ABSTRACT
Background: The hands play a pivotal role in skilled movements. Anomalous muscles of the extensors of the hand are seen usually in anatomical dissections and during surgeries. Variations of the muscles in the dorsum of hand may be asymptomatic or may cause dorsal wrist pain, particularly if a muscle belly encroaches on and obstruct the wrist’s small extensor compartments deep to extensor retinaculum. Methods: A total of 54 upper limb specimens were used for the current study from the Anatomy Department of an undergraduate & postgraduate teaching Medical College in India. Incidence of additional muscle belly and its tendon in the posterior compartment of the forearm and dorsum of the hand were noted and photographed. Results: The anomalous muscle bellies and tendons in extensor compartment of forearm and dorsum of hand were observed in 10 limbs (18.5%) of 54 limbs. Of which, the extensor medii proprius (EMP) was 9.3%, extensor digitorum brevis manus (EDBM) was 3.7%. The numbers of the tendon of the extensor digitorum (ED) were varied in 3 limbs (5.6%). Conclusion: Knowledge of anatomical data of such variant muscles and additional belly or tendon in the extensor compartment of forearm and dorsum of hand is essential for surgeons to modify treatment plan, so as to avoid reporting error and of surgical procedures while operating on hand.
ABSTRACT
RESUMEN: El músculo extensor corto de los dedos (ECD) se sitúa junto con el músculo extensor corto del hallux (ECH) en la región dorsal del pie y están encargados de colaborar con la acción agonista de los músculos extensor largo de los dedos (ELD) y extensor largo del hallux (ELH), en la extensión de los cuatro dedos mediales en las articulaciones metatarsofalángicas. Esta condición complementaria permite su transferencia quirúrgica hacia otras regiones receptoras sin afectar la funcionalidad extensora de los dedos del pie motivo por el cual durante las últimas décadas se ha convertido en un tejido importante para la reconstrucción de lesiones tisulares, sin embargo, son escasos los estudios biométricos que lo describan en detalle. El objetivo de esta investigación fue establecer la longitud, ancho y área de extensión de estos músculos acompañada de la determinación de las distancias de éstos respecto a la cuña medial y la base del quinto metatarsiano para su uso quirúrgico. Sumado a lo anterior y posterior a la descripción de las variantes musculares encontradas se determinó los puntos motores de inervación de estos dos músculos. Para ello se estudiaron 36 miembros inferiores formolizados de individuos adultos brasileños pertenecientes a la Universidad Federal de Alagoas (UFAL), Maceió, Brasil. Las mediciones se realizaron con un cáliper marca Mitutoyo de 0,01 mm de precisión obteniendo una longitud, ancho y área de 6,89 ± 1,64 cm, 3,81 ± 0,42 cm y 31,98 ± 7,60 cm2 en el lado derecho de 6,91 ± 1,64 cm, 3,68 ± 0,46 cm y 30,75 ± 7,61 cm2 en el izquierdo respectivamente. En el 17 % de los casos hay presencia de tendones accesorios para el músculo ECD. La distancia desde el margen medial del músculo ECH respecto a la cuña medial y del margen lateral del músculo ECD a la base del quinto metatarsiano fue de 1,97 ± 0,43 y 1,72 ± 0,41 al lado derecho y de 2,01 ± 0,62 y 1,87 ± 0,36 al lado izquierdo respectivamente. Los puntos motores (Pm) predominaron en un 64 % en el tercio medio del músculo ECH y en un 64 % en el tercio proximal del músculo ECD. Estos resultados son un aporte significativo, tanto para quienes realizan cirugía ortopédica como para el conocimiento detallado de la anatomía dorsal del pie.
SUMMARY: The extensor digitorum brevis muscle (EDB) is located along with the extensor hallucis brevis (EHD) in the dorsal region of the foot and are responsible for collaborating with the agonist action of the extensor digitorum longus muscles (EDL) and extensor hallucis longus (EHL) in the extension of the four medial fingers in the metatarsophalangeal joints. This complementary condition allows its surgical transfer to other receptor regions without affecting the extensor functionality of the toes, which is why during the last decades it has become an important tissue for the reconstruction of tissue injuries, however, there are few studies biometrics that describe it in detail. The objective of this investigation was to establish the length, width and area of extension of these muscles accompanied by the determination of their distances from the medial wedge and the base of the fifth metatarsal for surgical use. In addition to the above and after the description of the muscle variants found, the innervation motor points of these two muscles were determined. To do this, 36 formalized lower limbs of Brazilian adult individuals belonging to the Federal University of Alagoas (UFAL), Maceió, Brazil, were studied. Measurements were made with a 0.01 mm precision Mitutoyo caliper obtaining a length, width and area of 6.89 ± 1.64 cm, 3.81 ± 0.42 cm and 31.98 ± 7.60 cm2 on the right side of 6.91 ± 1.64 cm, 3.68 ± 0.46 cm and 30.75 ± 7.61 cm2 on the left, respectively. In 17 % of cases there is presence of accessory tendons for the EDB muscle. The distance from the medial margin of the EHB muscle with respect to the medial wedge and the lateral margin of the EDB muscle to the base of the fifth metatarsal was 1.97 ± 0.43 and 1.72 ± 0.41 on the right side and 2,01 ± 0.62 and 1.87 ± 0.36 on the left side respectively. Motor points (Pm) predominated in 64 % in the middle third of the EHB muscle and in 64 % in the proximal third of the EDB muscle. These results are a significant contribution both for those who perform orthopedic surgery and for detailed knowledge of the dorsal foot anatomy.
Subject(s)
Humans , Male , Female , Adult , Hallux/anatomy & histology , Toes/anatomy & histology , Muscle, Skeletal/anatomy & histology , Surgical Flaps , Brazil , Muscle, Skeletal/innervation , Foot/anatomy & histologyABSTRACT
A 78-year-old male cadaver showed bilateral anomalous muscles on the dorsum of the hand. An extensor digitorum brevis manus was noted on the dorsum of the right hand. It originated from the distal end of the radius and the radiocarpal joint ligaments and inserted into the metacarpophalangeal joint of the third digit. On the dorsum of the left hand, an extensor digiti medii proprius was identified. It originated from the distal third of the ulna near the extensor indicis proprius and the interosseous membrane and inserted into the metacarpophalangeal joint of the third digit. Awareness of these combined muscular variation would be helpful in understanding the identification of digital extensors and in requiring careful consideration for the reconstruction surgery of the hand.
Subject(s)
Aged , Humans , Male , Cadaver , Forearm , Hand , Joints , Ligaments , Membranes , Metacarpophalangeal Joint , Muscles , Radius , UlnaABSTRACT
During routine dissection, additional muscular head of extensor digitorum brevis muscle attaching to the third toe and accessory muscle perforated by the branch of the deep peroneal nerve were observed in the right foot of a 71-year-old male cadaver. The additional muscular head originated from the dorsal surface of cuboid bone, and ran parallel with the third tendon of the extensor digitorum brevis muscle. It was conjoined with the third tendon of extensor digitorum brevis at the middle of its course. The accessory muscle was a small muscle which was covered with the muscle belly of the extensor hallucis brevis muscle. It originated from the dorsal surface of the calcaneus, and inserted to the lateral one-third of transverse retinacular band. These two variants were innervated by the branches of deep peroneal nerve. The branches of deep peroneal nerve were compressed under the tendon of extensor hallucis brevis and around the site where the nerve branch perforated the small muscle. The clinical significances of these variations and tendon of extensor hallucis brevis muscle were discussed.
Subject(s)
Aged , Humans , Male , Cadaver , Calcaneus , Foot , Head , Peroneal Nerve , Tarsal Bones , Tarsal Tunnel Syndrome , Tendons , ToesABSTRACT
Extensor digitorum brevis manus (EDBM) is a rare variation of the extensor muscle of the dorsum of the hand, which is found incidentally during surgery or magnetic resonance imaging (MRI). EDBM arises from the wrist capsule inferior to the extensor retinaculum, which frequently goes into the ulna side of the basis of the proximal phalanx between the 2nd and 3rd fingers. The aim of this report is evaluate to investigate the symptomatic mass on the dorsum of the hand and wrist using an image study (MRI or ultrasonography) to confirm whether it is a tumor or EDBM. Surgical excision was chosen as a treatment.
Subject(s)
Fingers , Hand , Magnetic Resonance Imaging , Ulna , WristABSTRACT
En la región dorsal de la muñeca y la mano, se describen varios músculos accesorios o supernumerarios, que pueden actuar como simuladores de entidades patológicas y producir síntomas clínicos (gangliones, quistes sinoviales, etc.). El diagnóstico clínico es cada vez más accesible; la ecografía y la resonancia magnética han permitido conocer su naturaleza y extensión. La presencia de este músculo, por lo general, pasa desapercibida y no causa síntomas, aunque puede producir clínica de tumefacción y dolor en el carpo; se acentúa con la actividad, sobre todo, aquellas que requieran la extensión forzada de la muñeca y los dedos. Puede manifestarse bilateralmente en un tercio de los pacientes y la incidencia no difiere entre los sexos. Cuando los síntomas son graves, hay que recurrir al tratamiento quirúrgico que consiste en la resección completa del músculo o en la división del retináculo extensor; con ambas técnicas se obtienen buenos resultados; en algunos casos, se lo ha usado como colgajo para reconstruir lesiones tendinosas en otros niveles. Este músculo es muy poco frecuente; la revisión bibliográfica de este trabajo ayudaría a considerar esta patología a la hora de realizar diferentes diagnósticos diferenciales en la región de la muñeca y la mano.
In the dorsal region of the wrist and hand, various accessory and supernumerary muscles are described; they can act as simulators and produce clinical entities (ganglion, synovial cysts, etc.). The clinical diagnosis is increasingly accessible; ultrasound and magnetic resonance have allowed to evaluate their nature and extent. The presence of this muscle usually goes unnoticed without symptoms, but it can cause swelling and pain in the carp; it is accentuated with activities, especially those requiring the forced extension of the wrist and fingers. It can manifest bilaterally in one third of patients and the incidence did not differ between males and females. When symptoms are severe, surgical treatment is indicated with the complete resection of the muscle or the division of the extensor retinaculum; both techniques achieve good results; in some cases, it has been used as a flap to reconstruct tendon injuries at other levels. The frequency of this muscle is very low; our literature review will help to consider this condition among the various differential diagnoses in the region of the wrist and hand.
Subject(s)
Adolescent , Adult , Hand , MusclesABSTRACT
Introduction: A rare type of variation of extensor muscles on the dorsum of hand is extensor digitorum brevis manus (EDBM).It is a small muscle rarely present on the dorsum of the hand which can be misinterpreted a pathological mass on the dorsum of the hand. Aim: Aim of the present cadaveric study is to observe the incidence, anatomical morphology of EDBM and to study its phylogenetic significance. Material and Methods: Present study was conducted on 32 adult human cadaveric hands of which 24 were of male and 8 were of female cadavers. Results: The EDBM was observed in one incidence (3.1%) of the specimens. EDBM was found to be between the tendons of extensor digitorum for index and middle fingers. It was of Anatomical variant type I. Conclusion: The knowledge of incidence and morphology of EDBM is of greater relevance in clinical practice to rule out any pathological mass on the dorsum of the hand.
ABSTRACT
Most of the anatomical variations are noted during the cadaveric dissections. A rare variation of the Extensor digitorum brevis manus was observed on the dorsal aspect of the right hand of a 69-year-old male cadaver. This atavistic muscle had two bellies which originated from the dorsal aspect of the lower end of radius and the capsule of the wrist joint respectively. The two bellies fused to form a single tendon which inserted into the ulnar side of the dorsal digital expansion of the middle finger. Posterior interosseous nerve innervated the two bellies. This muscle may be involved in the wrist pain or may be misinterpreted as a ganglion or a nodule upon radiological examination. This muscle may be used for reconstructive purposes.
ABSTRACT
The extensor digitorum brevis muscle (EDB) is a practical option for use as an island flap or free flap when reconstructing soft tissue defects in the ankle as well as in the entire lower limb. It is frequently used to correct crossover toe deformity and other painful toe disorders. We evaluated the morphometry of the EDB in 44 formalin-fixed limbs. Length and width of the muscles were measured. Surface area was calculated as the product of length and width of the muscle. The length of each tendon was also measured from its origin to the point of distal attachment. Presence of any additional tendons was noted. Mean length, width, and surface area of the muscle were 7.39+/-0.71 cm, 4.1+/-0.37 cm, and 30.5+/-4.78 cm2 on the right side and 7.2+/-0.84 cm, 3.9+/-0.37 cm, and 28.4+/-5.35 cm2 on the left side, respectively. Morphometry of the tendons revealed that the tendon of the great toe had the highest mean length (9.5 cm) and the tendon of the fourth toe had the lowest mean length (6.3 cm). Four of the limbs studied (9.09%) had only three tendons. Three of the limbs studied (6.81%) had five tendons, and in one exceptional case (2.27%), six tendons were detected. These observations have significant value and are applicable to plastic and orthopedic surgery.
Subject(s)
Animals , Ankle , Congenital Abnormalities , Extremities , Free Tissue Flaps , Lower Extremity , Muscles , Orthopedics , Plastics , Tendon Transfer , Tendons , ToesABSTRACT
PURPOSE: To report of a series of successful reconstruction of soft tissue defect on distal leg with extensor digitorum brevis myo-cutaneous flap. METHODS: Between April 2002 to December 2004, 7 patients with soft tissue defect on distal leg were operated with Extensor Digiotorum Brevis myocutaneous flap. 6 of these patients had osteomyelitis. RESULTS: Extensor Digiotorum Brevis myocutaneous flap were used in 6 patients and reverse flow flap was used in one patient. Average follow up was 19 months. All flap were survived 100% without any complication and osteomyelitis were controled in all cases. Aesthetic and functional out come were excellent on both recipient and donor sites. CONCLUSION: The advantages of this flap are effectively control of local wound infection, constant and reliable anatomical structures, adequately thin flap. Technical easiness for raising flap and wide arch of rotation. Extensor Digitorum Brevis myo-cutaneous flap is one of ideal option for the reconstruction of distal leg and foot defects.
Subject(s)
Humans , Follow-Up Studies , Foot , Leg , Myocutaneous Flap , Osteomyelitis , Tissue Donors , Wound InfectionABSTRACT
The extensor digitorum brevis manus is one of the rare anatomic variations which occur on the dorsum of the hand. Only some 295 articles were found worldwide in an extensive bibliographic review carried out in 2003. This muscle was dissected bilaterally on a male corpse at the Human Anatomy Laboratory of the Morphophysiological Department of the Faculty of Medical Sciences of Minas Gerais. It is an elongated, small muscle, originating at the carpal bones and at the extensor retinaculum and inserting into one of the tendons of the fingers extensor muscle. Even though it does not present an essential function in the movement of the fingers nor the hand, it can lead to pain when hypertrophied, creating the need for clinical or even surgical treatment.
Subject(s)
Humans , Male , Female , Back , Back/physiology , Hand/anatomy & histology , Hand/pathology , Muscles/anatomy & histology , Cadaver , Diagnosis, Differential , DissectionABSTRACT
OBJECTIVE: To evaluate the neurophysiological changes after intramuscular botulinum toxin A (BTX-A) injection in normal adults. METHOD: Nine subjects were studied by electrophysiological measurements before and after the injections. BTX-A (5 IU, Botox , Allergen, USA) was injected in the extensor digitorum brevis (EDB) muscles. Thereafter, electrophysiological measurement was followed up during 6 months. RESULTS: The compound muscle action potential (CMAP) amplitude of injected EDB muscle decreased significantly for 8 weeks, a maximal decrement at 4 weeks after injection. CMAP peak area changes over time were nearly identical to those of CMAP peak amplitudes. The first/fourth amplitude change of CMAP with 3-Hz repetitive nerve stimulation decreased significantly for 8 weeks and the amplitude following post-exercise activation increased significantly after injection. There were no significant changes in F-wave amplitude and latency. CONCLUSION: Serial electrophysiological measurements after intramuscular BTX-A injection into EDB provide useful information for the neurophysiological change after injection.
Subject(s)
Adult , Humans , Action Potentials , Botulinum Toxins , MusclesABSTRACT
Innervation anomalies are well-known sources of erroneous interpretation in motor nerve conduction studies. The extensor digitorum brevis (EDB) muscle is supplied by the deep peroneal nerve and is commonly used as recording point in peroneal motor conduction study. If the compound muscle action potentials (CMAPs) are not evoked with EDB muscle recording without any symptoms or signs of peroneal neuropathy, we should lead one to consider either technical pitfall or anomalous innervation. We experienced an anomalous innervation in a woman in whom the bilateral EDB muscles were innervated exclusively by the tibial nerve. This was proved using a monopolar needle electrode for recording in extensor digitorum brevis (EDB) and flexor digitorum brevis (FDB) muscles, which encoded acceptable shape of CMAPs on tibial nerve stimulation. To avoid erroneous interpretation of electromyographic and nerve conduction studies, one should be aware of this possible innervation anomaly ("all tibial foot").