Accuracy of the sonographic fat pad sign for primary screening of pediatric elbow fractures: a preliminary study

The diagnostic value of sonographic findings in pediatric elbow fractures: A systematic review and meta-analysis

BACKGROUND

Sonography is a beneficial imaging modality for detecting elbow fractures in children, considering the lack of radiation exposure and time efficiency. This systematic review aims to determine the diagnostic value and clinical applicability of sonography and each sonographic finding in detecting pediatric elbow fractures.

METHODS

Pubmed, Scopus, and WOS databases were searched for related original articles until February 25, 2023, and data related to diagnostic performance were extracted. We used the Bivariate model and hierarchic summary receiver operating characteristic (HSROC) approach to calculate pooled diagnostic values. Cochrane Q test and I-squared were performed to evaluate heterogeneity. We assessed heterogeneity with meta-regression.

RESULTS

Eight studies were included, which involved a total number of 880 patients. According to meta-analysis, sonography demonstrated a pooled sensitivity of 97% (91-99%) and specificity of 90% (80-95%), positive likelihood ratio(LR+) of 9.82 (4.59-20.97), and negative likelihood ratio (LR-) of 0.03 (0.01-0.10). For the sonographic posterior fat pad sign as a sole diagnostic sign, we calculated a Pooled Sensitivity of 80% (70-88%), Specificity of 97% (87-99%), LR+ of 28.8 (6-139.3), and LR- of 0.2 (0.13-0.31). Also, lipohemarthrosis demonstrated a pooled sensitivity of 80% (70-88%), specificity of 97% (87-99%), LR+ of 28.8 (6-139.3), and LR- of 0.2 (0.13-0.31). The sensitivity of detecting fractures with cortical line disruption was significantly higher in studies that utilized a comprehensive technique compared to a conventional technique.

CONCLUSIONS

Sonography is a valuable diagnostic tool for the assessment of pediatric elbow injuries, and it can be capable of confirmation or exclusion of the diagnosis.

Sonographic Fracture Diagnosis in Children and Adolescents

BACKGROUND

Clinical examination after trauma, especially in young children, often proves difficult. As a result, the majority of images show unremarkable findings in the imaging workup of trauma by radiography. Sonography represents an imaging technique without the use of X-rays. As the quality of ultrasound equipment has increased over the past 20 years, numerous studies have demonstrated that fractures in children and adolescents can be detected with very high sensitivity and specificity by sonography.

METHOD

This paper reviews the results obtained so far in the literature. Based on these findings, the importance of sonographic fracture diagnosis in childhood and adolescence for the most important locations is demonstrated.

RESULTS

When examining with a high-frequency linear transducer, sensitivities and specificities of more than 90 % can be achieved for the detection of fractures. Dislocations are also reliably detected. In contrast to X-ray examination, sonography allows the diagnosis of cartilage and soft-tissue injuries. Sonography reveals callus formation earlier than radiographs. The examination causes less pain than X-ray examination. If sonographic clarification is limited purely to fracture detection or exclusion, less time is required compared to X-ray diagnosis. The procedure can be learned quickly. If the documentation follows a defined standard examination procedure, the results can also be reproduced by non-examiners.

CONCLUSION

So far, sonography has only been an additive procedure in fracture diagnosis. However, there are now initial recommendations for sonographic fracture diagnosis alone, such as in skull, clavicle and non-displaced distal forearm fractures.

KEY POINTS

· Sonography can be used to detect or rule out fractures very sensitively.. · Sonographic examination causes less pain than X-ray examination.. · Sonography is usually an additive procedure in fracture diagnosis.. · In the meantime, sonography alone may be sufficient for diagnosing individual fractures..

ZITIERWEISE

· Moritz JD. Sonografische Frakturdiagnostik im Kindes- und Jugendalter. Fortschr Röntgenstr 2023; 195: 790 - 796.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Could Ultrasound Be Used as a Triage Tool in Diagnosing Fractures in Children? A Literature Review

Fracture is one of the most frequent causes of emergency department visits in children, conventional radiography being the standard imaging tool used for following procedures and treatment. This imagistic method is irradiating and harmful, especially for children due to their high cell division rate. For this reason, we searched the literature to see if musculoskeletal ultrasound is a good alternative for diagnostic and follow-up regarding fractures in the pediatric population. After searching the databases using MeSH terms and manual filters, 24 articles that compare X-ray and ultrasound regarding their specificity and sensitivity in diagnosing fractures were included in this study. In the majority of the studied articles, the specificity and sensitivity of ultrasound are around 90–100%, and with high PPVs (positive predictive values) and NPVs (negative predictive values). Although it cannot replace conventional radiography, it is a great complementary tool in fracture diagnosis, having a sensitivity of nearly 100% when combined with clinical suspicion of fracture, compared with X-ray.

[Fracture sonography of the extremities]

In this article the basic principles of fracture sonography and meaningful areas of application in children and adults are explained. The sonographic fracture signs are presented and the typical areas of application, i.e. clavicular fracture, acromioclavicular (AC) joint dislocation, proximal humerus fracture, elbow fracture, wrist fracture, metacarpal 5 fracture, palmar plate, femoral bulge fracture, proximal tibia fracture, midfoot V fracture, toddler's fracture and march fracture, are outlined and known diagnostic algorithms are listed. When used correctly, fracture sonography is a safe, gentle and rapid diagnostic method.

Diagnostic accuracy of ultrasonography for diagnosis of elbow fractures in children

BACKGROUND

Elbow injuries and fractures are a common pathology in the pediatric emergency unit. X-ray and CT scan of the elbow are the standard diagnostic procedures, which increase exposure to radiation in children. Previous studies have shown that fractures can also be visualized by ultrasound (US); thus, this study aimed to evaluate the diagnostic accuracy of elbow US compared with radiography for the diagnosis of elbow fracture in children.

MATERIALS AND METHODS

This was a prospective observational study of patients aged 2-14 years that presented to emergency departments with a suspected elbow fracture requiring radiographic evaluation. Elbow US for diagnosing elevated posterior fat pad or lipohemarthrosis was performed. All patients underwent elbow radiography and received clinical follow-up. Initial or follow-up X-ray or CT scan was used as the reference standard for fracture diagnosis.

RESULTS

Seventy-five patients with a mean age of 6.51 ± 3.68 years were enrolled in the study. Twenty-eight (37.3%) patients had positive results for fracture. The sensitivity, specificity, and accuracy of US in the diagnosis of elbow fractures were 92.9% (95% CI 76.5-99.1%), 89.4% (95% CI 76.9-96.5%) and 90.7% (95% CI 81.7-96.2%). In patients with fracture, US demonstrated a lipohaemarthrosis in 20 patients (71.4%), elevated posterior fat pad in 19 patients (67.9%), cortical disruption in 10 patients (35.7%), and effusion in three patients (10.7%).

CONCLUSION

Our results showed high diagnostic accuracy for the ultrasonography diagnosis of an elbow fracture, which allows us to confirm ultrasonography imaging of the elbow as a safe alternative in the primary evaluation of pediatric elbow injuries.

Standardized sonographic examination of pediatric elbow injuries is an effective screening method and improves diagnostic efficiency

INTRODUCTION

Positive role of ultrasound in the diagnosis of pediatric elbow injuries were confirmed by many papers but no comprehensive, standardized method has been developed for daily clinical practice. The aim of our prospective diagnostic study was to prove the efficacy of a five point sonographic point of care method for detecting different pediatric elbow fractures or dislocations.

METHODS

Between 2016 January and 2017 March 365 children (age 1-14) with suspected closed elbow injury were enrolled in our study. Sonographic point of care examination was carried out by a properly trained resident and two orthopedic surgeons immediately after physical survey. We used a standardized five point sonographic examination. Two plane x-rays were made following sonography according to protocol. Utility of sonographic pictures were analyzed by a radiologist. Cases with images which have not met with standard requirements were excluded. In those cases when primary x-rays were negative and/or any of the ultrasound planes showed positive findings, radiography was repeated after 4 weeks of injury. If we detected callus formation the fracture was considered occult. Cases with images which have not met with standard requirements were excluded. Ultrasonic pictures, evaluation sheets and x-ray results were compared.

RESULTS

Out of the 365 cases we identified 165 with positive findings (45, 2%) by primary x-rays. Distribution of the different injuries were the following: Radial condylar fractures, (n = 29) supracondylar humeral fractures (n = 84 proximal radial fractures, (n = 19) proximal ulnar fractures, (n = 7) fractures with joint dislocations (n = 3) joint dislocations without fractures, n = 2 medial epicondyle fractures (n = 14) fracture combinations (n = 7) We did not find injuries in this series that we could not categorize into these groups. Evaluating the abnormal sonographic dorsal fat pad sign (FPS) as a sole parameter for fracture detection we found sensitivity: 0, 97, specificity: 0,97, positive predictive value: 0,97, negative predictive value: 0,97 Evaluating the effectivity of the four cortical planes we calculated sensitivity 0, 85 specificity 0.96 positive predictive value: 0. 95 negative predictive value 0.87. The overall values of the five planes were the following: specificity0.97 sensitivity 1, positive predictive value 0.97 negative predictive value: 1 Interrater agreements on the cortical plane abnormality were considered good at two examiners and very good at one examiner. (Kappa = 0.79, 0, 81, 0, 79) Agreements on differentiation of elevated, normal fat pad) or lipohaemarthrosis in sonographic pictures were very good in all cases. (Kappa = 0,83, 0,86,0,82) While identification of any displacement or dislocation was possible in 96%, of all cases(n = 59)the exact determination of the type of the injury was possible in only 70,3% (n = 116) CONCLUSIONS: Using the five point ultrasonic examination provides enough information for excluding or confirming the presence of any pediatric elbow fractures or dislocations. The method is quick, simple and can help in the immediate differentiation of the severity of injuries. Sonographic lipohaemarthrosis seems to be more sensitive than elevated fat pad sign for the detection of potential occult fractures. Positive cases should be cleared by x-rays because the exact nature of the fractures are not identifiable only by ultrasound.

Two- plane point of care ultrasonography helps in the differential diagnosis of pulled elbow

INTRODUCTION

Pulled elbow (PE) is one of the most common injury in children under the age of five years. Diagnosis of PE is usually based on the typical anamnesis and clinical symptoms. A simple reduction maneuver without the need of any imaging modality can eliminate the problem. Certain fractures however can mimic the physical findings of PE and in this cases reduction should not be attempted. The aim of our prospective diagnostic study was to evaluate the accuracy of a sonographic testing method in the differential diagnosis of PE.

METHODS

205 children aged 0-5 with clinical suspicion for PE were enrolled in our study. Inclusion criteria were the typical clinical sign of PE: painful, motionless, extended or slightly flexed and pronated arm following a traumatic event under the age of five. We excluded older children and patients with pronounced elbow swelling and initially flexed and supinated upper arm position. A two plane point of care sonographic examination was carried out at each patient immediately after history taking and primary physical survey. Presence of the elevated dorsal sonographic fat pad sign(FPS) and the synovial fringe enlargement (SFE) were examined from dorsal and ventral longitudinal planes. Children with FPS positivity and/or unsuccessful reduction were x-rayed. Suspected occult fractures with persistent complains were also x-rayed on the 3rd week. Sonographic pictures and x-rays were analyzed and compared to clinical findings.

RESULTS

The diagnosis of PE was confirmed in 196 cases. (95.6%). 9 children had type I. supracondylar humerus fractures. (4.39%) Out of these 2 proved to be occult fractures.(0.97%). SFE positivity was detected only in the PE group (156 cases, 76%) fractures have not shown this sign. Elevated FPS was negative in all but one PE cases, while all fractures showed FPS positivity without exception. Evaluating the two parameters together both sensitivity, specificity, negative and positive predictive value were 100%.

CONCLUSIONS

The two plane sonographic point of care method is an effective tool for confirming the diagnosis of PE and excluding the presence of fractures. It is an easy, standard and objective procedure which can be used as a fast diagnostic test before reduction attempts.

A Practical Method for Obtaining True Lateral Elbow X-rays in a Paediatric Age Group: Lateral Elbow X-ray in the Standing Salute Position

INTRODUCTION

Paediatric elbow fractures constitute 10% of all paediatric fractures. Radiological interpretation of the immature elbow is difficult due to its cartilaginous structure. We aimed to describe an X-ray technique in paediatric patients to obtain true lateral elbow X-rays and to prevent the repeat X-ray shots.

MATERIALS AND METHODS

Radiographs of 39 children, with a mean age of 48.17 months (range; 7-84 months), with elbow trauma were included. All elbow lateral radiographs were taken in the 90º flexion position. In the first group, radiographs were taken using the standard technique(lateral radiographs in shoulder internal rotation). In the second group, lateral radiographs of the elbow were taken while the patient was standing and the forearm was elevated passively with 90° shoulder abduction and 90° elbow flexion (standing salute position). Three criteria were examined from the graphs to determine the true lateral elbow graphy.

RESULTS

In group 1 (n = 20) and group 2 (n = 19), lateral elbow radiographs were evaluated. No statistically significant differences were found between the groups, in terms of mean age and distal humeral fractures. In group 2; the presence of humeroulnar joint space, partial coronoid superposition of the radius head and presence of the hourglass formation were significantly higher.

DISCUSSION

It is clear that radiographs taken in appropriate positions decreases diagnostic errors. In our study, the ratio of correct lateral radiographs was significantly higher in the radiograph group in the standing salute position, suggesting this method was safe for accurate lateral radiographs, in accordance with our hypothesis.

Diagnostic accuracy of ultrasound for upper extremity fractures in children: A systematic review and meta-analysis

OBJECTIVE

Ultrasound has an excellent diagnostic accuracy for fractures that is reportedly comparable to plain radiographs. We aim to summarize the diagnostic accuracy of ultrasound for upper extremity fractures in children.

METHODS

Databases were searched from inception through November 2019 using pre-defined index terms, including "ultrasound," "fractures of upper extremities" and "children". The study is reported using Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA). Meta-analysis of the diagnostic accuracy of ultrasound for fractures was conducted using the random-effects bivariate model. Subgroup analysis of fracture site (elbow vs non-elbow fractures) was also performed. Meta-regression was performed to determine if the site of fracture affected the diagnostic accuracy.

RESULTS

Thirty-two studies were identified in the meta-analysis. Ultrasound for fractures of the upper extremities has a sensitivity: 0.95 (95% CI: 0.93-0.97), specificity: 0.95 (95% CI: 0.91-0.98), positive likelihood ratio: 21.1 (95% CI: 10.8-41.5) and negative likelihood ratio: 0.05 (95% CI: 0.03-0.07), with an area under ROC (AUROC) curve of 0.98 (95% CI: 0.97-0.99). Subgroup analysis for elbow fracture showed ultrasound has a sensitivity: 0.95 (95% CI: 0.86-0.98), specificity: 0.87 (95% CI: 0.76-0.94), positive likelihood ratio: 7.3 (95% CI: 3.7-14.4) and negative likelihood ratio: 0.06 (95% CI: 0.02-0.16), with an AUROC of 0.96 (95% CI: 0.94-0.97). Meta-regression suggested the fracture sites would affect diagnostic accuracy of ultrasound (elbow vs non-elbow, p < 0.01).

CONCLUSIONS

Current evidence suggests ultrasound has excellent diagnostic accuracy for non-elbow upper extremity fractures in children, serving as an alternative diagnostic modality to plain radiographs.

Diagnostic Performance of Ultrasonography for Detection of Pediatric Elbow Fracture: A Meta-analysis

STUDY OBJECTIVE

We evaluate the diagnostic performance of ultrasonography for detection of elbow fracture in pediatric patients with trauma.

METHODS

PubMed and EMBASE databases were searched for diagnostic accuracy studies that used ultrasonography for detection of elbow fracture in pediatric patients. Bivariate modeling and hierarchic summary receiver operating characteristic (ROC) modeling were conducted to evaluate diagnostic performance. The pooled proportions of the false-negative rate were assessed with a DerSimonian-Laird random-effects model. We performed meta-regression analyses for heterogeneity exploration.

RESULTS

Ten articles involving a total of 519 patients were included. The summary sensitivity, summary specificity, and area under the hierarchic summary ROC curve were 96% (95% confidence interval 88% to 99%), 89% (95% confidence interval 82% to 94%), and 0.97 (95% confidence interval 0.95 to 0.98), respectively. The pooled proportion of the false-negative rate of ultrasonography was 3.7%. Among the various potential covariates, ultrasonographic performer (pediatric emergency physician versus others) and presence of extra musculoskeletal ultrasonographic training (trained versus not reported) were associated with heterogeneity of the specificity.

CONCLUSION

Elbow ultrasonography demonstrated high performance in the diagnosis of pediatric elbow fracture, particularly in studies of physicians with extra training in musculoskeletal ultrasonography. Ultrasonography may be performed by trained physicians as a first-line diagnostic tool to diagnose pediatric elbow fracture.

The Investigation of Suspected Fracture-a Comparison of Ultrasound With Conventional Imaging

BACKGROUND

Ultrasound imaging can be used to diagnose fractures in patients with acute trauma. Its main advantages over conventional imaging are the absence of radiation exposure and its greater availability.

METHODS

A systematic search in electronic databases (Medline, Embase, Cochrane CENTRAL) was supplemented by a manual search on the Internet and in the reference lists of pertinent publications. The QUADAS-2 instrument was used to assess the quality of the individual studies retrieved. In the metaanalysis, the sensitivity and specificity of the individual studies were pooled.

RESULTS

The available information on the diagnostic accuracy of ultrasound in the detection of fractures compared with that of conventional imaging (x-ray, CT, MRI) in patients with acute non-life-threatening trauma is summarized. The database search yielded 2153 hits, among which there were 48 studies that were suitable for inclusion in this review. The pooled sensitivity and specificity were 0.91 (95% confidence interval [0.90; 0.92]) and 0.94 [0.93; 0.95], although the analyzed studies were markedly heterogeneous (I²: sensitivity 74%, specificity 81%). The sensitivity of ultrasound was higher for the detection of fractures of the humerus, the forearm, the ankle, and the long bones in general, as well as fractures in children, and lower for fractures of the short bones of the hands and feet, and in adults.

CONCLUSION

Strong evidence supports the use of ultrasound imaging for certain indications in the detection of fractures.

Reduction of Radiography with Point-of-Care Elbow Ultrasonography for Elbow Trauma in Children

OBJECTIVES

To determine whether point-of-care elbow ultrasound (US), with history and physical examination, can decrease radiography for patients with elbow trauma. Secondary outcomes included evaluation of pediatric emergency department (PED) length of stay (LOS) and test performance characteristics.

STUDY DESIGN

This was a prospective study of patients up to age 21 years with elbow trauma necessitating radiography. After clinical examination and before radiography, pediatric emergency physicians performed elbow ultrasonography of the posterior fat pad and determined whether radiography was required. All patients underwent elbow radiography and received clinical follow-up. Times for US and radiography were recorded.

RESULTS

A total of 100 patients with a mean age of 7.9 years were enrolled, 42 of whom had a fracture. In 23 patients, the physician determined that radiography could be eliminated. Elbow US combined with clinical suspicion for fracture had a sensitivity of 100% (95% CI, 92%-100%). Elbow US took a median of 3 minutes (IQR, 2-5 minutes), and completion and interpretation of elbow radiography took a median of 60 minutes (IQR, 43-84 minutes). The overall sensitivity of elbow US was 88% (95% CI, 75%-96%).

CONCLUSIONS

Elbow US has a high sensitivity to rule out fracture and is best used in patients with a low clinical suspicion of fracture. The use of conventional radiography and PED LOS may be reduced in patients with a low clinical concern for fracture and normal elbow US.

[Sonographic fracture diagnostics]

BACKGROUND

In clinically suspected fractures taking radiographs is the standard procedure but the indications should be strictly limited. Ultrasound offers a safe and radiation-free alternative for fracture diagnostics.

OBJECTIVES

Sensitivity and specificity of sonographic fracture diagnostics and safety of sonographic algorithms for fracture evaluation.

METHODS

Presentation of useful applications for sonographic fracture evaluation and establishment of sonographic algorithms for safe fracture diagnosis.

RESULTS

In children distal forearm fractures can be diagnosed solely by ultrasound (sensitivity 96 % and specificity 97 %). The sonographic fat pad sign (SOFA) has been proven to be a useful primary screening tool for occult fractures of the pediatric elbow. A positive fat pad sign (SOFA+) is indicative of a fracture and radiographic diagnostics are necessary (sensitivity 97 % and specificity 91 %). Ultrasonography is also useful to exclude subcapital humeral fractures (sensitivity 94 % and specificity 100 %) and for correct estimation of displacement when present.

CONCLUSIONS

Sonographic algorithms for fracture evaluation (SAFE) offer a safe diagnosis and guidance of the therapeutic course of certain pediatric fractures, thereby reducing unnecessary radiation exposure.

[Sonographic fracture diagnosis in children]

X-rays are the standard imaging procedure for the diagnosis of pediatric long bone fractures. Recent studies show that ultrasound (US) imaging is also qualified to diagnose pediatric long bones fractures. Thus, the diagnosis and decision-making for the treatment of metaphyseal forearm fractures in children can be performed by solely using US. The sonographic fat pad sign has been proven to be a useful primary screening tool for pediatric elbow injuries. If there is a negative fat pad sign, a fracture is unlikely and taking additional radiographs is dispensable at this time. If there is a positive fat pad sign, a fracture is likely and radiographs should be taken. US is also useful to exclude subcapital humeral fractures and to estimate fracture displacement. If a fracture of the subcapital humerus is present, additional radiographs are necessary to avoid overlooking of pathologic fractures. For reliable sonographic fracture diagnosis in childhood, a detailed history und exact clinical examination are required.