Prospective evaluation of ultrasound features of magnesium-based bioabsorbable screw resorption in pediatric fractures

OBJECTIVE

Bioabsorbable magnesium-based alloy screws release gas upon resorption. The resulting findings in the adjacent soft tissues and joints may mimic infection. The aim of the study was to evaluate the ultrasound (US) findings in soft tissues and joints during screw resorption.

METHODS

Prospectively acquired US studies from pediatric patients treated with magnesium screws were evaluated for screw head visibility, posterior acoustic shadowing, twinkling artifact, foreign body granuloma, gas (soft tissue, intra-articular), alterations of the skin and subcutaneous fat, perifascial fluid, localized fluid collections, hypervascularization, and joint effusion.

RESULTS

Sixty-six US studies of 28 pediatric patients (nfemale = 9, nmale = 19) were included. The mean age of the patients at the time of surgery was 10.84 years; the mean time between surgery and ultrasound was 128.3 days (range = 6-468 days). The screw head and posterior acoustic shadowing were visible in 100% of the studies, twinkling artifact in 6.1%, foreign body granuloma in 92.4%, gas locules in soft tissue in 100% and intra-articular in 18.2%, hyperechogenicity of the subcutaneous fat in 90.9%, cobblestoning of the subcutaneous fat in 24.2%, loss of normal differentiation between the epidermis/dermis and the subcutaneous fat in 57.6%, localized fluid collection in 9.9%, perifascial fluid in 12.1%, hypervascularization in 27.3%, and joint effusion in 18.2%.

CONCLUSION

US findings in pediatric patients treated with magnesium screws strongly resemble infection, but are normal findings in the setting of screw resorption.

CLINICAL RELEVANCE STATEMENT

Bioabsorbable magnesium-based alloy screws release gas during resorption. The resulting US findings in the adjacent soft tissues and joints in pediatric patients may mimic infection, but are normal findings.

KEY POINTS

• Bioabsorbable magnesium-based alloy screws release gas upon resorption. • The resulting ultrasound findings in children's soft tissues and joints closely resemble those of soft tissue infection or osteosynthesis-associated infection. • Be familiar with these ultrasound findings in order to avoid inadvertently misdiagnosing a soft tissue infection or osteosynthesis-associated infection.

Ultrasound Assessment of an Isolated Rupture of the Medial Bundle of a Bifid Distal Biceps Tendon

This case study describes a patient with a clinically ruptured distal biceps tendon, with ultrasound detecting an isolated rupture of the medial bundle of a bifid distal biceps tendon. A 45-year-old male presented to the accident and emergency department with a week-old history of a right elbow injury. The ultrasound scan demonstrated a hypoechoic, corrugated distal biceps tendon with a tendon stump close to the radial tuberosity insertion in keeping with a rupture. However, a small caliber accessory or bifid distal biceps tendon was also identified and was intact. Typically, distal biceps tendon ruptures occur following a traumatic event with most detected clinically although imaging is required to confirm the diagnosis. Ultrasound is utilized to assess these injuries, and several different techniques or approaches are described in the literature. A combination of these approaches is required to make an accurate diagnosis. Detection of bifid distal biceps tendons is important for patient management, especially if a surgical repair is considered. This case highlights the anatomical variant of a bifid distal biceps tendon, which was ruptured clinically. The ultrasound diagnosis of distal biceps tendon ruptures can be challenging, especially when there is limited tendon retraction. This case also demonstrated the importance of dynamic ultrasound in the assessment of tendon ruptures.

Ultrasound exploration of the elbow: A user-friendly approach

Ultrasound is a strong diagnostic and therapeutic tool for the elbow joint. Existing guidelines and protocols list relevant structures to be scanned but lack some logical connection and intermediate exploration manoeuvres to link each step, which we consider crucial from an operator's perspective that aims to be efficient in regular clinical practice. We present thirteen steps that are described in detail and accompanied by forty-seven ultrasound images, logically linked in what we believe is the best balance between detail and a real-world applicable protocol to perform an ultrasound of the elbow joint.

Hearing and Seeing Nerve/Tendon Snapping: A Systematic Review on Dynamic Ultrasound Examination

Nerve/tendon snapping can occur due to their sudden displacement during the movement of an adjacent joint, and the clinical condition can really be painful. It can actually be challenging to determine the specific anatomic structure causing the snapping in various body regions. In this sense, ultrasound examination, with all its advantages (especially providing dynamic imaging), appears to be quite promising. To date, there are no comprehensive reviews reporting on the use of dynamic ultrasound examination in the diagnosis of nerve/tendon snapping. Accordingly, this article aims to provide a substantial discussion as to how US examination would contribute to 'seeing' and 'hearing' these pathologies' different maneuvers/movements.

Imaging of Anatomical Variants Around the Elbow

The elbow is a synovial joint able to perform flexion, extension, supination, and pronation. Knowledge of anatomical variants is crucial to avoid misinterpretation during the evaluation of the elbow joint. We address those anatomical variants simulating pathologic conditions.

Use of Ultrasonography in Diagnosis of Medial Compartment Disease of the Elbow in Dogs

OBJECTIVE

 The objective of this prospective study was to evaluate the use of ultrasonography in the diagnosis of medial coronoid process disease in unclear cases.

STUDY DESIGN

 Fifteen elbows (on thirteen dogs) for which radiography and computed tomography did not lead to a clear diagnosis of medial coronoid process disease were included. On each elbow, ultrasonography was performed with a high frequency linear transducer (12-18Hz). Then, arthroscopic examination of the joint was performed by a surgeon who was unaware of ultrasonographic findings to confirm medial coronoid process disease.

RESULTS

 At least one ultrasonographic lesion was detected in 13 out of 15 elbows. The main reported ultrasonographic lesions were joint effusion (10/15 elbows) and an abnormal shape of the medial coronoid process (irregular, ill-defined or fragmented) (9/15).

CONCLUSION

 Ultrasonography can be a helpful additional diagnostic tool to confirm medial coronoid process disease of the elbow joint before performing arthroscopy in unclear cases. Further studies will be needed to evaluate the use of higher frequency transducers and determine if it could improve the diagnostic value of ultrasonography.

The 50 most impactful articles on the medial ulnar collateral ligament: An altmetric analysis of online media

The purpose of this study was to use the Altmetric Attention Score to determine the 50 most impactful medial ulnar collateral ligament articles in online media and compare their characteristics to the most-cited medial ulnar collateral ligament articles in the scientific literature. The Altmetric database was queried to identify all published articles about the medial ulnar collateral ligament, and this list was stratified by the Altmetric Attention Score to identify the 50 highest scoring articles. Several data elements were extracted, including article topic, article type, journal name, and the number of online mentions on Facebook, Twitter, news, and other platforms. Each article's geographic origin was determined based on the institutional affiliation of the first author. Our index search yielded 1283 articles published between 1987 and 2020, from which the 50 articles with the highest Altmetric Attention Scores were included for analysis. Altmetric Attention Scores of the top 50 medial ulnar collateral ligament articles ranged from 20 to 482 (median: 32, interquartile range: 20-62). The most common article type was original research (72%), and the most common topic was epidemiology/risk factors (26%). A majority of studies were Level 3 (36%) or Level 4 evidence (36%). Of the top 50 medial ulnar collateral ligament articles, 94% originated from the United States. A few articles had a high Altmetric Attention Score, suggesting that medial ulnar collateral ligament research does not generate consistently high online attention. The lack of Level 1 studies suggests the need for high-level studies on the medial ulnar collateral ligament. Most studies originated in the United States and were published in the American Orthopaedic Society for Sports Medicine-affiliated journals. The medial ulnar collateral ligament articles included in this study differed substantially from a previous report of the most-cited medial ulnar collateral ligament articles in the literature, suggesting that alternative metrics add a unique dimension to understanding the overall impact of published research on the medial ulnar collateral ligament.

Ultrasound imaging in diagnostics of Monteggia lesion in children

PURPOSE

The aim of the study is to evaluate the use of ultrasound imaging in diagnostics of Monteggia lesion in children where conventional radiographs and the use of the radiocapitellar line fail to provide an accurate diagnosis.

METHODS

Prospective diagnostic study of 70 patients treated between May 2018 and July 2021 in a pediatric level 1 trauma center. In 20 patients with the confirmed radiographic diagnosis of Monteggia lesion, an ultrasound of the humeroradial joint was performed to determine signs of both normal and dislocated elbow joint. In 36 patients with suspected humeroradial dislocation on plain radiographs, ultrasound imaging was performed to determine the definitive diagnosis. Overall, 14 patients with elbow joint injury other than humeroradial dislocation were excluded from the study.

RESULTS

The "double-hump sign" and the "congruency sign" were determined as normal findings on ultrasound of the humeroradial joint. These signs were applied to patients with unclear findings on radiographs. In three patients, the dislocation of the humeroradial joint was confirmed by ultrasound. In two patients, "defect in congruency sign" was seen during reduction despite normal radiographs, which required re-reduction. In 31 patients, dislocation of the humeroradial joint was refuted. In 34 out of the 36 patients, the diagnosis determined by ultrasound was confirmed in follow-up. Two patients did not attend the follow-up examination.

CONCLUSION

Ultrasound imaging is an accessible, non-invasive, and dynamic point-of-care method that can be applied in children suffering from suspected humeroradial dislocation and/or subluxation.

LEVEL OF EVIDENCE

Level III-diagnostic study.

Posttreatment Changes of the Elbow

Radiologists should be familiar with the typical surgical procedures applied at the elbow and aware of the spectrum of normal and pathologic appearances of posttreatment situations throughout all radiologic modalities. Most important in the case of posttraumatic surgical elbow procedures is correct postoperative elbow joint alignment, appropriate fixation of joint-forming fragments, and proper insertion of screws, plates, and anchor devices that do not conflict with intra-articular or bony structures. To report soft tissue repair procedures correctly, radiologists need to know the broad spectrum of different techniques applied and their appearance on magnetic resonance imaging.

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.

Complications in Elbow Arthroscopy: Management and Prevention

With advances in the understanding of elbow anatomy, pathologies of the elbow, arthroscopic instrumentation, and surgical techniques over recent decades, elbow arthroscopy has become a valuable treatment modality for a variety of conditions. Elbow arthroscopy has gained utility for treating problems such as septic arthritis, osteoarthritis, synovitis, osteophyte and loose body excision, contracture release, osteochondral defects, select fractures, instability, and lateral epicondylitis. Accordingly, precise knowledge of the neurovascular anatomy, safe arthroscopic portal placement, indications, and potential complications are required to maximize patient outcomes and assist in educating patients. This comprehensive review provides the reader an understanding of the potential complications associated with arthroscopic procedures of the elbow and to describe strategies for prevention and management.

Ultrasonography, Microcomputed Tomography, and Macroscopic Preparation in an Anatomical Study of the Thoracic Limb of the Golden-Headed Lion Tamarin (Leontopithecus chrysomelas)

The aim of this study was to evaluate the normal anatomy of the forearm of the golden-headed lion tamarin (Leontopithecus chrysomelas) using microcomputed tomography (micro-CT) and ultrasonography (US) and then compare the results with the results of a gross anatomy dissection of the forearm. The results of the US examination of the musculoskeletal system of the tamarin forearm were not satisfactory. US imaging enabled observation of the shape of the soft tissue and the size of muscle groups; however, we distinguished more muscles by traditional methods. In addition, in the dissection study, the assessment of the muscles was easier. Examination of the forearm bones using micro-CT provided a complete picture of the bones in this part of the body and was less time-consuming than traditional methods. Imaging allows the anatomy to be represented as a 3D image. However, some methods are not accurate; as in our study, US did not allow a complete assessment of the forearm musculature.

Elbow Imaging: Variants and Asymptomatic Findings

One of the key principles in the interpretation of radiology images is the ability to differentiate between normal and abnormal findings. This article provides a comprehensive overview of normal structures and anatomical variants occurring around the elbow including potential diagnostic pitfalls. We discuss frequently observed anatomical variants found in routine clinical practice associated with osseous, ligamentous, musculotendinous, and neurovascular structures at the elbow that may simulate pathology or predispose to symptoms under specific circumstances.

Clinical Assessments and MRI Findings Suggesting Early Surgical Treatment for Patients with Medial Epicondylitis

Purpose

To evaluate the MRI findings and clinical factors that are characteristic of patients who ultimately undergo surgery for medial epicondylitis.

Materials and Methods

Fifty-two consecutive patients who were diagnosed with medial epicondylitis and underwent an elbow MRI between March 2010 and December 2018 were included in this retrospective study. The patients' demographic information, clinical data, and MRI findings were evaluated. All variables were compared between the conservative treatment and surgical treatment groups. Logistic regression analyses were conducted to identify which factors were associated with surgical treatment.

Results

Common flexor tear (CFT) tear size showed a statistically significant difference in both the transverse and longitudinal planes (p < 0.001, p = 0.013). The CFT abnormality grade significantly differed in both the transverse and longitudinal planes (p = 0.022, p = 0.003). A significant difference was also found in the medial collateral ligament abnormality (p = 0.025). Logistic regression analyses showed that only the transverse diameter of the CFT tear size (odds ratio: 1.864; 95% confidence interval: 1.264-2.750) was correlated with surgical treatment.

Conclusion

Of patients diagnosed with medial epicondylitis, patients with a larger transverse CFT tear size tend to undergo surgical treatment ultimately.

Feasibility and technique of ultrasound traumatic elbow lesion assessment

INTRODUCTION

The present study aimed to describe the technique of ultrasound traumatic elbow lesion assessment performed by an orthopedic surgeon.

METHODS

Nine patients were included in a single-center study. Clinical examination assessed pain, ranges of elbow motion, neurovascular status and elbow ligament testing. Ultrasound was associated to radiography between days 7 and 15, screening for lesions of the bone, medial ligament (in 30-90° flexion), lateral ligament (elbow at 90° in cobra position) and epitrochlear and epicondylar muscle insertions. Ultrasound scanning time and echogenicity were assessed.

RESULTS

Four radial head osteochondral fractures were detected on ultrasound in addition to the 4 fractures seen on radiography, without significant difference (p=0.071). Clinical examination found 2 cases of valgus laxity and 5 of varus laxity. Ultrasound, performed blind to radiography, found 1 medial collateral ligament anterior bundle lesion (in 1 of the 2 patients with valgus laxity) and 4 lateral collateral ligament ulnar bundle lesions (in 4 of the 5 patients with varus laxity). There were no epicondylar or epitrochlear tendon lesions. Scanning time decreased significantly over the study period, from a mean 30minutes in the first 5 cases to a mean 24.8minutes in the last 5 (p=0.046). Three patients could not be put in the cobra position, and 3 showed poor echogenicity.

DISCUSSION

Ultrasound assessment of traumatic elbow lesions could be performed by an orthopedic surgeon on a well-defined protocol. Lesions on ultrasound matched clinical symptomatology. Inter- and intra-observer reproducibility remain to be assessed.

LEVEL OF EVIDENCE

IV.

Ultrasound Examination Techniques for Elbow Injuries in Overhead Athletes

Elbow pain is a frequent complaint among overhead athletes. Standard evaluation of the elbow uses history and physical examination, with radiographic imaging and MRI aiding in the confirmation of diagnosis. Musculoskeletal ultrasonography (US) provides dynamic, functional assessment of tendons and ligaments in the elbow, allowing the visualization of structures under stress and motion. Stress US offers the ability to detect injuries to the ulnar collateral ligament by measuring changes in joint space under stress. The freedom of dynamic imaging means results are dependent on the skill of the US operator to obtain the most accurate and complete evaluation. US is cost efficient and portable, allowing for quick examination at the point of care. This article provides a technique guide for sports medicine specialists performing US examination of the elbow.

Clinical applicability of shear wave elastography for the evaluation of medial epicondylitis

OBJECTIVES

To evaluate the ability of shear wave elastography (SWE) in diagnosing medial epicondylitis and to compare the diagnostic performance of SWE with that of grey-scale ultrasound (GSU) and strain elastography (SE).

METHODS

GSU, SE, and SWE were performed on 61 elbows of 54 patients from March 2018 to April 2019. An experienced radiologist evaluated the GSU findings (swelling, cortical irregularity, hypoechogenicity, calcification, and tear), colour Doppler findings (hyperaemia), SE findings (strain ratio [SR]), and SWE findings (stiffness and shear wave velocity [SWV]). Participants were divided in two groups: patients with clinically diagnosed medial epicondylitis and patients without medial elbow pain. Findings from the two groups were compared, and the receiver operating characteristic (ROC) curves were calculated for significant features.

RESULTS

Of the 54 patients, 25 patients with 28 imaged elbows were clinically diagnosed with medial epicondylitis and 29 patients with 33 imaged elbows had no medial elbow pain. Cortical irregularity, hypoechogenicity, calcification, hyperaemia, SR, stiffness, and SWV were significantly different between the two groups. The areas under the ROC curves were 0.838 for hypoechogenicity, 0.948 for SR, 0.999 for stiffness, and 0.999 for SWV. The diagnostic performances of SR, stiffness, and SWV were significantly superior compared to that of hypoechogenicity. However, there were no significant differences among SR, stiffness, and SWV.

CONCLUSIONS

SWE can obtain both stiffness and SWV, which are valuable diagnostic tools in the diagnosis of medial epicondylitis. The diagnostic performance of SWE and SE is similar in detecting medial epicondylitis.

KEY POINTS

• Shear wave elastography providing stiffness and shear wave velocity showed excellent performance in the diagnosis of medial epicondylitis. • There was no significant difference in the ability of SE and SWE for diagnosing medial epicondylitis.

Ultrasonographic Technique, Appearance, and Diagnostic Accuracy for Common Elbow Sports Injuries

Ultrasonography is a valuable diagnostic imaging tool because of its availability, tolerability, low cost, and utility in real-time dynamic evaluation. Its use in diagnosing elbow injuries has expanded recently and continues to do so. In particular, stress ultrasonography represents a unique imaging technique that directly visualizes the ulnar collateral ligament (UCL) and allows the assessment of ligament laxity, offering an advantage over magnetic resonance imaging and magnetic resonance arthrography in this patient population. Furthermore, ultrasonography has shown particular usefulness in instances where invasive techniques might be less desirable. This is particularly important in athletes since more invasive procedures potentially result in lost time from their sport. Ultrasonography is an important imaging tool that complements a thorough history and physical examination in the evaluation of elbow injuries in athletes. The use of ultrasonography in orthopaedic sports medicine has been investigated previously; however, to our knowledge, there has been no comprehensive review regarding the utility of ultrasonography for common elbow injuries in athletes. The current study provides a comprehensive, detailed review of the utility and indications for the use of ultrasonography for common elbow injuries in athletes.

Distal insertional anatomy of the triceps brachii muscle: MRI assessment in cadaveric specimens employing histologic correlation and Play-doh® models of the anatomic findings

OBJECTIVES

Assess the insertional anatomy of the distal aspect of the triceps brachii muscle using magnetic resonance imaging (MRI) in cadavers with histologic correlation and Play-doh^® models of the anatomic findings.

MATERIALS

Elbows were obtained from twelve cadaveric arm specimens by transverse sectioning through the proximal portion of the humerus and the midportion of the radius and ulna. MRI was performed in all elbows. Two of the elbow specimens were then dissected while ten were studied histologically. Subsequently, Play-doh^® models of the anatomic findings of the distal attachment sites of the triceps brachii muscle were prepared.

RESULTS

MRI showed a dual partitioned appearance of the distal attachment sites into the olecranon in all specimens. In the deeper tissue planes, the medial head muscle insertion was clearly identified while superficially, the terminal portion of the long and lateral heads appeared as a conjoined tendon. Histologic analysis, however, showed continuous tissue rather than separate structures attaching to the olecranon.

CONCLUSION

Although MRI appeared to reveal separate and distinct attachments of the triceps brachii muscle into the olecranon, histologic analysis delineated complex but continuous tissue related to the attachments of the three heads of this muscle. The Play-doh^® models were helpful for the comprehension of this complex anatomy and might serve as a valuable educational tool when applied to the analysis of other musculoskeletal regions.

Ultrasound of the elbow with emphasis on the sonoanatomy of the distal biceps tendon and its importance for the surgical treatment of tendon lesions

Degenerative or traumatic ruptures of the distal biceps tendon are less common than proximal lesions. Distal lesions lead to a significant loss of function with usually considerable discomfort for patients. Therefore, precise diagnostics using operator-dependent high-resolution musculoskeletal ultrasound with illustration of the extent of the affected tendon lesion are important for optimizing patient management. In this article, we discuss the precise high-resolution musculoskeletal ultrasound and sonoanatomy of the distal biceps tendon and emphasize its importance for the surgical treatment of tendon lesions. In this review and pictorial essay, we first focus on the description of the precise anatomy and ultrasound anatomy of this clinically important region. Furthermore, we highlight different ultrasound scanning techniques for the correct assessment of the distal biceps tendon. Various approaches for optimal sonographic assessment of the distal biceps tendon have been suggested in the literature: the anterior approach, the lateral access, the medial access and the posterior approach. In the second part of the article, we focus on the evaluation of surgical repair techniques of distal biceps tendon lesions considering the extent of the rupture zone of the distal biceps tendon based on the ultrasound findings. Surgical techniques are explained from the orthopedic surgical point of view.

Revision Medial Ulnar Collateral Ligament Reconstruction in Baseball Pitchers: Review of Epidemiology, Surgical Techniques, and Outcomes

PURPOSE OF REVIEW

The purposes of this review are to describe the epidemiology, treatment options, and clinical outcomes of revision medial ulnar collateral ligament reconstruction in baseball pitchers.

RECENT FINDINGS

Rates of revision UCL range from 1 to 15% and have slowly increased over the past several years. Revision UCL procedures are associated with higher complication rates, likely due to the distortion of innate anatomy after primary reconstruction. Techniques for reconstruction are largely influenced by the index surgery and integrity of the ulnar and humeral bone tunnels/sockets. Current literature reporting on the outcomes following revision UCL reconstruction is limited to case series and database studies. Mean time between primary reconstruction and revision surgery is approximately 5 years and return to play rates range from 47 to 85%. Outcomes following revision UCL reconstruction are relatively guarded compared with those of primary UCL reconstruction with the most studies reporting lower return to play rates, decreased workloads compared with pre-injury levels of play, and shorter career longevity following revision surgery. Future research regarding optimal reconstruction techniques and post-operative rehabilitation are needed as the incidence and demand for this procedure is expected to increase.

Diagnostic Accuracy of Echo Envelope Statistical Modeling Compared to B-Mode and Power Doppler Ultrasound Imaging in Patients With Clinically Diagnosed Lateral Epicondylosis of the Elbow

OBJECTIVES

To compare the accuracy of homodyned K quantitative ultrasound (QUS) with that of B-mode and Doppler ultrasound imaging for discriminating between lateral epicondylosis (LE) and asymptomatic elbows.

METHODS

This prospective study received Institutional Review Board approval, and participants provided written informed consent. Between February 2015 and March 2017, 30 LE elbows in 27 patients and 24 asymptomatic elbows in 13 volunteers underwent B-mode, Doppler, and radiofrequency ultrasound imaging of the common extensor tendon (CET) and radial collateral ligament (RCL). Two readers classified the elbows independently on the basis of a review of B-mode and Doppler images. The global and local estimates of QUS parameters (μ _n , 1/α, and k) were computed in the CET and CET-RCL regions, respectively, and the area of each region was calculated. A random-forest classifier identified the most discriminating 3-parameter combination: CET global estimate of 1/α, CET-RCL area, and local estimate of k.

RESULTS

The patients with LE had a mean age of 50 years (range, 31-66 years), and the volunteers had a mean age of 50 years (range, 37-57 years). The area under the receiver operating characteristic curve, sensitivity, and specificity of reader 1, reader 2, and the QUS-based model were 0.80 (95% confidence interval [CI], 0.66-0.95), 0.72 (95% CI, 0.56-0.89), and 0.88 (95% CI, 0.72-1.04); 0.79 (95% CI, 0.66-0.93), 0.65 (95% CI, 0.47-0.82), and 0.84 (95% CI, 0.67-1.01); and 0.82 (95% CI, 0.80-0.85), 0.73, and 0.79, respectively.

CONCLUSIONS

An automated, computer-based QUS technique diagnosed LE with accuracy of 0.82. This technique could provide quantitative biomarkers for the characterization of LE disease.

[Ultrasound of the elbow-standard examination technique and normal anatomy]

CLINICAL/METHODICAL ISSUE

Ultrasound of the elbow facilitates easily accessible evaluation of different pathologic conditions. The background for evaluating any pathologic state is the well-grounded knowledge of normal anatomy and standard ultrasound technique.

STANDARD RADIOLOGICAL METHODS/METHODICAL INNOVATIONS/PERFORMANCE

A unique feature of ultrasound compared to other imaging modalities of the elbow is the possibility of dynamic imaging, the examination of the patient at the bedside and the direct assessment of the contralateral side as a reference.

AIM

The aim of this article is to present standard ultrasound technique in examining the elbow. A four-quadrant model of the elbow is used and the recommendations of the DEGUM (German Society of Ultrasound in Medicine) and ESSR (European Society of Musculoskeletal Radiology) are followed.

Wrist Flexion Exercise Increases the Width of the Medial Elbow Joint Space During a Valgus Stress Test

OBJECTIVES

The medial elbow is stabilized during valgus loading by the ulnar collateral ligament, the flexor pronator mass (FPM), and the radial head. Impairment of the FPM can occur as a result of repeated wrist flexion activity. The purpose of this study was to determine the effect of repeated elbow flexion exercise on medial elbow stability.

METHODS

Thirty volunteers were included in this study. Ultrasound images of the medial joint space of the nondominant elbow of the participants were collected during a valgus stress test. The images were collected before and immediately after a wrist flexion exercise protocol.

RESULTS

The wrist flexion strength measure decreased (7.5%) after the exercise protocol (t = 3.840; P = .001). The medial elbow width increased between unstressed (mean ± SD, 2.8 ± 0.1 mm) and stressed (3.6 ± 0.1 mm) conditions (P < .001). The stress-by-fatigue interaction was significant (P = .048). The medial elbow width increased after fatigue (0.9 ± 0.09 mm) while remaining unchanged in the unstressed condition.

CONCLUSIONS

This study found an effect of repeated wrist flexion exercise on decreasing the stability of the medial elbow. Future research needs to explore the mechanisms leading to the decrease in medial elbow stability and to identify the effect of FPM fatigue on the development of medial elbow pain associated with activities.

Ultrasound-Assisted Assessment of Medial Elbow Stability

OBJECTIVES

An assessment of medial elbow stability is essential to the patient with an ulnar collateral ligament injury. Ultrasound imaging can be used to assess medial elbow stability. This study determined the effect of the elbow flexion angle on the medial elbow joint space during clinical tests of medial elbow stability.

METHODS

Ultrasound images of the nondominant elbow were collected during 3 tests of medial elbow stability: valgus stress test, weighted valgus test, and milking maneuver. The elbow flexion angle increased between the valgus stress test and milking maneuver. The width of the medial joint space was measured on ultrasound images collected in unstressed and stressed conditions.

RESULTS

Across test conditions, the medial joint width was greater in the stressed condition (mean ± SD, 3.7 ± 0.1 mm) than in the unstressed condition (2.9 ± 0.09 mm). The medial elbow joint space width was less (mean difference, 0.16 ± 0.01 mm; P = .01) in the milking maneuver position compared to the valgus stress test positions.

CONCLUSIONS

This study provides evidence that changes in the width of the medial elbow during clinical evaluation of the unimpaired elbow can be detected by ultrasound. Changing the elbow flexion angle did not affect the change in width of the medial elbow during valgus loading.

The spread of Injectate after ultrasound-guided lateral elbow injection - a cadaveric study

Background

Injections into the tendinous portion of the common extensor origin are a common intervention in the treatment of Lateral Elbow Tendinopathy (LET). Clinical trials report a heterogeneous selection of injectate volumes and delivery techniques, with systematic reviews finding no clear consensus. The aim of this study was to assess the intratendinous distribution and surrounding tissue contamination of ultrasound-guided injections into the Common Extensor Tendon (CET) of the elbow.

Methods

Twenty cadaveric elbows were injected by a Consultant Radiologist under Ultrasound guidance. Elbows were randomised to equal groups of 1 or 3 mls of methylene blue injection, delivered using single shot or fenestrated techniques. Following injection, each cadaver underwent a dry arthroscopy and dissection of superficial tissues. The CET was excised, set and divided into 1 mm sections using microtome. Each slice was photographed and analysed to assess spread and pixel density of injectate in four colour graduations. The cross-sectional area of distribution was calculated and compared between groups.

Results

In all 20 cadaveric samples, contamination of the joint was noted on arthroscopy and dissection. Injectate spread through over 97% of the cross-sectional area. No differences were found in intratendinous spread of injectate between differing volumes or techniques.

Conclusion

This study found that commonly used injection volumes and techniques distribute widely throughout cadaveric CETs. There was no improvement when the volume was increased from 1 to 3 mls or between single shot of fenestrated injection techniques. It should be noted that joint contamination using these techniques and volumes may be inevitable.

Electronic supplementary material

The online version of this article (10.1186/s40634-018-0142-8) contains supplementary material, which is available to authorized users.

Ultrasound-guided tendon fenestration versus open-release surgery for the treatment of chronic lateral epicondylosis of the elbow: protocol for a prospective, randomised, single blinded study

INTRODUCTION

Chronic lateral epicondylosis (CLE) of the elbow is a prevalent condition among middle-aged people with no consensus on optimal care management but for which surgery is generally accepted as a second intention treatment. Among conservative treatment options, ultrasound (US)-guided fenestration has shown encouraging results that should be explored before surgery is considered. The primary objective of this study is to compare the efficacy of US-guided fenestration with open-release surgery in patients with failure to improve following a minimum 6 months of conservative treatment.

METHODS AND ANALYSIS

This study protocol entails a two-arm, single-blinded, randomised, controlled design. Sixty-four eligible patients with clinically confirmed CLE will be assigned to either US-guided fenestration or open-release surgery. Fisher's exact test will be used to compare the proportion of patients reporting a change of 11/100 points or more in the Patient Rated Tennis Elbow Evaluation score at 6 months, according to an intention-to-treat analysis. Secondary analyses will compare the two treatment groups in terms of pain and disability, functional limitations at work, pain-free grip strength, medication burden, patients' global impression of change and level of satisfaction at 6 weeks, 3, 6 and 12 months, using mixed linear models for repeated measures or Fisher's exact test, as appropriate. Finally, recursive partitioning analyses will investigate US and elastography parameters as predictors of treatment success at 6 and 12 months. This data will contribute to evidence-based treatment guidelines for CLE and explore the value of imaging biomarkers to improve risk stratification plans and assist clinicians.

ETHICS AND DISSEMINATION

The study has been approved by the Research Ethics Board of our institution on 23 March 2016 (REB 15.327). In case of important protocol modifications, a new version of the protocol with appropriate amendments will be submitted to the REB for approval. Study results will be published in peer-reviewed journals and presented at local, national and international conferences.

TRIAL REGISTRATION NUMBER

NCT02710682.

Medial Elbow Joint Space Increases With Valgus Stress and Decreases When Cued to Perform A Maximal Grip Contraction

BACKGROUND

Previous research indicates that the amount of valgus torque placed on the elbow joint during overhead throwing is higher than the medial ulnar collateral ligament (UCL) can tolerate. Wrist and finger flexor muscle activity is hypothesized to make up for this difference, and in vitro studies that simulated activity of upper extremity musculature, specifically the flexor digitorum superficialis and flexor carpi ulnaris, support this hypothesis.

PURPOSE

To assess the medial elbow joint space at rest, under valgus stress, and under valgus stress with finger and forearm flexor contraction by use of ultrasonography in vivo.

STUDY DESIGN

Controlled laboratory study.

METHODS

Participants were 22 healthy males with no history of elbow dislocation or UCL injury (age, 21.25 ± 1.58 years; height, 1.80 ± 0.08 m; weight, 79.43 ± 18.50 kg). Medial elbow joint space was measured by use of ultrasonography during 3 separate conditions: at rest (unloaded), under valgus load (loaded), and with a maximal grip contraction under a valgus load (loaded-contracted) in both limbs. Participants lay supine with their arm abducted 90° and elbow flexed 30° with the forearm in full supination. A handgrip dynamometer was placed in the participants' hand to grip against during the contracted condition. Images were reduced in ImageJ to assess medial elbow joint space. A 2-way (condition × limb) repeated-measures analysis of variance and Cohen's d effect sizes were used to assess changes in medial elbow joint space. Post hoc testing was performed with a Bonferroni adjustment to assess changes within limb and condition.

RESULTS

The medial elbow joint space was significantly larger in the loaded condition (4.91 ± 1.16 mm) compared with the unloaded condition (4.26 ± 1.23 mm, P < .001, d = 0.712) and the loaded-contracted condition (3.88 ± 0.94 mm, P < .001, d = 1.149). No significant change was found between the unloaded and loaded-contracted conditions ( P = .137).

CONCLUSION

Medial elbow joint space increases under a valgus load and then decreases when a maximal grip contraction is performed. This indicates that wrist and finger flexor muscle contraction may assist in limiting medial elbow joint space, a result similar to findings of previous research in vitro.

CLINICAL RELEVANCE

Muscle activation of the upper extremity limits the medial elbow joint space, suggesting that injury prevention programs for throwing athletes should incorporate exercises for the elbow, wrist, and hand to limit excessive medial elbow joint space gapping during activities that create high valgus load.

The 2017 EULAR standardised procedures for ultrasound imaging in rheumatology

BACKGROUND

In 2001, the European League Against Rheumatism developed and disseminated the first guidelines for musculoskeletal (MS) ultrasound (US) in rheumatology. Fifteen years later, the dramatic expansion of new data on MSUS in the literature coupled with technological developments in US imaging has necessitated an update of these guidelines.

OBJECTIVES

To update the existing MSUS guidelines in rheumatology as well as to extend their scope to other anatomic structures relevant for rheumatology.

METHODS

The project consisted of the following steps: (1) a systematic literature review of MSUS evaluable structures; (2) a Delphi survey among rheumatologist and radiologist experts in MSUS to select MS and non-MS anatomic structures evaluable by US that are relevant to rheumatology, to select abnormalities evaluable by US and to prioritise these pathologies for rheumatology and (3) a nominal group technique to achieve consensus on the US scanning procedures and to produce an electronic illustrated manual (ie, App of these procedures).

RESULTS

Structures from nine MS and non-MS areas (ie, shoulder, elbow, wrist and hand, hip, knee, ankle and foot, peripheral nerves, salivary glands and vessels) were selected for MSUS in rheumatic and musculoskeletal diseases (RMD) and their detailed scanning procedures (ie, patient position, probe placement, scanning method and bony/other landmarks) were used to produce the App. In addition, US evaluable abnormalities present in RMD for each anatomic structure and their relevance for rheumatology were agreed on by the MSUS experts.

CONCLUSIONS

This task force has produced a consensus-based comprehensive and practical framework on standardised procedures for MSUS imaging in rheumatology.

Ultrasound evaluation of the ulnar collateral ligament of the elbow: Which method is most reproducible?

INTRODUCTION

The ulnar collateral ligament (UCL) is an important medial stabilizer of the elbow, particularly in overhead-throwing athletes. However, there is no universally accepted method for evaluating UCL thickness with ultrasound (US).

OBJECTIVE

To assess reproducibility of previously published methods, as well as a modified technique, for evaluating the UCL via US. We hypothesize that a modified technique would show greater reproducibility.

MATERIAL AND METHODS

Using US, the thickness of the UCL in 50 volunteers was measured by two musculoskeletal trained radiologists using two different measurement techniques. The techniques utilized were as described by Nazarian and Jacobson/Ward (JW). Technique measurements were evaluated using interclass correlation coefficients (ICC) to determine the reproducibility of each method. Twenty-eight of the subjects also underwent measurement via a modified JW technique, measured perpendicular to the ligament rather than the frame of imaging. This technique was also evaluated with ICC values.

RESULTS

The ICC value for the Nazarian technique was 0.82 (very good) and 0.51 (moderate) for the JW technique. When using the modified JW technique, we found an ICC value of 0.84 (very good). Mean ligament thickness was greatest with the Nazarian technique, 6.41 mm, with the JW technique measuring 1.86 mm and the modified technique measuring 1.38 mm.

CONCLUSION

US assessment of UCL thickness by all three measurement techniques are reproducible. The JW technique had less interobserver agreement when compared to the Nazarian method, whereas the modified JW technique had greater reproducibility compared to the JW technique and similar to the Nazarian technique.

Ultrasonographic Characteristics of the Common Extensor Tendon of the Elbow in Asymptomatic Individuals: Thickness, Color Doppler Activity, and Bony Spurs

Background:

Ultrasonography (US) of the common extensor tendon (CET) of the elbow is often part of the assessment of patients with lateral epicondylitis. This US assessment is currently based on general tendinopathy references and not well-defined US entities.

Purpose:

To describe CET thickness, color Doppler activity, and bony spurs on US in asymptomatic volunteers and to investigate the influence of sex, age, height, body mass index (BMI), weight, and elbow dominance on the measurements.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Tendon thickness, color Doppler activity, and bony spurs of the CET were measured sonographically in 264 adults (50% women) aged 20 to 96 years. Two different tendon-thickness measuring techniques were applied, labeled the “plateau measure” and the “1-cm measure.” Color Doppler activity was based on a 0 to 4 rating scale (negative, grades 0 and 1; positive, grades 2-4). A bony spur was defined as a bony outgrowth (≥0.3 mm) arising at the insertional site of the CET.

Results:

With both tendon-thickness measuring techniques, the CET in the dominant elbow was thicker than that in the nondominant elbow, and male tendons were thicker than female tendons (all P ≤ .03). In regression analysis, tendon thickness correlated with weight, color Doppler activity, and arm dominance for both measuring techniques in multiple regression analysis. In addition, the plateau measure correlated with height and the presence of bony spurs. No correlations were observed regarding BMI, sex, or age. Positive color Doppler activity was found in 9% of examined elbows, with no difference between the sexes regarding dominant versus nondominant elbows (all P ≥.20). Bony spurs were found to increase with age, from 23% for people in their 20s to 74% in people older than 70 years. Bony spurs were more common in the dominant elbow (P ≤ .01). Women had a higher prevalence of bony spurs than men, but only in the dominant elbow (P = .03).

Conclusion:

This study presents the US characteristics and normal values of the CET. In 264 asymptomatic participants, the CET was found to be thicker in men and in the dominant elbow. No difference in tendon thickness could be demonstrated with regard to different age groups. Color Doppler activity was found to be positive in nearly 1 of 10 asymptomatic subjects. Bony spurs were a common finding; they increased in prevalence with every decade in age and were considered part of the aging process. Normal variations in CET morphologic characteristics should therefore be considered when implementing US in trials and clinical practice.

Interobserver and intraobserver agreement of ligamentous injuries on conventional MRI after simple elbow dislocation

Background

The primary objective of this study was to assess the interobserver and intraobserver agreement on ligamentous injuries on conventional magnetic resonance imaging (MRI) in acute simple elbow dislocation. The secondary objectives were to determine the interobserver agreement on the assessment of joint congruity, joint effusion, loose bodies and chondral lesions on conventional MRI.

Methods

Conventional MRIs (1.5 Tesla, elbow specific surface coil) of 30 patients (40.7 years; range 14–72) with simple elbow dislocations were evaluated by four blinded examiners. An analysis of the interobserver agreement of all raters and for several subgroups (radiologists, orthopaedics, experienced, non-experienced) was performed. The examiners assessed the integrity (intact, partial tear, complete tear) of the lateral collateral ligament (LCL), medial collateral ligament (MCL), extensor and flexor tendons, as well as the presence of joint congruity, joint effusion, loose bodies and chondral lesions. Agreement strength, correlation and proportion of exact agreement were determined for interobserver agreement, and intraobserver agreement analyses.

Results

Interobserver agreement of all examiners was fair to moderate for collateral ligaments (LCL: 0.441, MCL: 0.275). Exact agreement of all raters was found in 33.3% for the LCL and in 26.7% for the MCL. The both experienced examiners showed highest agreement strength for the LCL (0.619) and the radiologists showed highest agreement strength for the MCL (0.627), the proportion of exact agreement was 60.0% in both categories. A high proportion of exact agreement regarding joint congruity (90%), joint effusion (100%), loose bodies (96.7%) and chondral lesion (80%) was found among the radiologists. The evaluation of the intraobserver agreement revealed slight to substantial agreement (0.227 to 0.718) for the collateral ligaments.

Conclusions

This study shows difficulties in the evaluation of ligaments by conventional MRI technique as demonstrated by a weak inter- and intraobserver agreement. This should be the basis to develop new MRI quality standards with special focus on coronal oblique reconstructions to improve the evaluation of ligament injuries after simple elbow dislocations.

Sonoelastography of the Common Flexor Tendon of the Elbow with Histologic Agreement: A Cadaveric Study

Purpose To determine the correlation of the results of conventional B-mode ultrasonography (US) and compression sonoelastography with histologic results in common flexor tendons of the elbow in human cadavers. Materials and Methods Twenty-five common flexor tendons were evaluated in 16 fresh, unembalmed cadavers of 11 women with a median age of 85 years (range, 71-101 years) and five men with a median age of 78 years (range, 70-88 years). Informed consent was provided according to the last will of the donors. B-mode US results were classified as grade 1, normal tendon with homogeneous fibrillar pattern; grade 2, tendon thickening or hypoechoic areas and/or calcifications in less than 30% of the tendon; or grade 3, hypoechoic areas and/or calcifications greater than 30% of the tendon. Sonoelastographic results were grade 1, blue (hardest) to green (hard); grade 2, yellow (soft); and grade 3, red (softest). The intraclass correlation coefficient was calculated to determine agreement with histologic findings for each B-mode US, sonoelastographic, and combined B-mode US and sonoelastographic examination. Histologic results were grade 1, normal, with parallel fibrillar pattern; grade 2, mild tendinopathy, with cellular infiltration, angiogenesis, or fatty vacuoles; or grade 3, severe tendinopathy, with loss of parallel collagen structure and necrosis. Results Histologic alterations were detected in 44% (11 of 25) of biopsy specimens. Intraclass correlation with histologic results was 0.57 for B-mode US, 0.68 for sonoelastography, and 0.84 for the combination of the two approaches. Conclusion The addition of sonoelastography to B-mode US provided statistically significant improvement in correlation with histologic results compared with the use of B-mode US alone (P < .02). ^© RSNA, 2016 Online supplemental material is available for this article.

The morphologic change of the ulnar collateral ligament of elbow in high school baseball pitchers, with and without symptoms, by sonography

BACKGROUND

Few reports in the literature relate morphologic changes of the ulnar collateral ligament (UCL) to prior elbow symptoms. This study used ultrasonography (US) to assess the ulnohumeral joint space width, with and without stress, and elucidate morphologic changes of the UCL of the elbow in high school pitchers with and without a history of elbow symptoms.

METHODS

Each of 122 high school baseball pitchers who underwent US of the medial aspect of both elbows completed a self-administered questionnaire related to the self-satisfaction score (0-100) for pitching performance and throwing-related elbow joint pain sustained during the prior 3 years. We conducted gravity stress US elbow examination with 30° of flexion with and without valgus stress. Comparisons of the UCL thickness and ulnohumeral joint space width, with and without valgus stress, were made among the 122 high school pitchers with and without a history of elbow symptoms.

RESULTS

Pitchers with an elbow symptom history exhibited a greater difference between the UCL thickness on the throwing side than those with no elbow symptom history (P = .0013). A negative significant association was found between UCL thickness on the pitching side and the self-evaluation score for pitching performance (r = -0.20, P = .04).

CONCLUSIONS

US assessment demonstrated that the UCL in the dominant side with elbow symptom history was thicker than that with no elbow symptom history. The UCL thickness might reflect the prior pitching condition of high school baseball pitchers.

Ultrasonic Observation and Clinical Application of Arcade of Struthers in the Mid-Arm

BACKGROUND

The mid-arm structure named arcade of Struthers has been shrouded in controversy since it was identified. Most specimens in previous studies were European. The occurrence, component, extent, and position of this structure in the xanthoderm are not clear. Moreover, research into the arcade of Struthers has been at the anatomic level and there has been no ultrasonic research. The aim of this study was to elucidate and measure this anatomy by both anatomic dissection and ultrasonic observation to provide clear and definite criteria to classify the arcade of Struthers, as well as operation guidelines for identifying the arcade of Struthers in ultrasonic imaging and surgical decompression.

METHODS

Sixty-four upper limb specimens of 32 adult cadavers were dissected. The tendinous arcade of Struthers (TAS) and muscular arcade of Struthers (MAS) were observed and measured, as well as the position at which the medial intermuscular septum was pierced by the ulnar nerve. The position at which the concomitant blood vessel began to accompany the ulnar nerve was also recorded. Twenty healthy adult participants were enrolled for ultrasonic research. The ulnar nerve was scanned from the cubital tunnel to the fossa axillaris for the anatomic structure crossing it. Once the arcade of Struthers was found, the distal and proximal limits were marked on the skin and it was then measured.

RESULTS

Anatomic study showed TASs in 21 limbs, and MASs were found in 16 limbs. The total incidence of the arcade of Struthers was 57.8%. The length of TAS (2.12 ± 0.62 cm) and MAS (4.46 ± 1.96 cm) had a significant difference and the distance between its proximal limit and the medial humeral epicondyle were 8.93 ± 1.38 cm and 9.50 ± 1.69 cm, respectively. Ultrasonic study showed that the incidence of the arcade of Struthers was 50.0%. The distance between its proximal limit and the medial humeral epicondyle was 8.52 ± 1.88 cm and 9.45 ± 1.76 cm. The length was 1.85 ± 1.8 cm and 4.23 ± 1.93 cm, respectively.

CONCLUSIONS

We believed that an arcade of Struthers described by multiple investigators did exist in Chinese people, and based on our study, it was classified into 2 types: TAS and MAS. Caution should be used to preserve the superior ulnar collateral artery when incising the arcade of Struthers. Ultrasonography can detect the existence ratio, dimension, and location of the arcade of Struthers.

Management of Lateral Elbow Tendinopathy: One Size Does Not Fit All

Synopsis Clear guidelines for the clinical management of individuals with lateral elbow tendinopathy (LET) are hampered by many proposed interventions and the condition's prognosis, ranging from immediate resolution of symptoms following simple advice in some patients to long-lasting problems, regardless of treatment, in others. This is compounded by our lack of understanding of the complexity of the underlying pathophysiology of LET. In this article, we collate evidence and expert opinion on the pathophysiology, clinical presentation, and differential diagnosis of LET. Factors that might provide prognostic value or direction for physical rehabilitation, such as the presence of neck pain, tendon tears, or central sensitization, are canvassed. Clinical recommendations for physical rehabilitation are provided, including the prescription of exercise and adjunctive physical therapy and pharmacotherapy. A preliminary algorithm, including targeted interventions, for the management of subgroups of patients with LET based on identified prognostic factors is proposed. Further research is needed to evaluate whether such an approach may lead to improved outcomes and more efficient resource allocation. J Orthop Sports Phys Ther 2015;45(11):938-949. Epub 17 Sep 2015. doi:10.2519/jospt.2015.5841.

A systematic, multimodality approach to emergency elbow imaging

The elbow is a complex synovial hinge joint that is frequently involved in both athletic and nonathletic injuries. A thorough understanding of the normal anatomy and various injury patterns is essential when utilizing diagnostic imaging to identify damaged structures and to assist in surgical planning. In this review, the elbow anatomy will be scrutinized in a systematic approach. This will be followed by a comprehensive presentation of elbow injuries that are commonly seen in the emergency department accompanied by multimodality imaging findings. A short discussion regarding pitfalls in elbow imaging is also included.

Elbow US: Anatomy, Variants, and Scanning Technique

As with other musculoskeletal joints, elbow ultrasonography (US) depends on the examination technique. Deep knowledge of the relevant anatomy, such as the bone surface anatomy, tendon orientation, nerves, and vessels, is crucial for diagnosis. It is important to be aware of the primary imaging pitfalls related to US technique (anisotropy) in the evaluation of deep tendons such as the distal biceps and peripheral nerves. In this article, US scanning technique for the elbow as well as the related anatomy, primary variants, and scanning pitfalls are described. In addition, an online video tutorial of elbow US describes a possible approach to elbow evaluation. Online supplemental material is available for this article.

Optimal Elbow Angle for Sonographic Visualization of the Ulnar Collateral Ligament

OBJECTIVE

To formally examine the sonographic appearance of the elbow ulnar collateral ligament (UCL) at 30° versus 70° of elbow flexion in asymptomatic baseball pitchers.

DESIGN

A prospective, cross-sectional design.

SETTING

Sports medicine clinic in a tertiary academic medical center.

PARTICIPANTS

Thirty asymptomatic adolescent baseball pitchers 13-18 years of age (mean 15.8 years), with at least 3 years of continuous pitching experience and no significant history of elbow pain or injury.

METHODS

Static sonographic images of the bilateral UCLs were obtained at 30° and 70° of elbow flexion by a single experienced examiner. Images were anonymized and randomized into a slide set. Three clinicians with different levels of ultrasound experience reviewed the static 30° and 70° images for each elbow and chose their preferred image based on UCL conspicuity. The clinicians reviewed a re-randomized slide set 1 week later. A different study co-investigator measured UCL cross-sectional area (CSA) on all images using ultrasound machine electronic calipers.

MAIN OUTCOME MEASURES

Preference for the sonographic conspicuity of the UCL at 30° versus 70° of elbow flexion, and UCL CSA at 30° versus 70° of flexion.

RESULTS

Each clinician demonstrated a significant preference for UCL images obtained at 70° of flexion when compared to those obtained at 30° (80.3% overall preference for 70°, P < .001). There was no statistically significant effect of clinician experience or arm dominance on image preference. The sonographically determined CSA of the UCLs were on average 1.4 mm(2) greater at 70° than at 30° of flexion (P < .001) when combining dominant and nondominant arms.

CONCLUSIONS

Static sonographic evaluation of the UCL at 70° of elbow flexion should be integrated into UCL imaging protocols. Furthermore, when performing sonographically guided procedures targeting the UCL, clinicians should consider positioning the elbow at >30° of flexion to optimize UCL conspicuity and CSA.