, bone scintigraphy showed a contusion of the wrist in 7/56 (13%) patients (Figure 3.4).
All scaphoid fractures were immobilised for 6 weeks. For 2 patients this period was extended to 10 weeks, due to pain. Patients with normal scintigrams were allowed free movement.
At 3 months, 53 patients were free of complaints, with full wrist function. Three patients had little pain with daily activities. Of these 3, 1 was diagnosed with a scaphoid fracture, the other 2 patients had a distal radius fracture and a wrist contusion.
Table 3.1
Outcome of bone scintigraphy in 56 consecutive patients with a clinically suspected scaphoid fracture that could not be demonstrated on scaphoid radiographs.
Diagnosis Number Percent
Scaphoid fracture 15 26,8%
Distal radius fracture 11 19,6%
Other carpal fracture 9 16,1%
Metacarpal fracture 3 5,4%
Wrist contusion 7 12,5%
Normal 11 19,6%
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Figure 3.2
Bone scintigraphy showing a scaphoid fracture.
Figure 3.3
Bone scintigraphy showing a distal radius fracture.
Figure 3.4
Bone scintigraphy showing a scaphoid fracture and an additional contusion of the wrist.
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Chapter 3Outcome of bone scintigraphy
Discussion
There is evidence that early diagnosis and treatment of occult scaphoid fractures limits the number of delayed and non-unions.10,55It also reduces the number of patients unnecessarily immobilised in a cast.
Repeated radiographs and carpal box radiographs may not provide the required diagnostic refinement.15,30There is little known about the diagnostic value of the CT-scan.15 Recent studies demonstrated promising results of MR imaging, however, no study has clearly evaluated the predictive value of MR imaging in the acute setting. On the other hand bone scintigraphy has been shown in several reports to achieve a high sensitivity, but it also has some disadvantages.17,56Bone scintigraphy is invasive, it may not be routinely available in all hospitals, it exposes patients to (a low dose of ) radiation, it has a long duration and does not reach its maximum predictive power until 72 hours following the injury.
In this study over a quarter of the patients with clinical signs of a scaphoid fracture were shown on bone scintigraphy to have an occult scaphoid fracture. Just as important was the fact that the remaining patients could be treated without a plaster (32%) or with different treatment (41%). This greatly reduces the recovery period and sick leave of the patients and decreases direct and indirect costs.
Two observers (a resident and consultant surgeon) have, blinded to the outcome of bone scintigraphy, re-evaluated all 111 scaphoid radiographs and found no flaws in the original diagnosis. Moreover, 4 different observers initially judged all scaphoid radiographs before the bone scintigraphy. Therefore, we believe that the surprising distribution of fractures demonstrated on the bone scintigraphy is due to insensitivity of the scaphoid radiographs.
Three months after injury, all but 1 of the patients that were diagnosed as not having a fracture were free of complaints, so we assume that no occult scaphoid fracture was missed. Our current protocol with the use of bone scintigraphy for suspected scaphoid fractures, therefore, seems to prove a justified balance between diagnostic efforts and treatment outcome.
We suggest that in patients with a clinically suspected scaphoid fracture and normal scaphoid radiographs, bone scintigraphy should be performed.
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Chapter 3Outcome of bone scintigraphy
