Early Computed Tomography Compared With Bone Scintigraphy in Suspected Scaphoid Fractures

Epidemiology of carpal fractures: is it only about the scaphoid?

Because of their low incidence, studies about carpal fractures are rare. The aim of the present study was to analyze epidemiology and treatment of fractured carpal bones. We retrospectively analyzed data of 178 patients admitted to our emergency room with carpal fractures over 6 years. More males than woman were injured. In 91%, a CT scan was performed. The most commonly affected bone was the triquetrum followed by the scaphoid. Almost all triquetral fractures were treated conservatively as opposed to perilunate dislocations that were all operated on. Half of all patients with scaphoid fractures were operated. Young men had the highest risk to sustain a carpal fracture. The triquetrum and the scaphoid are most frequently affected. Usually a CT scan is needed. Treatment of scaphoid and perilunate luxation fractures is rather operative whereas the other fractures mostly allow conservative casting. Nevertheless, correct indication for treatment is important to avoid sequelae.

What Is the Diagnostic Performance of Conventional Radiographs and Clinical Reassessment Compared With HR-pQCT Scaphoid Fracture Diagnosis?

BACKGROUND

Conventional radiographs and clinical reassessment are considered guides in managing clinically suspected scaphoid fractures. This is a unique study as it assessed the value of conventional radiographs and clinical reassessment in a cohort of patients, all of whom underwent additional imaging, regardless of the outcome of conventional radiographs and clinical reassessment.

QUESTIONS/PURPOSES

(1) What is the diagnostic performance of conventional radiographs in patients with a clinically suspected scaphoid fracture compared with high-resolution peripheral quantitative CT (HR-pQCT)? (2) What is the diagnostic performance of clinical reassessment in patients with a clinically suspected scaphoid fracture compared with HR-pQCT? (3) What is the diagnostic performance of conventional radiographs and clinical reassessment combined compared with HR-pQCT?

METHODS

Between December 2017 and October 2018, 162 patients with a clinically suspected scaphoid fracture presented to the emergency department (ED). Forty-six patients were excluded and another 25 were not willing or able to participate, which resulted in 91 included patients. All patients underwent conventional radiography in the ED and clinical reassessment 7 to 14 days later, together with CT and HR-pQCT. The diagnostic performance characteristics and accuracy of conventional radiographs and clinical reassessment were compared with those of HR-pQCT for the diagnosis of fractures since this was proven to be superior to CT scaphoid fracture detection. The cohort included 45 men and 46 women with a median (IQR) age of 52 years (29 to 67). Twenty-four patients with a median age of 44 years (35 to 65) were diagnosed with a scaphoid fracture on HR-pQCT.

RESULTS

When compared with HR-pQCT, conventional radiographs alone had a sensitivity of 67% (95% CI 45% to 84%), specificity of 85% (95% CI 74% to 93%), positive predictive value (PPV) of 62% (95% CI 46% to 75%), negative predictive value (NPV) of 88% (95% CI 80% to 93%), and a positive and negative likelihood ratio (LR) of 4.5 (95% CI 2.4 to 8.5) and 0.4 (95% CI 0.2 to 0.7), respectively. Compared with HR-pQCT, clinical reassessment alone resulted in a sensitivity of 58% (95% CI 37% to 78%), specificity of 42% (95% CI 30% to 54%), PPV of 26% (95% CI 19% to 35%), NPV of 74% (95% CI 62% to 83%), as well as a positive and negative LR of 1.0 (95% CI 0.7 to 1.5) and 1.0 (95% CI 0.6 to 1.7), respectively. Combining clinical examination with conventional radiography produced a sensitivity of 50% (95% CI 29% to 71%), specificity of 91% (95% CI 82% to 97%), PPV of 67% (95% CI 46% to 83%), NPV of 84% (95% CI 77% to 88%), as well as a positive and negative LR of 5.6 (95% CI 2.4 to 13.2) and 0.6 (95% CI 0.4 to 0.8), respectively.

CONCLUSION

The accuracy of conventional radiographs (80% compared with HR-pQCT) and clinical reassessment (46% compared with HR-pQCT) indicate that the value of clinical reassessment is limited in diagnosing scaphoid fractures and cannot be considered directive in managing scaphoid fractures. The combination of conventional radiographs and clinical reassessment does not increase the accuracy of these diagnostic tests compared with the accuracy of conventional radiographs alone and is therefore also limited in diagnosing scaphoid fractures.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Improved Detection of Scaphoid Fractures with High-Resolution Peripheral Quantitative CT Compared with Conventional CT

BACKGROUND

Computed tomography (CT), magnetic resonance imaging, and bone scintigraphy are second-line imaging techniques that are frequently used for the evaluation of patients with a clinically suspected scaphoid fracture. However, as a result of varying diagnostic performance results, no true reference standard exists for scaphoid fracture diagnosis. We hypothesized that the use of high-resolution peripheral quantitative CT (HR-pQCT) in patients with a clinically suspected scaphoid fracture could improve scaphoid fracture detection compared with conventional CT in the clinical setting.

METHODS

The present study included 91 consecutive patients (≥18 years of age) who presented to the emergency department with a clinically suspected scaphoid fracture between December 2017 and October 2018. All patients were clinically reassessed within 14 days after first presentation, followed by CT and HR-pQCT. If a scaphoid fracture was present, the fracture type was determined according to the Herbert classification system and correlation between CT and HR-pQCT was estimated with use of the Kendall W statistic or coefficient of concordance (W) (the closer to 1, the higher the correlation).

RESULTS

The cohort included 45 men and 46 women with a median age of 52 years (interquartile range, 29 to 67 years). HR-pQCT revealed a scaphoid fracture in 24 patients (26%), whereas CT revealed a scaphoid fracture in 15 patients (16%). Patients with a scaphoid fracture were younger and more often male. The correlation between CT and HR-pQCT was high for scaphoid fracture type according to the Herbert classification system (W = 0.793; 95% confidence interval [CI], 0.57 to 0.91; p < 0.001) and very high for scaphoid fracture location (W = 0.955; 95%, CI 0.90 to 0.98; p < 0.001).

CONCLUSIONS

In the present study, the number of patients diagnosed with a scaphoid fracture was 60% higher when using HR-pQCT as compared with CT. These findings imply that a substantial proportion of fractures-in this study, more than one-third-will be missed by the current application of CT scanning in patients with a clinically suspected scaphoid fracture.

LEVEL OF EVIDENCE

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

The interobserver reliability of the diagnosis and classification of scaphoid fractures using high-resolution peripheral quantitative CT

Aims

Besides conventional radiographs, the use of MRI, CT, and bone scintigraphy is frequent in the diagnosis of a fracture of the scaphoid. However, which techniques give the best results remain unknown. The investigation of a new imaging technique initially requires an analysis of its precision. The primary aim of this study was to investigate the interobserver agreement of high-resolution peripheral quantitative CT (HR-pQCT) in the diagnosis of a scaphoid fracture. A secondary aim was to investigate the interobserver agreement for the presence of other fractures and for the classification of scaphoid fracture.

Methods

Two radiologists and two orthopaedic trauma surgeons evaluated HR-pQCT scans of 31 patients with a clinically-suspected scaphoid fracture. The observers were asked to determine the presence of a scaphoid or other fracture and to classify the scaphoid fracture based on the Herbert classification system. Fleiss kappa statistics were used to calculate the interobserver agreement for the diagnosis of a fracture. Intraclass correlation coefficients (ICCs) were used to assess the agreement for the classification of scaphoid fracture.

Results

A total of nine (29%) scaphoid fractures and 12 (39%) other fractures were diagnosed in 20 patients (65%) using HR-pQCT across the four observers. The interobserver agreement was 91% for the identification of a scaphoid fracture (95% confidence interval (CI) 0.76 to 1.00) and 80% for other fractures (95% CI 0.72 to 0.87). The mean ICC for the classification of a scaphoid fracture in the seven patients diagnosed with scaphoid fracture by all four observers was 73% (95% CI 0.42 to 0.94).

Conclusion

We conclude that the diagnosis of scaphoid and other fractures is reliable when using HR-pQCT in patients with a clinically-suspected fracture. Cite this article: Bone Joint J 2020;102-B(4):478–484.

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.

Diagnostic accuracy of history taking, physical examination and imaging for phalangeal, metacarpal and carpal fractures: a systematic review update

BACKGROUND

The standard diagnostic work-up for hand and wrist fractures consists of history taking, physical examination and imaging if needed, but the supporting evidence for this work-up is limited. The purpose of this study was to systematically examine the diagnostic accuracy of tests for hand and wrist fractures.

METHODS

A systematic search for relevant studies was performed. Methodological quality was assessed and sensitivity (Se), specificity (Sp), accuracy, positive predictive value (PPV) and negative predictive value (NPV) were extracted from the eligible studies.

RESULTS

Of the 35 eligible studies, two described the diagnostic accuracy of history taking for hand and wrist fractures. Physical examination with or without radiological examination for diagnosing scaphoid fractures (five studies) showed Se, Sp, accuracy, PPV and NPV ranging from 15 to 100%, 13-98%, 55-73%, 14-73% and 75-100%, respectively. Physical examination with radiological examination for diagnosing other carpal bone fractures (one study) showed a Se of 100%, with the exception of the triquetrum (75%). Physical examination for diagnosing phalangeal and metacarpal fractures (one study) showed Se, Sp, accuracy, PPV and NPV ranging from 26 to 55%, 13-89%, 45-76%, 41-77% and 63-75%, respectively. Imaging modalities of scaphoid fractures showed predominantly low values for PPV and the highest values for Sp and NPV (24 studies). Magnetic Resonance Imaging (MRI), Computed Tomography (CT), Ultrasonography (US) and Bone Scintigraphy (BS) were comparable in diagnostic accuracy for diagnosing a scaphoid fracture, with an accuracy ranging from 85 to 100%, 79-100%, 49-100% and 86-97%, respectively. Imaging for metacarpal and finger fractures showed Se, Sp, accuracy, PPV and NPV ranging from 73 to 100%, 78-100%, 70-100%, 79-100% and 70-100%, respectively.

CONCLUSIONS

Only two studies were found on the diagnostic accuracy of history taking for hand and wrist fractures in the current review. Physical examination was of moderate use for diagnosing a scaphoid fracture and of limited use for diagnosing phalangeal, metacarpal and remaining carpal fractures. MRI, CT and BS were found to be moderately accurate for the definitive diagnosis of clinically suspected carpal fractures.

How Trustworthy Are Clinical Examinations and Plain Radiographs for Diagnosis of Scaphoid Fractures?

Background

Sometimes patients with a scaphoid fracture, especially in an acute phase of injury, can have normal radiographs and, therefore, initial diagnosis of the scaphoid fracture may be neglected. In this study, we determined the value in of clinical examination and a radiograph in the diagnosis of scaphoid fracture based on the results of a two-week follow-up magnetic resonance imaging (MRI).

Objectives

In this study, sought to assess the value of using both a clinical examination (tenderness of scaphoid tubercle, tenderness of anatomical snuffbox, and compression test) and radiographic imaging in the diagnosis of scaphoid fractures based on the results after a two-week follow-up MRI.

Patients and Methods

From December 2012 to February 2013, we enrolled 48 patients with suspected scaphoid fractures who had been referred to the emergency department of Baqiyatallah hospital, Tehran, Iran. Patients with negative results for clinical and radiographic examinations were excluded from the study. Cast immobilization was done for patients who had at least one positive finding during a physical examination test and who had normal radiographs. Patients who had a normal physical examination, but abnormal radiographs were referred to the orthopedic clinic after cast or split treatment. These patients also had a follow-up MRI two weeks after wrist trauma; the MRI was used to determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the clinical and radiographic examinations.

Results

Scaphoid tubercle tenderness had a sensitivity of 95.23% and a specificity of 74.07% in the diagnosis of scaphoid fracture. This test did not show a statistically difference with MRI results (P = 0.05). The results of the tenderness of the anatomical snuff box (sensitivity = 85.71%, specificity = 29.62%) was statistically different from the MRI results (P = 0.000). The results for the sensitivity (42.85%) and specificity (29.62%) for a compression test were not statistically different from the MRI results (P = 0.05). All of the radiographic tests that we applied in our project had 100% specificity for the diagnosis of a scaphoid fracture. However, the results were significantly different from the MRI results (P = 0.000).

Conclusions

A clinical examination combined with a plain radiograph should be considered to improve the diagnostic precision for patients presenting with scaphoid fractures in an emergency department. In this way, both overtreatment and undertreatment of patients can be avoided.

6-week radiographs unsuitable for diagnosis of suspected scaphoid fractures

INTRODUCTION

Six week follow-up radiographs are a common reference standard for the diagnosis of suspected scaphoid fractures. The main purpose of this study was to evaluate the interobserver reliability and diagnostic performance characteristics of 6-weeks radiographs for the detection of scaphoid fractures. In addition, two online techniques for evaluating radiographs were compared.

MATERIALS AND METHODS

A total of 81 orthopedic surgeons affiliated with the Science of Variation Group assessed initial and 6-week scaphoid-specific radiographs of a consecutive series of 34 patients with suspected scaphoid fractures. They were randomized in two groups for evaluation, one used a standard website showing JPEG files and one a more sophisticated image viewer (DICOM). The goal was to identify the presence or absence of a (consolidated) scaphoid fracture. Interobserver reliability was calculated using the multirater kappa measure. Diagnostic performance characteristics were calculated according to standard formulas with CT and MRI upon presentation in the emergency department as reference standards.

RESULTS

The interobserver agreement of 6-week radiographs for the diagnosis of scaphoid fractures was slight for both JPEG and DICOM (k = 0.15 and k = 0.14, respectively). The sensitivity (range 42-79 %) and negative predictive value (range 79-94 %) were significantly higher using a DICOM viewer compared to JPEG images. There were no differences in specificity (range 53-59 %), accuracy (range 53-58 %), and positive predictive value (range 14-26 %) between the groups.

CONCLUSIONS

Due to low agreement between observers for the recognition of scaphoid fractures and poor diagnostic performance, 6-week radiographs are not adequate for evaluating suspected scaphoid fractures. The online evaluation of radiographs using a DICOM viewer seem to improve diagnostic performance characteristics compared to static JPEG images and future reliability and diagnostic studies should account for variation due to the method of delivering medical images.

LEVEL OF EVIDENCE

Diagnostic level II.

Comparison of MRI, CT and bone scintigraphy for suspected scaphoid fractures

PURPOSE

The best diagnostic modality for confirmation of the diagnosis of a scaphoid fracture that is not visible on the initial radiograph (occult scaphoid fracture) is still subject of debate. The aim of this study was to compare the accuracy of magnetic resonance imaging (MRI), computed tomography (CT) and bone scintigraphy (BS) for the diagnosis of these occult scaphoid fractures.

PATIENTS AND METHODS

In a study period of 12 months, 33 consecutive patients with a clinically suspected scaphoid fracture without a fracture on the scaphoid radiographs were evaluated with MRI, CT and BS. In case of a discrepancy between the diagnostic modalities, the final diagnosis was based on standardised follow-up with clinical examination and a repeated radiograph.

RESULTS

Three of the 33 patients had a scaphoid fracture. MRI missed one scaphoid fracture and did not over-diagnose. CT missed two scaphoid fractures and did not over-diagnose. BS missed no scaphoid fractures and over-diagnosed one scaphoid fracture in a patient with a fracture of the trapezium.

CONCLUSION

This study shows that neither MRI, nor CT and BS are 100 % accurate in diagnosing occult scaphoid fractures. MRI and CT miss fractures, and BS tends to over-diagnose. The specific advantages and limitations of each diagnostic modality should be familiar to the treating physicians and taken into consideration during the diagnostic process.

Initial experience of SPECT/CT in the diagnosis of occult scaphoid fracture

BACKGROUND

*Equal contributors.Planar bone scintigraphy (PBS) is often advocated for diagnosing occult scaphoid fractures. PBS is a sensitive diagnostic modality, but lacks specificity, which may result in over-diagnosis.

PURPOSE

To examine, in a pilot study, the potential additional value of single photon emission computed tomography (SPECT) combined with low dose computed tomography (CT) for the diagnosis of an occult scaphoid fracture.

MATERIAL AND METHODS

Ten patients that underwent combined PBS and SPECT/CT for a clinically suspected scaphoid fracture, where radiographs could not detect a fracture, were included in this pilot study. The PBS and SPECT/CT results were independently and separately evaluated by a nuclear physician for scaphoid fractures and other injuries.

RESULTS

PBS was positive for a scaphoid fracture in four patients and diagnosed three other fractures. SPECT/CT showed five scaphoid fractures and one other fracture. SPECT/CT - PBS had discrepant results in three patients. In two patients PBS diagnosed a trapezoid fracture where SPECT/CT showed a scaphoid fracture. The other patient was diagnosed with a scaphoid fracture on PBS, whereas SPECT/CT showed bone bruise of other carpal bones.

CONCLUSION

SPECT/CT has the potential to be more accurate than PBS as it uses anatomical information of the CT to discriminate between the scaphoid, other carpal bones, and bone bruises. Larger studies with an independent reference standard are needed for confirmation of these preliminary data.

Cost-Effectiveness of Diagnostic Strategies for Suspected Scaphoid Fractures

OBJECTIVES

The aim of this study was to assess the cost effectiveness of multiple competing diagnostic strategies for suspected scaphoid fractures.

METHODS

With published data, the authors created a decision-tree model simulating the diagnosis of suspected scaphoid fractures. Clinical outcomes, costs, and cost effectiveness of immediate computed tomography (CT), day 3 magnetic resonance imaging (MRI), day 3 bone scan, week 2 radiographs alone, week 2 radiographs-CT, week 2 radiographs-MRI, week 2 radiographs-bone scan, and immediate MRI were evaluated. The primary clinical outcome was the detection of scaphoid fractures. The authors adopted societal perspective, including both the costs of healthcare and the cost of lost productivity. The incremental cost-effectiveness ratio (ICER), which expresses the incremental cost per incremental scaphoid fracture detected using a strategy, was calculated to compare these diagnostic strategies. Base case analysis, 1-way sensitivity analyses, and "worst case scenario" and "best case scenario" sensitivity analyses were performed.

RESULTS

In the base case, the average cost per scaphoid fracture detected with immediate CT was $2553. The ICER of immediate MRI and day 3 MRI compared with immediate CT was $7483 and $32,000 per scaphoid fracture detected, respectively. The ICER of week 2 radiographs-MRI was around $170,000. Day 3 bone scan, week 2 radiographs alone, week 2 radiographs-CT, and week 2 radiographs-bone scan strategy were dominated or extendedly dominated by MRI strategies. The results were generally robust in multiple sensitivity analyses.

CONCLUSIONS

Immediate CT and MRI were the most cost-effective strategies for diagnosing suspected scaphoid fractures.

LEVEL OF EVIDENCE

Economic and Decision Analyses Level II. See Instructions for Authors for a complete description of levels of evidence.

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.

Clinical diagnostic evaluation for scaphoid fractures: a systematic review and meta-analysis

PURPOSE

To provide an overview of available clinical evaluation tests for scaphoid fractures and to compare their diagnostic accuracies.

METHODS

PWe performed a systematic review of all studies assessing diagnostic characteristics of clinical evaluation in scaphoid fractures by searching MEDLINE, EMBASE, Cochrane, and CINAHL databases. Only studies on clinical testing prior to radiographic evaluation and with acceptable reference standard for occult fractures were included. Thirteen relevant articles were analyzed that described a total of 25 tests. Diagnostic characteristics of the tests were used to construct contingency tables. If possible, data were pooled and summary receiver operating characteristic curves were fitted.

RESULTS

Anatomic snuff-box tenderness (ASB, 8 studies, 1,164 patients) and longitudinal thumb compression (LTC, 8 studies, 961 patients) had sufficient data for statistical analyses. Sensitivity for ASB ranged from 0.87 to 1.00; for LTC, 0.48 to 1.00. Specificity of ASB ranged from 0.03 to 0.98; for LTC, 0.22 to 0.97. Owing to considerable heterogeneity, pooled estimate points were not calculated. Other high-sensitivity tests were scaphoid tubercle tenderness, with sensitivity and specificity ranging from 0.82 to 1.00 and 0.17 to 0.57, respectively, and painful ulnar deviation, ranging from 0.67 to 1.00 and 0.17 to 0.60, respectively. Three studies showed that combining tests increased the specificity and post-test fracture probability while maintaining high sensitivity. Quality assessment showed high or unclear risk of bias and applicability concerns in reference standard and patient selection. Twelve study designs were prospective, and 1 was retrospective.

CONCLUSIONS

Anatomical snuff box tenderness was the most sensitive clinical test. The low specificity of the clinical tests may result in a considerable number of overtreated patients. Combining tests improved the post-test fracture probability. This can be used to limit unnecessary immobilization, number of hospital visits, and use of imaging. The data presented herein may help to develop clinical prediction rules that could increase specificity without reducing sensitivity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

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.

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.

Early CT for suspected occult scaphoid fractures

In this study, the use of computed tomography (CT) early in the management of suspected occult scaphoid fractures was evaluated. We retrospectively reviewed the notes and radiology of patients who had scaphoid CT scans over the preceding 3 years. Eighty-four patients that had CT scans within 14 days from injury were identified. Of the CT scans, 64% (n = 54) excluded a fracture and these patients were promptly mobilized. No patients returned with any complications from this management. Overall, 36% of CT scans were abnormal (n = 30), 7% revealed occult scaphoid fractures, 18% revealed occult carpal fractures of the triquetrum, capitate, and lunate, respectively, and 5% revealed distal radius fractures. All patients diagnosed with fractures were successfully managed with plaster immobilization and there was one case of complex regional pain syndrome. Early CT alters therapeutic decision making in suspected occult fractures preventing unnecessary immobilization in a working population without increase in cost.