The Pediatric Ankle: Normal Variations and Maturation-Dependent Pathology

The pediatric ankle can present a broad range of normal variation and pathology unique to certain stages of development. Understanding the expected age ranges of ossification and fusion about the ankle is essential to provide accurate diagnoses regarding skeletal integrity. This conclusion has been well characterized radiographically and is supported by cadaveric research.The range of appearances on magnetic resonance imaging has also been well described. Knowledge about the structure of the periosteum and perichondrium aids in image interpretation as well as explaining typical injury patterns. The expected appearance of the physis and regional bone marrow signal is also of utmost importance.Ultrasonography is a valuable tool in pediatric musculoskeletal imaging but is limited when there is concern for intra-articular pathology. Computed tomography tends to be reserved for preoperative evaluation. We describe normal variation and maturation-dependent pathology of the pediatric ankle with an emphasis on imaging considerations.

A novel case of ulnar nerve compression neuropathy with co-existing accessory flexor carpi ulnaris and accessory abductor digiti minimi

There are numerous cases reported of the accessory muscles of the hand and wrist in surgical, cadaveric, and imaging-based studies. Anatomical muscle variations in the flexor compartment of the wrist and forearm can present as a pseudo mass or space-occupying lesion causing external compression on the traversing nerves. Guyon's canal is a compact space with a high potential for nerve entrapment. Common etiologies include ganglion cysts, osteophytes, or soft tissue masses. This rare case illustrates the combined existence of two accessory muscles, an accessory flexor carpi ulnaris, and an accessory abductor digiti minimi, causing ulnar nerve compression in Guyon's canal with imaging correlation. One can raise the suspicion of an anomalous muscle when symptoms concern a patient of a younger age group in the absence of common etiologies. Furthermore, detailed anatomical knowledge of muscles around Guyon's canal is essential in making a diagnosis and aiding treatment.

Unusual Duplication of Flexor Tendons in the Middle Finger Leading to Trigger Finger: A Case Report and Comprehensive Review

Duplication of the flexor digitorum profundus (FDP) tendon is an extremely uncommon anatomical anomaly found within the flexor digitorum superficialis (FDS) muscle, with minimal documentation in the current literature. We present the case of a 45-year-old female manual laborer who exhibited symptoms suggestive of trigger finger in her right middle finger. Surgical exploration uncovered a duplicated FDP tendon, a previously unreported anatomical anomaly in this context. Despite attempting conservative treatment initially, surgical intervention involving release of the A1 pulley, excision of the A1 pulley, and identification of the duplicated tendon was performed. The unusual nature of this anatomical variation highlights the need for additional research into its clinical significance and treatment options. This case highlights the significance of conducting comprehensive anatomical assessments to diagnose and treat uncommon variations within the FDS muscle. It underscores the continued need for collaborative research to enhance treatment approaches, especially in instances where trigger finger symptoms are present.

The tendon of the fibularis brevis muscle - Systematic overview and new classification system

The fibularis brevis muscle belongs to the lateral compartment of the leg. It originates from the lower two-thirds of the lateral surface of the fibula bone and it also is attached to the anterior intermuscular septum. Its insertion is normally located on the tuberosity at the base of the fifth metatarsal bone, on its lateral side. However, distal attachment of this muscle is morphologically variable. Different variations have been identified and some classification systems have been created for both adults and foetuses. Based on various literature references, we have created a new classification system and compared the frequency of each type. The main aim of this review is to present morphological variations of the fibularis brevis tendon with their clinical significance, especially in autografting in case of surgical treatment of fibularis brevis tendon rupture. The clinical aspect of this pathology and some medical cases will also be presented.

Reconsidering the nomenclature of the flexor digiti minimi muscles: a proposed solution to ambiguity in anatomical description

Background

The nomenclature surrounding the 'flexor digiti minimi brevis' muscle prompts deliberation concerning its accuracy and potential variations. Addressing this uncertainty entails expunging the term 'brevis' from nomenclature references to the muscle, opting instead for the term 'flexor digiti minimi.' This nomenclatural adjustment currently being advocated raises inquiries about the necessity for descriptors denoting the muscle's specific placement along the upper or lower extremities. This study was conducted with a dual objective: to illuminate this topic and consolidate existing research on this issue.

Main body of the abstract

Research encompassing the terms 'flexor digiti minimi' OR 'flexor digiti minimi brevis' was screened within this field. The inclusion criteria involved original articles, case reports, case series, relevant books, and book chapters. Excluded from this review were articles mentioning 'flexor digiti minimi' and 'digiti minimi' that were unrelated to the subject, as well as poster presentations, proceedings, conference materials, abstracts, and atlases.

Short conclusion

In summary, changing the name of the muscle enhances anatomical understanding, promotes clarity and precision in communication, facilitates research efforts, and helps prevent confusion in medical education and clinical practice. These benefits highlight the importance of revising nomenclature to reflect anatomical accuracy and improve healthcare outcomes. It also promotes consistency in studies and allows for more meaningful comparisons across studies, ultimately advancing our understanding of anatomical variations and their clinical significance. Furthermore, it allows for more effective teaching and learning experiences, enabling medical practitioners to make accurate diagnoses, develop effective treatment strategies.

Accessory Flexor Carpi Ulnaris Muscle in Humans: A Rare Anatomical Case with Clinical Considerations

Anatomical variations of the forearm flexor muscles are occasionally encountered. Though usually observed incidentally during autopsies or imaging studies, they may at times cause concern due to associated clinical symptoms. This report presents a case of unilateral accessory flexor carpi ulnaris (AFCU) muscle observed in a human male cadaver aged 78 years. During routine cadaveric dissection, an anomalous AFCU muscle was observed in the left forearm of a human male cadaver aged 78 years. Standard institutional guidelines pertaining to the use of human cadaver for teaching and research were followed. A thorough literature review about the flexor carpi ulnaris (FCU) through the PubMed, Embase and Google scholar databases was undertaken, using the keywords - accessory flexor carpi ulnaris muscle, aberrant flexor carpi ulnaris muscle and anatomical variation of flexor carpi ulnaris muscle. Relevant gross anatomical findings were recorded and photographed. AFCU was identified on the medial aspect of the distal third of the left forearm. The AFCU was found originating from the ante-brachial fascia and the fascia covering the FCU on the left forearm, forming a small separate belly deep to the main muscle. It terminated as a thin tendon running alongside the hypothenar muscles and attached distally to the base of the proximal phalanx of the little finger. The AFCU was found to be innervated by a branch of the ulnar nerve. Awareness about the rare AFCU muscle is clinically important as a possible cause of ulnar nerve compression but also as a possible graft in reconstruction surgeries.

Accessory plantaris muscle can result in symptomatic hardware impingement following ACL reconstruction

Anatomic variants of lower extremity musculature, such as the gastrocnemius, popliteus, and the plantaris have been well described in the literature. The impact of these anatomical variations on clinical outcomes depends on their proximity to and effects on adjacent anatomical structures, particularly in the context of planned surgical procedures in the region. While the presence of the accessory plantaris is rare, no previous cases have described it negatively affecting surgical outcomes to our knowledge. We present a case of a 42-year-old patient who underwent an anterior cruciate ligament (ACL) reconstruction using a femoral Endobutton for graft fixation positioned just beneath an accessory plantaris, leading to impingement and persistent knee pain. This case highlights the importance of understanding anatomical variations when planning and performing surgical procedures and suggests the need for further research in this area.

Accessory Tibionavicular Muscle: An Unusual Cause of Medial Ankle Pain

Accessory or anomalous muscles around the ankle are not uncommon and are usually asymptomatic. They are traditionally encountered during imaging undertaken for evaluation of ankle pain. We reported the first case of a new accessory muscle in the anteromedial part of the ankle with associated partial thickness tear in an 18-year-old football player presenting as symptomatic pathology. In this article, we described the role of cross-sectional imaging in its diagnosis including successful management of the condition with ultrasound-guided platelet-rich plasma therapy and review-associated literature.

Imaging of Tendinous and Muscular Anatomical Variants Around the Ankle

Tendinous and muscular anatomical variants around the ankle are usually an unexpected finding on imaging. Magnetic resonance imaging offers the best visualization of the accessory muscles; however, they can also be detected on radiography, ultrasonography, and computed tomography. Their accurate identification facilitates appropriate management of the rare symptomatic cases, mostly caused by accessory muscles in the posteromedial compartment. Symptomatic patients present with chronic ankle pain, most commonly as tarsal tunnel syndrome. The most frequently observed accessory muscle around the ankle is the peroneus tertius muscle, an accessory muscle in the anterior compartment. The tibiocalcaneus internus and peroneocalcaneus internus are uncommon; anterior fibulocalcaneus is rarely mentioned. We describe the anatomy of the accessory muscles with their anatomical relations accompanied by schematic drawings and radiologic images from clinical practice.

Accessory Hand Muscles Over the Transverse Carpal Ligament: An Obstacle in Carpal Tunnel Surgery

BACKGROUND

Carpal tunnel syndrome (CTS) is an entrapment neuropathy caused by compression of the median nerve throughout the carpal tunnel. It is the most common entrapment neuropathy, with an estimated prevalence of 4%-7%. Surgical management is more effective in moderate to severe and severe CTS. CTS recurs in approximately 20% of patients, and up to 12% of these patients require reoperation. Knowledge of normal anatomy and variations would improve the success rate of the index surgery. Atypical causes of CTS were reported, including ganglion cysts, synovial hypertrophy, lipomas, bone fracture, bone fragments, tumor of soft tissues or bones, neurofibromas, neuromas, vascular malformations, and accessory muscles. Accessory muscles are commonly detected in upper limbs. However, their concomitant presentation with CTS has rarely been reported. We aimed to present different accessory muscles diagnosed during CTS surgery through a systematic review of the literature with our exemplary case.

METHODS

A systematic review/meta-analysis was performed concomitant with a case presentation.

RESULTS

Accessory muscles associated with CTS were as follows: palmaris longus, 28.6%; lumbrical muscles, 19.3%; palmaris profundus, 17.8%; flexor digitorum superficialis, 16.1%; transverse carpal muscle, 5%; flexor digitorum indicis, 4.2%; flexor superficialis indicis, 4.2%; flexor sublimis, 0.8%; accessory superficialis longus, 0.8%; flexor pollicis longus, 0.8%; abductor digiti minimi, 0.8%; abductor digiti quinti, 0.8%; and flexor digitorum superficialis brevis, 0.8%. Accessory muscles were mostly noticed during CTS surgery (88.2%).

CONCLUSIONS

Knowledge of possible variations within the carpal tunnel would improve the surgeon's capability during CTS surgery.

Morphologic observation for anomalous patterns of the flexor carpi radialis muscle and atypical insertions: a proposal for a new classification

In the present study, four types of variations of the flexor carpi radialis with accessory muscular bundles were classified depending on the origin of the accessory muscular bundle and relationships with the bicipital aponeurosis, biceps brachii, pronator teres, and coracobrachialis. Six types of insertions of the tendon of the flexor carpi radialis were also divided according to their inserted positions on the carpal and metacarpal bones. An accessory muscular bundle of the flexor carpi radialis was found in 4 (1 female and 3 males) of 68 cadavers (5.88%), with five examples in 136 arms (3.68%). It was bilateral in one cadaver and unilateral (two on the right and one on the left) in three. The insertion of the flexor carpi radialis tendon was not only on the proximal surface of the base of the second metacarpal bone but also on the third metacarpal bone, the tubercle of the trapezium, and the scaphoid. These findings and classifications are important in anatomical education, and have important significances in clinical diagnosis and therapies.

VARIATIONS OF THE STRUCTURE, TOPOGRAPHY, BLOOD SUPPLY AND INNERVATION OF THE BRACHIORADIALIS IN HUMAN FETUS

OBJECTIVE

The aim of the research was to establish the features of age-related and individual anatomical variability of the brachioradialis, its blood supply, and innervation options.

PATIENTS AND METHODS

Materials and methods: The study of the variant anatomy of the brachioradialis and its vascular and nervous structures was carried out on 25 preparations of human fetuses of 4-7 months, 81.0-270.0 mm parietal-coccygeal length (PCL) using macromicroscopic preparation, injection vessels, and morphometry.

RESULTS

Results: Spindle-like (56%) and round (24%) shapes of the brachioradialis were found in most of the studied fetuses; its elongated flat (12%) and triangular (8%) forms occur less often. In a fetus of 185.0 mm TKD, the right brachioradialis consisted of two separate parts: upper and lower, which were connected at the level of the middle of the forearm into a common short muscle belly. In another human fetus of 220.0 mm TKD, the right brachioradialis also consisted of two separate parts - upper and lower, triangular in shape, but separated by a pronounced horizontal gap.

CONCLUSION

Conclusions: The features of the fetal anatomy of the brachioradialis are established: its variability and bilateral asymmetry of shape and size, variability of the places of origin and attachment, etc. In individual human fetuses, the brachioradialis consists of two separate parts that have special topographical relationships. The area of the greatest concentration of both extra- and intramuscular nerves and arteries is the upper and middle third of the brachioradialis. In the area of the forearm, the course of radial vascular-nerve formations is determined by the brachioradialis.

The prevalence of the anatomical variation in a Turkish population: supernumerary muscle-anconeus epitrochlearis

INTRODUCTION

The anconeus epitrochlearis (AE) muscle is an accessory muscle located between the medial cortex of the olecranon and the inferior surface of the medial epicondyle, posterior to the ulnar nerve. This muscle may compress the ulnar nerve causing a clinical neuropathy. We aimed to determine the gender and side characteristics of the AE muscle in patients who underwent elbow magnetic resonance imaging (MRI) and report its prevalence in a Turkish population.

MATERIALS AND METHODS

A total of 209 patients (210 elbows) who underwent elbow MRI between January and December 2020 were retrospectively evaluated. Cases with the AE muscle were included in the study. The craniocaudal (CC) dimension was examined from the coronal section, and the transverse (TR) and anteroposterior (AP) dimensions from the axial sections. Statistical analyses were performed to determine the relationship between the presence of the AE muscle and age, gender, and side (right/left). Differences between sexes and sides in terms of muscle sizes were evaluated using statistical tests.

RESULTS

The AE muscle was detected in 17 patients (18 elbows) (8.1%). The mean age of the patients was 41.52 ± 14.63 years. There was no statistically significant difference between the male and female patients in terms of age. This accessory muscle was found in nine female (9.8%) and eight male (6.3%) patients in total. There was one (0.5%) patient with the bilateral AE muscle, who was female. The accessory muscle was located in the right elbow in 13 patients (10.71%), and left elbow in five (4.10%). It was more common in the right elbow in both genders. The muscle was larger in the male patients and the right elbow, but this was not statistically significant.

CONCLUSION

The prevalence of the AE muscle was determined to be 8.1% in a Turkish population, and this muscle was more common among the women and in the right elbow.

Imaging Features of Soft Tissue Tumor Mimickers: A Pictorial Essay

Soft tissue lesions are commonly encountered and imaging is an important diagnostic step in the diagnosis and management of these lesions. While some of these lesions are true neoplasms, others are not. These soft tissue tumor mimickers can be due to a variety of conditions including traumatic, iatrogenic, inflammatory/reactive, infection, vascular, and variant anatomy. It is important for the radiologist and clinician to be aware of these common soft tissue tumor mimickers and their characteristic imaging features to avoid unnecessary workup and provide the best treatment outcome.

Tarsal Tunnel Syndrome: An Ultrasound Pictorial Review

Tarsal tunnel syndrome may be idiopathic or may be caused by various conditions: bone disease, thickening of the retinaculum, hematoma, or iatrogenic nerve damage; tendinopathy or tenosynovitis; the presence of supernumerary muscles such as an accessory soleus, peroneocalcaneus internus, or accessory flexor digitorum muscle; bone or joint disorders; expansile tumors or cysts; and venous aneurysm or kinking of the tibial artery. The purpose of this article is to describe and illustrate most of the causes of tarsal tunnel syndrome, as diagnosed by ultrasound, which is a practical, inexpensive method.

Atavistic muscles in human anatomy: Evolutionary origins and clinical implications

The evolution and variations of human anatomy are of great interest to physicians and anatomists. Variations can be categorized as vestigial, accessory or atavistic structures. Vestigial muscles are frequently encountered structures that are normally present but have become rudimentary through evolution. Muscles that disappeared during evolution sometimes arise again, although rarely; such muscles are referred to as atavistic. They arise from failure of suppression of genetic loci. Some common atavistic muscles seen clinically are the extensor digitorum brevis manus, chondroepitrochlearis and plantaris. Atavistic muscles appear more frequently in the upper limb than in any other region of the human body. One explanation for the appearance of these muscles, mainly within the upper limbs, is based on the evolution of the complex upper extremities formed in humans today. Often, the presence of atavistic muscles is asymptomatic, but they can compromise the function of normal anatomical structures and complicate clinical situations if their presence is unknown. They can cause complications if they are confused with soft tissue pathology, if they compress or displace surrounding structures, or if they require an additional blood supply during times of exercise and stress. The purpose of this paper was to describe the common atavistic muscles, their hypothesized evolutionary origins, their potential complications and possible treatments for the diagnosing clinician.

Posterior Leg Pain: Understanding Soleus Muscle Injuries

Soleus muscle injuries are frequently unrecognized, representing a common cause of sports inactivity. This is mainly because little is known about the anatomy of the soleus muscle and the clinical manifestations of injury. Unlike other muscles, the soleus muscle has a complex myoconnective structure with three intramuscular tendons, which makes the interpretation of muscle pathologic conditions challenging. Soleus muscle injuries can be acute or chronic and are usually considered to be a minor discomfort by both the patient and the sports medicine physician, leading to a relatively quick return to sporting activity with a high risk for reinjury. The authors review the soleus muscle anatomy and the importance of being familiar with the most frequent locations of injuries, which are fundamental aspects that every radiologist should understand to avoid underdiagnosis. The role of imaging, the clinical manifestations of injuries, and the differential diagnoses are key aspects to know when evaluating posterior leg pain. The online slide presentation from the RSNA Annual Meeting is available for this article. ^©RSNA, 2022.

The Gantzer transfer - Assessment of the feasibility of using the nerve supplying the Gantzer muscle for end-to-side supercharging of the ulnar nerve

Our study aimed at assessing the anatomical feasibility of using the nerve supplying the Gantzer muscle (GM) to supercharge the ulnar nerve following injury. The GM nerve was dissected and measured in 36 forearms. The distance between its origin and the lateral epicondyle of humerus and between the GM nerve and the ulnar nerve was measured. The GM was present in 15 forearms (47%). The average distance between the origin of the GM nerve and the lateral epicondyle was 7.34 cm (range 3.3-9.1 cm). The average length of the GM nerve was 3.05 cm (range 1.6-4.5 cm) from origin to neuromuscular junction. The average distance from the ulnar nerve was 2.56 cm (range 1.8-13 3.4 cm). The length of the GM nerve was significantly greater (p < 0.05) than the perpendicular distance between its origin and the ulnar nerve, allowing ample margin for side-to-side or end-to-side supercharging of the ulnar nerve with minimal or no need for further translocation or dissection. The use of the GM nerve as donor following ulnar nerve injury may provide an alternative to the pronator quadratus nerve for supercharged end-to-side transfer, or as an addition, thus supercharging the ulnar nerve twice.

A rare case of chronic pain and atraumatic inability to flex the knee: Evidence of a unilateral accessory popliteus muscle

The literature describes a few case reports of bilateral accessory popliteus muscle, a rare variant of the popliteus muscle. We report a case of a 24-year-old male patient with acute pain and inability to flex the left knee, without a traumatic event. Additionally, the patient reported mild sensitive symptoms in the left calf region and no pain in the right knee. The patient underwent a series of other examinations which culminated in a Magnetic Resonance Imaging (MRI) that showed an accessory popliteus muscle. The comparative study of the contralateral knee showed no evidence of this anatomic variant.

The morphological variability of fibularis tertius origin in human foetuses

BACKGROUND

The purpose of this study was to characterize the morphology of the fibularis tertius (FT) in human fetuses, and to provide a classification based on its modes of origin in human fetuses.

METHODS

The material comprised 100extremities from 50 spontaneously aborted human fetuses (19 male, 31 female, 100 lowerlimbs in total), aged 18- 38 weeks of gestation. These were dissected and the presence or absence of the FT muscle as well as the type of its proximal attachment were determined, and the FT was measured morphometrically.

RESULTS

The FT was present in 50% of fetuses. Four types of FT muscle origin were identified. The most common was Type 2, characterized by an origin on the middle third of the fibula and the intermuscular septum. Three other types were observed: Type 1 with an origin located on proximal third of the fibula and to the intermuscular septum, Type 3 characterized by an absent muscle belly, and an independent tendon originating from the that of the extensor digitorum longus, and Type 4 with an origin located on the distal third of the fibula and the intermuscular septum.

CONCLUSIONS

The fibularis tertius demonstrates high morphological variability, with the most common origin located on third of the fibula and to the intermuscular septum.

MRI Evaluation of Various Elbow, Forearm, and Wrist Neuropathies: A Pictorial Review

Upper extremity entrapment neuropathies are common and can cause pain, sensory loss, and muscle weakness leading to functional disability. We conducted a retrospective review from January 2007 until March 2020 of the magnetic resonance imaging (MRI) features of intrinsic and extrinsic causes of wrist, forearm, and elbow neuropathies of 637 patients who received a diagnosis of neuropathy by means of clinical and electrodiagnostic testing. We discuss cases with varying intrinsic and extrinsic nerve pathologies, including postoperative examples, affecting the median, radial, and ulnar nerve.Our collection of cases demonstrates a diversity of intrinsic and extrinsic causative factors. Intrinsic pathologies include neuritis as well as tumors arising from the nerve. Extrinsic causes resulting in nerve entrapment include masses, acute and chronic posttraumatic cases, anatomical variants, inflammatory and crystal deposition, calcium pyrophosphate deposition disease, and dialysis-related amyloidosis. Finally, we review postsurgical cases, such as carpal tunnel release and ulnar nerve transposition.Although upper extremity neuropathies tend to have a typical clinical presentation, imaging, particularly MRI, plays a vital role in evaluating the etiology and severity of each neuropathy and ultimately helps guide clinical management.

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.

Morphological variability of the fibularis longus tendon in human fetuses

INTRODUCTION

The morphological variability of the fibularis longus tendon (FLT) in adults is well understood. However, no comprehensive classification exists in human fetuses. The goal of this study was to prepare the first comprehensive classification of the fibularis longus tendon based on its insertion in human fetuses.

MATERIAL AND METHODS

Forty-seven spontaneously-aborted human fetuses were examined: 38 male, 56 female, a total of 94 lower limbs (Central European population). Age ranged from18-38 weeks of gestation at death.

RESULTS

The classification comprised three types of FLT. The most common type was Type I (49%), characterized by the single distal attachment. This type was divided into two subtypes (A-B): A - the tendon inserts to the lateral tubercle of the base of the 1st metatarsal bone, B - the tendon inserts to the head of the 1st metatarsal bone. The second most type was Type II, characterized by a bifurcated distal attachment (24.5%). This type was divided into three subtypes (A-C): A - the main tendon inserts to the lateral tubercle of the base of the 1st metatarsal bone and the accessory band inserts to the medial cuneiform bone; B - the strong, main tendon inserts to both the base of the 1st metatarsal bone and medial cuneiform bone, including the first metatarsal-cuneiform joint, and the accessory bands inserts to the fourth interosseus dorsalis muscle; C - the main tendon inserts to the lateral tubercle of the base of the 1st metatarsal bone and the accessory band inserts to the first interosseus dorsalis muscle. The rarest type was Type III, characterized by a trifurcated distal attachment: the main tendon inserts to the lateral tubercle of the base of the 1st metatarsal bone and the first accessory band inserts to the medial cuneiform bone and the second accessory bands inserts to the first interosseus dorsalis muscle. The anterior frenular ligament was observed in 16% of all cases, and posterior frenular ligament in 6.4%.

CONCLUSION

The FLT displays high morphological variability. The proposed classification consists of three main types, with Type I and Type II divided into sub-types; it also provides additional data regarding its accessory tendon bands.

Anatomical work-up of an individual with multiple muscular variants on both forearms

Muscular variants of the forearm are common and frequently cause neurovascular compression syndromes, especially when interfering with the compact topography of the carpal tunnel or the Canalis ulnaris. Here, we report on a male body donor with multiple muscular normal variations on both forearms. The two main findings are (1) an accessory variant muscle (AVM) on the right forearm originating from the M. brachioradialis, the distal radius, and the M. flexor pollicis longus. It spanned the wrist beneath the Fascia antebrachia and inserted at the proximal phalanx of the digitus minimus. (2) Moreover, we found a three-headed palmaris longus variant on the left arm with proximal origin tendon and a distal, trifurcated muscle belly, with separated insertions at the palmar aponeurosis, the flexor retinaculum, and, in analogy to the accessory muscle on the contralateral arm, at the base of the proximal phalanx of the digitus minimus. We found a considerable thickening of the left-hand median nerve right before entering the carpal tunnel indicative of a possible chronic compression syndrome adding clinical relevance to this anatomical case. We also discuss the notion that both, the AVM and the contralateral three-headed palmaris variant are developmental descendants of the M. palmaris longus. Additionally, we found a previously not recorded variant of the M. palmaris brevis on the left hand.

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.

Multimodality Pitfalls of Wrist Imaging With a Focus on Magnetic Resonance Imaging: What the Radiologist Needs to Know

Numerous pitfalls are frequently encountered at multimodality imaging of the wrist, which may mimic various tendinous, osseous, capsuloligamentous, muscular, and neurovascular pathologic conditions. These pitfalls may be secondary to variant anatomy, artifactual due to magnetic resonance imaging or sonographic technique, or represent varying ranges of structure-specific normal including a spectrum of findings associated with aging in asymptomatic subjects. When an imaging finding of questionable significance is encountered, it is critical that the interpreting radiologist make every attempt to review any relevant clinical information in an effort to determine whether the imaging findings in question may account for the patient's presenting symptomology. In order to accurately diagnose true pathology at wrist imaging, it is imperative that the radiologist be familiar with the pitfalls discussed throughout this manuscript that may mimic disease. This familiarity will allow the radiologist to provide a more useful report for referring providers focusing on true pathology while eliminating potentially confusing or misleading findings which are inconsistent with the patient's clinical presentation.

Impact of plantaris ligamentous tendon

There are countless morphological variations among the muscles, tendons, ligaments, arteries, veins and nerves of the human body, many of which remain undescribed. Anatomical structures are also subject to evolution, many disappearing and others continually emerging. The main goal of this pilot study was to describe a previously undetected anatomical structure, the plantaris ligamentous tendon, and to determine its frequency and histology. Twenty-two lower limbs from 11 adult cadavers (11 left, and 11 right) fixed in 10% formalin were examined. The mean age of the cadavers at death was 60.1 years (range 38–85). The group comprised six women and five men from a Central European population. All anatomical dissections of the leg and foot area accorded with the pre-established protocol. Among the 22 lower limbs, the PLT was present in 16 (72.7%) and absent in six (27.3%). It originated as a strong fan-shaped ligamentous tendon from the superior part of the plantaris muscle, the posterior surface of the femur and the lateral aspect of the knee joint capsule. It inserted to the ilio-tibial band. Histologically, a tendon and ligament were observed extending parallel to each other. A new anatomical structure has been found, for which the name plantaris ligamentous tendon is proposed. It occurs around the popliteal region between the plantaris muscle, the posterior surface of the femur, and the ilio-tibial band.

A Possible Accessory Muscle of the Serratus Posterior Superior Muscle

Anatomical variation is defined as the normal range of possibilities in the topography and morphology of body structures. In contrast, an anomaly is any structural or functional anatomical finding beyond the normal range of possibilities. This case study describes a muscular anomaly found in a 73-year-old preserved Caucasian male. We observed a left-sided anomalous muscle originating from the transverse process of the C1 (Atlas) vertebra and inserting onto the proximal attachment of the serratus posterior superior (SPS) muscle at the C7 level. We suggest that this anomaly is a result of early embryological development and hypothesize that the atypical neck muscle may reinforce the action of the SPS. This finding is rare and no reference of it can be found in the literature. Reporting anatomical anomalies is important for the medical literature and education.

Variant Anatomy and Its Terminology

Variant anatomy, which is an integral part of anatomical science, is related to abnormalities in the human body structure. Our understanding of variant anatomy is based on thousand years of anatomical experience. These abnormalities generally do not interfere with the function of the human body and do not typically manifest as pathological nosological units. However, under certain conditions, these abnormalities can worsen existing pathological states or even evoke new ones. Understanding variant anatomy is a basic skill not only of mere anatomists, but also of clinicians who work in fields involving both diagnostic techniques and therapeutic interventions. To gain and retain a good knowledge of the most frequent and clinically relevant anatomical variations, a simple, clear, and exactly defined nomenclature of variant structures is needed. A list of items comprising variant anatomy, which have been incorporated into the internationally accepted nomenclatures Terminologia Anatomica (1998) and Terminologia Neuroanatomica (2017), is described and analyzed. Examples of the most common anatomical variations related to terminology are mentioned, and variant anatomy as a whole and its role in understanding current anatomy are discussed.

Managing uncommon and unexpected findings during neuromuscular ultrasound

One barrier to widespread adoption of neuromuscular ultrasound by clinical neurophysiologists is concern over how to identify and manage non-neuromuscular findings. This review addresses this concern by describing the sonographic appearance of a variety of commonly observed pathologies and anatomic variants in dermal, subcutaneous, bony, glandular, lymphatic, vascular, and other superficial tissues. Additionally, it outlines techniques to ensure proper clinical and ultrasound evaluation of unexpected or uncommon findings. Finally, it highlights strategies to manage unexpected findings, including how to best communicate findings to patients and referring clinicians to avoid unnecessary testing and ensure appropriate follow-up. Ultrasound extends the ability of the neuromuscular sonographer-clinician to contribute to patient care.

Accessory Soleus Muscle: Two Case Reports with a Completely Different Presentation Caused by the Same Entity

Accessory soleus muscle (ASM) is a rare supernumerary anatomical variant that commonly presents as a posteromedial ankle swelling, which may become painful during physical activity. As it may mimic a soft tissue tumor, it is essential to differentiate this condition from ganglion, lipoma, hemangioma, synovioma, and sarcoma. However, ASM may also present with a painful syndrome, characterized by pain and paresthesia of the ankle and foot, mimicking the tarsal tunnel syndrome (TTS). Two cases of ASM are presented in this article. The first case had a typical presentation with painful posteromedial ankle swelling. After the initial assessment, the diagnosis was confirmed by magnetic resonance imaging (MRI), and ASM was treated by complete resection. The second case presented with pain and paresthesia in the right ankle and foot, but no swelling was noticeable. It was initially misdiagnosed by a rheumatologist and afterward overlooked on an MRI by a musculoskeletal radiology specialist and therefore mistreated by numerous physicians before being referred to our outpatient clinic. After further assessment, the diagnosis has been confirmed, and ASM was treated by complete resection combined with tarsal tunnel decompression. To the best of our knowledge, this is the first case reported in which ASM caused symptoms but presented without posteromedial swelling. This might be due to a proximally positioned belly of the ASM, followed by a tendinous insertion on the medial side of the calcaneus.

Ultrasound and Magnetic Resonance Imaging Diagnosis of Isolated Tear of the Accessory Soleus Tendon: A Case Report and Review of the Literatures

Introduction:

The accessory soleus muscle (also known as the supernumerary soleus or soleus secundus) is an uncommon congenital anatomical. The presence of this muscle is generally asymptomatic. In cases of symptomatic accessory soleus muscle, it manifests with painful swelling of the posteromedial region of the ankle. To the best of our knowledge, partial or complete accessory soleus tendon tears were reported in literature in only three cases; all of them were diagnosed with magnetic resonance imaging (MRI) examination while only one was diagnosed with both ultrasound (US) and MRI.

Case Report:

We presented a case of a 63-year-old Caucasian woman presented to our emergency department with severe pain in the posteromedial region of her right ankle. US and MRI of the calf and ankle were performed and a complete tear of the right accessory soleus tendon with fluid gap and myotendinous retraction was diagnosed.

Conclusion:

An accessory soleus muscle partial or complete tears are very uncommon injuries. This condition can mimic many other pathologies, and therefore, radiologists should know the physiological and pathological imaging findings for a correct interpretation of ankle injuries, avoiding misinterpretations.

Magnetic resonance imaging of the ankle and foot

This article reviews the magnetic resonance imaging (MRI) findings of the normal anatomy and various pathologic conditions of the ankle and foot commonly encountered in clinical practice. The spectrum of entities discussed includes osseous and osteochondral injuries, ligamentous injuries, common traumatic and degenerative tendon pathology, abnormalities of transverse tarsal joint (Chopart) and tarsometatarsal joint (Lisfranc) complexes, pathological conditions affecting capsuloligamentous structures of the great toe and lesser toes, as well as pedal infection, with a focus on diabetic osteomyelitis and neuropathic osteoarthropathy.

Accessory flexor carpi ulnaris: case report and review of the literature

Most of the accessory muscles of the forearm described in the radiology literature are located either in the radial aspect of the forearm or towards the hypothenar eminence. We present an unusual case of an ulnar-sided distal forearm accessory flexor carpi ulnaris muscle presenting as a “pseudotumour“ demonstrated with both ultrasound and MRI, rarely reported in the current surgical and anatomical literature. Given the location and relation to the ulnar nerve towards Guyon’s canal, the accessory muscle may also predispose to distal ulnar nerve entrapment.

Magnetic resonance imaging of the wrist and hand

The anatomy of the wrist and hand is complex and contains numerous small structures. Magnetic resonance imaging (MRI) is often an ideal imaging modality in the assessment of various traumatic and pathologic conditions of this region, and it is frequently performed after initial radiographs. In this manuscript we describe the normal anatomy, imaging techniques, and MRI findings of various traumatic and pathologic conditions of the wrist and hand including occult fractures, osteonecrosis, ligamentous and tendon injuries, and entrapment neuropathies.

Unusual Triad of Bifid Median Nerve, Persistent Median Artery, and Aberrant Muscle Causing Carpal Tunnel Syndrome: A Case Report

CASE

A 15-year-old boy presented with intermittent pain, in the left nondominant hand, for the past 3 years. He recently developed numbness in the radial 3 and a half digits. Ultrasonography revealed a bifid median nerve (BMN) with a persistent median artery (PMA). An open carpal tunnel release was performed, which revealed an accessory lumbrical muscle in addition to the BMN and a PMA.

CONCLUSION

The surgeon should be aware of the possible coexistence of 3 anomalous structures while performing carpal tunnel release in a young patient.

Carpal tunnel sonography

Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy of peripheral nerves, with an incidence of 1-3 patients in 1000. CTS typically occurs between 45 and 60 years of age, and it is more frequent in women than in men. The main cause of CTS is chronic compression of the median nerve and ischemic suffering secondary to increased pressure in the carpal tunnel. There are many possible causes of CTS, which can be differentiated into idiopathic causes, which include most cases, and secondary causes. Classical CTS diagnosis is based on the patient's clinical examination and electrophysiological tests, such as electromyography and nerve conduction studies. The latter are helpful for determining the site of nerve compression, assessing its severity, monitoring the course of the disease after therapy, and excluding other causes of median nerve pain, such as cervical radiculopathies, brachial plexopathies, polyneuropathy, or other forms of mononeuropathies. However, clinical examination and electrophysiological tests are not able to differentiate idiopathic forms from secondary forms of CTS, and discrepancies are possible between clinical examination and electrophysiological tests (false negatives). Ultrasound examination is able to recognize most of the secondary forms of CTS. It can evaluate the morphological alterations of the nerve and correlate them with the severity of nerve suffering in all cases, even idiopathic ones, with a sensitivity and specificity equal to those of electrophysiological tests. It can also highlight some anatomical predisposing variants or conditions that may represent contraindications to minimally invasive treatments. Ultrasound examination also plays a fundamental role in evaluating patients with an unfavorable outcome after surgical treatment.

New classification of the distal attachment of the fibularis brevis - Anatomical variations and potential clinical implications

BACKGROUND

Although the lateral compartment of the leg is characterized by a high degree of morphological variation, very little information exists on the morphological variability of the fibularis brevis muscle (FBM) and fibularis digiti quinti (FDQ). The main aim of the study was to characterize the morphology of the FBM tendon and its accessory bands, to classify them and to determine the incidence of FDQ. The work attempts to determine the relationship between the types of the insertion of the FBM tendon and the occurrence of FDQ.

METHODS

Classical anatomical dissection was performed on 102 lower limbs fixed in 10% formalin solution. The morphology of the insertion of the FBM and of the FDQ was evaluated.

RESULTS

The FBM was present in all specimens. Two types of insertion were observed, the most common being Type I (70.6%): a single distal attachment in which the tendon inserts into the tuberosity at the base of the fifth metatarsal bone. The second most common was Type II (29.4%); this group was divided into three subtypes (A-C). The FDQ was present in 17.7% of specimens and always with Type I FBM.

CONCLUSION

Both the FBM tendon and FDQ present significant morphological variation. Two main types of the FBM tendon determine the presence of the FDQ.

LEVEL OF EVIDENCE

II Basic Science Research.

Radiographic/MR Imaging Correlation of Soft Tissues

MR imaging is nowadays regarded as the preferred imaging modality for evaluation of soft tissue lesions. As plain radiographs are often the first step in evaluation of musculoskeletal disorders, identification of subtle soft tissue signs may be helpful to select patients who need to be referred for subsequent MR imaging. Although not very sensitive, certain plain film findings, such as intralesional calcification or gas, may allow one to make to a more specific tissue diagnosis and may obviate the need for invasive diagnostic procedures and potential harmful treatment.

Irreducible Knee Dislocation Associated With a Tertiary Gastrocnemius Head: A Case Report

CASE

A 43-year-old man suffered an irreducible posterolateral knee dislocation while snowboarding with associated tears of the anterior cruciate, posterior cruciate, medial collateral, and posterolateral corner ligaments. Two closed reduction attempts failed, and magnetic resonance imaging revealed incarcerated soft tissue from a tertiary gastrocnemius muscle head. The patient underwent open reduction and repair/reconstruction of his multiligamentous knee injury. At the 6-year follow-up, the patient did not have pain or instability and returned to recreational activities.

CONCLUSIONS

This case demonstrates that a tertiary gastrocnemius muscle head, the most common anatomical variation, may complicate the closed reduction of an irreducible posterolateral knee dislocation.

Tarsal Tunnel Syndrome Secondary to Accessory Musculature: A Case Report

Tarsal tunnel syndrome (TTS) is a relatively uncommon compression neuropathy caused by impingement of the tibial nerve or one of the terminal branches. The presence of accessory musculature at the posteromedial aspect of the ankle has been identified as a rare cause of this condition. Despite the rarity of this condition, it must be considered in patients with refractory symptoms consistent with tibial nerve dysfunction. The accurate diagnosis of this condition relies heavily on a detailed history and physical examination, adequate imaging read by both surgeon and trained musculoskeletal radiologist, as well as a high level of suspicion for such pathology. In this case report, we describe a 46-year-old male with history, examination, and imaging all consistent with TTS secondary to accessory musculature. Following excision of an accessory soleus and flexor digitorum accessorius longus, as well as simultaneous tarsal tunnel release, the patient experienced full resolution of his symptoms. This highlights the importance of considering accessory musculature as a potential cause of TTS in patients presenting with tibial compression neuropathy. Levels of Evidence: Level V: Case Report.

Congenital bilateral absence of the semimembranosus muscles

Variations of the anatomy of the hamstring muscle complex are uncommon. In particular, absence of some or all of the hamstring muscles is rarely described in the literature. This report presents a case of absent semimembranosus musculature detected incidentally on knee magnetic resonance imaging (MRI), then found to be bilateral on MRI of both thighs performed shortly thereafter. Imaging also demonstrated atypical morphologies of the semitendinosus and biceps femoris muscles in both thighs.

Fibularis Tertius: Anatomical Study and Review of the Literature

Although there is much morphological variation in the anterior compartment of the leg, there is little information about the morphological variability of the fibularis tertius muscle (FTM). The main aim of the present study was to characterize the morphology (origin and insertion) and frequency of occurrence of the FTM and to use these findings as the basis for a new classification of the fibularis tertius tendon. Classical anatomical dissection was performed on 106 lower limbs fixed in 10% formalin. The presence of the FTM and the morphology of both its origin and its insertion were described. The FTM was present in 91 limbs (85.8%). Three types of origin were observed: Type 1, the most common type, with its origin on the distal half fibula (67%); Type 2, with the origin on the distal third fibula (22%); and Type 3, with an origin from the tendon of the extensor digitorum longus (11%). In addition, six types of insertion were distinguished. The most common was Type I (45%), a single distal attachment where the tendon inserts into the shaft of the fifth metatarsal bone. The rarest was Type VI, characterized by fusion with an additional band of the fibularis brevis tendon, which gives rise to the fourth interosseus dorsalis muscle. Two morphological variants of insertion could be distinguished, fan-shaped and band-shaped. Both the origin and insertion of the FTM are very morphologically variable, with three types of origin (Types 1-3) and six types of insertion point (Types I-VI) observed. Knowledge of such variations is essential for both clinicians and anatomists. Clin. Anat. 32:1082-1093, 2019. © 2019 Wiley Periodicals, Inc.