The Accessory Muscular Head of the Triceps Brachii Muscle with Tendinous Attachment / Cabeza Muscular Accesoria del Músculo Triceps Braquial con Inserción Tendinosa

SUMMARY: Variations in the triceps brachii muscle are uncommon, and especially limited reports exist on the accessory heads of tendinous origin that attach near the upper medial part of the humerus. During anatomical training at Nagasaki University School of Medicine, the accessory head of the triceps brachii muscle was observed on the right upper arm of a 72-year-old Japanese female. It arose tendinously from the medial side of the upper humerus, then formed a muscle belly and joined the distal side of the long head. This accessory head had independent nerve innervation, and the innervating nerve branched from a bundle of the radial nerve, which divided the nerve innervating the long head and the posterior brachial cutaneous nerve. The origin of the innervation of the accessory head was the basis for determining that this muscle head was an accessory muscle to the long head of the triceps brachii muscle. Embryologically, we discuss that part of the origin of the long head of the triceps brachii muscle was separated early in development by the axillary nerve and the posterior brachial circumflex artery, and it slipped into the surgical neck of the humerus and became fixed there. The accessory head crossed the radial nerve and deep brachial artery. When clinicians encounter compression of the radial nerve or profunda brachii artery, they should consider the presence of accessory muscles as a possible cause.

Las variaciones en el músculo tríceps braquial son poco comunes y existen informes especialmente limitados sobre las cabezas accesorias de origen tendinoso que se insertan cerca de la parte medial superior del húmero. Durante un entrenamiento anatómico en la Facultad de Medicina de la Universidad de Nagasaki, se observó la cabeza accesoria del músculo tríceps braquial en la parte superior del brazo derecho de una mujer japonesa de 72 años. Se originaba tendinosamente desde el lado medial de la parte superior del húmero, luego formaba un vientre muscular y se unía al lado distal de la cabeza larga. Esta cabeza accesoria tenía inervación nerviosa independiente, cuyo nervio se ramificaba a partir de un ramo del nervio radial, que dividía el nervio que inervaba la cabeza larga y el nervio cutáneo braquial posterior. El origen de la inervación de la cabeza accesoria fue la base para determinar que esta cabeza muscular era un músculo accesorio de la cabeza larga del músculo tríceps braquial. Embriológicamente, discutimos que parte del origen de la cabeza larga del músculo tríceps braquial se separó temprananamente en el desarrollo por el nervio axilar y la arteria circunfleja braquial posterior, y se deslizó hacia el cuello quirúrgico del húmero y quedó fijado allí. La cabeza accesoria cruzaba el nervio radial y la arteria braquial profunda. Cuando los médicos encuentran compresión del nervio radial o de la arteria braquial profunda, deben considerar la presencia de mús- culos accesorios como una posible causa.

Accessory heads of biceps brachii muscle its embryogenesis and clinical implications: Cadaveric study.

Background: Biceps brachii is an elongated two-headed fusiform muscle of the anterior compartment of the arm which crosses the shoulder as well as the elbow joint. It assists in flexion of the shoulder joint and elbow joint and powerful supinator of the forearm. It also assists in the abduction of the shoulder joint. Accessory heads of biceps brachii muscle not only give additional strength to the joints, at the same time, they may also simulate soft-tissue tumors that can result in neurovascular compression. Aims and Objectives: Accordingly, the aim of this study was designed to evaluate the prevalence of accessory heads of biceps brachii muscle in human cadavers. Materials and Methods: This study was conducted on 107 formalin embalmed human cadavers (male 62 and 45 female), and dissections were performed in accordance with the institutional ethical standards and the Indian Anatomy Act. Results: Out of 107 cadavers, three-headed biceps brachii was noted in 18 cadavers (16.82%) associated with the unusual course of musculocutaneous nerve. Rare and unusual unilateral five-headed biceps brachii was noted in one male cadaver (0.93%). All accessory heads noted in this study were supplied by the separate branches of musculocutaneous nerve except the humeral head of five-headed biceps, which was supplied by the radial nerve. Conclusion: Awareness of these anatomical variations, knowledge is necessary for radiologists, anesthetists, physiotherapists, and orthopedic surgeons to avoid complications during various radiodiagnostic procedures or surgeries of flexor deformities of the upper arm and forearm.

Résumé Contexte: Le biceps brachial est un muscle allongé fusiforme à deux têtes de la loge antérieure du bras qui traverse l'épaule ainsi que l'articulation du coude. Il aide à la flexion de l'articulation de l'épaule et du coude et supinateur puissant de l'avant-bras. Il aide également à l'abduction de l'articulation de l'épaule. Les têtes accessoires du muscle biceps brachial donnent non seulement une force supplémentaire aux articulations, en même temps, ils peuvent également simuler des tumeurs des tissus mous pouvant entraîner une compression neurovasculaire. Buts et objectifs: En conséquence, le but de ce étude a été conçue pour évaluer la prévalence des têtes accessoires du muscle biceps brachial chez les cadavres humains. Matériels et méthodes: ce étude a été menée sur 107 cadavres humains embaumés au formol (hommes 62 et 45 femmes), et des dissections ont été réalisées dans conformément aux normes éthiques institutionnelles et à la loi sur l'anatomie indienne. Résultats: Sur 107 cadavres, biceps brachial à trois têtes a été notée sur 18 cadavres (16,82 %) associée à l'évolution inhabituelle du nerf musculo-cutané. Unilatérale rare et inhabituelle Un biceps brachial à cinq têtes a été noté sur un cadavre masculin (0,93 %). Toutes les têtes accessoires notées dans cette étude ont été fournies par le branches du nerf musculo-cutané à l'exception de la tête humérale du biceps à cinq têtes, qui était alimentée par le nerf radial. Conclusion: Conscience de ces variations anatomiques, une connaissance est nécessaire aux radiologues, anesthésistes, kinésithérapeutes, et chirurgiens orthopédistes pour éviter les complications lors de diverses procédures de radiodiagnostic ou de chirurgies des déformations des fléchisseurs de la partie supérieure bras et avant-bras. Mots-clés: Asymétrie, tumeurs dermoïdes, hypertrophie et lipome, névralgie mandibulaire.

The crucial role of titin in fetal development: recurrent miscarriages and bone, heart and muscle anomalies characterise the severe end of titinopathies spectrum.

BACKGROUND: Titin truncating variants (TTNtvs) have been associated with several forms of myopathies and/or cardiomyopathies. In homozygosity or in compound heterozygosity, they cause a wide spectrum of recessive phenotypes with a congenital or childhood onset. Most recessive phenotypes showing a congenital or childhood onset have been described in subjects carrying biallelic TTNtv in specific exons. Often karyotype or chromosomal microarray analyses are the only tests performed when prenatal anomalies are identified. Thereby, many cases caused by TTN defects might be missed in the diagnostic evaluations. In this study, we aimed to dissect the most severe end of the titinopathies spectrum. METHODS: We performed a retrospective study analysing an international cohort of 93 published and 10 unpublished cases carrying biallelic TTNtv. RESULTS: We identified recurrent clinical features showing a significant correlation with the genotype, including fetal akinesia (up to 62%), arthrogryposis (up to 85%), facial dysmorphisms (up to 73%), joint (up to 17%), bone (up to 22%) and heart anomalies (up to 27%) resembling complex, syndromic phenotypes. CONCLUSION: We suggest TTN to be carefully evaluated in any diagnostic process involving patients with these prenatal signs. This step will be essential to improve diagnostic performance, expand our knowledge and optimise prenatal genetic counselling.

Botulinum Toxin Injection for the Treatment of Compression of Lateral Plantar Nerve by Flexor Digitorum Accessorius Longus.

ABSTRACT: The flexor digitorum accessorius longus is an anomalous muscle with a reported prevalence of 1.6%-12.2% in cadaveric studies. Flexor digitorum accessorius longus courses through the tarsal tunnel and has been reported as an etiology of tarsal tunnel syndrome in previous case reports. The flexor digitorum accessorius longus is intimately related to the neurovascular bundle and may impinge on the lateral plantar nerves. However, very few cases of lateral plantar nerve compression by the flexor digitorum accessorius longus have been reported. Herein, we report a case of lateral plantar nerve compression caused by the flexor digitorum accessorius longus muscle in a 51-year-old man who complained of insidious pain at the lateral sole and hypoesthesia at the left third-fifth toe and lateral sole, and the pain improved after treatment of botulinum toxin injection into the flexor digitorum accessorius longus muscle.

Anomalous Extensor Indicis Proprius Muscle Extending Beyond the Extensor Retinaculum: A Case Report.

CASE: During dissection of the upper limb of a cadaver in preparation for a first-year anatomy course, an extensor indicis proprius (EIP) variant was discovered with its muscle belly extending distal to the extensor retinaculum and beyond what has been previously described in the literature. CONCLUSION: EIP is commonly used as a tendon transfer for extensor pollicis longus rupture. Few anatomic variants of EIP have been reported in the literature, but such variants should be considered because of their consequences to the success of tendon transfer and potential implications for diagnosis of an otherwise unexplained mass of the wrist.

A rare variation of radial nerve coexisting with the intercalated ectopic muscle from latissimus dorsi muscle / Una rara variación del nervio radial que coexiste con el músculo ectópico intercalado del músculo latísimo del dorso

SUMMARY: The axilla is the main communication channel connecting the upper limbs, the neck and chest. Stabilization of the internal structure is essential for upper limb and shoulder mobility. In this case, we observed and recorded the characteristics of the variation of the radial nerve as well as the intercalated ectopic muscle from latissimus dorsi muscle. The position relationship between both, was also particularly noted by us. In view of the presence of the variation we reported, related clinical research, surgery and disease diagnosis are expected to take this case into account.

La axila es el principal canal de comunicación que conecta los miembros superiores, el cuello y el tórax. La estabilización de la estructura interna es fundamental para la movilidad del miembro superior y del hombro. En este caso observamos y registramos las características de la variación del nervio radial así como del músculo ectópico intercalado del músculo latísimo del dorso. La relación de posición entre ambas también fue significativa en este estudio. En vista de la presencia de la variación que informamos, se espera que la investigación clínica relacionada con la cirugía y el diagnóstico de la enfermedad tengan en cuenta este caso.

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.

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.

Anomalous retrogressive palmaris longus.

An interesting case of unusual unilateral variant of palmaris longus (PL) tendon of forearm was noticed by us. We found two bellies of PL as well as their different insertions. These observations will help in understanding morphological variations of this muscle and its clinical implications. PL is a fusiform muscle in the superficial flexor group of muscles of forearm. It originates from medial epicondyle of humerus by common flexor tendon. We found PL having one origin, i.e., from medial epicondyle from common tendinous origin of flexor muscles and then it divided to form two bellies having two long tendons distally. Understanding of presence or absence or anomalies of PL is not only important for medical professionals but also for evolutionary biologists. Awareness of anatomy and variations of flexor tendons is important for health care practitioners for the correct diagnosis and management of pain, disease, and trauma of forearm and hand.

Résumé Nous avons remarqué un cas intéressant de variante unilatérale inhabituelle du tendon du long palmaire (PL) de l'avant-bras. Nous avons retrouvé deux ventres de PL ainsi que leurs différentes insertions. Ces observations aideront à comprendre les variations morphologiques de ce muscle et ses implications cliniques. Le PL est un muscle fusiforme du groupe des muscles fléchisseurs superficiels de l'avant-bras. Il provient de l'épicondyle médial de l'humérus par le tendon fléchisseur commun. Nous avons trouvé que le PL avait une origine, c'est-à-dire de l'épicondyle médial provenant de l'origine tendineuse commune des muscles fléchisseurs, puis il s'est divisé pour former deux ventres ayant deux longs tendons distalement. Comprendre la présence, l'absence ou les anomalies de PL est non seulement important pour les professionnels de la santé mais également pour les biologistes évolutionnistes. La connaissance de l'anatomie et des variations des tendons fléchisseurs est importante pour les praticiens de la santé afin de diagnostiquer et de gérer correctement la douleur, la maladie et les traumatismes de l'avant-bras et de la main. Mots-clés: Palmaris longus, greffe tendineuse, variation, contracture ischémique de Volkmann.

The prevalence and distribution of the flexor carpi radialis brevis muscle in the Turkish population.

The flexor carpi radialis brevis (FCRB) is a very rare anomalous muscle that is usually asymptomatic but may cause various pathologies, such as radial-sided wrist pain. The aim of this study was to determine the prevalence of FCRB in the Turkish population, its location, and sex differences. Forearm, wrist, and hand magnetic resonance images of 849 individuals aged 18-65 years were retrospectively evaluated in this study. The survey found an FCRB prevalence of 4%, with a prevalence of 3.6% among women and of 4.7% among men. However, the difference between the sexes was not statistically significant (p = 0.629). The origin of all 34 FCRBs identified was the distal third of the anterior aspect of the radius; the insertion site of 28 was the second metacarpal bone, whereas that of the remaining 6 was the os trapezium. In conclusion, the data of this study report the prevalence of FCRB for the first time in the Turkish population, which will contribute to radiological and surgical evaluations in the region and help in early and accurate diagnosis of various pathological conditions that may be caused by FCRB.

Bilateral absence: A rare anomaly of the gemelli muscles.

The superior and inferior gemelli are deep muscles of the gluteal region, that facilitate the maintenance of a dynamic stability of the hip joint. Their absence could increase the chances of failure in the management of total hip anthroplasty and column acetabular ring fractures. We present a case of an adult female cadaver, with bilateral absence of the superior and inferior gemelli muscles.

Congenital Contracture of the Ulnar Digits and Its Differentiation From Ischemic Contracture.

PURPOSE: To describe the clinical features, radiologic findings, differential diagnosis, and surgical treatment of a congenital flexion deformity of the middle, ring, and little fingers. The cause of the condition is the aberrant origin of the flexor digitorum profundus, leading to a congenital contracture of the ulnar digits. METHODS: We reviewed 8 patients with congenital contracture of the ulnar digits. The mean age at the time of surgery was 14 years. An examination revealed a flexion contracture of the middle, ring, and small fingers. Plain radiographs, 3-dimensional computed tomography, magnetic resonance imaging, and ultrasound were used to characterize bony and soft tissue pathology. Surgical treatments included resection of the aberrant origin and a muscle-sliding procedure. RESULTS: Bony prominence on the proximal ulna was seen in the plain radiographs and/or 3-dimensional computed tomography. A cord that extended from this bony prominence to the tendons of flexor digitorum profundus was revealed in the magnetic resonance imaging. The bony prominence and the cord were also seen using ultrasound. The median time of patient follow-up was 1.7 years. A simple resection of the tendinous origin only resulted in a release in 2 patients who were 4 years old. Older patients required a further muscle-sliding procedure. The average grip strength ratio on the contralateral side was 82%. CONCLUSIONS: Congenital contracture of the ulnar digits is a new congenital flexion deformity involving the middle, ring, and small fingers. Bony prominence on the proximal ulna is the key finding for establishing its diagnosis and distinguishing it from an ischemic contracture. We recommend treating this surgically at 12 years of age or older after the phase of rapid growth of the extremities. We recommend the resection of the aberrant origin, combined with a muscle-sliding procedure, as the treatment of choice, even for young patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic V.

Anomalous Flexor Digitorum Profundus Muscle Bellies as a Cause of Snapping Wrist and Carpal Tunnel Syndrome: A Case Report.

CASE: A 20-year-old right hand dominant woman presented with an audible and painful snapping wrist occurring with finger flexion. This bothersome mechanical finding and concomitant carpal tunnel syndrome (CTS) did not resolve with conservative measures. Dynamic magnetic resonance imaging revealed anomalous flexor digitorum profundus (FDP) muscle bellies as the cause of the mechanical snapping and irritation of the median nerve. Carpal tunnel release and excision of anomalous muscle within the carpal tunnel and distal forearm provided complete resolution of symptoms. CONCLUSION: Anomalous muscle bellies of the FDP is a rare cause of a volar snapping wrist and CTS.

An accessory muscle of the posterior compartment of leg of clinical significance: a cadaveric case report / Un músculo accesorio del compartimento posterior de la pierna de importancia clínica: reporte de un caso cadavérico

SUMMARY: Accessory and anomalous muscles are common in humans, although their unique morphologic characteristics can make accurate identification difficult. In this case report, we attempt to identify an anomalous accessory muscle of the posterior compartment of the leg [Compartimentum posterius cruris] detected during cadaveric dissection and discuss its clinical significance. The muscle was found on the right lower limb of an 81-year-old female cadaver and extended from the distal femur to attach to the gastrocnemius muscle at the point where the medial and lateral heads fuse. At its origin, the muscle was found lateral to the popliteal vessels and crossed posterior to these vessels and tibial nerve. It displayed characteristics similar to both an accessory plantaris muscle and gastrocnemius tertius, thus making its ultimate identification difficult. Though the muscle displayed a morphologically similar appearance to the plantaris, we suggest that its common insertion with the gastrocnemius best identifies it as a gastrocnemius tertius. In addition, due to its relationship with the popliteal neurovasculature, it is possible that this muscle could have resulted in neurovascular entrapment although it is unknown whether or not this cadaver exhibited symptoms.

RESUMEN: Los músculos accesorios y anómalos son comunes en los seres humanos, aunque sus características morfológicas pueden dificultar la identificación precisa. En este reporte de caso, intentamos identificar un músculo accesorio anómalo del compartimento posterior de la pierna [Compartimentum posterius cruris] detectado durante la disección cadavérica y discutir su importancia clínica. El músculo fue encontrado en el miembro inferior derecho de una mujer de 81 años de edad y se extendía desde la parte distal del fémur para unirse al músculo gastrocnemio en la fusión de sus cabezas medial y lateral. En su origen, el músculo se encontraba lateral a los vasos poplíteos y cruzaba posteriormente a estos vasos y al nervio tibial, presentando características similares tanto al músculo plantar accesorio como al gastrocnemio tercero, lo que dificultaba su identificación final. Similar al músculo plantar, sugerimos que debido a su inserción común con el gastrocnemio lo identifica mejor como un músculo gastrocnemio tercero. Además, debido a su relación con la neurovasculatura poplítea, es posible que este músculo haya dado lugar a un síndrome de compresión neurovascular aunque se desconoce si este individuó presentó síntomas o no en vivo.

Normalizing calf circumference to identify low skeletal muscle mass in older women: a cross-sectional study / Normalización de la circunferencia de la pantorrilla para identificar la masa muscular esquelética baja en las mujeres mayores: un estudio transversal

Introduction: functional limitation is a result of sarcopenia and is associated with loss of skeletal muscle mass (SMM). Cost-effective methods are important for the identification of sarcopenia. Objective: to propose cutoff points for normalized calf circumference (CC) in order to identify low SMM in older women based on their functional limitation.Methods: in this descriptive, cross-sectional study the CC values of a young female sample (n = 78) were used to establish cutoff points (-2 SD) for low SMM in older women (n = 67). Functional limitation was identified by the six-minute walk test (≤ 400 m). CC was normalized by body mass, height, and BMI. The diagnostic accuracy of CC was calculated with a ROC curve, using functional limitation as standard. Results: cutoff points and area under the curve (AUC) were: CC (≤ 28.5; 0.62); CC·body mass-1 (≤ 0.40; 0.63); CC·height-2 (≤ 8.52; 0.55) and CC·BMI-1 (≤ 1.10; 0.73). Only CC·BMI-1 achieved a desirable accuracy (AUC > 0.7) to distinguish functional limitation. Conclusion: the accuracy attained supports the use of CC·BMI-1 to identify low SMM in older women. In the clinical context it is possible to predict the risk of sarcopenia when sophisticated methods for determining SMM are not available. (AU)

Introducción: la limitación funcional es consecuencia de la sarcopenia y se asocia con la pérdida de masa muscular esquelética (MME). Los métodos rentables son importantes para la identificación de la sarcopenia. Objetivo: proponer puntos de corte para la circunferencia de la pantorrilla (CP), normalizada para identificar un MME bajo en mujeres mayores en función de su limitación funcional. Métodos: en este estudio descriptivo de carácter transversal se utilizaron los valores de CP de una muestra de mujeres jóvenes (n = 78) para establecer los puntos de corte (-2 DS) de la MME baja en las mujeres mayores (n = 67). La limitación funcional se identificó mediante la prueba de la marcha de seis minutos (≤ 400 m). La CP se normalizó por la masa corporal, la altura y el IMC. La precisión diagnóstica de la CP se calculó con la curva ROC, utilizando como estándar la limitación funcional. Resultados: los puntos de corte y el área bajo la curva (AUC) fueron: CP (≤ 28,5; 0,62); CP·masa corporal-1 (≤ 0,40; 0,63); CP·altura-2 (≤ 8,52; 0,55) y CP·IMC-1 (≤ 1,10; 0,73). Solo el CP·IMC-1 logró la precisión deseable (AUC > 0,7) para distinguir la limitación funcional. Conclusión: la precisión alcanzada respalda el uso de CP·IMC-1 para identificar la MME baja en las mujeres mayores. En el contexto clínico es posible predecir el riesgo de sarcopenia cuando no se dispone de métodos sofisticados para determinar la MME. (AU)

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.

Finger abduction as a novel function of the extensor digitorum brevis manus muscle.

A 25-year-old female presented with a chronic scapho-lunate ligament injury with development of carpal instability requiring reconstruction. During a standard dorsal longitudinal mid-line approach to the carpus, an extensor digitorum brevis manus (EDBM) muscle was found taking its origin from the dorsal wrist capsule overlying the lunate with innervation from the posterior interosseous nerve (PIN). Electrical stimulation of the muscle belly demonstrated abduction of the middle finger. The EDBM is a rare anatomical variant of the extensor compartment of the wrist and may be encountered during surgical approaches. Where possible these variant muscles should be carefully dissected off underlying structures, preserved and repaired at the conclusion of a procedure to ensure no perceived functional deficit to the patient. We present a case of a previously undescribed EDBM muscle function of pure finger abduction with no extension and a surgical technique of preserving its origin. We propose that the middle finger variant of the EDBM should be re-named the extensor digitorum brevis medius to reflect our findings.

Normalizing calf circumference to identify low skeletal muscle mass in older women: a cross-sectional study.

INTRODUCTION: Introduction: functional limitation is a result of sarcopenia and is associated with loss of skeletal muscle mass (SMM). Cost-effective methods are important for the identification of sarcopenia. Objective: to propose cutoff points for normalized calf circumference (CC) in order to identify low SMM in older women based on their functional limitation. Methods: in this descriptive, cross-sectional study the CC values of a young female sample (n = 78) were used to establish cutoff points (-2 SD) for low SMM in older women (n = 67). Functional limitation was identified by the six-minute walk test (≤ 400 m). CC was normalized by body mass, height, and BMI. The diagnostic accuracy of CC was calculated with a ROC curve, using functional limitation as standard. Results: cutoff points and area under the curve (AUC) were: CC (≤ 28.5; 0.62); CC·body mass-1 (≤ 0.40; 0.63); CC·height-2 (≤ 8.52; 0.55) and CC·BMI-1 (≤ 1.10; 0.73). Only CC·BMI-1 achieved a desirable accuracy (AUC > 0.7) to distinguish functional limitation. Conclusion: the accuracy attained supports the use of CC·BMI-1 to identify low SMM in older women. In the clinical context it is possible to predict the risk of sarcopenia when sophisticated methods for determining SMM are not available.

INTRODUCCIÓN: Introducción: la limitación funcional es consecuencia de la sarcopenia y se asocia con la pérdida de masa muscular esquelética (MME). Los métodos rentables son importantes para la identificación de la sarcopenia. Objetivo: proponer puntos de corte para la circunferencia de la pantorrilla (CP), normalizada para identificar un MME bajo en mujeres mayores en función de su limitación funcional. Métodos: en este estudio descriptivo de carácter transversal se utilizaron los valores de CP de una muestra de mujeres jóvenes (n = 78) para establecer los puntos de corte (-2 DS) de la MME baja en las mujeres mayores (n = 67). La limitación funcional se identificó mediante la prueba de la marcha de seis minutos (≤ 400 m). La CP se normalizó por la masa corporal, la altura y el IMC. La precisión diagnóstica de la CP se calculó con la curva ROC, utilizando como estándar la limitación funcional. Resultados: los puntos de corte y el área bajo la curva (AUC) fueron: CP (≤ 28,5; 0,62); CP·masa corporal-1 (≤ 0,40; 0,63); CP·altura-2 (≤ 8,52; 0,55) y CP·IMC-1 (≤ 1,10; 0,73). Solo el CP·IMC-1 logró la precisión deseable (AUC > 0,7) para distinguir la limitación funcional. Conclusión: la precisión alcanzada respalda el uso de CP·IMC-1 para identificar la MME baja en las mujeres mayores. En el contexto clínico es posible predecir el riesgo de sarcopenia cuando no se dispone de métodos sofisticados para determinar la MME.