Assessment of the suspected fracture of the scaphoid

Can we avoid casting for suspected scaphoid fractures? A multicenter randomized controlled trial

BACKGROUND

In suspected scaphoid fractures with normal initial radiographs, the usual care is casting, but only 10% of patients have scaphoid fractures. To reduce overtreatment, we evaluated whether bandaging, instead of casting, resulted in noninferior functional outcomes.

PATIENTS AND METHODS

We included adults with suspected scaphoid fractures and normal initial radiographs at the emergency department in our multicenter randomized controlled trial. Patients were randomized to 3-day bandaging or 2-week casting. Questionnaires, physical examination, and radiographs were performed at 2 weeks and 1 year. Additional questionnaires were sent after inclusion, 6 weeks, and 3 months. Our primary outcome was the adjusted estimated difference between groups of the Quick Disabilities of the Arm, Shoulder, and Hand (QDASH) score at 3 months (natural logarithm of the margin of noninferiority = 2.0). Secondary outcomes included the QDASH score, Patient-Rated Hand/Wrist Evaluation Score, visual analog scale pain, wrist range of motion, patient satisfaction, and complications during follow-up.

RESULTS

Of the 180 patients (91 bandaging and 89 casting), 16 had scaphoid fractures and there were no scaphoid nonunions. Functional outcome in the bandaging group was noninferior at 3 months compared with the casting group [adjusted estimated difference QDASH score 0.30 (95% CI 0.02-0.62)]. All other patient-reported function and pain scores were not significantly different between groups. Range of motion at 2 weeks was better in the bandaging group, and they were more satisfied with the treatment than the casting group.

CONCLUSIONS

Casting for suspected scaphoid fractures but normal initial radiographs can be avoided because bandaging seems to be an alternative treatment option when patients are reevaluated after 2 weeks. Level of evidence Level II. Trial registration Trial registered at the Trialregister on 2018-02-28 on www.trialregister.nl , NTR7164.

The incidence of surgical intervention following a suspected scaphoid fracture

Aims

The underlying natural history of suspected scaphoid fractures (SSFs) is unclear and assumed poor. There is an urgent requirement to develop the literature around SSFs to quantify the actual prevalence of intervention following SSF. Defining the risk of intervention following SSF may influence the need for widespread surveillance and screening of SSF injuries, and could influence medicolegal actions around missed scaphoid fractures.

Methods

Data on SSF were retrospectively gathered from virtual fracture clinics (VFCs) across a large Scottish Health Board over a four-year period, from 1 January 2018 to 31 December 2021. The Bluespier Electronic Patient Record System identified any surgical procedure being undertaken in relation to a scaphoid injury over the same time period. Isolating patients who underwent surgical intervention for SSF was performed by cross-referencing the unique patient Community Health Index number for patients who underwent these scaphoid procedures with those seen at VFCs for SSF over this four-year period.

Results

In total, 1,739 patients were identified as having had a SSF. Five patients (0.28%) underwent early open reduction and internal fixation (ORIF). One patient (0.06%) developed a nonunion and underwent ORIF with bone grafting. All six patients undergoing surgery were male (p = 0.005). The overall rate of intervention following a SSF was 0.35%. The early intervention rate in those undergoing primary MRI was one (0.36%), compared with three in those without (0.27%) (p > 0.576).

Conclusion

Surgical intervention was rare following a SSF and was not required in females. A primary MRI policy did not appear to be associated with any change in primary or secondary intervention. These data are the first and largest in recent literature to quantify the prevalence of surgical intervention following a SSF, and may be used to guide surveillance and screening pathways as well as define medicolegal risk involved in missing a true fracture in SSFs.

Routine MRI Among Patients With a Suspected Scaphoid Fracture Risks Overdiagnosis

BACKGROUND

In the setting of a suspected scaphoid fracture, MRI may result in overdiagnosis and potential overtreatment. This is in part because of the low prevalence of true fractures among suspected fractures, but also because of potentially misleading variations in signal that may be more common than fracture-related signal changes. To better understand the risk of overdiagnosis, we first need insight into the relative prevalence of useful and potentially distracting signal changes among patients with a suspected scaphoid fracture.

QUESTION/PURPOSE

What is the proportion of signal changes representing definite and possible scaphoid fractures relative to other types of signal changes on MRI among patients with a suspected scaphoid fracture?

METHODS

In a retrospective study in an orthopaedic trauma clinic associated with a Level I trauma center, we evaluated MR images of patients 16 years and older with a clinically suspected scaphoid fracture. At our institution, patients with symptoms and signs of a possible scaphoid fracture and negative radiographs undergo MRI scanning. Between January 1, 2012, and September 1, 2019, a total of 310 patients 16 years or older had an MRI to evaluate a suspected scaphoid fracture. Exclusion criteria included a scaphoid fracture that was visible on radiographs before MRI as reported by the radiologist (four patients), no available radiographs before MRI (two), MRI more than 3 weeks after injury (28), unknown date of injury (nine), and repeat or bilateral MRI scans (11), leaving 256 MR images for analysis. Sixty percent (153) of patients were women, and the median age was 34 years (IQR 21 to 50 years). The images were taken a median of 8 days (IQR 2 to 12 days) after injury. MR images were screened for the presence of scaphoid signal changes. We identified the following patterns of signal change with a reliability of kappa 0.62: definite scaphoid fracture, possible scaphoid fracture, signal in the waist area other than possible or definite fractures, and other signal changes. A definite scaphoid fracture was defined as a linear, focal, and bicortical signal abnormality, with adjacent edema and a relatively transverse orientation relative to the scaphoid long axis. The transverse linear signal was visible on more than one cut in multiple planes. A possible scaphoid fracture had a transverse linear signal on more than one cut on sagittal or coronal planes, with or without adjacent edema.

RESULTS

Six percent (16 of 256) of MR images were categorized as revealing definite (2% [four of 256]) or possible (5% [12 of 256]) scaphoid fractures, whereas 29% (74 of 256) were categorized as revealing nonspecific signal changes at the waist (14% [35 of 256]) and other areas (15% [39 of 256]). Of the 51 patients with scaphoid waist signal changes, 69% (35) were categorized as having distracting and potentially misleading MRI findings.

CONCLUSION

The high prevalence of signal changes that are distracting and potentially misleading, the low prevalence of signal changes that clearly represent a scaphoid fracture, and the low pretest odds of a true fracture among patients with a suspected scaphoid fracture illustrate that routine MRI of suspected scaphoid fractures carries a notable risk of overdiagnosis and potential overtreatment. Two alternative strategies are supported by preliminary evidence and merit additional attention: more-selective use of MRI in people deemed at higher risk according to a clinical prediction rule and strategies for involving the patient in decisions regarding how to manage the notably small risk of future symptomatic nonunion.

LEVEL OF EVIDENCE

Level IV, diagnostic study.

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.

Evaluating cone-beam CT in the diagnosis of suspected scaphoid fractures in the emergency department: preliminary findings

OBJECTIVES

Scaphoid fractures are challenging to accurately diagnose with delayed and missed diagnoses risking poor patient outcomes. Cone beam CT (CBCT) is an emerging technology facilitating alternative access to multi-planar imaging. The aim of this study was to evaluate the use of early CBCT in the diagnosis of suspected scaphoid fractures presenting via the Emergency Department (ED).

METHODS

In this single centre the imaging pathway was adapted to include early CBCT in adult patients with a persisting high index of clinical suspicion for scaphoid fracture despite normal radiographs. Evaluation of referrals between September 2019 and February 2020 was undertaken. Statistical analysis and temporal pathway metrics were assessed including interrater agreement for CBCT and radiography examinations.

RESULTS

Over the six-month timeframe 100 CBCT wrist scans were performed on 99 adult patients. 94% of CBCT scans were performed within 1 day of referral. 25% of scans demonstrated acute injuries including 12 radius, 6 trapezium and 2 scaphoid fractures. For fracture, CBCT had a sensitivity of 96.2% and specificity of 100%. There was a highly significant difference in interobserver variation between fracture detection on CBCT and radiographs.

CONCLUSION

CBCT heralds the potential for early accurate diagnosis of radiocarpal fractures, at lower cost, shortening clinical pathways and reducing clinical risk in the ED.

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.

Association between bone shape and the presence of a fracture in patients with a clinically suspected scaphoid fracture

Scaphoid fractures are difficult to diagnose with current imaging modalities. It is unknown whether the shape of the scaphoid bone, assessed by statistical shape modeling, can be used to differentiate between fractured and non-fractured bones. Therefore, the aim of this study was to investigate whether the presence of a scaphoid fracture is associated with shape modes of a statistical shape model (SSM). Forty-one high-resolution peripheral quantitative computed tomography (HR-pQCT) scans were available from patients with a clinically suspected scaphoid fracture of whom 15 patients had a scaphoid fracture. The scans showed no motion artefacts affecting bone shape. The scaphoid bones were semi-automatically contoured, and the contours were converted to triangular meshes. The meshes were registered, followed by principal component analysis to determine mean shape and shape modes describing shape variance. The first five out of the forty shape modes cumulatively explained 87.8% of the shape variance. Logistic regression analysis was used to study the association between shape modes and fracture presence. The regression models were used to classify the 41 scaphoid bones as fractured or non-fractured using a cut-off value that maximized the sum of sensitivity and specificity. The classification of the models was compared with fracture diagnosis on HR-pQCT. A regression model with four shape modes had an area under the ROC-curve of 72.3% and correctly classified 75.6% of the scaphoid bones (fractured: 60.0%, non-fractured: 84.6%). To conclude, fracture presence in patients with a clinically suspected scaphoid fracture appears to be associated with the shape of the scaphoid bone.

Management of acute scaphoid fractures: a pragmatic approach for the non-specialist

Scaphoid fractures are common and can cause significant morbidity if treated incorrectly. Thus, a working knowledge of the initial assessment and management of scaphoid fractures by non-specialists is crucial to allow quick diagnosis and avoid potentially catastrophic complications of scaphoid fracture. This article summarises the anatomy of the scaphoid, discusses methods to assess for scaphoid fractures and delineates management plans (conservative or operative) for fractures of the scaphoid based on location of vascular compromise. This article can also help the clinician predict which fractures may not unite with conservative management and therefore need referral to a specialist orthopaedic surgeon for possible surgery.

How to manage scaphoid waist fractures? Introduction of pragmatic imaging efficient pathway and literature review of the recent evidence

INTRODUCTION AND OBJECTIVE

The scaphoid bone sustains about 90 % of carpal bone fractures and is the second-highest bone at risk of post-traumatic osteonecrosis. Delayed diagnosis and treatment could lead to non-union and advanced carpal bones collapse. This study aimed to introduce an imaging efficient and practical scaphoid waist fracture management pathway (SWFMP) and measure its efficacy in clinical practice.

MATERIALS AND METHODS

The SWFMP was introduced in January 2020. Suspected occult fractures were approached by early orthopaedic clinical assessment and subsequent urgent MRI scan without repeating scaphoid X-rays. Scaphoid waist fractures displaced < 2 mm were treated with 8 weeks below elbow cast immobilization followed by CT scan if delayed union was suspected. Waist fractures displaced > 2 mm were managed with surgical fixation. Adult patients referred from the emergency department (ED) to the Virtual Fracture Clinic (VFC) with acute scaphoid injury from January 2019 to October 2019 (Pre SWFMP, n = 29), were identified and compared to those managed from January 2020 to October 2020 (Post SWFMP, n = 33).

RESULTS

Mean age was 37.9 (SD = 20.61) and 36.2 (SD = 17.06) years in the pre-SWFMP and post-SWFMP cohorts respectively. Fiften patients (51.7%) had the right side affected in the pre-SWFMP cohort and twenty-three patients (69.7%) in the post-SWFMP cohort. Scaphoid X-rays requested by ED have increased from 19 (65.5%) to 31 (94%) and repeated X-rays reduced from 17 (58.6%) to 10 (30.3%) after the introduction of the SWFMP. Mean wrist cast immobilization for patients without scaphoid fractures dropped from 16.9 days (SD = 5.57) to 3.6 days (SD = 6.24) after the SWFMP (p = 0.001). In the pre-SWFMP cohort, 24 patients had no fracture, 4 achieved full healing and 1 developed non-union. In the post-SWFMP cohort, 29 patients had no fracture, 1 achieved full union and delayed union was detected in 3 patients at 8 weeks.

CONCLUSIONS

The SWFMP has improved the clinical practice by reducing unnecessary ionizing radiation, unnecessary cast immobilization, and by using a timely fracture fixation intervention.

Bayesian Statistics to Estimate Diagnostic Probability of Scaphoid Fractures from Clinical Examinations: A Meta-Analysis

BACKGROUND

Management of suspected scaphoid fractures includes repeated evaluation and casting in symptomatic patients with nondiagnostic radiographs. In this systematic review and meta-analysis, the authors compare the diagnostic accuracy of clinical examinations for scaphoid fractures and create a decision guide using Bayesian statistics.

METHODS

The MEDLINE, Embase, and Cumulative Index to Nursing and Allied Health Literature databases were queried for studies that evaluated clinical index tests and their diagnostic accuracies for scaphoid fracture. Summary estimates were achieved by a bivariate random effects model and used in Bayes' theorem. The authors varied the scaphoid fracture prevalence for sensitivity analysis.

RESULTS

Fourteen articles with 22 index tests and 1940 patients were included. Anatomical snuffbox pain/tenderness (11 studies, 1363 patients), pain with axial loading (eight studies, 995 patients), and scaphoid tubercle tenderness (five studies, 953 patients) had sufficient data for pooled analysis. Anatomical snuffbox pain/tenderness was the most sensitive test (0.93; 95 percent CI, 0.87 to 0.97), and pain with axial loading was the most specific test (0.66; 95 percent CI, 0.41 to 0.85), but all three tests had lower estimated specificities compared with sensitivities. In the base case, the probability of fracture was approximately 60 percent when a patient presented with all three findings after acute wrist injury.

CONCLUSIONS

The posttest probability of scaphoid fracture was sensitive to both prevalence and diagnostic accuracy of individual clinical index tests. In a population with a fracture prevalence of 20 percent, patients presenting with concurrent anatomical snuffbox pain/tenderness, pain on axial loading, and scaphoid tubercle tenderness may benefit from early advanced imaging to rule out scaphoid fractures if initial radiographs are nondiagnostic.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, II.

What is the role of ultrasonography in the early diagnosis of scaphoid fractures?

Scaphoid fractures are the most prevalent type of carpal bone fractures. High-spatial-resolution sonography detects direct signs of scaphoid fractures such as scaphoid cortical disruption; nevertheless, indirect signs such as radiocarpal effusion and scapho-trapezium-trapezoid effusion can also be visible. The diagnosis is performed when both direct and indirect signs of scaphoid fracture are presented. The presence of indirect signs alone is not enough to complete the diagnosis, for which more advanced imaging modalities are usually required. Here, we review the anatomy of the scaphoid, the clinical manifestations of scaphoid fractures, as well as ultrasonographic findings and differential diagnosis.

Photon-counting spectral basis component material decomposition for musculoskeletal radiographs

As a very fast and non-invasive examination, conventional X-ray radiography is well established as the first line diagnostic imaging method of the human bone system. While major bone injuries such as fractures and dislocations are usually easily detectable on conventional X-ray images, more subtle injuries such as microfractures are often missed, leading to mistreatment and potential long-term consequences. The technology of Photon-Counting Dual-Energy Radiography (PCDER) yields the possibility to decompose conventional X-ray images into basis material images such as bone- and soft-tissue-equivalence images. The obtained basis material images offer significant advantages in terms of image contrast and image details over the raw attenuation image which shows an overlap of bone and soft tissue. Whereas the advantages of bone- and soft-tissue-equivalence images have been broadly discussed referring to bone subtraction images in the detection of pulmonary diseases, this method has not been considered for the analysis of musculoskeletal images until present. In this study we show that basis component equivalence images have high potential to improve the diagnostic accuracy of the detection of minor bone lesions during clinical trauma imaging. A reader study performed by three experienced radiologists compares the image quality of basis material images to a standard radiograph image of a non-fractured cadaveric hand.

DEMOGRAPHIC AND CLINICAL PROFILE OF ADULT PATIENTS WITH SCAPHOID FRACTURES IN POPULATION OF DISTRICT D.I.KHAN, PAKISTAN

Background: Scaphoid fractures are common and account for 60-70 % of all carpal fractures. The objectives of this study were to determine the demographic and clinical profiles of adult patients with scaphoid fractures in population of District D.I.Khan, Pakistan. Materials & Methods: This cross-sectional study was conducted in Department of Orthopedics, Gomal Medical College, D.I.Khan, Pakistan from January 2015 to December 2019. Sample size was 40. Demographic variables were sex, age groups and time to presentation in weeks. Research variables were; cause, laterality, site, management options, time to union in months and presence of infection. All variables were categorical and analyzed by count and percentages for sample and as CI at 80% CL for proportion for population using Wilson score for binomial distribution. Results: Forty patients included 34 (85%) men & 16 (15%) women, 24 (60%) in 17-30 and 16 (40%) in age group 31-50 years. Time to presentation was ≤1 week of injury in 19 (47.5%) patients and 21 (52.5%) presented later. Cause was fall on out-stretched hand in 27 (67.5%) and RTA in 13 (32.5%) patients. Right hand was involved in 29 (72.5%), left in 9 (22.5%) while bilateral in 2 (5%) patients. Site of fracture was waist in 24 (60%), proximal pole 11 (27.5%) and distal pole 5 (12.5%) cases. Conservative treatment was done in 7 (17.50%) patients, percutaneous screw fixation 7 (17.50%), open reduction and internal fixation through palmar in 11 (27.50%) and though dorsal 15 (37.50%) cases. Time to union was ≤3 in 7 (17.50%), >3-6 months 29 (72.5%), while >6 months in 4 (10%) patients. Presence of infection was 1/40 (2.38%). Conclusion: Scaphoid fractures are more common in men and younger adults and most are presented within a week of injury. These are caused mostly by fall on outstretched hand, involving right hand and involving waist. Substantial number of cases requires open reduction with internal fixation. Mostly unite in 3-6 months.

Detecting scaphoid fractures in wrist injury: a clinical decision rule

INTRODUCTION

The aim of this study was to develop and validate an easy to use clinical decision rule, applicable in the ED that limits the number of unnecessary cast immobilizations and diagnostic follow-up in suspected scaphoid injury, without increasing the risk of missing fractures.

METHODS

A prospective multicenter study was conducted that consisted of three components: (1) derivation of a clinical prediction model for detecting scaphoid fractures in adult patients following wrist trauma; (2) internal validation of the model; (3) design of a clinical decision rule. The predictors used were: sex, age, swelling of the anatomic snuffbox, tenderness in the anatomic snuffbox, scaphoid tubercle tenderness, painful ulnar deviation and painful axial thumb compression. The outcome measure was the presence of a scaphoid fracture, diagnosed on either initial radiographs or during re-evaluation after 1-2 weeks or on additional imaging (radiographs/MRI/CT). After multivariate logistic regression analysis and bootstrapping, the regression coefficient for each significant predictor was calculated. The effect of the rule was determined by calculating the number of missed scaphoid fractures and reduction of suspected fractures that required a cast.

RESULTS

A consecutive series of 893 patients with acute wrist injury was included. Sixty-eight patients (7.6%) were diagnosed with a scaphoid fracture. The final prediction rule incorporated sex, swelling of the anatomic snuffbox, tenderness in the anatomic snuffbox, painful ulnar deviation and painful axial thumb compression. Internal validation of the prediction rule showed a sensitivity of 97% and a specificity of 20%. Using this rule, a 15% reduction in unnecessary immobilization and imaging could be achieved with a 50% decreased risk of missing a fracture compared with current clinical practice.

CONCLUSIONS

This dataset provided a simple clinical decision rule for scaphoid fractures following acute wrist injury that limits unnecessary immobilization and imaging with a decreased risk of missing a fracture compared to current clinical practice.

CLINICAL PREDICTION RULE

1/(1 + EXP (-(0.649662618 × if man) + (0.51353467826 × if swelling anatomic snuffbox) + (-0.79038263985 × if painful palpation anatomic snuffbox) + (0.57681198857 × if painful ulnar deviation) + (0.66499549728 × if painful thumb compression)-1.685).

TRIAL REGISTRATION

Trial register NTR 2544, www.trialregister.nl.

Management of Scaphoid Fractures

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Understand the epidemiology, classification, and anatomy pertinent to the scaphoid. 2. Appropriately evaluate a patient with suspected scaphoid fracture, including appropriate imaging. 3. Understand the indications for operative treatment of scaphoid fractures, and be familiar with the various surgical approaches. 4. Describe the treatment options for scaphoid nonunion and avascular necrosis of the proximal pole.

SUMMARY

The goal of this continuing medical education module is to present the preoperative assessment and the formation and execution of a surgical treatment plan for acute fractures of the scaphoid. In addition, secondary surgical options for treatment of scaphoid nonunion and avascular necrosis are discussed.

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.

The Palpable Scaphoid Surface Area in Various Wrist Positions

PURPOSE

To determine the theoretical amount of surface area available for palpation of the scaphoid in various wrist positions and to provide a guide depicting which wrist position will expose proximal pole, waist, and distal pole fractures.

METHODS

Using 3 fresh-frozen male cadaver wrists, we digitized palpable surface areas (dorsal, volar, and snuffbox) of the scaphoid in several wrist positions. The entire scaphoid was then excised and a digitized 3-dimensional reconstruction of the entire scaphoid was obtained. The 2 images were superimposed and the surface area was calculated

RESULTS

The maximum palpable area of the scaphoid was achieved with the wrist in neutral extension and maximum ulnar deviation and the wrist in maximum flexion and neutral deviation. Neutral wrist extension and ulnar deviation exposed all but the most proximal portion of the proximal pole and the distal pole, which made this the ideal position to detect tenderness from a scaphoid waist fracture and larger proximal pole fractures. Maximum wrist flexion with neutral wrist deviation exposed the entire proximal pole, which made this the ideal position to detect tenderness from a proximal pole scaphoid fracture.

CONCLUSIONS

Wrist position influences the amount of scaphoid surface area available for palpation and should be considered when examining a patient with a suspected scaphoid fracture.

CLINICAL RELEVANCE

The scaphoid should be palpated in 3 anatomic regions with the wrist placed in different positions to maximally expose the anatomical region being palpated.

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.

Scaphoid fractures: a higher order analysis of clinical tests and application of clinical reasoning strategies

INTRODUCTION

The purpose of this study was to identify clinical tests for scaphoid fractures and, using a higher order analysis, to determine their diagnostic accuracy.

METHODS

A literature review of the databases CINAHL, Embase, Medline and PUBMED from 1980 to September 30, 2011 was conducted to obtain applicable literature on clinical tests used in identifying scaphoid fractures. Methodological quality was determined using the criteria for validity suggested by Sackett et al (2000). Using a random effects model, pooled positive likelihood ratios (PPLR) were established for any test evaluated in at least 3 published studies. Moderator analyses provided insight into heterogeneity of results.

RESULTS

Higher order analysis indicated that the scaphoid compression test, anatomical snuffbox tenderness and scaphoid tubercle tenderness demonstrated statistically significant ability to identify scaphoid fractures with PPLR of 2.37 (1.27-4.41), 1.52 (1.12-2.06) and 1.67 (1.33-2.09) respectively. Descriptive factors (gender and mechanism of injury) were also identified but did not demonstrate significant diagnostic ability. Pooled data revealed the existence of heterogeneity for the three clinical tests and descriptive factors, which could not be easily explained.

CONCLUSION

Three clinical tests with statistically significant diagnostic validity were identified. In isolation, the clinical significance of each is questionable. Further studies with description of sample characteristics, blinded assessments, and agreement on a reference standard are recommended.

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.

Predictors of fracture following suspected injury to the scaphoid

A prospective study was performed to develop a clinical prediction rule that incorporated demographic and clinical factors predictive of a fracture of the scaphoid. Of 260 consecutive patients with a clinically suspected or radiologically confirmed scaphoid fracture, 223 returned for evaluation two weeks after injury and formed the basis of our analysis. Patients were evaluated within 72 hours of injury and at approximately two and six weeks after injury using clinical assessment and standard radiographs. Demographic data and the results of seven specific tests in the clinical examination were recorded. There were 116 (52%) men and their mean age was 33 years (13 to 95; SD 17.9). In 62 patients (28%) a scaphoid fracture was confirmed. A logistic regression model identified male gender (p = 0.002), sports injury (p = 0.004), anatomical snuff box pain on ulnar deviation of the wrist within 72 hours of injury (p < 0.001), and scaphoid tubercle tenderness at two weeks (p < 0.001) as independent predictors of fracture. All patients with no pain at the anatomical snuff box on ulnar deviation of the wrist within 72 hours of injury did not have a fracture (n = 72, 32%). With four independently significant factors positive, the risk of fracture was 91%. Our study has demonstrated that clinical prediction rules have a considerable influence on the probability of a suspected scaphoid fracture. This will help improve the use of supplementary investigations where the diagnosis remains in doubt.

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.