The economic evidence for advanced imaging in the diagnosis of suspected scaphoid fractures: systematic review of evidence

The patient with an acute painful wrist

Patients with wrist pain commonly present to primary care and emergency departments. A detailed history and examination, alongside relevant imaging, will help find the correct diagnosis and ensure that patients receive the correct treatment in a timely manner. This article summarises the key points in history and examination and the role of imaging, including suggestions of which modality should be requested. Finally, important acute pathologies are highlighted, including fractures, soft tissue injuries and infection, with examples of their relevant imaging.

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.

Is Advanced Imaging a Must in the Assessment of Progressive Collapsing Foot Deformity?

Advanced imaging modalities have, in very recent years, enabled a considerable leap in understanding progressive collapsing foot deformity, evolving from a simple confirmation of clinical diagnostic using basic measurements to minute understanding of soft tissue and bone involvements. MRI and weight-bearing cone-beam computed tomography are enabling the development of new 3-dimensional measurement modalities. The identification of key articular and joint markers of advanced collapse will allow surgeons to better indicate treatments and assess chances of success with conservative therapies and less invasive surgical procedures, with the hope of improving patient outcomes.

Cost-Effectiveness of Immediate Magnetic Resonance Imaging In the Management of Patients With Suspected Scaphoid Fracture: Results From a Randomized Clinical Trial

OBJECTIVES

Given the limited diagnostic accuracy of radiographs on presentation to the emergency department (ED), the management of suspected scaphoid fractures remains clinically challenging and poses an unknown economic burden to healthcare systems. We aimed to evaluate the cost-effectiveness of immediate magnetic resonance imaging (MRI) in the management of patients presenting with suspected scaphoid fracture to an ED in England.

METHODS

A pragmatic, randomized, single-center trial compared the use of immediate MRI in the ED against standard care with radiographs only. Participants' use of healthcare services and costs were estimated from primary care and secondary care databases and questionnaires at baseline, 1, 3, and 6 months postrecruitment. Costs were compared using generalized linear models and combined with quality-adjusted life years (QALYs, based on the EQ-5D-5L) to estimate cost-effectiveness at 6 months postrecruitment. Cost-effectiveness acceptability curves and bootstrapping techniques were used to estimate the probability of cost-effectiveness at different willingness-to-pay (WTP) thresholds. Four deterministic sensitivity scenarios were considered around key parameters.

RESULTS

The MRI intervention dominated standard care in the base case and all 4 deterministic sensitivity scenarios, costing less and achieving more QALY gains, with a probability of 100% of being cost-effective at 6 months using the conventional United Kingdom WTP thresholds of £20 000 to £30 000 per QALY.

CONCLUSION

The use of immediate MRI is a cost-effective intervention in the management of suspected scaphoid fractures in a Central Hospital in London. Routine clinical practice at our institution has been changed to include the intervention.

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.

Scaphoid fractures: has magnetic resonance imaging become a cost-effective alternative to definitive diagnosis?

BACKGROUND

A clinical examination finding of anatomical snuffbox tenderness (AST) with plain film radiographs alone yields low sensitivity and specificity in diagnosing scaphoid fractures. International guidelines suggest immediate referral for magnetic resonance imaging (MRI) following one non-diagnostic radiograph in such patients. Perceived cost, high demand and limited capacity of MRI scanners have resulted in few suspected fractures following this pathway in our institution.

AIMS

Our study aimed to audit cost-effectiveness of immediate MRI referral following one non-diagnostic radiograph in the patient with AST versus current local practice.

METHODS

Retrospective analysis of all patients with suspected scaphoid fractures referred from the ED to the orthopaedic service over a six-month period was performed. Mean pricing per radiograph, casting, MRI and fracture clinic presentation was obtained from our hospital's Finance department.

RESULTS

Ninety-seven patients were identified; 26 had scaphoid fractures (26.8%). Seventy-one patients with no fractures cost a mean €82,111.50 (IQR: €55,025, €98,335) having a mean of 3.1 clinic visits, 4.6 radiographs and 4.7 weeks casted, versus €40,115 for early MRI referral as per guidelines (p > 0.05).

CONCLUSIONS

In conclusion, when compared with current local practice, immediate referral of the patient with AST for MRI following one non-diagnostic ED radiograph is potentially cost-effective in establishing efficient diagnosis of scaphoid fractures. We recommend the implementation of published international guidelines in the investigation of query scaphoid fractures as a pragmatic and cost-effective practice.

Imaging for Acute and Chronic Scaphoid Fractures

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

Clinical and cost implications of using immediate MRI in the management of patients with a suspected scaphoid fracture and negative radiographs results from the SMaRT trial

AIMS

The aim of the Scaphoid Magnetic Resonance Imaging in Trauma (SMaRT) trial was to evaluate the clinical and cost implications of using immediate MRI in the acute management of patients with a suspected fracture of the scaphoid with negative radiographs.

PATIENTS AND METHODS

Patients who presented to the emergency department (ED) with a suspected fracture of the scaphoid and negative radiographs were randomized to a control group, who did not undergo further imaging in the ED, or an intervention group, who had an MRI of the wrist as an additional test during the initial ED attendance. Most participants were male (52% control, 61% intervention), with a mean age of 36.2 years (18 to 73) in the control group and 38.2 years (20 to 71) in the intervention group. The primary outcome was total cost impact at three months post-recruitment. Secondary outcomes included total costs at six months, the assessment of clinical findings, diagnostic accuracy, and the participants' self-reported level of satisfaction. Differences in cost were estimated using generalized linear models with gamma errors.

RESULTS

The mean cost up to three months post-recruitment per participant was £542.40 (sd £855.20, n = 65) for the control group and £368.40 (sd £338.60, n = 67) for the intervention group, leading to an estimated cost difference of £174 (95% confidence interval (CI) -£30 to £378; p = 0.094). The cost difference per participant increased to £266 (95% CI £3.30 to £528; p = 0.047) at six months. Overall, 6.2% of participants (4/65, control group) and 10.4% of participants (7/67, intervention group) had sustained a fracture of the scaphoid (p = 0.37). In addition, 7.7% of participants (5/65, control group) and 22.4% of participants (15/67, intervention group) had other fractures diagnosed (p = 0.019). The use of MRI was associated with higher diagnostic accuracy both in the diagnosis of a fracture of the scaphoid (100.0% vs 93.8%) and of any other fracture (98.5% vs 84.6%).

CONCLUSION

The use of immediate MRI in the management of participants with a suspected fracture of the scaphoid and negative radiographs led to cost savings while improving the pathway's diagnostic accuracy and patient satisfaction. Cite this article: Bone Joint J 2019;101-B:984-994.

Single-shot CT after wrist trauma: impact on detection accuracy and treatment of fractures

OBJECTIVE

To evaluate accuracy of fracture detection and therapeutic impact of a single-shot CT protocol as a primary imaging tool in all patients with clinical suspicion of wrist injury, and evaluate the resulting impact on therapy.

MATERIALS AND METHODS

We performed a single-institution study on all patients with suspicion of fractures of the wrist and carpus. All patients underwent conventional radiography, thereafter single-shot wrist CT, and then 1-year follow-up. Physicians and radiologists prospectively scored likelihood of fracture presence on a five-point scale before and after CT. Three surgeons proposed a treatment regimen (functional, cast, reduction, or operative) based on clinical and radiological data, first with knowledge of conventional radiography, and then with knowledge of CT. The reference standard for fracture presence was based on all data. We performed receiver operating characteristic (ROC) analyses and calculated proportion of wrists with treatment changes due to CT imaging.

RESULTS

Ninety-eight patients participated (63% female, mean age 53, range, 18-87 years old) with 100 wrist CTs. Conventional radiography detected true-positive fractures in 45, and CT in 61 wrists. The areas under the curve for fracture detection were 0.85 (95% CI 0.77-0.93) for conventional radiography and 0.97 (95% CI 0.93-1.00) for CT. Treatment changed in 24 (24%, 95% CI 16-33%) - 31 (31%, 95% CI 23-41%) wrists, mostly involving a decrease in the rate of cast immobilization.

CONCLUSIONS

Single-shot CT in patients with clinical suspicion of wrist injury increases accuracy of fracture detection. This has a significant impact therapy in this population, mainly on cast immobilization.

TRIAL REGISTRATION

We registered the study at www.clinicaltrials.gov , NL43482.091.13.