Accuracy of Ultrasound-Guided Pudendal Nerve Block in the Ischial Spine and Alcock's Canal Levels: A Cadaveric Study.

BACKGROUND: Blockade of the pudendal nerve (PN) using ultrasound (US) guidance has been described at the levels of the ischial spine and Alcock's canal. However, no study has been conducted to compare anatomical accuracy between different approaches in targeting the PN. OBJECTIVE: To investigate the accuracy of US-guided injection of the PN at the ischial spine and Alcock's canal levels. This study also compared the accuracy of the infiltrations by three sonographers with different levels of experience. SUBJECTS: Eight Thiel-embalmed cadavers (16 hemipelvises). METHODS: Three physiatrists trained in musculoskeletal US imaging with 12 years, five years, and one year of experience performed the injections. Each injected a 0.1-mL bolus of colored dye in both hemipelvises of each cadaver at the ischial spine and Alcock's canal levels under US guidance. Each cadaver received three injections per hemipelvis. The accuracy of the injection was determined following hemipelvis dissection by an anatomist. RESULTS: The injections were accurate 33 times out of the total 42 attempts, resulting in 78% accuracy. Sixteen out of 21 injections at the ischial spine level were on target (76% accuracy), while the approach at Alcock's canal level yielded 17 successful injections (81% accuracy). The difference between the approaches was not statistically significant. There was also no significant difference in accuracy between the operators. CONCLUSIONS: US-guided injection of the PN can be performed accurately at both the ischial spine and Alcock's canal levels. The difference between the approaches was not statistically significant.

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.

US Assessment of Sports-related Hip Injuries.

Traumatic and overuse hip injuries occur frequently in amateur and professional athletes. After clinical assessment, imaging plays an important role in diagnosis and in defining care management of these injuries. Ultrasonography (US) is being increasingly used in assessment of hip injuries because of the wide availability of US machines, the lower cost, and the unique real-time imaging capability, which allows both static and dynamic evaluation as well as guidance of point-of-care interventions such as fluid aspiration and steroid injection. Accurate diagnosis of hip injuries is often challenging, given the complex soft-tissue anatomy of the hip and the wide spectrum of injuries that can occur. To conduct a skillful US evaluation of hip injuries, physicians must have pertinent knowledge of the normal anatomy and should make judicious use of surface anatomy landmarks while using a compartmentalized diagnostic approach. In this article, common sports-related injuries of the anterior, lateral, and posterior hip compartments are discussed. This review includes assessment of joint effusion, acetabular labral tear, acute and chronic tendon injuries including tendinopathy, partial and full-thickness tears, snapping hip syndromes, relevant US-guided procedures, and some other conditions such as Morel-Lavallée lesion and perineal nodular induration. Principles of care management and current knowledge on imaging findings that may affect return to activity are also presented. Using an oriented US examination technique and having knowledge of the normal hip anatomy will help physicians characterize US findings of common sports-related hip injuries and make accurate diagnoses. Online supplemental material is available for this article. ©RSNA, 2018.

Ultrasound-guided interventional procedures around the shoulder.

The aim of this review is to illustrate the spectrum of ultrasound-guided procedures around the shoulder. The shoulder is affected by a wide range of both, traumatic and degenerative diseases. Ultrasound guidance is a low-cost and safe tool to perform minimally invasive interventional procedures around the shoulder. The clinical outcome is shown by the use of clinical scores: visual analogue scale (VAS), Constant's score and Shoulder Pain Disability Index (SPADI). Rotator cuff calcification is a common painful condition that occurs in up to 7.5 % of otherwise healthy adults. Ultrasound-guided procedures include single-needle and double-needle approach with different needles. These techniques are described and the results are critically compared. Ultrasound-guided viscosupplementation is a new therapeutic approach for treatment of several shoulder pain disorders: osteoarthritis, rotator cuff tear and tendinosis. In adhesive capsulitis, different therapeutic ultrasound-guided techniques such as corticosteroid injection, capsular distension (sodium chlorate solution; sodium chlorate and corticosteroids; air) and viscosupplementation are evaluated. Acromion-clavear injection of steroid and lidocaine solution under ultrasound guidance is easy to perform and is indicated in conservative treatment of painful osteoarthrosis. The treatment of rotator cuff tendinosis and partial tears with ultrasound-guided injection of concentrated autologous platelets is also described.

The deltoid, a forgotten muscle of the shoulder.

The deltoid is a fascinating muscle with a significant role in shoulder function. It is comprised of three distinct portions (anterior or clavicular, middle or acromial, and posterior or spinal) and acts mainly as an abductor of the shoulder and stabilizer of the humeral head. Deltoid tears are not infrequently associated with large or massive rotator cuff tears and may further jeopardize shoulder function. A variety of other pathologies may affect the deltoid muscle including enthesitis, calcific tendinitis, myositis, infection, tumors, and chronic avulsion injury. Contracture of the deltoid following repeated intramuscular injections could present with progressive abduction deformity and winging of the scapula. The deltoid muscle and its innervating axillary nerve may be injured during shoulder surgery, which may have disastrous functional consequences. Axillary neuropathies leading to deltoid muscle dysfunction include traumatic injuries, quadrilateral space and Parsonage-Turner syndromes, and cause denervation of the deltoid muscle. Finally, abnormalities of the deltoid may originate from nearby pathologies of subdeltoid bursa, acromion, and distal clavicle.

Sonographic appearance of the posterior interosseous nerve at the wrist.

OBJECTIVES: The purpose of this study was to determine whether sonography can identify the distal posterior interosseous nerve at the wrist. METHODS: On the basis of previous anatomic descriptions, high-resolution musculoskeletal sonography was used in an attempt to identify the distal posterior interosseous nerve in the wrists of 20 unembalmed cadaveric specimens (11 male and 9 female; ages 54-98 years). High-frequency scanning (17-5 MHz) of the fourth dorsal extensor compartment revealed a small (1-3 mm) hypoechoic structure located on the compartment floor, presumed to represent the posterior interosseous nerve. Electronic calipers measured the distance between Lister's tubercle and this structure, as well as the structure's radial-ulnar width and volar-dorsal height. The presumed posterior interosseous nerves of 10 specimens were then injected with diluted colored latex using sonographic guidance. Subsequent dissection definitively identified the sonographically visualized and injected structure. RESULTS: Dissection revealed latex within the posterior interosseous nerve in all 10 injected specimens, thus confirming that the sonographically visualized structure represented the distal posterior interosseous nerve. The nerve was identified sonographically in all 20 examined specimens, was located an average of 4.88 mm (range, 2.10-10.0 mm) ulnar to Lister's tubercle, and had an average width and height of 2.35 mm (range, 1.20-3.50 mm) and 1.01 mm (range, 0.80-1.40 mm), respectively. CONCLUSIONS: High-resolution sonography can reliably identify the distal posterior interosseous nerve within the fourth dorsal extensor compartment. Clinicians should consider formal evaluation of the posterior interosseous nerve in patients presenting with dorsal wrist pain syndromes. Future investigations should explore the potential role of sonographically guided percutaneous procedures directed at the posterior interosseous nerve.

US imaging of the musculocutaneous nerve.

PURPOSE: To describe the potential value of high-resolution sonography for evaluation of the musculocutaneous nerve (MCN). MATERIALS AND METHODS: The normal anatomy of the MCN was evaluated on three cadaveric limbs and correlated with the US images obtained in 15 healthy subjects. Seven consecutive patients with MCN neuropathy were then evaluated with sonography using 17.5 and 12.5-MHz broadband linear array transducers. All patients had abnormal nerve conduction studies and underwent correlative MR imaging on a 1.5-T system. RESULTS: One-to-one comparison between cadaveric specimens and sonographic images showed that the MCN can be reliably identified from the axilla through the elbow, including the lateral antebrachial cutaneous (LAbC) nerve. In the patients group with MCN neuropathy, sonography allowed detection of a wide spectrum of abnormalities. In 5/7 cases, a spindle neuroma was depicted in continuity with the nerve. In one case, US identified focal swelling of the nerve and in another case US was negative. The neuroma was hyperintense on T2-weighted sequences in 75% of cases. In one patient, the nerve showed Gd-enhancement on fat-suppressed T1-weighted sequences. The nerve was never detected on unenhanced T1-scans. Owing to its small-size and out-of-plane course, the MCN may be more reliably depicted with sonography rather than with MR imaging. CONCLUSIONS: US is promising for evaluating traumatic injuries of the MCN. By providing unique information on the entire course of the nerve, US can be used as a valuable complement of clinical and electrophysiologic findings.

Ultrasound demonstration of distal biceps tendon bifurcation: normal and abnormal findings.

We demonstrate the US appearance of the distal biceps tendon bifurcation in normal cadavers and volunteers and in those affected by various disease processes. Three cadaveric specimens, 30 normal volunteers, and 75 patients were evaluated by means of US. Correlative MR imaging was obtained in normal volunteers and patients. In all cases US demonstrated the distal biceps tendon shaped by two separate tendons belonging to the short and long head of the biceps brachii muscle. Four patients had a complete rupture of the distal insertion of the biceps with retraction of the muscle belly. Four patients had partial tear of the distal biceps tendon with different US appearance. In two patients the partial tear involved the short head of the biceps brachii tendon, while in the other two patients, the long head was involved. Correlative MR imaging is also presented both in normal volunteers and patients. US changed the therapeutic management in the patients with partial tears involving the LH of the biceps. This is the first report in which ultrasound considers the distal biceps tendon bifurcation in detail. Isolated tears of one of these components can be identified by US. Knowledge of the distal biceps tendon bifurcation ultrasonographic anatomy and pathology has important diagnostic and therapeutic implications.

Muscle variants of the upper and lower limb (with anatomical correlation).

Several accessory muscles in the upper and lower limb have been described in the medical literature. Most are asymptomatic and represent incidental findings at imaging. In some instances, however, these muscles may become clinically relevant producing palpable swelling, entrapment of neurovascular structures, or exercise-related pain. The diagnosis of accessory muscles is based on recognition of their typical location and on cross-sectional imaging features. Familiarity with their most common location and knowledge of the possible clinical syndromes caused by these supernumerary structures may aid in diagnosis and treatment.

Imaging of neuropathies about the ankle and foot.

Neuropathies about the ankle and foot may be the cause of chronic pain and disability. In most cases, these conditions derive from mechanical or dynamic compression of a segment of a nerve within a narrow osteofibrous tunnel, an opening in a fibrous structure, or a passageway close to a ligament or a muscle. Although the evaluation of nerve disorders primarily relies on neurological examination and electrophysiology, diagnostic imaging is currently used as a complement to help define the site and etiology of nerve compression and exclude other disease possibly underlying the patient' symptoms. In this article, a review of the anatomical and pathological features of nerve entrapments in the distal lower extremity is presented on ultrasound and magnetic resonance imaging, according to the nerve involved.

Pan-American League of Associations for Rheumatology (PANLAR) recommendations and guidelines for musculoskeletal ultrasound training in the Americas for rheumatologists.

OBJECTIVE: To develop guidelines for Musculoskeletal Ultrasound (MSKUS) training for rheumatologists in the Americas. METHODS: A total of 25 Rheumatologists from 19 countries of the American Continent participated in a consensus-based interactive process (Delphi method) using 2 consecutive electronic questionnaires. The first questionnaire included the following: the relevance of organizing courses to teach MSKUS to Rheumatologists, the determination of the most effective educational course models, the trainee levels, the educational objectives, the requirements for passing the course(s), the course venues, the number of course participants per instructor, and the percentage of time spent in hands-on sessions. The second questionnaire consisted of questions that did not achieve consensus (>65%) in the first questionnaire, topics, and pathologies to be covered at each course MSKUS level. RESULTS: General consensus was obtained for MSKUS courses to be divided into 3 educational levels: basic, intermediate, and advanced. These courses should be taught using a theoretical-didactic and hands-on model. In addition, the group established the minimum requirements for attending and passing each MSKUS course level, the ideal number of course participants per instructor (4 participants/instructor), and the specific topics and musculoskeletal pathologies to be covered. In the same manner, the group concluded that 60% to 70% of course time should be focused on hands-on sessions. CONCLUSION: A multinational group of MSKUS sonographers using a consensus-based questionnaire (Delphi method) established the first recommendations and guidelines for MSKUS course training in the Americas. Pan-American League of Associations for Rheumatology urges that these guidelines and recommendations be adopted in the future by both national and regional institutions in the American continent involved in the training of Rheumatologists for the performance of MSKUS.

Accuracy of Two Ultrasound-Guided Coracohumeral Ligament Injection Approaches: A Cadaveric Study.

BACKGROUND: Glenohumeral idiopathic adhesive capsulitis is a common shoulder condition that hinders functionality. Addressing the pathology has been extensively researched. Ultrasound (US)-guided injections have shown their efficacy. However, no study has been conducted to compare anatomical accuracy between different approaches in targeting the coracohumeral ligament (CHL). OBJECTIVE: To investigate whether US-guided injection of the CHL can be performed accurately using either the rotator interval (RI) or the coracoidal (CO) approach. METHODS: An experimental cadaveric case series. SETTING: Anatomy laboratory. SPECIMENS: Both shoulders of 13 Thiel-embalmed cadavers. INTERVENTIONS: Three physiatrists each injected a 0.1 mL bolus of colored dye in both shoulders of each cadaver using either the RI or the CO approach under US guidance. Each cadaver received a total of six injections (three injections per shoulder). The accuracy of the injection was determined following shoulder dissection by an anatomist. MAIN OUTCOME MEASURE: The accuracy of the US-guided injection of the CHL. RESULTS: The RI approach yielded 36 accurate injections, giving it an accuracy of 100%. With the CO approach two injections were deemed inaccurate yielding an accuracy of 94%. There was no significant difference in accuracy between all operators. CONCLUSIONS: US-guided injection of the CHL can be performed accurately with both the RI and CO approaches. The RI approach was likely to be more accurate.

Ultrasound demonstration of distal triceps tendon tears.

PURPOSE: Rupture of the distal triceps tendon is an uncommon injury that may be unrecognized on clinical examination. The purpose of the study is to describe the role of US in distal triceps tendon tears evaluation. MATERIALS AND METHODS: IRB approval was obtained and patients gave written informed consent. Of 77 consecutive US examinations of the elbow obtained over a five-year period, eight patients with correlative MR and surgery available were identified having partial or complete distal triceps tendon tear. RESULTS: N = 4 complete tears of the triceps tendon and n = 4 partial tears of the distal triceps involving the lateral/superficial head were identified. Patients with partial tear had a history of a single traumatic event that determined a sudden eccentric contraction of the triceps muscle against resistance. US demonstrated on axial and longitudinal planes a partial tear of the triceps brachii tendon that resulted in a fusiform swelling and retraction of the lateral/superficial head in four patients. It was possible to identify the normal insertion of the medial head of the triceps moving the transducer medially. MR and surgical findings were concordant with US findings in every patient. CONCLUSION: Ultrasound is able to differentiate complete from partial triceps tendon tears. US has the potential to identify isolated lesions of the lateral/superficial head of the triceps with an intact medial head.

Wrist injuries in nonprofessional tennis players: relationships with different grips.

BACKGROUND: Recent advances in tennis teaching techniques have been applied in nonprofessional tennis players to develop a more effective play. Hits with enormous amount of top-spin and lower technical and physical training are responsible for most wrist injuries in nonprofessional tennis players. HYPOTHESIS: The use of different grips (Eastern, Western, semi-Western) determines the pattern of wrist injuries in nonprofessional tennis players. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Between January 2006 and August 2007, we evaluated 370 nonprofessional division III and IV tennis players. The screening consisted of a questionnaire appropriately prepared to investigate wrist injuries. Medical records of players who reported a wrist injury were reviewed. Body mass index, years of practice, weekly hours of training, racket weight, grip (Eastern, Western and semi-Western), kind of strings, injury type, time out of competition, and therapy (medical or surgical) were recorded. Statistical analysis was performed to assess the association of different wrist injuries with these variables. RESULTS: A total of 320 players reported no injuries in their activity; 50 (13%) reported injuries to the wrist. Medical records of these players were reviewed, and 30 extensor carpi ulnaris lesions, 3 lesions of the extensor tendons, 5 injuries to the flexor carpi radialis, 6 de Quervain diseases, 5 triangular fibrocartilage lesions, and 1 intersection syndrome were found. Ulnar-sided injuries were more frequently associated with Western or semi-Western grips while radial-sided injuries were associated with Eastern grip (chi(2) = 20.7; P < .001). Average time out of competition was 69 days; 4 players underwent surgery; the others received medical and rehabilitative therapy. No differences were observed regarding body mass index, years of practice, weekly hours of training, racket weight, and strings. CONCLUSION: In nonprofessional tennis players with wrist injuries, different grips of the racket are related to the anatomical site of the lesion: Eastern grip with radial-side injuries and Western or semi-Western with ulnar-side injuries. Knowledge of this relationship may influence training, prevention, diagnosis, and therapy of wrist problems in nonprofessional tennis players.