Prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers.

BACKGROUND: Radiographic and physical examination findings of ulnar nerve instability have been recognized in overhead throwing athletes, despite the fact that some of these abnormalities may be asymptomatic and represent adaptive changes. While recommendations for screening and early detection have been made that can adversely impact an athletes' career, the presence of bilateral ulnar nerve subluxation and its relationship with medial elbow symptoms has not been characterized in professional overhead throwing athletes. PURPOSE: To characterize the prevalence of bilateral ulnar nerve subluxation among professional baseball pitchers. METHODS: A cross-sectional observational analysis was conducted utilizing standardized ultrasonographic examinations of bilateral elbows in 91 consecutive professional baseball pitchers (median age, 22 years; range, 17-30 years). The relationship between ulnar nerve subluxation and ulnar nerve signs, symptoms, and provocative physical examination maneuvers was also investigated. RESULTS: The prevalence of bilateral ulnar nerve subluxation was 26.4% (95% CI, 17.7%-36.7%; 24 of the 91 athletes). Thirty-five athletes (38.5%; 95% CI, 28.4%-49.2%) had subluxation in at least 1 elbow. No athletes with subluxation had positive ulnar nerve signs, symptoms, or provocative tests. CONCLUSION: Ulnar nerve subluxation is common among professional pitchers, and is more often than not bilateral. In this population of athletes, ulnar nerve subluxation does not appear to be associated with pathological findings.

Physical Examination Versus Ultrasonography for Detection of Ulnar Nerve Subluxation in Professional Baseball Pitchers.

Background: Despite the importance of accurately detecting ulnar nerve subluxation in vulnerable athletes, few studies have compared the performance of physical examination and ultrasound in this population. Purpose/Hypothesis: The purpose of this study was to compare the diagnostic validity of physical examination versus ultrasound in detecting ulnar nerve subluxation at the cubital tunnel of the elbow in professional baseball pitchers. It was hypothesized that ultrasound would more sensitively detect ulnar nerve subluxation. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Physical and sonographic examinations for ulnar nerve subluxation were performed on 186 elbows of 95 consecutive male professional baseball pitchers (age, 17-30 years) as a routine part of their spring training assessments. Provocative maneuvers consisting of the Tinel and elbow flexion-compression tests were evaluated over the cubital tunnel. The validity of physical examination for detecting ulnar nerve subluxation at the elbow was determined using ultrasonographic examination for comparison. Results: Ulnar nerve subluxation was detected by physical examination in 58 (31.2%) elbows and by ultrasonography in 61 (32.8%) elbows. Of the 58 elbows with positive physical examination, 47 were positive on ultrasound. Using a positive ultrasound as a reference, the accuracy of the physical examination was 86.6%, with 77% sensitivity and 91.2% specificity. The positive and negative predictive values of physical examination were 81% and 89.1%, respectively. There was no relationship between nerve instability and positive provocative tests overall, in dominant versus nondominant arms, or in right versus left arms (P > .05 for all). Conclusion: Physical examination had moderate sensitivity and high specificity for detecting ulnar nerve subluxation at the cubital tunnel of the elbow when compared with ultrasound. These findings suggest that when detecting the presence of a subluxating ulnar nerve is most important, it may be advisable to obtain an ultrasound evaluation instead of relying on a physical examination; however, physical examination alone may be appropriate for ruling out subluxation.

In Vivo Effect of Partial Ulnar Collateral Ligament Tear Location on Ulnohumeral Joint Gapping With Stress Ultrasound in Baseball Pitchers.

BACKGROUND: Stress ultrasonography (SUS) has provided clinicians with an alternative means of evaluating ulnar collateral ligament (UCL) injury by dynamically assessing ulnohumeral joint space gapping under applied valgus stress. However, 3 previous cadaveric studies have evaluated the biomechanical effect of partial UCL tears at different anatomic locations with conflicting results. PURPOSE/HYPOTHESIS: The purpose of this study was to use in vivo data from patients with magnetic resonance (MR)-confirmed partial UCL tears to determine if anatomic partial tear location influenced the resultant stability of the elbow in terms of ulnohumeral joint gapping on SUS. It was hypothesized that no difference would be seen in the amount of ulnohumeral joint gapping based on MR-identified anatomic partial UCL tear location. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients diagnosed with elbow injury from 2015 to 2020 were screened to identify competitive baseball pitchers with a partial UCL tear who received an SUS. Partial UCL tear was diagnosed via surgeon and radiologist interpretation of elbow MR imaging (MRI) as well as confirmation at the time of surgery as documented in the operative report. Demographic, injury, and treatment data were collected from the clinic notes, MRI reports, and stress ultrasound reports. Ulnohumeral joint gapping on SUS was calculated as the difference between ulnohumeral joint gapping without valgus stress versus ulnohumeral joint gapping with valgus stress (delta) as performed by a musculoskeletal radiologist. RESULTS: Overall, 60 male baseball pitchers (age, 19.2 ± 2.1 years), including 22 (37%) high school, 26 (43%) collegiate, and 12 (20%) professional pitchers, were evaluated. Regarding the location of partial UCL tears, 32 (53%) pitchers had proximal tears and 28 (47%) had distal tears. The mean delta value cohort was 2.1 ± 1.1 mm, and 34 pitchers (57%) had delta values >2.0 mm. Ulnohumeral joint gapping (high school [1.9 mm] vs collegiate [2.6 mm] vs professional [1.6 mm]; P = .004) and the percentage of pitchers with delta values >2.0 mm (45% vs 77% vs 33%; P = .017) differed based on level of competition. After controlling for age, body mass index, and level of competition in a multivariate linear regression, tear location was not related to ulnohumeral joint gapping (P = .499). CONCLUSION: No difference was observed in the amount of ulnohumeral joint gapping on SUS in symptomatic baseball pitchers with MR-identified partial UCL tears at differing anatomic locations. The findings of this study are contrary to previous cadaveric studies that have evaluated the effects of UCL tear characteristics on delta laxity.

Ultrasonography of the pediatric elbow.

Ultrasound of the elbow can be incorporated into routine pediatric practice in the radiology department, emergency department, orthopedic clinic, and interventional suite. Ultrasound is complementary to radiography and magnetic resonance imaging for the evaluation of elbow pain in athletes with overhead activities or valgus stress, focusing on the ulnar collateral ligament medially and capitellum laterally. As a primary imaging modality, ultrasound can be used for a variety of indications including inflammatory arthritis, fracture diagnosis, and ulnar neuritis/subluxation. Ultrasound is also well-suited to guide diagnostic and therapeutic elbow joint interventions with precise localization of anatomic landmarks and needle placement. Here, we describe technical aspects of elbow ultrasound and illustrate its application in pediatric patients from infants to teen athletes.

Use of High-Resolution Ultrasound to Guide Alcohol Neurolysis for Chronic Pain.

BACKGROUND: The diagnosis and treatment of neuropathic pain is often clinically challenging, with many patients requiring treatments beyond oral medications. To improve our percutaneous treatments, we established a clinical pathway that utilized ultrasound (US) guidance for steroid injection and alcohol ablation for patients with painful neuropathy. OBJECTIVES: To describe a collaborative neuropathy treatment pathway developed by a neurosurgeon, pain physicians, and a sonologist, describing early clinical experiences and patient-reported outcomes. STUDY DESIGN: A retrospective case series was performed. METHODS: Patients that received percutaneous alcohol ablation with US guidance for neuropathy were identified through a retrospective review of a single provider's case log. Demographics and treatment information were collected from the electronic medical record. Patients were surveyed about their symptoms and treatment efficacy. Descriptive statistics were expressed as medians and the interquartile range ([IQR]; 25th and 75th data percentiles). Differences in the median follow-up pain scores were assessed using a Wilcoxon signed-rank test. RESULTS: Thirty-five patients underwent US-guided alcohol ablation, with the average patient receiving one treatment (range: 1 to 2), having a median duration of 4.8 months until reinjection (IQR: 2.9 to 13.1). The median number of steroid injections that individuals received before US-guided alcohol ablation was 2 (IQR: 1 to 3), and the median interval between steroid injections was 3.7 months (IQR: 2.0 to 9.6). Most (20/35 [57%]) patients responded to the survey, and the median pain scores decreased by 3 units (median: -3, IQR: -6 to 0; P < 0.001) one week following the alcohol ablation. This pain reduction remained significant at one month (P < 0.001) and one year (P = 0.002) following ablation. Most (12/20 [60%]) patients reported that alcohol ablation was more effective in improving their pain than oral pain medications. LIMITATIONS: Given the small sample size, treatment efficacy for alcohol neurolysis cannot be generalized to the broader population. CONCLUSIONS: US-guided percutaneous treatments for neuropathic pain present a growing opportunity for interprofessional collaboration between neurosurgery, clinicians who treat chronic pain, and sonologists. US can provide valuable diagnostic information and guide accurate percutaneous treatments in skilled hands. Further studies are warranted to determine whether a US-guided treatment pathway can prevent unnecessary open surgical management.

International consensus conference recommendations on ultrasound education for undergraduate medical students.

OBJECTIVES: The purpose of this study is to provide expert consensus recommendations to establish a global ultrasound curriculum for undergraduate medical students. METHODS: 64 multi-disciplinary ultrasound experts from 16 countries, 50 multi-disciplinary ultrasound consultants, and 21 medical students and residents contributed to these recommendations. A modified Delphi consensus method was used that included a systematic literature search, evaluation of the quality of literature by the GRADE system, and the RAND appropriateness method for panel judgment and consensus decisions. The process included four in-person international discussion sessions and two rounds of online voting. RESULTS: A total of 332 consensus conference statements in four curricular domains were considered: (1) curricular scope (4 statements), (2) curricular rationale (10 statements), (3) curricular characteristics (14 statements), and (4) curricular content (304 statements). Of these 332 statements, 145 were recommended, 126 were strongly recommended, and 61 were not recommended. Important aspects of an undergraduate ultrasound curriculum identified include curricular integration across the basic and clinical sciences and a competency and entrustable professional activity-based model. The curriculum should form the foundation of a life-long continuum of ultrasound education that prepares students for advanced training and patient care. In addition, the curriculum should complement and support the medical school curriculum as a whole with enhanced understanding of anatomy, physiology, pathophysiological processes and clinical practice without displacing other important undergraduate learning. The content of the curriculum should be appropriate for the medical student level of training, evidence and expert opinion based, and include ongoing collaborative research and development to ensure optimum educational value and patient care. CONCLUSIONS: The international consensus conference has provided the first comprehensive document of recommendations for a basic ultrasound curriculum. The document reflects the opinion of a diverse and representative group of international expert ultrasound practitioners, educators, and learners. These recommendations can standardize undergraduate medical student ultrasound education while serving as a basis for additional research in medical education and the application of ultrasound in clinical practice.

Ultrasonography of Superficial Soft-Tissue Masses: Society of Radiologists in Ultrasound Consensus Conference Statement.

The Society of Radiologists in Ultrasound convened a panel of specialists from radiology, orthopedic surgery, and pathology to arrive at a consensus regarding the management of superficial soft-tissue masses imaged with US. The recommendations in this statement are based on analysis of current literature and common practice strategies. This statement reviews and illustrates the US features of common superficial soft-tissue lesions that may manifest as a soft-tissue mass and suggests guidelines for subsequent management.

Recommended Musculoskeletal and Sports Ultrasound Terminology: A Delphi-Based Consensus Statement.

OBJECTIVES: The current lack of agreement regarding standardized terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice, and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. METHODS: A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus which was defined as group level agreement >80%. RESULTS: Content was organized into seven general topics including: 1) General Definitions, 2) Equipment and Transducer Manipulation, 3) Anatomic and Descriptive Terminology, 4) Pathology, 5) Procedural Terminology, 6) Image Labeling, and 7) Documentation. Terms and definitions which reached consensus agreement are presented herein. CONCLUSIONS: The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients, and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

Shear wave elastography assessment and comparison study of the Achilles tendons in optimally conditioned asymptomatic young collegiate athletes.

OBJECTIVE: To assess the functional parameters of the Achilles tendons among asymptomatic college level athletes using shear wave elastography (SWE) and to describe the relationship to athlete demographics and anthropometric lower extremity measurements. MATERIAL AND METHODS: Sixty-five athletes were included in this IRB-approved study. SWE measurements were made on two tendon positions (neutral state and active maximum dorsiflexion) with two different probe orientations (longitudinal and transverse). Associations were assessed with BMI, tibial/foot length, type of sports, and resting/maximal dorsiflexion-plantar flexion angles. RESULTS: Thirty-five (53.8%) males and 30 (46.2%) females with an overall mean age of 20.9 years (± 2.8), mean height of 176 cm (± 0.11), and mean weight of 74.1 kg (± 12) were studied. In the neutral state, the mean wave velocity of 7.5 m sec-1 and the mean elastic modulus of 176.8 kPa were recorded. In active maximum dorsiflexion, the mean velocity was 8.3 m sec-1 and mean elastic modulus was 199 kPa. On the transverse view, the mean velocity and elastic measurements were significantly lower (p = 0.0001). No significant differences in SWE parameters were seen between male and female athletes regardless of probe orientation (p < 0.05) with SWE values being higher in the running group vs non-running group (p < 0.05). In neutral state, longitudinal SWE measurements correlated with the tibia-foot length whereas transverse measurements correlated with the tendon diameter and ankle resting angle (ARA) (p < 0.005). CONCLUSION: SWE can distinguish functional differences in Achilles tendon stiffness between athletes engaged in running-intensive sports compared with other athletes.

Ultrasonographic Technique, Appearance, and Diagnostic Accuracy for Common Shoulder Sports Injuries: A Narrative Review.

¼: Ultrasonography (US) is valued for its availability, tolerability, low cost, and utility in real-time dynamic evaluation. Its use in diagnosing upper-extremity shoulder injury has expanded, but several features require definition before more widespread adoption can be realized. ¼: In particular, the evaluation of rotator cuff tears (RCTs) with US has been extensively studied, and authors generally agree that US is comparable with magnetic resonance imaging for the detection of full-thickness RCTs, whereas partial-thickness RCTs are more difficult to accurately identify with US. Dynamic evaluation is particularly useful for pathologies such as subacromial impingement and glenohumeral instability. ¼: US has shown particular usefulness for the assessment of athletes, where there is additional motivation to delay more invasive techniques. US has demonstrated promising results as a diagnostic modality for common shoulder injuries in athletes, and it is an important imaging tool that complements a thorough history and physical examination.

Minimally Invasive Ultrasound-Guided Carpal Tunnel Release Improves Long-Term Clinical Outcomes in Carpal Tunnel Syndrome.

BACKGROUND. Ultrasound guidance allows performance of carpal tunnel release with smaller incisions and quicker recovery than traditional open or endoscopic surgery. OBJECTIVE. The purpose of this study was to evaluate the long-term effectiveness of ultrasound-guided carpal tunnel release in improving function and discomfort in patients with carpal tunnel syndrome. METHODS. Retrospective review was conducted of 61 ultrasound-guided carpal tunnel release procedures performed on 46 patients (15 bilateral procedures) with clinically diagnosed carpal tunnel syndrome. The procedures were performed with a single-use transection device and local anesthesia at an outpatient radiology office. Patients answered three questionnaires (Quick Disabilities of the Arm, Shoulder, and Hand [QDASH] and two parts of the Boston Carpal Tunnel Syndrome Questionnaire-the symptom severity [BCTSQ-SS] and functional status [BCTSQ-FS] scales) to assess the function of and discomfort in the affected wrist immediately before and 2 weeks and at least 1 year after the procedure. Higher scores indicated increasing disability. Patients also answered a global satisfaction question at follow-up. Preprocedure and postprocedure scores were compared by paired Wilcoxon signed rank tests. RESULTS. The 46 patients (25 women, 21 men; mean age, 60.6 years; range, 21-80 years) had median preprocedure scores of 45.4 for QDASH, 3.2 for BCTSQ-SS, and 2.5 for BCTSQ-FS. The median scores 2 weeks after the procedure were 22.5 for QDASH, 1.7 for BCTSQ-SS, and 1.9 for BCTSQ-FS. All scores decreased (p < .001) from preprocedure scores and surpassed reference standards for clinically important difference in scores. Follow-up questionnaires obtained for 90% (55/61) of wrists a median of 1.7 years (range, 1.0-2.8 years) after the procedure showed further declines (p < .001) in median scores: 2.3 for QDASH, 1.2 for BCTSQ-SS, and 1.1 for BCTSQ-FS. At long-term follow-up evaluation, 96% (52/54) of wrists had lower QDASH and 98% (53/54) had lower BCTSQ (average of BCTSQ-SS and BCTSQ-FS) scores compared with the preprocedure scores. Among the patients who participated in the survey, 93% (37/40) were satisfied or very satisfied with the long-term outcomes. No immediately postoperative complications occurred. Two patients needed surgical intervention 8 and 10 days after surgery, one for infection after injury and one for posttraumatic compartment syndrome. CONCLUSION. Ultrasound-guided carpal tunnel release quickly improves hand function and reduces hand discomfort; improvement persists beyond 1 year. CLINICAL IMPACT. Ultrasound-guided carpal tunnel release may be a safe, effective, and less invasive alternative to traditional surgery.

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.

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.

Medial Elbow Instability Resulting From Partial Tears of the Ulnar Collateral Ligament: Stress Ultrasound in a Cadaveric Model.

BACKGROUND: There is consensus that most complete ulnar collateral ligament (UCL) injuries in throwers would benefit from surgical intervention. Optimal treatment for partial UCL tears remains controversial. Stress ultrasonography has become a well-accepted diagnostic modality for assessing UCL injury. HYPOTHESIS: Partial UCL tears will result in an intermediate increase in ulnohumeral joint space gapping as compared with that of an intact UCL and a complete UCL tear, but the degree of joint space gapping will vary by anatomic location of the partial tear. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-one cadaveric elbows were divided into 7 groups representing different anatomic locations of UCL partial tears. Partial tears were simulated by cutting 50% of the measured width of the UCL at 6 locations: distal anterior/posterior, midsubstance anterior/posterior, and proximal anterior/posterior. A seventh partial tear was created by partially elevating the undersurface of the distal UCL to simulate the radiographic "T-sign." Valgus stress (15 daN) was applied to each cadaveric elbow at 30° of flexion using a standardized device. Each specimen was tested intact, partially torn, and completely torn. At each state, joint space was measured using stress ultrasonography, and the difference in joint space from unstressed to stressed (delta) was recorded. RESULTS: There were 10 right and 11 left upper extremity specimens. The mean delta was 0.58 mm for the intact state and <0.75 mm in all groups. Both distal partial tear groups had mean deltas <0.75 mm, similar to intact elbows. Proximal tears and the T-sign demonstrated intermediate deltas (0.99-1.23 mm). Midsubstance partial tears demonstrated the largest deltas (1.57-2.03 mm), similar to those of the complete tears. All complete tear groups had a mean delta >1.5 mm (1.54-3.03 mm). CONCLUSION: These findings suggest that partial tears introduce a spectrum of instability from functionally intact to completely torn. As a result, some may be biomechanically amenable to nonoperative treatment, while others would be indicated for early reconstruction. Further research into the biological and biomechanical determinants of nonoperative treatment failure will assist with more precise treatment recommendations. CLINICAL RELEVANCE: Describing the biomechanical consequences of different, clinically significant partial UCL tears potentially allows more precise recommendations for operative and nonoperative treatment.

Ultrasound-guided treatment of peripheral entrapment mononeuropathies.

The advent of high-resolution neuromuscular ultrasound (US) has provided a useful tool for conservative treatment of peripheral entrapment mononeuropathies. US-guided interventions require careful coordination of transducer and needle movement along with a detailed understanding of sonoanatomy. Preprocedural planning and positioning can be helpful in performing these interventions. Corticosteroid injections, aspiration of ganglia, hydrodissection, and minimally invasive procedures can be useful nonsurgical treatments for mononeuropathies refractory to conservative care. Technical aspects as well as the current understanding of the indications and efficacy of these procedures for common entrapment mononeuropathies are reviewed in this study. Muscle Nerve, 2019.

Ultrasound-Guided Hydroneurolysis of the Median Nerve for Recurrent Carpal Tunnel Syndrome.

BACKGROUND: Recurrent carpal tunnel syndrome is often associated with perineural scarring around the median nerve. Surgical options include relatively invasive procedures, such as fat pad grafting, ligament reconstruction, muscle transfer, and nerve wraps. All have limited success because of the possibility of repeated recurrent scarring postoperatively. METHODS: We discuss a technique involving injection with external hydroneurolysis of the median nerve under ultrasound guidance for recurrent carpal tunnel. Injection enables a gentler dissection of the surrounding tissues compared with open external neurolysis, with less chance of recurrent scarring. This technique is a unique alternative to repeat operative intervention in recurrent carpal tunnel, as well as a prelude to repeat open decompression and salvage procedures. RESULTS: Ultrasound-guided injection with external hydroneurolysis of the median nerve is a safer, more limited procedure compared with repeat open surgery, usually performed in an office setting. This procedure limits risk, anesthesia, and operating/recovery room expenses, offering relief in 70% to 80% of cases. Furthermore, in the 20% to 30% of patients with inadequate relief, surgery remains a viable option. US provides important information on the anatomy of the median nerve and carpal canal and can rule out covert pathology. CONCLUSIONS: We offer an alternative treatment for recurrent carpal tunnel syndrome, a difficult problem for which many surgeons recommend nonoperative treatment. US provides objective data concerning residual nerve compression and allows for dynamic assessment. Theoretically, this also offers a viable solution for surgeons and their patients with recurrent carpal tunnel syndrome before being pressed to consider repeat open surgery.