Role of MRI in the diagnosis and management of patients with clinical scaphoid fracture

Diagnosis of occult scaphoid fractures: an exploratory study to assess whether clusters of clinical features are diagnostic in comparison to reduced sequence magnetic resonance imaging

BACKGROUND

Occult scaphoid fractures are difficult to diagnose radiographically. Evidence regarding prevalence and diagnostic accuracy of clinical tests is growing; however, gaps in knowledge remain and further research is needed.

PURPOSE

This study aimed to determine the prevalence of occult scaphoid fractures and other hand/wrist fractures, plus any clinical/demographic findings diagnostic of scaphoid fractures.

METHODS

Prognostic prospective cohort study. Patients referred with diagnosis of occult scaphoid fractures, non-diagnostic radiographs, and one or more positive provocative test for scaphoid fractures were included. Clinical data were compared to reduce sequence magnetic resonance imaging. Univariate logistic regression was used to determine significance. Multivariable logistic regression was used to determine the effect size of these variables.

RESULTS

Of 197 included participants, 43(22%) had a scaphoid fracture and 59(30%) had an occult fracture other than scaphoid. Average age of patients with confirmed occult scaphoid fractures was 22 years old. Distal pole fractures were the most common scaphoid fracture (n = 28/65.1%, average age 16.9 years). Three clinical tests (pain with ulnar-deviation, anatomical snuffbox swelling and pain-free grip) plus two demographics (age <23 and male) resulted in accuracy of 81.7%, positive predictive value of 73.3%, and negative predictive value of 82.4% in diagnosing scaphoid fractures.

CONCLUSION

This study confirms a high prevalence of occult fractures in our population. Patients demonstrating the relevant demographics and positive clinical tests may be appropriate to treat as scaphoid fractures without advanced imaging. Most patients will present with differing clinical findings and/or demographics, and routine use of magnetic resonance imaging is recommended.

Review article: the differential diagnosis of bone marrow edema on wrist MRI

There is a large variety of conditions that can result in 'bone marrow edema' or 'bone marrow lesions' (BML) in the wrist on magnetic resonance imaging (MRI). The combination of clinical history and the distribution of the BML can serve as a valuable clue to a specific diagnosis. This article illustrates the different patterns of BML in the wrist to serve as a useful guide when reviewing wrist MRI studies. Imaging artefacts will also be briefly covered.

Why scaphoid fractures are missed. A review of 52 medical negligence cases

BACKGROUND

The "missed" scaphoid fracture is a common cause of litigation. This study investigates why a series of scaphoid fractures involved in medical negligence litigation were missed. It also assesses how many might have been detected if MRI had been used to assess all suspected scaphoid fractures with normal X-rays, as suggested by National Institute for Health and Care Excellence (NICE).

METHODS

Medical reports on 52 medical negligence cases of missed scaphoid fractures were reviewed. Complete sets of hospital and GP records and X-rays had been reviewed in every case.

RESULTS

The recorded mechanism of injury was consistent with a scaphoid fracture in 41 (79%) cases. There was no record of an examination for scaphoid tenderness in 37 (71%) cases. Scaphoid tenderness was assessed and not found in 10 of 15 cases. No X-rays were obtained in 13 (25%) cases, and a scaphoid fracture was only suspected, resulting in scaphoid series X-rays being performed, in only 3 (6%) cases. In only 5 (10%) cases was there a record of the patient being advised to return if the wrist remained painful.

CONCLUSIONS

Most of these scaphoid fractures were missed due to failure to consider the possibility of a scaphoid fracture and search for clinical signs of this injury. Some were missed due to failure to detect (or absence of) tenderness over the scaphoid bone. As a scaphoid fracture was never considered, or excluded by clinical examination, in 49 of the 52 cases, a policy of obtaining MRI for all suspected scaphoid fractures would only have detected three of 52 (6%) fractures. Improved awareness through better education is required to reduce the number of missed scaphoid fractures.

The utility of cross-sectional imaging in the management of suspected scaphoid fractures

INTRODUCTION

Scaphoid fractures are the commonest carpal bone fracture. If untreated they pose significant risk to patients, thus if a scaphoid fracture is suspected, patients are managed with immobilisation. Although scaphoid fractures may be difficult to diagnose on plain radiography, sometimes for months after injury, ongoing radiographic surveillance is preferred due to its low upfront cost. Patients in immobilising casts for long periods experience significant personal and social ramifications such as difficulty working and self-caring. This study examines whether cross-sectional imaging by computed tomography (CT) or magnetic resonance imaging (MRI) is quicker than serial X-ray surveillance at allowing a scaphoid fracture to be either excluded or confirmed.

METHODS

A retrospective record review was performed of the 1709 patients who presented to Royal North Shore Hospital in 2015 with wrist injuries, finding 104 patients clinically suspicious for a fractured scaphoid.

RESULTS

All patients were examined by X-ray during their initial hospital presentation, providing 33.7% of final diagnoses in 0.6 ± 1.7 days. However, if initial X-ray proved inconclusive, subsequent serial X-ray surveillance made a final diagnosis after a mean of 24.1 ± 17.2 days, with some being immobilised for up to 67 days before diagnosis. Cross-sectional imaging significantly reduced diagnosis time to 9.8 ± 5.8 days (P = 0.0016), with a maximum immobilisation time of 24 days.

CONCLUSION

Cross-sectional imaging allows for faster scaphoid fracture diagnosis than X-ray. We propose a protocol for scaphoid fracture diagnosis wherein patients undergo two episodes of X-ray separated by 7 days, followed by a single MRI if clinical suspicion remains, minimising unnecessary immobilisation.

Early scaphoid fractures are better diagnosed with ultrasonography than X-rays: A prospective study over 114 patients

PURPOSE

Wrist has a complex anatomy and undergoes complex injuries. Scaphoid fracture is one of such injuries. It is the most common fracture in carpal bone. Most of the scaphoid fractures are missed on initial X-rays. Magnetic resonance imaging (MRI) is considered as a gold standard for diagnosing scaphoid fractures. Ultrasonography (USG) is emerging as a good alternative to make an early diagnosis of scaphoid fractures. Our aim is to throw light upon the role of USG in detection of scaphoid fractures.

METHODS

The study was centered upon 114 patients in the age range 10-65 years, with traumatic wrist injury and were clinically suspected to have scaphoid fractures. Patient with non-traumatic history, bilateral wrist injury and late presentation were excluded. X-rays, USG using high frequency probe and MRI were done for all patients. MRI was considered to be the gold standard test. Patients were followed up at 6 weeks.

RESULTS

Of the 114 patients, X-ray could diagnose scaphoid fractures in 48 patients, 30 of which were confirmed by MRI. USG results were positive in 74 patients, of which MRI was positive in 67 patients. The accuracy of scaphoid fracture detection with USG was 98.04% in comparison to X-ray (20.58%), which was statistically significant.

CONCLUSION

USG provides a more accurate and reliable method of making an early diagnosis of scaphoid fracture than X-rays. It is non-invasive, non-expensive and allows better visualisation of cortical disruption.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Diagnostic Utility and Clinical Implications of Wrist MRI in the Pediatric Population

BACKGROUND

Unexplained wrist pain is a common presentation in children. To our knowledge, no studies have explored the clinical utility of magnetic resonance imaging (MRI) in the diagnostic workup of pediatric patients.

METHODS

We retrospectively reviewed 307 consecutive wrist MRIs ordered at a tertiary-care pediatric hospital. Demographic data and the indication for imaging were recorded and grouped into admitting categories. The final impression of each MRI was scored with regard to potential impact on future treatment (0 = normal, 1 = minimal, 2 = moderate, 3 = high). Patients who went on to wrist surgery within 1 year were noted.

RESULTS

In our cohort, 27% of all studies were normal, including 34% of those with pain. Although pain was the most common category, MRI was most useful in the delineation of a mass/cyst, evaluating for infection and evaluating arthropathy. Compared with all other categories, patients with pain were 3.6 times more likely to have a normal study and 4.6 times more likely to have a clinical score less than or equal to 1. Given an admitting diagnosis of pain, females were 1.7 times more likely to present for an MRI and 2.4 times more likely to have a normal MRI. The Spearman correlation revealed no linear relationship between age and MRI outcome. In all, 13% of patients went on to have surgery within 1 year of MRI.

CONCLUSIONS

At our pediatric institution, the majority of wrist MRIs were ordered for wrist pain. Given our data, wrist MRI is not an ideal screening tool in children, particularly in those with wrist pain, and should only be used to exclude or confirm a specific diagnosis.

Early MRI versus conventional management in the detection of occult scaphoid fractures: what does it really cost? A rural pilot study

INTRODUCTION

To compare the cost-effectiveness and patient impact between acute magnetic resonance imaging (MRI) management and conventional management in the diagnosis of occult scaphoid fractures in a rural setting.

METHODS

Consecutive patients presenting to a rural emergency department (ED) with a suspected scaphoid fracture were randomly assigned to either conventional management (6) or acute MRI management (10) (3 patients were excluded from the study analysis). All healthcare costs were compared between the two management groups and potential impacts on the patients' pain, mobility and lifestyle were also measured.

RESULTS

There were no significant differences between the two groups at baseline. There was one (10%) scaphoid fracture in the MRI group and none in the conventional group (P = 0.42). A larger proportion of other fractures were diagnosed in the MRI group (20% (2) vs. 16.7% (1), P = 0.87), as well as less clinic attendances (1 (0-2.25) vs. 4 (2.25-5)) and diagnostic services (1 (1-1.25) vs. 2 (1-3)). Median management costs were $485.05 (AUD) (MRI) and $486.90 (AUD) (conventional). The MRI group had better pain and satisfaction scores as well as less time of immobilisation, treatment and time off work.

CONCLUSION

MRI dramatically reduces the amount of unnecessary immobilisation, time of treatment and healthcare usage in a rural setting. The two protocols are suggested to be equivalent financially. When potential societal costs, the amount of unnecessary immobilisation, low prevalence of true fractures and patient satisfaction are considered, acute MRI should be the management technique of choice. Further studies are still required to assess the best method for managing bone bruise within the scaphoid.

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.

Diagnosis of Occult Scaphoid Fractures: A Cost-Effectiveness Analysis

BACKGROUND

Scaphoid fractures are common but may be missed on initial radiographs. Advanced imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) have improved diagnostic accuracy, but at an increased initial cost. The purpose of this study was to evaluate the cost-effectiveness of immediate advanced imaging for suspected occult scaphoid fractures.

METHODS

A decision analysis model was created to evaluate three diagnostic strategies for patients with concerning history and examination but negative radiographs: (1) empiric cast immobilization with orthopaedic follow-up and repeat radiography at two weeks post-injury, (2) immediate CT scanning, or (3) immediate MRI. Prevalence of occult scaphoid fracture, sensitivity and specificity of CT and MRI, and risks and outcomes of a missed fracture were derived from published clinical trials. Costs of imaging, lost worker productivity, and surgical costs of nonunion surgery were estimated on the basis of the literature.

RESULTS

Advanced imaging was dominant over empiric cast immobilization; advanced imaging had lower costs and its health outcomes were projected to be better than those of empiric cast immobilization. MRI was slightly more cost-effective than CT on the basis of the mean published diagnostic performance, but was highly sensitive to test performance characteristics. Advanced imaging would have to increase in cost to more than $2000 or decrease in sensitivity to <25% for CT or <32% for MRI for empiric cast immobilization to be cost-effective.

CONCLUSIONS

Given its relatively low cost and high diagnostic accuracy, advanced imaging for suspected scaphoid fractures in the setting of negative radiographs represents a cost-effective strategy for reducing both costs and morbidity. The decision to use CT compared with MRI is a function of individual institutional costs and local test performance characteristics.

Wrist and scaphoid fractures: a 17-year review of NHSLA litigation data

Wrist and scaphoid fractures are common injuries seen and treated in everyday orthopaedic practice. The purpose of the study was to assess the trends and reasons for litigation related to wrist and scaphoid fractures within the NHS. Under a freedom of information (FOI) request, data from 1995 to 2012 were provided by the National Health Service Litigation Authority (NHSLA) on all litigation claims made as a result of wrist and scaphoid fractures. A total of 1354 claims relating to the hand and wrist were identified. Wrist and scaphoid fractures accounted for 492 (36.3%) of these claims, and 365 of these claims were settled, representing 74.2% of all wrist and scaphoid fracture claims. Overall, the most common reason for lost claims was due to incorrect, missed or delayed diagnosis (43.5%). Alleged mismanagement (29.5%), poor care (10.1%) and incompetent surgery (8.0%) were other common causes for litigation. This paper augments previous work published in this area and explores litigation trends specific to wrist and scaphoid fractures. We discuss the trends and reasons for litigation in this area, suggesting areas for improvement that may aid health-care professionals who deal with these injuries and potentially help reduce future litigation.

Sonographic swelling of pronator quadratus muscle in patients with occult bone injury

Background

The disarranged fat stripe of the pronator quadratus muscle (PQ) on radiographs (the PQ sign) is reported to be predictive of subtle bone fractures. This study aimed to report the results of magnetic resonance imaging (MRI) study in the patients in whom bone injury was not radiographically detected around the wrist joint, and the PQ was sonographically swollen following acute trauma.

Methods

We evaluated sonographically the PQ of 55 patients who showed normal radiographs following acute trauma. The sonographic appearance of the PQ was checked on both longitudinal and transverse images. On the longitudinal image, the probe was positioned along the flexor carpi radialis tendon. For the transverse image, we adopted the image of the same level in which the PQ of the unaffected hand showed maximal thickness. The PQ was considered to be swollen with disproportionate hyperechogenicity and/or thickening compared with the unaffected side at least in one of the two images. Of the 55 patients, 25 patients whose PQ was considered to be swollen underwent MRI study. PQ thickness in millimeters was retrospectively measured on longitudinal and transverse sonographic images.

Results

Twenty-three patients (92.0%) had occult bone injury, and two adult patients (8.0%) showed only wrist joint effusion on MRI. Among these 23, the distal radius was the most frequent location of the occult bone injury (20 patients; 9 [36.0%] with an occult fracture line and 11 [44.0%] with bone bruising). In longitudinal image, the mean value of the PQ thickness of affected hands was 6.2 (3.7–9.6 mm; standard deviation [SD], 1.5) and that of unaffected hands was 4.5 (2.3–6.7 mm; SD, 1.2), respectively. In transverse image, that of dominant and nondominant hands was 7.6 (4.6–13.2 mm; SD, 2.0) and 5.5 (3.6–7.5 mm; SD, 1.1), respectively. The mean difference in PQ thickness between affected and unaffected hands was 1.7 (0.1–5.0 mm; SD, 1.1) in longitudinal image and 2.0 (0.3–6.8 mm; SD, 1.7) in transverse image.

Conclusions

Sonographic swelling of the PQ might be indicative of occult bone injury in patients with normal radiographs following acute trauma.

Adult post-mortem imaging in traumatic and cardiorespiratory death and its relation to clinical radiological imaging

The use of post-mortem imaging is expanding throughout the world with increasing use of advanced imaging techniques, such as contrast-enhanced CT and MRI. The questions asked of post-mortem imaging are complex and can be very different, for example for natural sudden death investigation will focus on the cause, whereas for trauma the cause of death is often clear, but injury patterns may be very revealing in investigating the background to the incident. Post-mortem imaging is different to clinical imaging regarding both the appearance of pathology and the information required, but there is much to learn from many years of clinical research in the use of these techniques. Furthermore, it is possible that post-mortem imaging research could be used not only for investigating the cause of death but also as a model to conduct clinically relevant research. This article reviews challenges to the development of post-mortem imaging for trauma, identification and cardiorespiratory death, and how they may be influenced by current clinical thinking and practice.

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

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

The role of magnetic resonance imaging in scaphoid fractures

Fractures of the scaphoid are the most common surgically treated carpal fracture, and early diagnosis is critical to minimize complications including osteonecrosis. If the initial radiographs after the injury are inconclusive, early magnetic resonance imaging (MRI) provides an immediate diagnosis to allow for proper management. This has been shown to be cost effective both in direct measureable costs and likely in difficult-to-measure indirect costs related to lost productivity. In the cases in which no scaphoid fracture is present, MRI provides alternate diagnoses such as identification of other fractures (eg, other carpals and distal radius), osseous contusions, and soft tissue injuries (preferably ≥ 1.5T). When MRI is contraindicated, computed tomography (CT) is a reasonable alternative after the initial and repeat negative radiographs. MRI is the best imaging modality for assessing osteonecrosis of the proximal pole in a scaphoid nonunion. Unfortunately, the most useful imaging sequences remain controversial. My institution relies on the noncontrast T1-weighted images for the primary diagnosis of osteonecrosis with dynamic contrast enhancement used in a supplemental fashion.