A comparison of bone scintigraphy and MRI in the early diagnosis of the occult scaphoid waist fracture

An Umbrella Review and Updated Meta-Analysis of Imaging Modalities in Occult Scaphoid and Hip and Femoral Fractures

Background: Occult fractures may cause multiple morbidities. If occult fractures were detected earlier, complications may be preventable. This umbrella review and updated meta-analysis will aim to evaluate the use of imaging modalities in detecting occult scaphoid and hip fractures. Methods: The protocol for this study is available in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42024525388). The literature search started and ended on 17 March 2024. We searched seven academic databases: MEDLINE, Cochrane Library, Pubmed, Science Direct, Google Scholar, WHO International Clinical Trials Registry Platform, and The Joanna Briggs Institute (JBI) database. The meta-analysis was conducted with the STATA program using the "midas" command. Results: There are four systematic reviews evaluating occult hip and femoral fractures with 6174 patients and two reviews evaluating occult scaphoid fractures with 1355 patients. The prevalence of occult scaphoid fracture and occult hip and femoral fractures is 23.87% (95% CI 18.25-29.49) and 44.8% (95% CI 39.38-51.4), respectively. Magnetic resonance imaging (MRI) had the best posterior probability of positive likelihood ratio (LR+) with 95% and 96% and negative likelihood ratio (LR-) with 0.15% and 1% for both occult scaphoid and hip fractures, respectively, assuming a 25% baseline. MRI could both confirm and exclude occult hip fractures while it can only confirm occult scaphoid fractures. Bone scans are inappropriate for either type of occult fractures The level of evidence for occult scaphoid fracture is weak while it is suggestive for occult hip fractures. Conclusion: The findings strengthen the use of MRI after an initially negative radiograph fracture for occult hip and femoral fractures, with a CT scan as a viable second option.

Diagnosis of Suspected Scaphoid Fractures

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Suspected scaphoid fractures are a diagnostic and therapeutic challenge despite the advances in knowledge regarding these injuries and imaging techniques. The risks and restrictions of routine immobilization as well as the restriction of activities in a young and active population must be weighed against the risks of nonunion that are associated with a missed fracture.

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The prevalence of true fractures among suspected fractures is low. This greatly reduces the statistical probability that a positive diagnostic test will correspond with a true fracture, reducing the positive predictive value of an investigation.

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There is no consensus reference standard for a true fracture; therefore, alternative statistical methods for calculating sensitivity, specificity, and positive and negative predictive values are required.

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Clinical prediction rules that incorporate a set of demographic and clinical factors may allow stratification of secondary imaging, which, in turn, could increase the pretest probability of a scaphoid fracture and improve the diagnostic performance of the sophisticated radiographic investigations that are available.

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Machine-learning-derived probability calculators may augment risk stratification and can improve through retraining, although these theoretical benefits need further prospective evaluation.

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Convolutional neural networks (CNNs) are a form of artificial intelligence that have demonstrated great promise in the recognition of scaphoid fractures on radiographs. However, in the more challenging diagnostic scenario of a suspected or so-called "clinical" scaphoid fracture, CNNs have not yet proven superior to a diagnosis that has been made by an experienced surgeon.

Streamlining Definitive Care for Occult Scaphoid Fractures: A Retrospective Review of the Workup of Scaphoid Nonunions and Applying Lessons Learned

INTRODUCTION

The process for working up scaphoid fractures from frontline providers to the specialty care clinic is variable. Initial imaging can often be negative and the management algorithm is not clearly defined. Delays in diagnosis are a contributing factor to scaphoid nonunion. Fractures may not be identified by frontline providers on initial presentation because of radiographically occult injuries. If not treated promptly, scaphoid fractures may be complicated by nonunion, avascular necrosis, and osteoarthritis.

MATERIALS AND METHODS

Retrospective review of scaphoid nonunions from 2017 to 2018 in a single tertiary care institution after internal review board approval was obtained (NMCSD.QI.2019.0003). Cases were identified using an ICD 10 search for "scaphoid (navicular) fracture non-union" and subtypes. Charts were examined for time between injury and presentation, injury and diagnosis, initial radiologic workup, and limited duty (LIMDU). Nonparametric statistical analysis for linear and categorical data was conducted using SPSS. A subgroup of patients who had a delay in diagnosis of greater than 30 days upon entering the medical system was further analyzed and identified as the "delayed diagnosis" cohort.

RESULTS

In total, 30 patients with scaphoid nonunion were identified. Overall, 35% of patients had negative initial X-rays and averaged 42.1 days until diagnosis. In total, 100% of patients required at least one LIMDU period, averaging 1.4 periods, for a total of 6,404 days and 16% went on to a physical evaluation board (PEB). In 9 (30%) of these patients, injury was initially not identified upon entering the medical system resulting in average of 139.7 days until diagnosis; this became known as the delayed diagnosis subgroup. Further analysis of the delayed diagnosis subgroup demonstrated significantly more initial negative X-rays (P < .005) at a rate of 77% (7/9). A delay in diagnosis was significantly associated with PEB (R = 0.4, P = .031) with 33% of these patients going on to a PEB.

CONCLUSIONS

Delayed diagnosis of a scaphoid fracture is a contributing factor for excessive light duty, high rates of LIMDU utilization, and ultimately medical separation of service members. Overall, in all patients who had scaphoid nonunions, the average time to diagnosis was 42.1 days with 35% of patients presenting with negative initial imaging. A delayed diagnosis subgroup was identified and notable for a higher rate of initial negative X-rays, an average of 139.7 days until diagnosis, and a 33% PEB rate. In total, 77% of patients with a delay in diagnosis of more than 30 days had an initial negative X-ray. An evidence-based algorithm for diagnosing occult scaphoid fractures may prevent delays in diagnosis, thus increasing the readiness of active duty service members.

Systematic Review of Diagnosis of Clinically Suspected Scaphoid Fractures

Background  Scaphoid fracture accounts for approximately 15% of acute wrist fractures. Clinical examination and plain X-rays are commonly used to diagnose the fracture, but this approach may miss up to 16% of fractures in the absence of clear-cut lucent lines on plain radiographs. As such, additional imaging may be required. It is not clear which imaging modality is the best. The goal of this study is to summarize the current literature on scaphoid fractures to evaluate the sensitivity, specificity, and accuracy of four different imaging modalities. Case Description  A systematic-review and meta-analysis was performed. The search term "scaphoid fracture" was used and all prospective articles investigating magnetic resonance imaging (MRI), computed tomography (CT), bone scintigraphy, and ultrasound were included. In total, 2,808 abstracts were reviewed. Of these, 42 articles investigating 51 different diagnostic tools in 2,507 patients were included. Literature Review  The mean age was 34.1 ± 5.7 years, and the overall incidence of scaphoid fractures missed on X-ray and diagnosed on advanced imaging was 21.8%. MRI had the highest sensitivity and specificity for diagnosing scaphoid fractures, which were 94.2 and 97.7%, respectively, followed by CT scan with a sensitivity and specificity at 81.5 and 96.0%, respectively. The sensitivity and specificity of ultrasound were 81.5 and 77.4%, respectively. Significant differences between MRI, bone scintigraphy, CT, and ultrasound were identified. Clinical Relevance  MRI has higher sensitivity and specificity than CT scan, bone scintigraphy, or ultrasound. Level of Evidence  This is a Level II systematic review.

Imaging for Acute and Chronic Scaphoid Fractures

The scaphoid is the most commonly fractured bone in the wrist but 20% to 40% of scaphoid fractures are radiographically occult. Delayed or misdiagnosis can have significant consequences with late complications such as nonunion, malunion, or the development of avascular necrosis in the proximal pole. After initial negative radiographs, advanced cross-sectional imaging, including CT and MRI, ultimately may provide more accurate and rapid diagnosis than conventional radiography. With chronic fractures, the preferred modality depends on the clinical question. New techniques are evolving that will further advance imaging for diagnosis and treatment of scaphoid fractures.

Radiographic analysis of anatomic risk factors for scaphoid fractures; A case-control study

AIM

The purpose of this study was to investigate the role of anatomic variations in distal radius radiographic indices in patients with or without scaphoid fractures.

MATERIALS AND METHODS

Radial inclination (RI), volar tilt (VT), radial height (RH) and ulnar variance (UV) were measured on wrist radiographs of 320 patients with (Group I, n = 167) or without (Group II, n = 153) scaphoid fracture, fall on outstretched hand (FOOSH). Receiver operating characteristics (ROC) curve analysis was used to assess the diagnostic performance for each variable. Sensitivity (Sn), specificity (Sp), cutoff value, and area under the ROC curve were analyzed. Odds ratio was calculated for defined cutoff values.

RESULTS

The mean age of the groups was similar (29.3 ± 10.2 vs 31.1 ± 9.9 years, p = 0.060). RI (30.0 ± 2.9 vs 26.8 ± 2.3°) VT (11.4 ± 2.4 vs 10.5 ± 2.2°), RH (14.8 ± 2.1 vs 13.2 ± 1.9 mm), UV (-0.46 ± 1.7 vs 0.00 ± 1.5 mm) were higher in scaphoid fracture group (Gr I vs Gr II, p = 0.000, p = 0.000, p = 0.001, p = 0.012 respectively). Ulna minus variant was more prevalent in fracture group (p = 0.001). Optimal cutoff points for RI, VT, RH and UV in differentiating fractured and intact scaphoid were 28.6° (Sn = 81.0%, Sp = 26.3%), 12.2° (Sn = 80.4%, Sp = 67.1%), 14.85 mm (Sn = 80.4%, Sp = 52.1%) and 0 mm (Sn = 88.6%, Sp = 75.8%), respectively. Odds ratios for defined cutoff points for RI, VT, RH and UV were 10.4 (95% CI, 6.2-17.4), 1.8 (95% CI, 1.1-3.0), 3.7 (95% CI, 2.3-6.2) and 2.2 (95% CI, 1.3-3.7) respectively.

CONCLUSION

Increased RI, VT, RH and negative UV were found to be predisposing anatomical risk factors for scaphoid fracture when FOOSH.

The diagnostic accuracy of cross-sectional imaging for detecting acute scaphoid fractures in children: a systematic review

OBJECTIVE

To determine the diagnostic accuracy of cross-sectional imaging for the diagnosis of acute scaphoid fractures in children.

METHODS

A systematic review of Medline, Embase and Cochrane databases between 1980 and July 2017 was independently performed by two observers. Criteria for study inclusion in a meta-analysis and assessment of the quality of such studies using the QADAS tool, were predetermined.

RESULTS

No studies were eligible for inclusion in a meta-analysis. Three studies (of low quality when assessed against the STARD guidelines for reporting of studies of diagnostic accuracy) assessed MRI (performed between Days 2 and 10 after acute injury) for the diagnosis of scaphoid fractures in a total of 119 children (age range 6 to 16 years). Study 1 (45 children) reported inter-observer reliability of radiographs and MRI of 0.53 and 0.95 respectively. Study 3 (18 children) reported a negative predictive value of MRI (even as early as Day 2), of 100%. No measure of diagnostic accuracy or observer reliability was reported in Study 2 (56 children). In all 3 studies, MRI identified more scaphoid fractures (and other carpal injuries) than radiographs. Study 3 showed that follow-up MRI between Days 38 and 45 added no new information compared to initial MRI.

CONCLUSION

Based on a systematic review of the literature, there is currently no evidence on which to suggest an imaging protocol for suspected scaphoid fracture in children. Until such evidence is available, existing guidelines (which are based on findings from adult studies) should be followed. Advances in knowledge: (1) There is low quality evidence regarding the diagnostic accuracy of cross-sectional imaging for suspected scaphoid fractures in children and no evidence on which to propose an optimal imaging strategy. (2) Until such evidence is available, current guidelines (based predominantly on findings in adults and expert opinion) should be followed.

Diagnostic Strategy for Suspected Scaphoid Fractures in the Presence of Other Fractures in the Carpal Region

Bone scintigraphy will identify up to 25% of occult scaphoid bone fractures after negative scaphoid X-rays. Consequently, it deserves a place in the diagnostic process of suspected scaphoid fractures. However, the role of bone scintigraphy is less clear if scaphoid X-rays show other fractures in the carpal region. We analysed 111 consecutive patients with a suspected scaphoid fracture on physical examination. Scaphoid X-rays revealed 61 fractures. Fifty-five patients had scaphoid fractures only and six patients had other fractures in the carpal region but no scaphoid fracture. In 50 cases, no bone injury was seen on these X-rays. In three out of the six patients with other fractures in the carpal region, bone scintigraphy revealed four occult concomitant fractures: one scaphoid, one scaphoid and trapezial and one capitate fracture. In conclusion, bone scintigraphy is required when scaphoid X-rays do not confirm a suspected scaphoid fracture, even in the presence of other fractures in the carpal region.

Diagnosis of occult scaphoid fractures: a randomized, controlled trial comparing bone scans to radiographs for diagnosis

BACKGROUND

Many patients with suspected scaphoid fractures but negative radiographs are immobilized for ≥ 2 weeks and are eventually found to have no fracture. Bone scans are reportedly 99% sensitive for these injuries if done ≥ 72 hours postinjury.

OBJECTIVE

The purpose of this study was to determine if early bone scans would allow for shorter cast immobilization periods in patients with suspected scaphoid fractures.

METHODS

Twenty-seven patients with clinically suspected scaphoid fractures and negative radiographs were randomized to early diagnosis (bone scan within 3-5 days; n  =  12) or traditional diagnosis (radiographs 10-14 days postinjury; n  =  15). The primary outcome was number of days immobilized in a cast.

RESULTS

The mean number of days immobilized was 26 in the traditional group and 29 in the bone scan group. Overall, 6 patients had scaphoid fractures (2 in the traditional diagnosis group and 4 in the bone scan group; p > 0.05), and 8 had other types of fractures. These other types of fractures included four distal radius fractures, two triquetral fractures, one trapezoid fracture, and one hamate fracture. There was no significant difference in the number of other types of fractures between groups. The Kaplan-Meier survival analysis using the log-rank test revealed that there was no statistically significant difference between days immobilized between the radiograph and bone scan groups (p  =  0.38).

CONCLUSIONS

The current study suggests that the use of bone scans to help diagnose occult scaphoid fractures does not reduce the number of days immobilized and that the differential diagnosis of occult scaphoid fractures should remain broad because other injuries are common.

Computed tomography versus magnetic resonance imaging versus bone scintigraphy for clinically suspected scaphoid fractures in patients with negative plain radiographs

BACKGROUND

In clinically suspected scaphoid fractures, early diagnosis reduces the risk of non-union and minimises loss in productivity resulting from unnecessary cast immobilisation. Since initial radiographs do not exclude the possibility of a fracture, additional imaging is needed. Computed tomography (CT), magnetic resonance imaging (MRI) and bone scintigraphy (BS) are widely used to establish a definitive diagnosis, but there is uncertainty about the most appropriate method.

OBJECTIVES

The primary aim of this study is to identify the most suitable diagnostic imaging strategy for identifying clinically suspected fractures of the scaphoid bone in patients with normal radiographs. Therefore we looked at the diagnostic performance characteristics of the most used imaging modalities for this purpose: computed tomography, magnetic resonance imaging and bone scintigraphy.

SEARCH METHODS

In July 2012, we searched the Cochrane Register of Diagnostic Test Accuracy Studies, MEDLINE, EMBASE, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials, the NHS Economic Evaluation Database. In September 2012, we searched MEDION, ARIF, Current Controlled Trials, the World Health Organization (WHO) International Clinical Trials Registry Platform, conference proceedings and reference lists of all articles.

SELECTION CRITERIA

We included all prospective or retrospective studies involving a consecutive series of patients of all ages that evaluated the accuracy of BS, CT or MRI, or any combination of these, for diagnosing suspected scaphoid fractures. We considered the use of one or two index tests or six-week follow-up radiographs as adequate reference standards.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts and assessed full-text reports of potentially eligible studies. The same authors extracted data from full-text reports and assessed methodological quality using the QUADAS checklist. For each index test, estimates of sensitivity and specificity from each study were plotted in ROC space; and forest plots were constructed for visual examination of variation in test accuracy. We performed meta-analyses using the HSROC model to produce summary estimates of sensitivity and specificity.

MAIN RESULTS

We included 11 studies that looked at diagnostic accuracy of one or two index tests: four studies (277 suspected fractures) looked at CT, five studies (221 suspected fractures) looked at MRI and six studies (543 suspected fractures) looked at BS. Four of the studies made direct comparisons: two studies compared CT and MRI, one study compared CT and BS, and one study compared MRI and BS. Overall, the studies were of moderate to good quality, but relevant clinical information during evaluation of CT, MRI or BS was mostly unclear or unavailable.As few studies made direct comparisons between tests with the same participants, our results are based on data from indirect comparisons, which means that these results are more susceptible to bias due to confounding. Nonetheless, the direct comparisons showed similar patterns of differences in sensitivity and specificity as for the pooled indirect comparisons.Summary sensitivity and specificity of CT were 0.72 (95% confidence interval (CI) 0.36 to 0.92) and 0.99 (95% CI 0.71 to 1.00); for MRI, these were 0.88 (95% CI 0.64 to 0.97) and 1.00 (95% CI 0.38 to 1.00); for BS, these were 0.99 (95% CI 0.69 to 1.00) and 0.86 (95% CI 0.73 to 0.94). Indirect comparisons suggest that diagnostic accuracy of BS was significantly higher than CT and MRI; and CT and MRI have comparable diagnostic accuracy. The low prevalence of a true fracture among suspected fractures (median = 20%) means the lower specificity for BS is problematic. For example, in a cohort of 1000 patients, 112 will be over-treated when BS is used for diagnosis. If CT is used, only 8 will receive unnecessary treatment. In terms of missed fractures, BS will miss 2 fractures and CT will miss 56 fractures.

AUTHORS' CONCLUSIONS

Although quality of the included studies is moderate to good, findings are based on only 11 studies and the confidence intervals for the summary estimates are wide for all three tests. Well-designed direct comparison studies including CT, MRI and BS could give valuable additional information.Bone scintigraphy is statistically the best diagnostic modality to establish a definitive diagnosis in clinically suspected fractures when radiographs appear normal. However, physicians must keep in mind that BS is more invasive than the other modalities, with safety issues due to level of radiation exposure, as well as diagnostic delay of at least 72 hours. The number of overtreated patients is substantially lower with CT and MRI.Prior to performing comparative studies, there is a need to raise the initially detected prevalence of true fractures in order to reduce the effect of the relatively low specificity in daily practice. This can be achieved by improving clinical evaluation and initial radiographical assessment.

Adult scaphoid fracture

OBJECTIVES

Scaphoid fractures are the most common carpal fracture, representing 70% of carpal bone fractures. The diagnostic accuracy of physical examination findings and emergency medicine (EM) imaging studies for scaphoid fracture has not been previously described in the EM literature. Plain x-rays are insufficient to rule out scaphoid fractures in a patient with a suggestive mechanism and radial-sided tenderness on physical examination. This study was a meta-analysis of historical features, physical examination findings, and imaging studies for scaphoid fractures not visualized on plain x-ray in adult emergency department (ED) patients, specifically to address which types of imaging tests should be recommended in patients with persistent concern for acute fracture after ED discharge.

METHODS

A medical librarian and two emergency physicians (EPs) conducted a medical literature search of PUBMED and EMBASE. The original studies' bibliographies were reviewed for additional references and unpublished manuscripts were located via a hand search of EM research abstracts from national meetings. All abstracts were independently reviewed by the two physicians, and Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2) was used to assess individual study quality. When two or more qualitatively similar studies were identified, meta-analysis was conducted using Meta-DiSc software. Primary outcomes were sensitivity, specificity, and likelihood ratios (LRs) for predictors of scaphoid fracture detected on follow-up in patients with normal ED x-rays.

RESULTS

A total of 957 unique citations were identified, yielding 75 studies eligible for inclusion in this systematic review. Studies were significantly heterogeneous in design, study population, and criterion standard. The majority of studies were conducted in non-ED settings (e.g., orthopedic clinics). No studies used accepted diagnostic research publishing guidelines, and the overall QUADAS-2 methodologic quality was low, indicating an increased risk of bias in the estimates of diagnostic accuracy. The prevalence of scaphoid fractures ranged from 12% to 57% with the point estimate of 25% pretest probability for adult ED patients with concern for scaphoid injuries, nondiagnostic index x-rays, and scaphoid fractures on later imaging studies. Except for the absence of snuffbox tenderness (LR- = 0.15), physical examination findings lack accuracy to rule in or rule out scaphoid fractures, and no validated clinical decision rules exist. In patients with persistent concern for injury, magnetic resonance imaging (MRI) is superior to bone scan, computed tomography (CT), or ultrasound (US) to both rule in and rule out scaphoid fractures. Both MRI and CT share the added benefit of identifying alternative etiologies for posttraumatic wrist pain.

CONCLUSIONS

Except for the absence of snuffbox tenderness, which can significantly reduce the probability of scaphoid fracture, history and physical examination alone are inadequate to rule in or rule out scaphoid fracture. MRI is the most accurate imaging test to diagnose scaphoid fractures in ED patients with no evidence of fracture on initial x-rays. If MRI is unavailable, CT is adequate to rule in scaphoid fractures, but inadequate for ruling out scaphoid fractures.

Early MRI diagnostics for suspected scaphoid fractures subsequent to initial plain radiography

AIM

In the United Kingdom, diagnostic management of patients presenting to emergency department with a scaphoid injury varies. Follow-up plain radiographs, after an initial inconclusive X-ray, are common practice. We optimised the diagnostic pathway for these patients by focusing on the most appropriate diagnostic modality and on minimising the time to follow-up diagnostics.

MATERIALS AND METHODS

A baseline audit in the period 2008-2009 involving a total of 184 patients was conducted, and after the introduction of new local guidelines for scaphoid injury diagnostics, a follow-up audit involving 79 patients was undertaken in 2010-2012.

RESULTS

In the original audit, 130 patients had only scaphoid radiographs, of which 23 underwent initial and follow-up X-rays, and 107 initial-only radiographs. Of those 23, just one single patient (4%) displayed a scaphoid fracture. Others underwent three imaging procedures: initial radiographs, follow-up radiographs and either bone scan (41 patients) or MRI (13 patients). A further 6/41 (15%) and 4/13 (31%) fractures were detected by bone scan and MRI, respectively. In the re-audit, when MRI replaced follow-up X-rays and bone scans, 7 out of 77 (9%) patients were diagnosed with scaphoid fracture. Time from initial plain radiograph to follow-up MRI was reduced from an original mean of 36 to 14 days during the re-audit period.

CONCLUSION

The introduction of early MRI enhances scaphoid injury diagnostics and accelerates patient management. We therefore endorse the introduction of this approach on a wider scale through an update of the clinical guidelines for scaphoid injuries.

Diagnostic accuracy of imaging modalities for suspected scaphoid fractures

Follow-up radiographs are usually used as the reference standard for the diagnosis of suspected scaphoid fractures. However, these are prone to errors in interpretation. We performed a meta-analysis of 30 clinical studies on the diagnosis of suspected scaphoid fractures, in which agreement data between any of follow-up radiographs, bone scintigraphy, magnetic resonance (MR) imaging, or CT could be obtained, and combined this with latent class analysis to infer the accuracy of these tests on the diagnosis of suspected scaphoid fractures in the absence of an established standard. The estimated sensitivity and specificity were respectively 91.1% and 99.8% for follow-up radiographs, 97.8% and 93.5% for bone scintigraphy, 97.7% and 99.8% for MRI, and 85.2% and 99.5% for CT. The results were generally robust in multiple sensitivity analyses. There was large between-study heterogeneity for the sensitivity of follow-up radiographs and CT, and imprecision about their sensitivity estimates.

If we acknowledge the lack of a reference standard for diagnosing suspected scaphoid fractures, MRI is the most accurate test; follow-up radiographs and CT may be less sensitive, and bone scintigraphy less specific.

MRI as a reference standard for suspected scaphoid fractures

OBJECTIVES

Some have suggested that MRI might be the best reference standard for a true fracture among patients with suspected scaphoid fractures. The primary aim of this study was to determine the rate of false-positive diagnosis of an acute scaphoid fracture in a cohort of healthy volunteers.

METHODS

In a prospective study, 33 healthy volunteers were recruited and both wrists of each were scanned, except for 2 volunteers for whom only one wrist was scanned. To simulate the usual clinical context the 64 scans of healthy volunteers were mixed with 60 MRI scans of clinically suspected scaphoid fractures but normal scaphoid radiographs. These 124 MRI scans were blinded and randomly ordered. Five radiologists evaluated the MRI scans independently for the presence or absence of a scaphoid fracture and other injuries according to a standard protocol.

RESULTS

To answer the primary question, only the diagnoses from the 64 scans of healthy volunteers were used. The radiologists diagnosed a total of 13 scaphoid fractures; therefore, specificity for diagnosis of scaphoid fracture was 96% (95% confidence interval: range 94-98%). The 5 observers had a moderate interobserver agreement regarding diagnosis of scaphoid fracture in healthy volunteers (multirater κ=0.44; p<0.001).

CONCLUSIONS

The specificity of MRI for scaphoid fractures is high (96%), but false-positives do occur. Radiologists have only moderate agreement when interpreting MRI scans from healthy volunteers. MRI is not an adequate reference standard for true fractures among patients with suspected scaphoid fractures.

Clinical utility of tomosynthesis in suspected scaphoid fracture. A pilot study

BACKGROUND

Radiography alone will not detect all scaphoid fractures. There is a reported prevalence between 9 and 33% of occult scaphoid fractures. The evidence-based literature suggests that magnetic resonance imaging (MRI) is the most suitable secondary imaging modality due to the ability to evaluate the bone marrow directly and to also identify other injuries. However, there is no consensus on the choice of follow-up imaging strategy-computed tomography, MRI, or bone scan-across different institutions. Tomosynthesis is a new digital tomographic method creating multiple thin tomographic sections. The purpose of this study was to evaluate the clinical utility of tomosynthesis in suspected occult fracture.

METHODS

Thirty-five patients with a clinically suspected occult scaphoid fracture after initial normal radiography were imaged with repeat radiography and tomosynthesis scan 2 weeks after trauma.

RESULTS

Repeat radiography revealed one previously undetected scaphoid tubercle avulsion and one scaphoid waist fracture, confirmed by tomosynthesis. Tomosynthesis revealed two additional scaphoid waist fractures. In total, three initially occult scaphoid waist fractures were detected (9%). No additional fractures were detected in the remaining 32 patients during a 1-year follow-up.

CONCLUSION

Tomosynthesis can demonstrate occult scaphoid fractures not visible at radiography.

Assessment of the suspected fracture of the scaphoid

A suspected fracture of the scaphoid remains difficult to manage despite advances in knowledge and imaging methods. Immobilisation and restriction of activities in a young and active patient must be balanced against the risks of nonunion associated with an undiagnosed and undertreated fracture of the scaphoid.

The assessment of diagnostic tests for a suspected fracture of the scaphoid must take into account two important factors. First, the prevalence of true fractures among suspected fractures is low, which greatly reduces the probability that a positive test will correspond with a true fracture, as false positives are nearly as common as true positives. This situation is accounted for by Bayesian statistics. Secondly, there is no agreed reference standard for a true fracture, which necessitates the need for an alternative method of calculating diagnostic performance characteristics, based upon a statistical method which identifies clinical factors tending to associate (latent classes) in patients with a high probability of fracture.

The most successful diagnostic test to date is MRI, but in low-prevalence situations the positive predictive value of MRI is only 88%, and new data have documented the potential for false positive scans. The best strategy for improving the diagnosis of true fractures among suspected fractures of the scaphoid may well be to develop a clinical prediction rule incorporating a set of demographic and clinical factors which together increase the pre-test probability of a fracture of the scaphoid, in addition to developing increasingly sophisticated radiological tests.

Diagnostic accuracy of multidetector computed tomography for patients with suspected scaphoid fractures and negative radiographic examinations

PURPOSE

The aim of this prospective study was to evaluate the diagnostic accuracy of multidetector computed tomography (MDCT) in detecting occult scaphoid fractures.

MATERIALS AND METHODS

A total of 54 patients with a clinically suspected scaphoid fracture and negative initial conventional radiographs were evaluated with 64-row MDCT wrist examinations within 1 week of the trauma. The gold standard used was the diagnosis on MRI done within 1 week after MDCT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDCT were calculated.

RESULTS

MRI showed a total of 22 fractures in 20 of 55 (36%) wrists. Fractures included 14 scaphoid and 8 other carpal bones. MDCT showed a total of 19 fractures in 17 of 55 (30%) wrists. Two isolated scaphoid fractures and one trapezium fracture were missed on MDCT. The sensitivity, specificity, PPV, and NPV of MDCT were 86%, 100%, 100%, and 91%, respectively.

CONCLUSION

MDCT offers highly accurate results, especially concerning cortical involvement, and is a useful alternative in facilities lacking MRI.

Current methods of diagnosis and treatment of scaphoid fractures

Fractures of the scaphoid bone mainly occur in young adults and constitute 2-7% of all fractures. The specific blood supply in combination with the demanding functional requirements can easily lead to disturbed fracture healing. Displaced scaphoid fractures are seen on radiographs. The diagnostic strategy of suspected scaphoid fractures, however, is surrounded by controversy. Bone scintigraphy, magnetic resonance imaging and computed tomography have their shortcomings. Early treatment leads to a better outcome. Scaphoid fractures can be treated conservatively and operatively. Proximal scaphoid fractures and displaced scaphoid fractures have a worse outcome and might be better off with an open or closed reduction and internal fixation. The incidence of scaphoid non-unions has been reported to be between 5 and 15%. Non-unions are mostly treated operatively by restoring the anatomy to avoid degenerative wrist arthritis.

Clinical prediction rule for suspected scaphoid fractures: A prospective cohort study

BACKGROUND

The low prevalence of true fractures amongst suspected fractures magnifies the shortcomings of the diagnostic tests used to triage suspected scaphoid fractures.

PURPOSE

The objective was to develop a clinical prediction rule that would yield a subset of patients who were more likely to have a scaphoid fracture than others who lacked the subset criteria.

METHODS

Seventy-eight consecutive patients diagnosed with a suspected scaphoid fracture were included. Standardised patient history, physical examination, range of motion (ROM) and strength measurements were studied. The reference standard for a true fracture was based on the results of magnetic resonance imaging, bone scintigraphy, follow-up radiographs and examination.

RESULTS

Analysis revealed three significant independent predictors: extension <50%, supination strength ≤ 10% and the presence of a previous fracture.

CONCLUSION

Clinical prediction rules have the potential to increase the prevalence of true fractures amongst patients with suspected scaphoid fractures, which can increase the diagnostic performance characteristics of radiological diagnostic tests used for triage.

Novel use of gamma correction for precise (99m)Tc-HDP pinhole bone scan diagnosis and classification of knee occult fractures

OBJECTIVE

The aim of this study was to introduce gamma correction pinhole bone scan (GCPBS) to depict specific signs of knee occult fractures (OF) on (99m)Tc-hydroxydiphosphonate (HDP) scan.

MATERIALS AND METHODS

Thirty-six cases of six different types of knee OF in 27 consecutive patients (male = 20, female = 7, and age = 18-86 years) were enrolled. The diagnosis was made on the basis of a history of acute or subacute knee trauma, local pain, tenderness, cutaneous injury, negative conventional radiography, and positive magnetic resonance imaging (MRI). Because of the impracticability of histological verification of individual OF, MRI was utilized as a gold standard of diagnosis and classification. All patients had (99m)Tc-HDP bone scanning and supplementary GCPBS. GCPBS signs were correlated and compared with those of MRI. The efficacy of gamma correction of ordinary parallel collimator and pinhole collimator scans were collated.

RESULTS

Gamma correction pinhole bone scan depicted the signs characteristic of six different types of OF. They were well defined stuffed globular tracer uptake in geographic I fractures (n = 9), block-like uptake in geographic II fractures (n = 7), simple or branching linear uptake in linear cancellous fractures (n = 4), compression in impacted fractures (n = 2), stippled-serpentine uptake in reticular fractures (n = 11), and irregular subcortical uptake in osteochondral fractures (n = 3). All fractures were equally well or more distinctly depicted on GCPBS than on MRI except geographic II fracture, the details of which were not appreciated on GCPBS. Parallel collimator scan also yielded to gamma correction, but the results were inferior to those of the pinhole scan.

CONCLUSIONS

Gamma correction pinhole bone scan can depict the specific diagnostic signs in six different types of knee occult fractures. The specific diagnostic capability along with the lower cost and wider global availability of bone scanning would make GCPBS an effective alternative.

Diagnosing suspected scaphoid fractures: a systematic review and meta-analysis

Imaging protocols for suspected scaphoid fractures among investigators and hospitals are markedly inconsistent. We performed a systematic review and meta-analysis to assess and compare the diagnostic performance of bone scintigraphy, MRI, and CT for diagnosing suspected scaphoid fractures. Twenty-six studies were included. Sensitivity, specificity, and diagnostic odds ratio were pooled separately and summary receiver operating characteristic curves were fitted for each modality. Meta-regression analyses were performed to compare these modalities. We obtained likelihood ratios derived from the pooled sensitivity and specificity and, using Bayes' theorem, calculated the posttest probability by application of the tests. The pooled sensitivity, specificity, natural logarithm of the diagnostic odds ratio, and the positive and negative likelihood ratios were, respectively, 97%, 89%, 4.78, 8.82, and 0.03 for bone scintigraphy; 96%, 99%, 6.60, 96, and 0.04 for MRI; and 93%, 99%, 6.11, 93, and 0.07 for CT. Bone scintigraphy and MRI have equally high sensitivity and high diagnostic value for excluding scaphoid fracture; however, MRI is more specific and better for confirming scaphoid fracture. We believe additional studies are needed to assess diagnostic performance of CT, especially paired design studies or randomized controlled trials to compare CT with MRI or bone scintigraphy.

LEVEL OF EVIDENCE

Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Acute scaphoid fractures

Scaphoid fractures are a common problem encountered in clinical practice. This manuscript provides an algorithm for the diagnosis, evaluation, and treatment of acute scaphoid fractures.

Multiple occult wrist bone injuries and joint effusions: prevalence and distribution on MRI

This study aims (1) to assess the prevalence and distribution of multiple occult injuries of the carpal bones and the distal forearm in patients with wrist pain and negative radiographs following trauma and (2) to evaluate the distribution and significance of joint effusions in the wrists with multiple osseous injuries. One hundred and thirty-one subjects, 74 men and 57 women, were consecutively examined in two institutions. All were acute trauma patients with negative X-rays whose clinical examination suggested possible fracture at the wrist or the distal forearm. Magnetic resonance (MR) wrist imaging was performed with and without fat saturation sequences. The MR images were analysed for detection of occult trabecular contusions and cortical discontinuity in the carpus, the distal forearm and the metacarpal bases. The prevalence and distribution of the injuries were assessed along with the distribution of joint effusions. Eight patients were excluded due to inadequate image quality. Two patients had bilateral injury. A total of 125 wrists were analysed. Seventy-eight (62.4%) wrists had occult bone injuries. Among these 78, 53 (68%) wrists had more than one injured bone. Twenty-five wrists (32%) had one injured bone. The highest number of injured bones per wrist was six. Injuries with a visible fracture line were seen in 29 (37.1%) wrists on MRI. The distal radius was the most frequent location for occult fracture line (11 cases). The injuries without a fracture line (contusion) were present in 49 (63%) wrists; they were detected more frequently in the scaphoid (35 cases). The lunate (29 cases) and the triquetrum (26 cases) were almost equally affected. The bone that was less frequently injured was the pisiform (four cases). Joint effusions were present in all 53 wrists with multiple bone lesions but more often situated in the ulnocarpal space [27 (50.3%) wrists]. There was no correlation between effusions in multiple locations (grades III and IV) and multiple bone injuries. This study revealed the presence of multifocal trabecular contusions without correlation with increased joint effusions in patients with negative radiographs and persistent pain. The clinical significance of these findings deserves further investigation.

Management of carpal instability in athletes

Hand and wrist injuries are common in most athletic events and sports. Carpal fractures and ligamentous injuries are common in athletes and require physicians, trainers, and therapists who treat and diagnosis these injuries to have an understanding of the carpal bone anatomy and vascularity along with the potential for progression to instability. Research is still needed to further investigate the optimal treatments of all carpal injuries in athletes along with designing new means to prevent these injuries.

Clinical examination of scaphoid fractures

Undetected scaphoid fractures may lead to complications, including nonunion, malunion, avascular necrosis, and wrist arthritis. A competent physical examination is essential for the diagnosis of scaphoid fractures in the setting of occult fractures presenting with normal radiographs. The differential diagnosis of occult scaphoid fractures includes acute tears of the scaphoid-lunate ligament, Kienbock's disease, occult ganglion, nondisplaced radial styloid fractures, and injury to the radial aspect of the radio-scapho-capitate ligament. All of these may have normal plain radiographs but often can be distinguished based on physical examination findings. The 2 key points of such an examination include the exact location of point tenderness and provocative special tests. Although Watson's scaphoid shift test is classically described for scaphoid instability, we highlight its significance in the setting of scaphoid fractures.

Early magnetic resonance imaging compared with bone scintigraphy in suspected scaphoid fractures

We evaluated 100 consecutive patients with a suspected scaphoid fracture but without evidence of a fracture on plain radiographs using MRI within 24 hours of injury, and bone scintigraphy three to five days after injury. The reference standard for a true radiologically-occult scaphoid fracture was either a diagnosis of fracture on both MRI and bone scintigraphy, or, in the case of discrepancy, clinical and/or radiological evidence of a fracture. MRI revealed 16 scaphoid and 24 other fractures. Bone scintigraphy showed 28 scaphoid and 40 other fractures. According to the reference standard there were 20 scaphoid fractures. MRI was falsely negative for scaphoid fracture in four patients and bone scintigraphy falsely positive in eight. MRI had a sensitivity of 80% and a specificity of 100%. Bone scintigraphy had a sensitivity of 100% and a specificity of 90%. This study did not confirm that early, short-sequence MRI was superior to bone scintigraphy for the diagnosis of a suspected scaphoid fracture. Bone scintigraphy remains a highly sensitive and reasonably specific investigation for the diagnosis of an occult scaphoid fracture.

The role of MR imaging in scaphoid disorders

The scaphoid bone of the wrist is one of the most commonly fractured bones in the body. Due to its importance in the biomechanics and functionality of the wrist, it is important to depict and characterize the type of injury. Plain radiographs and scintigraphy may fail to disclose the type and severity of the injury. In patients with normal initial plain radiographs, MR imaging can discriminate occult fractures from bone bruises and may also demonstrate ligamentous disruption. MR imaging can also discriminate the proximal pole viability versus avascular necrosis secondary to previous fracture, which is important for treatment planning. Treatment of non-united fractures with vascularized grafts can be evaluated with contrast-enhanced MR imaging. Idiopathic osteonecrosis or Preiser's disease was originally described after trauma. The non-traumatic disorders of the scaphoid include post-traumatic osteoarthritis, inflammatory bone marrow edema in patients with rheumatoid arthritis, and osteomyelitis. MR imaging is helpful in all the above disorders to demonstrate early bone marrow edema, cartilage degeneration and associated subchondral marrow changes. The most commonly found tumors in the scaphoid are usually benign and include enchondroma, osteoblastoma and osteoid osteoma. MR imaging is not mandatory for the initial diagnosis, which should be based on plain X-ray findings.

[The diagnosis of recent scaphoid fractures: review of the literature]

Fractures of the scaphoid are the most common carpal fractures. A review of the literature indicates that the prevalence of the fracture in the case of clinical suspicion is less than 50%. A quality X-ray examination remains essential as an initial diagnostic tool in the evaluation of scaphoid fractures. Its sensitivity varies from 59 to 79%. Patients with negative X-rays present with about 18.7% of scaphoid fractures; 5% of bruised scaphoid; 13% of radius fractures and 7% of miscellaneous bone lesions. If not treated promptly, a scaphoid fracture may be compounded by non-union with associated risk factors such as avascular necrosis and osteoarthritis. Considering these risks, patients with suspected scaphoid fracture with normal X-rays, routinely undergo wrist immobilization until imaging confirms or denies the presence of fracture. Consequently, more than half of the patients undergo wrist immobilization needlessly. This may have a negative impact on their professional life and personal activities while representing a high medical cost. MRI is the imaging technique of choice for suspicious or negatice X-rays. MDCT is less costly than MRI or bone scan, readily available and highly effective for trauma patients but is lacks accuracy and should be used with caution in this indication.

Early computerized tomography accurately determines the presence or absence of scaphoid and other fractures

OBJECTIVE

To validate the use of early CT in predicting scaphoid fracture and other fractures in patients with suspected scaphoid fracture.

METHOD

A prospective observational study of adult patients with a diagnosis of clinical scaphoid fracture presenting to a regional ED. Patients were immobilized in a scaphoid plaster and had a CT (wrist and carpals) same or next day. The gold standard used was the diagnosis on Day 10 with clinical examination and X-rays, with MRI performed in patients with persistent tenderness but normal X-rays.

RESULTS

Forty-seven patients completed the study protocol from September 2004 until February 2006. For all fractures, early CT had a 96.8% negative predictive value and 100% positive predictive value (94.4% sensitive, 100% specific). No scaphoid fracture was missed by early CT. One patient had a trapezium fracture on CT, with a coexistent subtle capitate fracture only detected on MRI.

CONCLUSION

Early CT scans show promise in the diagnosis of scaphoid and other fractures of the wrist and carpals. Further study is warranted to validate early CT in clinical scaphoid fracture as an alternative to other early advanced imaging, or plaster immobilization and 2 week review.

A prospective comparison for suspected scaphoid fractures: bone scintigraphy versus clinical outcome

Early diagnosis and treatment of scaphoid fractures limits the number of delayed and non-unions. Bone scintigraphy proved to be a sensitive diagnostic tool for the detection of occult scaphoid fractures. However, the results have to be interpreted with care.

OBJECTIVE

To prospectively correlate the results of bone scintigraphy with clinical outcome.

METHODS

In a prospective study, we analysed 50 consecutive patients with signs of a scaphoid fracture at physical examination but no evidence of a scaphoid fracture on scaphoid radiographs. All patients had a protocolised follow up at fixed intervals. The clinical outcome was defined according to a standardised algorithm.

MAIN RESULTS

Bone scintigraphy revealed 32% (16/50) occult scaphoid fractures and 40% (20/50) occult other fractures. Clinical outcome proved that bone scintigraphy was false positive in five patients and in one case false negative for a scaphoid fracture.

CONCLUSION

Bone scintigraphy in combination with protocolised physical examination is the gold standard for patients with signs of a scaphoid fracture that cannot be proven on scaphoid radiographs.

Acute scaphoid fractures

Scaphoid fractures are a common problem encountered in clinical practice. This manuscript provides an algorithm for the diagnosis, evaluation, and treatment of acute scaphoid fractures.

Imagerie du poignet du sportif

Wrist imaging is currently used for diagnosis of sport injuries as part of a global strategy of rapid recovery. Standard x-rays are the first step in this procedure. Although arthrography is still the reference for the diagnosis of intrinsic ligament and cartilaginous lesions, MRI can sometimes be sufficient. Ultrasonography is a dynamic process and is accurate in detecting tendon injuries. Wrist sport injuries are frequent and often asymptomatic. Here we review the usual aspects of bone, ligament, and tendon lesions encountered in each sport, while providing advice on the most appropriate imaging for each clinical symptom.

Computed tomography of suspected scaphoid fractures

PURPOSE

Computed tomography (CT) can be used to triage suspected scaphoid fractures. This study assessed intraobserver and interobserver reliability and positive and negative predictive values of CT for the diagnosis of a nondisplaced scaphoid fracture.

METHODS

Eight observers evaluated CT scans from 30 patients (13 with nondisplaced scaphoid fractures, 17 with no scaphoid fractures) for the presence or absence of a fracture. Five observers evaluated the scans a second time. Statistical analyses included intraobserver and interobserver reliability and diagnostic characteristics.

RESULTS

Computed tomography had substantial intraobserver and interobserver reliability for the diagnosis of a nondisplaced scaphoid fracture. The average sensitivity, specificity, and accuracy of CT for a nondisplaced scaphoid fracture were 89%, 91%, and 90% for the first round and 97%, 85%, and 88% for the second round of observations, respectively. Based on an estimated prevalence of 5% true fractures among patients with suspected scaphoid fractures, the average positive predictive value for the detection of radiographically occult scaphoid fractures with tomography of the wrist was 0.28. The average negative predictive value was 0.99.

CONCLUSIONS

Computed tomography should be used with caution for triage of nondisplaced scaphoid fractures because false-positive results occur, perhaps from misinterpretation of vascular foraminae or other normal lines in the scaphoid. Given the relative infrequency of true fractures among patients with suspected scaphoid fractures, CT is better for ruling out a fracture than for ruling one in.

Treatment of acute scaphoid fractures in the athlete

Scaphoid fractures in athletes can be very disabling and may limit successful and early return to play. Typically, the mechanism of injury is a fall onto an outstretched hand or a direct blow; the patient will present with swelling, limited motion, and snuffbox tenderness. Multiple-view plain images will very often reveal the diagnosis. In addition, diagnostic modalities such as CT scanning and MRI are helpful in better defining the architecture of the fracture and vascularity of the scaphoid, and diagnosing occult fractures. Early and accurate diagnosis is critical to help ensure appropriate treatment and optimal outcome. Traditional treatment of stable nondisplaced fractures remains cast immobilization. However, if early return to play is desired operative fixation may be warranted. For nondisplaced fractures operative techniques include open reduction and internal fixation (ORIF), and percutaneous fixation through a dorsal or volar approach. Arthroscopy can be used as an adjunct to the percutaneous technique. For displaced fractures, the preferred technique remains ORIF through either a volar or dorsal approach. Considerations in treatment type are based on the stability and location of the fracture as well as patient issues such as compliance and the need for return to play. With appropriate diagnosis and individualization of treatment, scaphoid fractures can be successfully managed in most athletes with few or no long-term sequelae.

Occult scaphoid fractures: comparison of multidetector CT and MR imaging--initial experience

PURPOSE

To compare the diagnostic performance of multidetector computed tomography (CT) and magnetic resonance (MR) imaging in patients clinically suspected of having a scaphoid fracture and who had normal initial radiographs, with radiographs obtained 6 weeks after trauma as the reference standard.

MATERIALS AND METHODS

The ethics committee approved the study, and all patients gave written informed consent. Twenty-nine patients (17 male, 12 female; age range, 17-62 years; mean age, 34 years +/- 13) underwent multidetector CT and MR imaging within 6 days after trauma. CT data were obtained with 0.5-mm collimation. For image review, 0.7-mm-thick multiplanar reformations were performed in transverse, coronal, and sagittal planes relative to the wrist. The 1.0-T MR examination consisted of coronal and transverse short inversion time inversion-recovery, coronal and transverse T1-weighted spin-echo, and coronal volume-rendered T2-weighted gradient-echo sequences. Two radiologists analyzed the CT and MR images. A binomial test was used to evaluate the significance of the differences between MR imaging and CT in detection of scaphoid fractures and cortical involvement (P < .05).

RESULTS

The 6-week follow-up radiographs depicted a scaphoid fracture in 11 (38%) patients. Eight patients had a cortical fracture, while three patients had only a bandlike lucency within the trabecular portion of the scaphoid. MR imaging depicted all 11 fractures but only three [corrected] cortical fractures. Multidetector CT depicted all eight cortical fractures but failed to depict trabecular fractures. No false-positive fractures were seen on MR or CT images. Differences between MR imaging and CT were not significant for the detection of scaphoid fractures (P = .25) but were significant for cortical involvement (P = .03).

CONCLUSION

Multidetector CT is highly accurate in depicting occult cortical scaphoid fractures but appears inferior to MR imaging in depicting solely trabecular injury. MR imaging is inferior to multidetector CT in depicting cortical involvement.

Scaphoid fractures and nonunions: diagnosis and treatment

BACKGROUND

Scaphoid fractures are commonly seen in orthopedic practice. An organized and thoughtful approach to diagnosis and treatment can facilitate good outcomes. However, despite optimal treatment, complications may ensue. In the setting of nonunion or an avascular proximal pole, vascularized bone grafting may be needed.

METHODS AND RESULTS

In this article we review the literature regarding these injuries and describe an approach to diagnosis, treatment, and management of scaphoid fractures and nonunions.

CONCLUSION

Scaphoid fractures and nonunions may present as challenging problems in practice, but a systematic and deliberate approach can facilitate optimal results.

Outcome of routine bone scintigraphy in suspected scaphoid fractures

Undisplaced scaphoid fractures are easily missed on conventional scaphoid radiographs, but these occult fractures may seriously impair hand function. Routine bone scintigraphy (BS) is often advocated if there are clinical signs of a scaphoid fracture without radiological evidence. However, the results require careful therapeutic management.

OBJECTIVE

To determine the diagnostic value of BS in daily practice for clinically suspected scaphoid fractures.

METHODS

We evaluated our protocol of routine BS in suspected scaphoid fractures.

SUBJECTS

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 BS.

MAIN RESULTS

On average, the BS was performed after 4 days. It showed a fracture in 38/56 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, BS is a valuable diagnostic tool.

Management of clinical fractures of the scaphoid: results of an audit and literature review

OBJECTIVES

Two to 5% of scaphoid fractures are missed on initial presentation. The failure of early recognition and treatment are considered to contribute to delayed union and non-union. Despite advances in diagnostic imaging, a dogmatic approach has persisted in the management of patients with clinical suspicion but no radiographic evidence of scaphoid fracture. A critical analysis of the current treatment protocol of indiscriminate cast immobilization and serial clinical and radiographic follow-up is presented.

METHODS

A prospective study involving 90 patients with clinical signs suggestive of scaphoid injury, followed up until a definite boney injury was demonstrated or the patient was discharged. A review of the literature was conducted to question the need for immobilization in these patients and the potential use of other forms of diagnostic imaging in screening for occult scaphoid fractures.

RESULTS

The incidence of true fractures of the scaphoid was 6.66% (5/75). Ten patients (13.33%) had other injuries around the wrist unrelated to the scaphoid. Eighty per cent of the patients had no definite boney injury and were needlessly immobilized, and followed up. A total of 128 scaphoid casts, 135 sets of scaphoid X-rays, 135 clinic appointments and a cumulative 148 weeks of cast immobilization involved patients with normal wrists.

CONCLUSION

The incidence of radiologically inapparent fractures of the scaphoid is low. The use of a tender anatomical snuff box as the only clinical sign in the diagnosis of scaphoid injury is unsatisfactory. Other injuries around the wrist must be carefully excluded. There is insufficient evidence to support immobilizing all patients with clinical scaphoid fractures. For suspected fractures with no radiological evidence, symptomatic treatment is probably sufficient. Most occult fractures are visible at 2 weeks. Both magnetic resonance imaging and bone scintigraphy are accurate and cost effective and should be performed earlier rather than later.

The management of scaphoid fractures

Appropriate management of scaphoid fractures is important because of the risk of long-term complications such as delayed or non-union, pain and disability. Up to 25% of scaphoid fractures are not visible on the initial radiographs. Consequently, all clinically suspected scaphoid fractures are treated as fractures with cast immobilisation until cause of the symptoms is clarified. The diagnosis often utilises a number of second line investigations that are generally performed 10-14 days after the injury. Bone scintigraphy is currently the most commonly used of these as it rarely misses a fracture. However, it does not visualise anatomical structure and therefore alternative diagnoses are difficult. Magnetic resonance imaging (MRI) is at least as sensitive and more specific than bone scanning and has the advantages of being able to identify other lesions and not expose the patient to any radiation. Furthermore, the scan may be performed as early as 2.8 days following an injury rather than 10 days later in the case of a bone scan. Although the cost of MRI is higher than other imaging modalities, it may be cost-effective in the overall management of patients with occult scaphoid fractures since it may prevent unnecessary cast immobilisation in active people. The most appropriate method of cast immobilisation is presently unclear but evidence exists for improved clinical outcomes in those that have both the thumb and elbow immobilised for the first six weeks.