Anterior and posterior bands of the anterior bundle in the elbow ulnar collateral ligament: ultrasound anatomy

The advantages of utilizing different ultrasound imaging techniques on joints of human cadavers in the teaching of anatomy - A scoping review

BACKGROUND

A common approach to define sonoanatomy is a reciprocal exchange of macroscopic and microscopic information in ultrasound imaging. High-resolution ultrasound has been long established and is crucial as an inexpensive and adaptable tool, not just in clinical settings but also while teaching anatomy. Early application of ultrasonography provides medical students with a couple of benefits: they acquire an improved understanding of anatomy and learn how to use it.

METHODS

A comprehensive literature review has been carried out, with relevant studies discovered in the following databases: MEDLINE, EMBASE, CENTRAL, BIOSIS Previews and Web of Science Core Collection. Gray literature was also considered in two different ways: (1) Regarding grey literature databases: National Gray Literature Collection. (2) For PhD theses and dissertations, the databases EThOS and Open Access Theses and Dissertations were screened for relevant studies by combining the keywords used in the search string. The reference lists of all relevant papers were scanned. Search process was performed on January 3rd, 2023. The search string was developed with the aid of and finally checked by a professional librarian. Only ultrasound studies on human cadavers were included, not animals or phantoms. If the studied subject was a joint, the article was included. Only B-Mode ultrasound was included, whereas Elastosonography, Doppler sonography and quantitative approaches including among others sound speed, backscatter attenuation were excluded. Intravascular, intraosseous, intraarticular, and three-dimensional or four-dimensional ultrasonography were also eliminated from the analysis. All appropriate information comprising articles, PhD theses, dissertations and chapters in textbooks were considered. There were solely English and German studies covered. There was no additional restriction on the publishing year. The included studies' general characteristics and ultrasound techniques were taken from them and examined. Using VOS viewer, a keyword analysis was also carried out.

RESULTS

142 of the 8899 results that were returned by the search satisfied the requirements. With a quarter of the included studies, the knee joint was the most extensively studied joint, followed by the elbow joint (10.6%) and the shoulder joint (9.2%). The methodological analysis includes 125 studies. Both the sample size and the ultrasonographer's qualifications were diverse. The probe position and the ultrasound method were precisely documented so that a reader could duplicate them in about three-quarters of the included studies (72.8%).

CONCLUSION

The current study, in our perspective, is the first scoping review to screen ultrasound studies on human cadaver joints. A heterogeneous field was shown by the methodological investigation. We suggest using a uniform method for conducting and presenting ultrasound examinations in future studies.

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.

Validation study of novel grading system for ulnar collateral ligament injury of the elbow with high-resolution magnetic resonance imaging

Background

Recently, magnetic resonance imaging (MRI) classification of medial ulnar collateral ligament (UCL) tears has been introduced, but little is known about the relationship between MRI grading and medial joint laxity. It has been reported that microscopy coils could make it possible to achieve high-resolution images of upper extremities with a superior diagnostic ability to conventional MRI. However, there is no report that has compared the diagnostic reliability between microscopic and conventional MRI. The purpose of this study was to assess the relationship between MRI findings and medial joint laxity evaluated with stress ultrasound (US). Secondary objective was to compare the reliabilities of UCL evaluation between microscopic and conventional MRI.

Methods

One-hundred thirty baseball players who underwent MRI of the elbow for the diagnosis of UCL injury using both conventional and microscopy MRI were included in this study. They also underwent stress US for assessment of medial joint laxity against valgus stress. Our MRI grading system for UCL injuries was compared to medial joint laxity evaluated with stress US. The intrarater and interrater reliabilities of our grading system were assessed with both microscopic and conventional MRI.

Results

Our grading system was related to valgus stability, especially with microscopic MRI. The reliabilities were fair when combined with microscopic MRI, which exhibited better intrarater and interrater reliabilities than conventional MRI.

Conclusion

High-resolution microscopic MRI may contribute to the accurate diagnosis of UCL injuries.

Risk factors for throwing elbow injuries during pitching analyzed by simulation using human musculoskeletal model in youth baseball pitchers

BACKGROUND

Pitching mechanics are believed to be risk factors for throwing elbow injury. Thus, a prospective study of abnormal mechanics in youth baseball players is needed. This study aimed to analyze the ulnar collateral ligament during normal pitching using SIMM (Software for Interactive Musculoskeletal Modeling) for analysis and investigate the risk parameters of throwing elbow injuries in youth baseball players. We hypothesized that excessive ulnar collateral ligament force during pitching would be a risk factor for throwing elbow injuries in this population.

METHODS

In this cohort study, youth baseball pitchers (aged 9-11 years) were instructed to throw a ball into a netted target. Using a SIMM musculoskeletal model, we analyzed the force of the anterior band of the anterior oblique ligament, posterior band of the anterior oblique ligament (AOL_PB), and elbow varus moment during pitching (foot contact to ball release). We calculated the integral of each force of the anterior band of the anterior oblique ligament and AOL_PB during pitching and summarized these data to establish an impulse at the medial epicondyle. Each participant was followed up for 12 months to assess the occurrence of throwing elbow injury.

RESULTS

During the 12-month follow-up period, 18 pitchers (28.1%) reported throwing elbow injuries in the throwing arm. The results of this study showed that the maximum AOL_PB force and the impulse at the medial epicondyle were risk factors for throwing elbow injuries. The maximum AOL_PB force was significantly higher in the throwing elbow injury group than in the uninjured group (59.4 ± 17.8 N vs. 47.1 ± 17.5 N, P = .014). The impulse at the medial epicondyle was also significantly different (11.1 ± 4.0 N ･ s in the throwing elbow injury group vs. 8.3 ± 4.4 N ･ s in the uninjured group, P = .025).

CONCLUSIONS

Increasing the AOL_PB force or the impulse at the medial epicondyle may increase the risk of throwing elbow injuries in youth baseball pitchers. It may be possible to reduce injury risk by focusing on ways to decrease AOL_PB load and cumulative stress on the medial epicondyle throughout the throwing motion while still maintaining high levels of ball velocity.

Magnetic resonance imaging of the elbow

Elbow pain can cause disability, especially in athletes, and is a common clinical complaint for both the general practitioner and the orthopaedic surgeon. Magnetic resonance imaging (MRI) is an excellent tool for the evaluation of joint pathology due to its high sensitivity as a result of high contrast resolution for soft tissues. This article aims to describe the normal imaging anatomy and biomechanics of the elbow, the most commonly used MRI protocols and techniques, and common MRI findings related to tendinopathy, ligamentous and osteochondral injuries, and instability of the elbow.

The pathoanatomy of the anterior bundle of the medial ulnar collateral ligament

BACKGROUND

The purpose of this study was to increase our understanding of the pathoanatomy of the ulnar collateral ligament (UCL) by performing a descriptive analysis of the surgical inspection of the anterior bundle in patients undergoing reconstruction.

METHODS

A single-surgeon series of 163 patients who underwent UCL reconstruction between 2009 and 2017 was retrospectively analyzed. Descriptions of the pathoanatomy of injury were obtained from the operative reports. Magnetic resonance imaging data were reviewed to assess whether the presence and location of tissue disruptions were accurately recognized. Demographic and clinical characteristics were obtained from medical records and correlated to observed pathoanatomy.

RESULTS

Injuries to the anterior bundle were characterized by a single tissue disruption (65%), tissue disruptions at more than 1 location (23%), or injuries without distinct fiber tissue disruptions (12%). The presence and location of tissue disruptions matched magnetic resonance imaging findings in 124 of 153 patients (81%). Partial tears more frequently affected the anterior band of the anterior bundle distally as opposed to the posterior band of the anterior bundle proximally (P = .012). Patients with single tissue disruptions more frequently reported a popping sensation than patients with non-tear insufficiency (P = .030).

CONCLUSIONS

This study shows the heterogeneity of anterior bundle injuries in patients undergoing UCL reconstruction. A variety of injury configurations and chronic attritional damage to the anterior bundle were observed, as well as distinct tear patterns at the distal and proximal attachment sites. Future research may elucidate the diagnostic value of a pop sign for UCL injury.