Possible Points of Ulnar Nerve Entrapment in the Arm and Forearm: An Ultrasound, Anatomical, and Histological Study

Background: Ulnar nerve entrapment is one of the most common entrapment neuropathies, usually occurring in the cubital tunnel of the elbow and in Guyon’s canal of the wrist. However, it can also occur at other anatomical locations. Purpose: Our aim was to review other possible locations of ulnar nerve entrapment in an ultrasound and anatomical study. Material and Methods: Eleven upper limbs from eight adult corpses were ultrasonographically examined and subsequently dissected in a dissection laboratory. Four specific anatomical points were analysed, and any anatomical variations were documented. Moreover, six samples of the nerve were taken for histological analysis. Results: Distinct anatomical relationships were observed during ultrasound and dissection between the ulnar nerve and the medial intermuscular septum, the triceps aponeurosis, Osborne’s fascia at the elbow, the arcuate ligament of Osborne and the intermuscular aponeurosis between the flexor carpi ulnaris and the flexor digitorum superficialis muscles. A statistical study showed that these locations are potential areas for ulnar nerve compression. In addition, a fourth head of the triceps brachii muscle was found in some specimens. Conclusion: Results demonstrate that ultrasound is a good tool to investigate ulnar nerve entrapment neuropathy and to identify other anatomical points where the nerve can remain compressed.

Sonographic Assessment of Hand Injuries: Diagnostic Accuracy and Review of Pathology

Background: The high soft-tissue contrast of magnetic resonance imaging (MRI) makes it useful for evaluation of hand injuries, but its limitations include cost, imaging artifacts, and patient claustrophobia. Ultrasound is readily available, fast, noninvasive, and radiation free, but its utility for the evaluation of hand soft-tissue injury and pathology is less well known. Purpose: We sought to examine the accuracy of ultrasound for the evaluation of hand injury at a single institution. Methods: We queried a radiology information system for ultrasound cases between 2014 and 2020 at a tertiary care institution using the keyword "hand" and injury terms. We performed a retrospective chart review of cases found according to the type of injury detected on ultrasound. To evaluate the diagnostic accuracy of ultrasound in hand injury and pathology, we recorded postimaging clinical diagnoses and surgical findings. Results: We found 154 patients who underwent ultrasound for hand injuries and had confirmed surgical diagnosis and/or robust clinical follow-up. Tendon injury was the most commonly diagnosed condition on ultrasound (70/154); others detected were retained foreign body (31), mass (21), ligamentous injury (9), pulley injury (8), nerve injury (11), and traumatic arthropathy (4). Ultrasound correctly characterized hand injury in 150/154 cases (97.4%) based on surgical and/or clinical follow-up. Ultrasound failed to diagnose 3 cases of partial tendon tear and 1 case of digital nerve injury. Conclusion: In this retrospective, single-institution review, ultrasound was found to be highly accurate in the detection of soft tissue hand injury and pathology, demonstrating a high concordance rate with surgical and clinical findings. Further study is warranted.

EURO-MUSCULUS/USPRM Dynamic Ultrasound Protocols for Wrist and Hand

ABSTRACT

In this dynamic protocol, ultrasound evaluation of the wrist and hand is described using various maneuvers for relevant conditions. Scanning videos are coupled with real-time patient examination videos. The authors believe that this practical guide - prepared by the international consensus of several experts - will help musculoskeletal physicians perform a better and uniform/standard examination approach.

Sonography, My Personal Assistant at Hand Outpatient Clinic

Ultrasonography in hand surgery offers the option of imaging trauma consequences or degenerative problems in the wrist and fingers, involving bones, joints, ligaments, tendons, annular pulley, carpal and digital changes, soft masses, and foreign bodies including dynamic changes during motion. In the hands of the treating surgeon, ultrasonography allows immediately to plan conservative treatment versus surgery, to precisely infiltrate joints or tendon spaces as well as to perform miniinvasive assisted surgery.

Hand and Wrist Neuropathies: High-resolution Ultrasonography and MR Neurography

High-resolution ultrasonography (US) and magnetic resonance neurography (MRN) have followed parallel paths for peripheral nerve imaging with little comparison of the two modalities. They seem equally effective to study a variety of neuropathies affecting large and small nerves in the wrist and hand. This article outlines the technical considerations of US and MRN and discusses normal and abnormal imaging appearances of hand and wrist nerves from etiologies such as entrapment, injury, tumor, and proximal and diffuse neuropathy, with specific case illustrations.

Thumb ultrasound: Technique and pathologies

Ultrasound is ideally suited for the assessment of complex anatomy and pathologies of the thumb. Focused and dynamic thumb ultrasound can provide a rapid real-time diagnosis and can be used for guided treatment in certain clinical situations. We present a simplified approach to scanning technique for thumb-related pathologies and illustrate a spectrum of common and uncommon pathologies encountered.

Hand Masses

Hand and wrist soft tissue masses may be classified as pseudotumors, benign neoplasms, or malignant neoplasms. The vast majority of hand lesions are benign. Consideration of the location of the lesion and its imaging characteristics often leads to a specific diagnosis. Pseudotumors discussed in this article are ganglion cysts, accessory muscles, and inflammatory lesions. True tumors are described according to their tissue type: nerve sheath tumors, adipocytic tumors, so-called fibrohistiocytic tumors, pericytic tumors, and vascular lesions. We also outline the imaging features of masses encountered in the hand and wrist.

Imaging for Dupuytren disease: a systematic review of the literature

BACKGROUND

As treatment of Dupuytren disease (DD) is expected to shift towards prevention of progression, the use of imaging in patients with DD becomes more important. In this systematic review an overview is given of the different methods for and applications of imaging for DD that have been described.

METHODS

The MEDLINE and EMBASE databases were searched for articles reporting the use of imaging in patients with DD, published before May 17, 2018. Studies were systematically examined in two rounds by two observers according to the PRISMA systematic. All studies containing original data on imaging for DD were considered for inclusion.

RESULTS

Three hundred and seven unique studies were identified, of which 23 were included in the study. Only studies on the use of ultrasound (US) and magnetic resonance imaging (MRI) were identified. Broadly, articles could be divided into 5 categories. Seven studies were found on diagnosis, two on measurement of disease extent, four on measurement of disease activity, seven on guidance of minimally invasive procedures and five studies on evaluation of treatment. According to the Oxford CEBM, the levels of evidence were low, ranging from level 3 to 5.

CONCLUSIONS

A variety of applications for US and MRI for patients with DD has been described. Based on the results of this review, the largest value for imaging lies in the measurement of disease activity and the follow-up of treatment of patients with early stage disease. Unfortunately, the overall level of evidence of the available literature was low. Future research is necessary to define the exact value of US and MRI in the management of patients with DD.

Pitfalls in the cytological diagnosis of tenosynovial giant cell tumor: An illustration of eight discordant cases

Tenosynovial giant cell tumor (TSGCT) is a highly recurrent benign tumor of the extremities. Wide local excision is usually sufficient to achieve its recurrence-free outcome. However, that needs a confident pre-operative cytological diagnosis as TSGCT. Aspirates from this tumor express the characteristic polymorphic cytological pattern, enough to impose a definite diagnosis. However rarely so, inadequate sampling from smaller tumors or due to faulty techniques, and selective sampling from topographic clusters of any individual component may lead to wrong interpretation. An unorthodox location near the larger limb joints further complicates the diagnostic misery on occasions. Such tumors are amenable to incomplete removal and risk for future recurrence. In this report, we describe eight cases of TSGCTs that were cytologically diagnosed otherwise. The cytological features of these discrepant tumors and the factors attributable to such dilemma are elaborated. Finally, a possible remedy has been proposed at conclusion in order to avoid future inconveniences.

Ultrasound Guidance in Performing a Tendoscopic Surgery to Treat Posterior Tibial Tendinitis: A Useful Tool?

A 25-year-old man with a pronation-external rotation type of fracture was surgically treated using a fibular plate. Five years later, he underwent resection of bone hyperplasia because of the ankle pain and limitation of range of motion. Thereafter, the left ankle became intermittently painful, which persisted for about one year. He presented at the age of 43 with persistent ankle pain. Physical and image analysis findings indicated a diagnosis of posttraumatic posterior tibial tendinitis, which we surgically treated using tendoscopy. Endoscopic findings showed tenosynovitis and fibrillation on the tendon surface. We cleaned and removed the synovium surrounding the tendon and deepened the posterior tibial tendon groove to allow sufficient space for the posterior tibial tendon. Full weight-bearing ambulation was permitted one day after surgery and he returned to his occupation in the construction industry six weeks after surgery. The medial aspect of the ankle was free of pain and symptoms at a review two years after surgery. Although tendoscopic surgery for stage 1 posterior tibial tendon dysfunction has been reported, tendoscopic surgery to treat posttraumatic posterior tibial tendinitis has not. Our experience with this patient showed that tendoscopic surgery is useful not only for stage 1 posterior tibial dysfunction, but also for posttraumatic posterior tibial tendinitis.

Current status of ultrasonography of the finger

The recent development of advanced high-resolution transducers has enabled the fast, easy, and dynamic ultrasonographic evaluation of small, superficial structures such as the finger. In order to best exploit these advances, it is important to understand the normal anatomy and the basic pathologies of the finger, as exemplified by the following conditions involving the dorsal, volar, and lateral sections of the finger: sagittal band injuries, mallet finger, and Boutonnière deformity (dorsal aspect); flexor tendon tears, trigger finger, and volar plate injuries (volar aspect); gamekeeper's thumb (Stener lesions) and other collateral ligament tears (lateral aspect); and other lesions. This review provides a basis for understanding the ultrasonography of the finger and will therefore be useful for radiologists.

Ultrasound of the hand and wrist

There have been immense technical innovations and broadened clinical applications of ultrasound in the musculoskeletal system over the past 20 years. Specifically with regard to the hand and wrist, the advent of higher resolution transducers and postprocessing software applications have resulted in overall enhanced visualization of soft tissue structures (tendons/ligaments) as well as surface osseous lesions such as subclinical erosions in rheumatoid arthritis. Quantitative ultrasound, using either power Doppler or contrast-enhanced imaging, has become a central outcomes measure used to evaluate and document patient response to treatment in inflammatory arthropathies such as rheumatoid arthritis. This review will summarize the current state of clinical applications of ultrasound in the evaluation of the hand and wrist, with a summary of technical advances and specific applications in rheumatologic conditions.This review was exempt from institutional review board approval.

Flexor carpi radialis tendon ultrasound pictorial essay

Disorders of the flexor carpi radialis tendon (FCRt) are often missed even though they are a relatively frequent cause of volar radial wrist pain. They can manifest as tenosynovitis, tendinopathy, synovial sheath cysts with or without scaphoid-trapezoid-trapezium (STT) joint pathology, and partial or complete rupture. Because FCRt disorders often present with non-specific symptoms and a non-diagnostic clinical examination, imaging is often necessary for accurate evaluation and therapeutic planning. Conventional radiography provides good visualization of the neighboring bones and joints, as well as rare intratendinous calcifications. MRI enables evaluation of the FCRt and adjacent anatomical structures with excellent tissue resolution. In comparison, ultrasound (US) evaluation of the FCRt is less commonly described in the radiology literature, despite its affordability, exquisite soft tissue resolution, and the advantages of quick, dynamic diagnostic imaging. This pictorial essay describes and demonstrates the normal anatomy of the FCRt, its US examination technique and normal US appearance, and US findings of clinically relevant FCRt disorders.

Neglected ruptured flexor carpi ulnaris tendon mimics a soft tissue tumor in the wrist

A wrist mass is rarely caused by a ruptured tendon in the forearm. The common pathologies are ganglia, tendon tenosynovitis, and giant cell tumors of tendon sheaths. Less common causes are nerve sheath tumors, vascular lesions, or an accessory muscle belly. The authors investigated a case of neglected ruptured flexor carpi ulnaris tendon that mimics a mass in the wrist. To the authors' knowledge, this is the first case report in relevant literature. During investigation, the high-resolution musculoskeletal ultrasound suggested a soft tissue tumor or a ruptured flexor carpi ulnaris tendon. The magnetic resonance imaging scan indicated an accessory flexor carpi ulnaris muscle belly. The diagnosis of ruptured flexor carpi ulnaris tendon was confirmed by surgical exploration. This case indicates that ultrasound may be better suited than magnetic resonance imaging in evaluating a wrist mass for its accuracy, availability, and portability.

Ultrasound case report of a palmar lipoma causing carpal tunnel syndrome

Ultrasound as an imaging technique is well established for the assessment of patients presenting with a palpable lump. Lipomata of the hand are relatively rare and are rarely the cause of neuropathy. Previous case reports of these rare types of lipomata have primarily involved imaging with magnetic resonance imaging in order to provide diagnostic information. This case report of a deep-seated lipoma of the flexor digitorum superficialis tendon sheath causing carpal tunnel syndrome and trigger wrist demonstrates that ultrasound can play a key role in the diagnosis and can provide vital diagnostic information for ongoing management and surgical resection without the need for further imaging.

Comprehensive musculoskeletal sonographic evaluation of the hand and wrist

Sonography is widely used for evaluation of hand and wrist lesions. The easy accessibility, cost-effectiveness, and good diagnostic accuracy of sonography coupled with the numerous benefits of real-time imaging make it desirable. The aim of this article is to describe the typical sonographic appearances of lesions in the hand and wrist that are encountered frequently in routine clinical practice, such as inflammatory arthropathies, tumors, traumatic injuries, foreign bodies, and nerve entrapment syndromes. Relevant anatomy, scanning methods, and recent developments in musculoskeletal sonography are also discussed.

Sonography-guided arthroscopy for wrist ganglion

PURPOSE

To describe how to combine the complementary features of sonography and arthroscopy to make the arthroscopic resection of wrist ganglions a safer and more reliable surgery.

METHODS

A total of 22 patients with wrist ganglions had sonography-assisted arthroscopic resection. Sonographic visualization of ganglions, adjacent structures (ie, vessels, nerves, and tendons), and the cycling tip of the arthroscopic shaver was assessed. Arthroscopic visualization of the ganglions or ganglion stalk was also assessed. Clinical outcome measures included wrist range of motion, grip strength, and our patient-rated Hand 20 questionnaire.

RESULTS

Sonographic visualization of the ganglion stalk, adjacent structures, and the cycling tip of the arthroscopic shaver was possible in all 22 cases. However, ganglion stalks were visualized by arthroscopy in only 4 cases. The mean range of motion and grip strength were not significantly changed following surgery. However, the mean Hand 20 score was significantly improved from 17 to 6 at final follow-up. Ganglion recurrence was seen in 2 cases at 6 and 8 months after surgery.

CONCLUSIONS

Sonography-guided wrist arthroscopy provides several advantages for surgeons, including visualization of the ganglions and ganglion stalk, as well as of the arthroscopic shaver and adjacent structures such as nerves, vessels, and tendons to perform surgery safely.

Sonography-assisted arthroscopic resection of volar wrist Ganglia: a new technique

Although satisfactory arthroscopic resection of volar wrist ganglia has been reported recently, the risk of damage to arteries, nerves, and tendons remains. Furthermore, ganglia and their stalks cannot be visualized arthroscopically in many cases, and surgeons must perform a blind resection of the joint capsule until ganglion cysts or their stalks appear. Sonography has limited resolution, but recent improvements in hardware and software have made it an excellent noninvasive and dynamic imaging technique for assessing the musculoskeletal system. Ganglia, tendons, nerves, and vessels around the lesion can be clearly observed by sonography. Furthermore, the cyclic motion of the arthroscopic shaver tip makes identification by sonography easy and assists in guiding the surgeon to the lesion.

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.

Pseudotumoural soft tissue lesions of the hand and wrist: a pictorial review

Mimickers of soft tissue tumours in the hand and wrist are more frequent than true neoplastic lesions. Pseudotumours belong to a large and heterogeneous group of disorders, varying from normal anatomical variants, cystic lesions, post-traumatic lesions, skin lesions, inflammatory and infectious lesions, non-neoplastic vascular lesions, metabolic disorders (crystal deposition disease and amyloidosis) and miscellaneous disorders. Although the imaging approach to pseudotumoural lesions is often very similar to the approach to “true” soft tissue tumoral counterparts, further management of these lesions is different. Biopsy should be performed only in doubtful cases, when the diagnosis is unclear. Therefore, the radiologist plays a pivotal role in the diagnosis of these lesions. Awareness of the normal anatomy and existence and common imaging presentation of these diseases, in combination with relevant clinical findings (clinical history, age, location and skin changes), enables the radiologist to make the correct diagnosis in most cases, thereby limiting the need for invasive procedures.

Lobular capillary hemangioma in the soft tissue of the finger: sonographic findings

OBJECTIVE

The purpose of this study was to describe the sonographic findings of pathologically confirmed subcutaneous lobular capillary hemangioma of the finger in six patients.

MATERIALS AND METHODS

The clinical records were reviewed for data, including the patients' age and gender, the clinical presentation, a history of trauma, and the tumor site. The sonographic findings were retrospectively analyzed for the specific location within the superficial tissue, the tumor's size, shape, and margin, the internal echogenicity, the internal echo texture, the presence of calcification, the presence of a hypoechoic rim, and the internal vascularity.

RESULTS

The study group consisted of three men and three women, and the six patients' mean age was 39 years (age range: 13-67 years). All the patients were admitted with a painful nodule or a painless protruding nodule in the finger with easy bleeding on contact. In all cases, there was no history of trauma. The mean size of the tumors was 0.85 cm. All the tumors were ill-defined, oval, subcutaneous nodules without calcifications or any hypoechoic rim. Color Doppler sonography showed marked internal vascularity in both the central and peripheral tumor regions in three cases and scanty vascularity in the peripheral region in three cases.

CONCLUSIONS

Subcutaneous lobular capillary hemangioma should be considered when an ill-defined, oval, vascular subcutaneous nodule without calcifications or a hypoechoic rim is seen in the soft tissue of the finger, especially if this tumor is a painful small nodule or a painless protruding small nodule with easy bleeding on contact.