Ultrasound of the elbow

Non-Inferiority of Point-of-Care Ultrasound Compared to Radiography to Diagnose Upper Extremity Fractures in Children

Conventional X-ray imaging for fracture diagnosis is time-consuming and exposes patients to ionizing radiation. Additionally, the positioning of the injured limb for standardized X-ray imaging is painful. Point-of-care ultrasound (POCUS) is increasingly available in medical offices and emergency rooms. This study aimed to prove the non-inferiority of POCUS compared to X-ray imaging with respect to diagnostic sensitivity, pain, and investigation time in the diagnosis of long-bone fractures of the upper extremity in children. Children and adolescents (1−18 years old) presenting to the UKBB emergency service between May 2020 and May 2021 with suspected upper extremity fracture were included in the study. Before obtaining X-ray images, we conducted a POCUS examination of the injured limb. Pain scores at inclusion as well as maximum pain scores during X-ray and ultrasound examinations were documented. The duration of POCUS and X-ray examinations was compared. We examined 403 children with POCUS and plain X-ray imaging. The mean age (±SD) of the children was 10.6 (±3.5) years. The non-inferiority of POCUS compared to X-ray was confirmed with an estimated sensitivity of 0.95 and a lower confidence interval of 0.93. Maximum pain during POCUS was significantly lower compared to pain at inclusion (p = 0.002) or maximum pain during radiographic examination (p = 0.03). POCUS examination took 3.9 (±2.9) min in the mean whilst the mean duration for obtaining the X-ray images was 16 (±37) min (p < 0.001). POCUS for diagnosing upper extremity fractures in children proved as sensitive as standard X-ray imaging and was significantly faster and less painful. Future prospective studies are required to confirm our findings.

Ulnar Neuropathy at the Elbow: From Ultrasound Scanning to Treatment

Ulnar neuropathy at the elbow (UNE) is commonly encountered in clinical practice. It results from either static or dynamic compression of the ulnar nerve. While the retroepicondylar groove and its surrounding structures are quite superficial, the use of ultrasound (US) imaging is associated with the following advantages: (1) an excellent spatial resolution allows a detailed morphological assessment of the ulnar nerve and adjacent structures, (2) dynamic imaging represents the gold standard for assessing the ulnar nerve stability in the retroepicondylar groove during flexion/extension, and (3) US guidance bears the capability of increasing the accuracy and safety of injections. This review aims to illustrate the ulnar nerve's detailed anatomy at the elbow using cadaveric images to understand better both static and dynamic imaging of the ulnar nerve around the elbow. Pathologies covering ulnar nerve instability, idiopathic cubital tunnel syndrome, space-occupying lesions (e.g., ganglion, heterotopic ossification, aberrant veins, and anconeus epitrochlearis muscle) are presented. Additionally, the authors also exemplify the scientific evidence from the literature supporting the proposition that US guidance is beneficial in injection therapy of UNE. The non-surgical management description covers activity modifications, splinting, neuromobilization/gliding exercise, and physical agents. In the operative treatment description, an emphasis is put on two commonly used approaches-in situ decompression and anterior transpositions.

[Ultrasound of the Elbow (Adapted According to SGUM Guidelines)]

Ultrasound of the Elbow (Adapted According to SGUM Guidelines) Abstract. This review paper explains the simplified ultrasound anatomy of the elbow. The adapted basic standard planes are described in detail according to SGUM guidelines and illustrated with a selection of high-resolution ultrasound images. A profound knowledge of the sonographic anatomy is essential for the detection of pathologies.

Optimal Elbow Positions for Identification of the Radial Collateral Ligament Using Ultrasonography

BACKGROUND

The standard position for examining the lateral elbow with ultrasonography is an "extended" or "slightly flexed" position. However, because the radial collateral ligament (RCL) is more deeply attached on the lateral epicondyle than the common extensor tendon, an anisotropic artifact of the RCL could be observed in the conventional positions, making it difficult to fully visualize the RCL.

OBJECTIVES

To determine optimal elbow positions for accurate identification of the RCL and to explore the relevant landmarks in ultrasonography.

DESIGN

Prospective study.

SETTING

Tertiary university hospital.

PARTICIPANTS

Forty healthy elbows of 20 participants.

METHODS

The RCL was evaluated using ultrasonography in six elbow flexion positions (0°, 30°, 60°, 90°, 120°, and 140°). The relative depth, defined as the depth of the capitellum subtracted by the depth of the radial head under ultrasonography, was measured at each angle. The rates of successful identification of ultrasonographic landmarks for localizing the RCL were calculated. After ultrasonography, the optimal elbow position for identifying the RCL was determined by group consensus.

MAIN OUTCOME MEASUREMENTS

Relative depth between radial head and capitellum, rates of successful identification of ultrasonographic landmarks, and consensus-based determination of the optimal angle.

RESULTS

The relative depth significantly decreased with an increase in the flexion angle (P for trend <.001), approaching zero at the angles of 90° and 120°. The rates of successful identification of the superior tubercle, hyperechogenic line, and anterior and posterior tubercles were 100%, 100%, 90%, and 80%, respectively. In the group consensus, the 90° and 120° flexion angles were selected with the highest frequency (90%; 36/40).

CONCLUSION

Our findings suggest that elbow flexion at 90° or 120° is optimal for visualization of the RCL with the least possibility of anisotropy under ultrasonography, suggesting that the elbow should be flexed considerably beyond the conventional extended or slightly flexed position.

Ultrasound evaluation of bursae: anatomy and pathological appearances

A bursa is an extra-articular sac that may communicate with a joint and functions to decrease friction between tendons and either bone or skin. Bursae can be classified as native and non-native (adventitious) bursae. The native bursae are lined with a synovial membrane and occur at predictable anatomical sites; knowledge of these normal structures can help distinguish them from other pathological entities. An adventitious bursa can form at sites of friction rather than at predictable anatomical sites, but otherwise have imaging features similar to native bursae. Bursal distention can occur from many pathological processes, most commonly resulting from chronic overuse injury. When imaging bursal pathological conditions, there is often an overlap of imaging findings, regardless of the cause. In general, ultrasound of a distended bursa reveals a fluid collection with either simple anechoic or more complex hypoechoic fluid. Bursal distention is characteristically unilocular and compressible, unlike other structures such as ganglion cysts, which are usually multilocular and non-compressible. This article reviews the anatomical locations of common bursae and shows pathological examples using ultrasound. Knowledge of typical locations and imaging appearances of bursae can aid in narrowing the differential diagnosis and guiding further management and treatment decisions.

Cross-sectional area of the ulnar nerve after decompression at the cubital tunnel

A total of 48 patients undergoing surgical decompression of the ulnar nerve at the cubital tunnel between February 2010 and May 2013 were retrospectively studied to determine changes in the cross-sectional area of the nerve by the technique of neurosonography. The mean follow-up was 46 months. Post-operative follow-up examination of the cross-sectional area of the ulnar nerve showed a slight reduction in the mean value from 13.8 mm(2) (pre-operative) to 12.9 mm(2) (post-operative). Of the 48 patients, 36 showed a reduction in the cross-sectional area. No correlation was detected between the clinical and sonographic outcomes. Ultrasound seems to be of limited value in the post-operative assessment of patients with entrapment neuropathy of the ulnar nerve.

LEVEL OF EVIDENCE

IV.

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

PURPOSE

The purpose of this study was to evaluate the diagnostic accuracy of the sonographic fat pad sign (FPS) as a predictor for pediatric elbow fractures.

PATIENTS AND METHODS

This is a prospective study of children under 14 years with suspected elbow fractures. All participants underwent at first ultrasonography focused on a FPS followed by standard elbow radiographs. US findings were compared to final fracture diagnosis.

RESULTS

38 out of 79 children had an elbow fracture. A sonographic FPS predicted an elbow fracture with a sensitivity/specificity of 97.3/90.5 %, positive/negative likelihood ratios (LR) were 10.2/0.03 and correct/false classification rates were 93.7/6.3 %. Primary US findings were later reviewed by a blinded physician giving a congruity of 96.2 %. These secondary US findings predicted an elbow fracture with a sensitivity/specificity of 92.1/92.7 %, positive/negative LRs were 12.6/0.09 and correct/false classification rates were 92.4/7.5 %.

CONCLUSION

The sonographic FPS could serve as a useful screening tool in primary evaluation of pediatric elbow injuries. If a fracture is unlikely after clinical and US evaluation, additional radiographs are dispensable, thereby potentially minimizing the radiation burden in childhood and reducing the length of stay in the Emergency Department.

Clinical and ultrasonographic evidence of a proximal positional fault of the radius. A case report

Positional faults are considered a possible underlying mechanism mimicking the symptoms of a joint sprain. Despite numerous clinical studies indicating the presence of positional faults, there is limited evidence of imaging studies confirming positional faults. This case report is a preliminary study that offers clinical and ultrasonographic evidence of a proximal positional fault of the radius, treated successfully with manual therapy techniques. Three weeks after a bike fall on the outstretched hand, the patient in this study presented with right wrist pain and a lack of progress with conventional conservative treatment (NSAIDs, rest and immobilization). Clinical findings indicating a proximal positional fault of the radius included pain during active pronation increased by associating a passive movement of the radius in a proximal direction and it was reduced by associating a passive movement of the radius in a distal direction. Ultrasonographic (US) images showed a reduction of radio-capitellar distance on the right side (11.4 mm) compared to the left side (13.3 mm). A positive response with a distal mobilization of the radius supported the proximal positional fault of the radius. After two manual therapy sessions, the patient had recovered normal asymptomatic function. The outcomes used to assess function and pain were active pronation range of motion, the Spanish version of the DASH questionnaire and a 0-10 numeric pain rating scale. Each measure was conducted prior and after each treatment session and one week post treatment. The patient was re-examined at 6 months follow-up, during which US images, demonstrated a normalization of the right radio-capitellar distance.

Magnetic resonance imaging of the elbow in athletes

Acute and chronic elbow pain is common, particularly in athletes. Although plain radiographs, ultrasound, and computed tomography all have a role to play in the investigation of elbow pain, magnetic resonance imaging (MRI) has emerged as the imaging modality of choice for diagnosis of soft tissue disease and osteochondral injury around the elbow. The high spatial resolution, excellent soft-tissue contrast, and multiplanar imaging capabilities of MRI make it ideal for evaluating the complex joint anatomy of the elbow. This article reviews imaging of common disease conditions occurring around the elbow in athletes, with an emphasis on MRI.

Feasibility of Using a Hand-Carried Sonographic Unit for Investigating Median Nerve Pathology

Numerous research studies describe the prevalence of work-related musculoskeletal disorders (WRMSD) in diagnostic medical sonographers, but little research has investigated contributing factors and biological changes in symptomatic individuals. Improved image quality and portability, combined with lower cost and dynamic capabilities, have led to increased use of sonography over magnetic resonance imaging (MRI) in musculoskeletal evaluations. The purpose of this pilot study was to develop a valid and reliable sonographic protocol for the evaluation of work-related median nerve pathology with a hand-carried sonographic unit. A GE Logiq i (Milwaukee, Wisconsin) hand-carried unit with a 12-MHz linear transducer was used to collect nine longitudinal and transverse images of the median nerve at various anatomical locations in the distal upper extremity of three healthy volunteers. Doppler waveforms were also collected in the median nerve sheath. Qualitative review indicated high-quality images with well-defined structures, resulting in valid measures between multiple researchers of anterior-posterior diameter, cross-sectional area, anterior transverse carpal ligament bulge, and Doppler flow. The use of a hand-carried sonographic unit appears to be a feasible alternative to MRI to detect musculoskeletal changes in symptomatic sonographers. Additional basic and clinical studies are necessary to validate the use of hand-carried sonography as a measure of biological changes in longitudinal WRMSD research.

The clinical applications of peripheral nerve imaging in the upper extremity

Use of different imaging modalities in the diagnosis of peripheral nerve pathology has been growing steadily. This review attempts to summarize their use, particularly with regard to ultrasound and magnetic resonance imaging, and their practical applications in the clinical setting.

Ultrasound of the elbow: Examination techniques and US appearance of the normal and pathologic joint

Ultrasound studies are frequently requested for the work-up of patients with local elbow pain, which is generally caused by overuse syndromes, trauma, inflammatory diseases, or neuropathies. The technique used to examine this joint will vary to some extent depending on the precise location of the pain and other clinical findings. The aim of this article is to describe the standard technique used for elbow ultrasound, the normal anatomy of the joint, and the appearance on ultrasound of normal elbow anatomy and the alterations associated with some of the more common disorders affecting this joint.

Demonstration of the appearance of the paraspinal musculoligamentous structures of the cervical spine using ultrasound

The application of ultrasound in the imaging of the neck has primarily focussed on anterior structures (e.g., thyroid gland). Structures located on the posterior aspect of the neck have received little attention. This study illustrates the capability of modern ultrasound equipment in visualising the musculoligamentous structures of the neck, particularly the paraspinal musculature. Ten healthy adult volunteers (6 female; 4 male) underwent ultrasound examination of the cervical spine. A standardised technique for transducer placement was adopted and successive images of the neck of each subject were obtained. Spatial compound (extended field of view) images were obtained in subjects using one of two different ultrasound systems. Images of structures produced by ultrasound were compared to those achieved with magnetic resonance imaging in three subjects. Identification of key landmarks aided orientation and identification of structures. The internal architecture of the musculoligamentous structures of the cervical spine, especially the posterior neck muscles, was demonstrated well using ultrasound. Our study showed that modern ultrasound equipment is capable of producing clear images of the posterior cervical spine musculature and certain bony features.

Radiographic and special studies: recent advances in imaging of the elbow

Advanced imaging techniques such as computed tomography, ultrasound, and magnetic resonance imaging provide clinically useful information by detecting and characterizing pathologic conditions of the elbow. The information provided by these techniques can help establish an anatomic diagnosis in a noninvasive fashion. A timely and accurate imaging diagnosis may be an important piece of the puzzle in a diagnostic workup that allows implementation of proper treatment and improved outcome. In this article, the authors focus on recent advances in diagnostic imaging of the elbow joint.

The ultrasonographic and electrodiagnostic findings of ulnar neuropathy at the elbow11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

OBJECTIVE

To evaluate and compare the morphologic changes of the ulnar nerve at the elbow, using ultrasonography, between patients with cubital tunnel syndrome and retrocondylar compression syndrome determined with electrodiagnosis.

DESIGN

Prospective study using electrodiagnosis and ultrasonography.

SETTING

An outpatient rehabilitation clinic in a tertiary university hospital in South Korea.

PARTICIPANTS

Thirteen patients (8 men, 5 women; mean age, 48.2y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

In the electrodiagnostic study, we used the inching technique to localize the ulnar nerve lesion at the elbow. In the ultrasonography study, we measured the length of the swollen ulnar nerve and the ratio of the nerve diameter between the proximal end of the medial epicondyle to the elbow joint level and the tip of medial epicondyle to the elbow joint level.

RESULTS

The mean length of the swollen ulnar nerve segment in retrocondylar compression syndrome (2.58+/-0.58cm) was significantly longer than that of cubital tunnel syndrome (1.64+/-0.31cm). The mean ratio of the nerve diameter between the proximal end of medial epicondyle and the elbow joint level was significantly larger in retrocondylar compression syndrome (1.52+/-0.25) than that of cubital tunnel syndrome (1.06+/-0.06).

CONCLUSIONS

Ultrasonography detected the morphologic changes and the extent of the ulnar nerve lesion at the elbow, and it can become a screening and follow-up imaging modality in patients with ulnar neuropathy at the elbow.

Ultrasound of nerve and muscle

Over the last two decades, ultrasound has developed into a useful technology for the evaluation of diseases of nerve and muscle. Since it is currently not used at by the majority of clinicians involved in diagnosis or care of patients with neuromuscular disorders, this review briefly describes the technical aspects of ultrasound and its physical principles. It relates normal muscle anatomy and movement to ultrasound images in the axial and sagittal planes and follows with a discussion of ultrasound findings in chronic muscle disease. These include evident atrophy and the loss of the hypoechoic architecture of normal muscle tissue. It highlights evolving uses of the technique to measure other pathologic changes in disease including altered muscle dynamics. With high-resolution instruments nerve imaging has now become standard, and the relationships of median nerve anatomy and observations of static and dynamic images from ultrasound are reviewed. Changes seen in carpal tunnel syndrome include significant increases in the cross-sectional area of the nerve just proximal to the site of compression, loss of hyperechoic intensities within nerve, and reduced mobility. Preliminary use of the technique for the study of other nerves is reviewed as well. Ultrasound is an ideal tool for the clinical and research investigation of normal and diseased nerve and muscle complementary to existing diagnostic techniques. As the technology continues to evolve, it will likely assume a more significant role in these areas as those most able to exploit its potential, clinical neurophysiologists and neuromuscular clinicians, incorporate its use at the bedside.

Ultrasound of the elbow

The elbow is an important synovial hinge joint of the upper extremity. This joint represents a common site of musculoskeletal symptomatology, affecting all age groups. The advantages of ultrasound imaging of the elbow include easy availability, multiplanar capability and the ability to assess structures dynamically. Patient symptomatology and site of maximal tenderness can be directly correlated with imaging findings. Comparison is easily made with the contralateral side. Particular strengths include the ability to assess para-articular structures, such as regional tendons and ligaments, in addition to assessment of joint effusions, loose bodies and regional bursae. With operator experience and excellent technique, ultrasound is a valuable imaging tool for assessment of disorders of the elbow joint.

US of the anterior bundle of the ulnar collateral ligament: findings in five cadaver elbows with MR arthrographic and anatomic comparison--initial observations

PURPOSE

To characterize the ultrasonographic (US) appearance of the anterior bundle of the ulnar collateral ligament of the elbow by comparing US images with magnetic resonance (MR) arthrograms and anatomic slices.

MATERIALS AND METHODS

The ulnar collateral ligament in four cadavers (eight elbows) was blindly evaluated with US by one musculoskeletal radiologist with experience in musculoskeletal US. These results were compared with standard arthrograms, MR arthrograms, and anatomic slices by consensus reading of two musculoskeletal radiologists. The criteria for an abnormal ulnar collateral ligament included contrast material extension into the ligament or fiber discontinuity, as documented by MR arthrography and anatomic slices.

RESULTS

Standard arthrography, MR arthrography, and anatomic slices demonstrated the ulnar collateral ligament to be unequivocally normal in three specimens and abnormal in two. The remaining three elbows did not meet the criteria for classification as either normal or abnormal, and thus they were excluded from the study. With US, the normal ulnar collateral ligament was fibrillar and hyperechoic between the medial epicondyle and proximal ulna. In the two abnormal cases, abnormal hypoechogenicity and ligament fiber disruption were noted. In addition, the proximal aspect of the ulnar collateral ligament varied from a cordlike structure to a broad attachment to the undersurface of the medial epicondyle with variable fat.

CONCLUSION

In this small sample, the anterior bundle of the ulnar collateral ligament is identified with US by its hyperechoic and compact fibrillar echotexture. The proximal attachment of the ulnar collateral ligament has a variable appearance. Hypoechogenicity and fiber disruption indicated ulnar collateral ligament abnormality.