What Physical Examination Findings and Diagnostic Imaging Modalities Are Most Useful in the Diagnosis of Scaphoid Fractures?

Which clinical features best predict occult scaphoid fractures? A systematic review of diagnostic test accuracy studies

BACKGROUND

Plain radiographs cannot identify all scaphoid fractures; thus ED patients with a clinical suspicion of scaphoid injury often undergo immobilisation despite normal imaging. This study determined (1) the prevalence of scaphoid fracture among patients with a clinical suspicion of scaphoid injury with normal radiographs and (2) whether clinical features can identify patients that do not require immobilisation and further imaging.

METHODS

This systematic review of diagnostic test accuracy studies included all study designs that evaluated predictors of scaphoid fracture among patients with normal initial radiographs. Quality assessment was undertaken using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Meta-analyses included all studies.

RESULTS

Eight studies reported data on 1685 wrist injuries. The prevalence of scaphoid fracture despite normal radiographs was 9.0%. Most studies were at overall low risk of bias but two were at unclear risk; all eight were at low risk for applicability concerns. The most accurate clinical predictors of occult scaphoid fracture were pain when the examiner moved the wrist from a pronated to a supinated position against resistance (sensitivity 100%, specificity 97.9%, LR+ 45.0, 95% CI 6.5 to 312.5), supination strength <10% of contralateral side (sensitivity 84.6%, specificity 76.9%, LR+ 3.7, 95% CI 2.2 to 6.1), pain on ulnar deviation (sensitivity 55.2%, specificity 76.4%, LR+ 2.3, 95% CI 1.8 to 3.0) and pronation strength <10% of contralateral side (sensitivity 69.2%, specificity 64.6%, LR+ 2.0, 95% CI 1.2 to 3.2). Absence of anatomical snuffbox tenderness significantly reduced the likelihood of an occult scaphoid fracture (sensitivity 92.1%, specificity 48.4%, LR- 0.2, 95% CI 0.0 to 0.7).

CONCLUSION

No single feature satisfactorily excludes an occult scaphoid fracture. Further work should explore whether a combination of clinical features, possibly in conjunction with injury characteristics (such as mechanism) and a normal initial radiograph might exclude fracture. Pain on supination against resistance would benefit from external validation.

TRIAL REGISTRATION NUMBER

CRD42021290224.

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.

Comparison of scattered entrance skin dose burden in MSCT, CBCT, and X-ray for suspected scaphoid injury: Regional dose measurements in a phantom model

INTRODUCTION

Scaphoid radiography has poor sensitivity for acute fracture detection and often requires repeat delayed imaging. Although magnetic resonance (MR) imaging is considered the gold standard, computed tomography (CT) is often used as an alternative due to ease of access. Cone-Beam CT (CBCT) offers equivalent diagnostic efficacy to Multi Slice CT (MSCT) at reduced dose. We aimed to establish the difference in scattered dose between modalities for scaphoid imaging.

METHODS

Anatomical regional entrance surface dose measurements were taken at 3 regions on an anthropomorphic torso phantom positioned as a patient to a wrist phantom undergoing scaphoid imaging for three modalities (CBCT, MSCT, four-view projection radiography). Exposure factors were based on audit of clinical exposures. Each dose measurement was repeated three times per anatomical region, modality, exposure setting and projection.

RESULTS

Under unpaired T-test CBCT gave significantly lower mean dose at the neck (1.64 vs 18 mGy), chest (2.78 vs 8.01) and abdomen (1.288 vs 2.93) than MSCT (p < .0001). However CBCT had significantly higher mean dose than four-view radiography at the neck, chest and abdomen (0.031, 0.035, and 0.021 mGy) (p < .0001).

CONCLUSION

CBCT of the wrist carries a significantly higher scattered radiation dose to the neck, chest and abdomen than four view scaphoid radiography, but significantly lower scattered dose than MSCT of the wrist of equivalent diagnostic value.

IMPLICATIONS FOR PRACTICE

The use of CBCT for scaphoid injury carries significantly lower scattered dose to radio-sensitive structures investigated here than equivalent MSCT, and may be of greater use as an early cross-sectional investigation for suspected scaphoid fracture.

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.

Has NICE guidance changed the management of the suspected scaphoid fracture: A survey of UK practice

INTRODUCTION

Despite scaphoid fractures being relatively uncommon pro-active treatment of suspected fractures has been seen as a risk management strategy. The poor positive predictive value of X-rays has led to published guidelines advocating MRI as a first-line or early imaging tool. It is unclear whether UK hospitals have been able to introduce early scanning and this national survey sought to establish the current management strategies for patients with a suspected scaphoid fracture.

METHOD

An electronic survey of UK emergency departments (ED) was conducted to establish the initial and follow up strategies for patients with negative imaging. Comparison of first and second-line imaging modalities was undertaken together with review of the clinical speciality responsible for ongoing management.

RESULTS

166 UK NHS Trusts were identified with emergency department facilities of which 66 (39.8%) responded. All sites perform an X-ray as the initial examination. For those with a negative examination ED follow up was the most common approach (54.6%), although many sites refer patients to other specialities including orthopaedics (39.4%) for follow up. The data demonstrated inconsistencies in the number of follow-up episodes and the different imaging investigations utilised. Frustration with the challenges presented by this patient cohort was evident.

CONCLUSION

The suspected scaphoid fracture represents an ongoing challenge to the NHS with many resource intensive pathways reliant on access to complex imaging investigations.

IMPLICATIONS FOR PRACTICE

Our study identified that UK Emergency Departments have limited early access to complex imaging for scanning of the scaphoid. A range of strategies are used for follow up of suspected scaphoid fractures and these are resource intensive. Overtreatment of patients with suspected scaphoid fracture is used as a risk management approach.

Clinically SUspected ScaPhoid fracturE: treatment with supportive bandage or CasT? 'Study protocol of a multicenter randomized controlled trial' (SUSPECT study)

INTRODUCTION

Some scaphoid fractures become visible on radiographs weeks after a trauma which makes normal radiographs directly after trauma unreliable. Untreated scaphoid fractures can lead to scaphoid non-union progressing to osteoarthritis. Therefore, the general treatment for patients with a clinically suspected scaphoid fracture and normal initial radiographs is immobilisation with below-elbow cast for 2 weeks. However, most of these patients are treated unnecessarily because eventually less than 10% of them are diagnosed with an occult scaphoid fracture. To reduce overtreatment and costs as a result of unnecessary cast treatment in patients with a clinically suspected scaphoid fracture and normal initial radiographs, we designed a study to compare below-elbow cast treatment with supportive bandage treatment. We hypothesise that the functional outcome after 3 months is not inferior in patients treated with supportive bandage compared to patients treated with below-elbow cast, but with lower costs in the supportive bandage group.

METHODS AND ANALYSIS

The SUSPECT study is an open-labelled multicentre randomised controlled trial with non-inferiority design. A total of 180 adult patients with a clinically suspected scaphoid fracture and normal initial radiographs are randomised between two groups: 3 days of supportive bandage or 2 weeks of below-elbow cast. We aim to evaluate the functional outcome and cost-effectiveness of both treatments. The primary outcome is the functional outcome after 3 months, assessed with the Quick Disability of the Arm, Shoulder and Hand score. Secondary outcomes include functional outcome, recovery of function, pain, patient satisfaction, quality of life and cost-effectiveness measured by medical consumption, absence from work or decreased productivity.

ETHICS AND DISSEMINATION

The Medical Ethics Committee of the Erasmus MC Medical Centre, Rotterdam, approved the study protocol (MEC-2017-504). We plan to present the results after completion of the study at (inter)national conferences and publish in general peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NL6976.

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.