Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.
3,303 results found
Article
Supraodontoid space
The supraodontoid space, also known as the supradental space or apical cave, is an extradural space at the anterior craniocervical junction superior to the odontoid process of C2 (dens axis).
Gross anatomy
Boundaries
The space is a cave-shaped region facing posteriorly with the following boun...
Article
Hair
Hair (TA: pilus/pili) remains important physiologically and psychologically for humans. The hair shaft develops from a structure known as the hair follicle. Each hair has an arrector pili muscle and both sensory and sympathetic neural connections.
Gross anatomy
The hair shaft (TA: stipes pili)...
Article
Posterior superior aortic recess
The posterior superior aortic recess, also known as the superior pericardial recess or the superior sinus, is one of the variable invaginations of the superior aortic recess and is located posterior to the ascending aorta. It may mimic mediastinal lymphadenopathy or a bronchogenic cyst.
Article
Posterior pericardial recess
The posterior pericardial recess is one of the pericardial recesses forming a small space within the pericardium. It arises from the superior margin of the oblique pericardial sinus, posterior to the right pulmonary artery and medial to the bronchus intermedius.
It may mimic mediastinal lymphad...
Article
Talar tilt
Talar tilt is a measurement of the angle between the talus and the distal tibia, used in the assessment of ankle instability and ankle osteoarthritis (OA).
Usage
Talar tilt is an important measurement in the assessment of ankle osteoarthritis. It is measured as part of the Kellgren and Lawrenc...
Article
Nasal septal cartilage
The nasal septal cartilage, also known as quadrangular cartilage, forms most of the anterior portion of the nasal septum, and is one of five named nasal cartilaginous components supporting the external nose.
Gross anatomy
Most of the anterior one-third of the nasal septum is formed by the sept...
Article
Superficial epigastric vein
The superficial epigastric vein (TA: vena epigastrica superficialis) is an important tributary of the great saphenous vein that drains the anterior abdominal wall inferior to the level of the umbilicus.
The superficial epigastric vein drains into the great saphenous vein at the saphenous openin...
Article
Lateral thoracic vein
The lateral thoracic vein (TA: vena thoracica lateralis) is a tributary of the axillary vein. It provides venous drainage for the axilla, anterolateral chest wall, including serratus anterior and pectoralis muscles and breast, and the supraumbilical abdominal wall.
Terminology
In some texts, t...
Article
Long head of biceps tendon
The long head of the biceps tendon (LHBT) is the proximal tendon of the long head of the biceps muscle and encircles the humeral head on its course. It has an intraarticular extrasynovial and an extraarticular portion.
Summary
location: shoulder
insertion: supraglenoid tubercle of the scapula...
Article
Autonomic nervous system
The autonomic nervous system (ANS) is a subdivision of the peripheral nervous system. The autonomic system provides innervation of the involuntary muscles, i.e. myocardium and smooth muscle, and glands, through which fine control of homeostasis is maintained.
The afferent innervation of the aut...
Article
Peripheral nervous system
The peripheral nervous system (PNS) consists of the nerves (cranial nerves III-XII and spinal) and their related ganglia outside the central nervous system (CNS). The latter comprising the brain and spinal cord. The central nervous system and peripheral nervous system together form the nervous s...
Article
Neurocranium
The neurocranium (plural: neurocrania) is the name given to the portion of the skull that encloses the brain. It comprises the skull base and the skull vault. The neurocranium and facial bones (viscerocranium) together form the skull.
Article
Nasolacrimal canal
The nasolacrimal canal is the short bony passage along which the nasolacrimal duct courses in the face.
Gross anatomy
lateral wall
lacrimal groove of the medial maxilla
lacrimal hook of the lacrimal bone
medial wall
superiorly: lacrimal bone
inferiorly: lacrimal process of the inferior n...
Article
Carotid cistern
The carotid cistern is one of the basal (subarachnoid) cisterns that surrounds the supraclinoid internal carotid artery.
Gross anatomy
Relations and/or Boundaries
The carotid cistern lies between these brain structures:
medially: the optic chiasm and nerve
laterally: the mesial temporal lob...
Article
Central nervous system
The central nervous system (CNS) is the part of the nervous system that includes the brain and spinal cord.
Gross anatomy
The main components of the CNS are the brain and spinal cord. In addition, the CNS includes the optic nerves (cranial nerve II), retinas, olfactory nerves (cranial nerve I)...
Article
Oropharyngeal isthmus
The oropharyngeal isthmus, a.k.a. isthmus of fauces, is the relative constriction of the anterior oropharynx that borders the oral cavity. The isthmus is sometimes described as the passage that transitions between the oral cavity and pharynx, but strictly speaking, it is part of the oropharynx.
...
Article
Superior hypogastric plexus
The superior hypogastric plexus is an autonomic nerve plexus and ganglia located in the lower abdomen.
Summary
location: the plexus and ganglia lie anterior to the aortic bifurcation extending inferiorly between the common iliac arteries and along the left common iliac vein and median sacral v...
Article
Modiolus (disambiguation)
The modiolus (plural: modioli) may refer to one of two different anatomical structures, both in the head and neck region:
modiolus (cochlea)
modiolus (mouth)
History and etymology
The Latin word, "modiolus" means hub of a wheel, and is well-named, as in both the cochlea and at the angle of t...
Article
Modiolus (mouth)
The modiolus (plural: modioli), also known as the modiolus anguli oris or commissural modiolus, is a small fibromuscular structure at the corner of the mouth where fibers from multiple facial muscles converge, and helps coordinate the action of these muscles.
Gross anatomy
The convergence of t...
Article
Gomphosis
A gomphosis (plural: gomphoses), also known as the dentoalveolar syndesmosis, is the specific name for the fibrous joint between the teeth and the alveolar bone of the maxilla/mandible 1,2.
Article
Incisivus labii inferioris muscle
The incisivus labii inferioris muscle (TA: pars labialis musculi orbicularis oris) is one of the facial muscles. It acts as a supplementary muscle to the orbicularis oris muscle.
Terminology
The incisivus labii inferioris muscle is often omitted from major anatomical texts or articles on the f...
Article
Commissure (disambiguation)
A commissure (TA: commissura) is a location at which two anatomical structures are united. Though the term most commonly refers to the commissures in the brain, there are a number which exist in the human body:
central nervous system
corpus callosum
anterior commissure
posterior commissure
...
Article
Right atrial appendage
The right atrial appendage, also known as the right auricule (TA) or auricle, is a trapezoidal pouch forming the anterosuperior part of the right atrium. Pacemaker/defibrillator leads are often placed at this site.
Gross anatomy
The right atrial appendage is delineated from the rest of the rig...
Article
Egyptian eye sign
"Egyptian eye sign" or "sonographic eye sign" refers to the normal appearance of great saphenous vein on ultrasound, in transverse view 1,2.
Ultrasound examination of the great saphenous vein shows echogenic fascia surrounding it, with the saphenous fascia superiorly and the muscular fascia inf...
Article
Trochlea (eye)
The trochlea is a cartilaginous structure acting as a pulley for the superior oblique muscle of the eye.
Gross anatomy
The trochlea inserts on the trochlear fovea and spine located on the anteromedial part of the orbital roof. The tendon of superior oblique muscle passes through it 1.
Functi...
Article
Interstitial cells of Cajal
The interstitial cells of Cajal are mesenchymal cells closely apposed to neural and smooth muscle cells of the gut. They form a heterogeneous group with differing ultrastructure and functions.
One cell type has an ancillary neural function as a gastrointestinal pacemaker, generating electrical ...
Article
Scapular medial rotation
Scapular medial rotation describes the rotation of the scapula (scapulothoracic joint) such that the glenoid fossa faces downwards - thus it may also be called downward rotation. It is the opposite of scapular lateral rotation - similarly, this motion requires motion at the sternoclavicular and ...
Article
Scapular lateral rotation
Scapular lateral rotation describes the rotation of the scapula (scapulothoracic joint) such that the glenoid fossa faces upwards - thus it may also be called upward rotation. This motion allows elevation of the humerus as seen in abduction of the arm. It is almost always associated with scapula...
Article
Scapular retraction
Scapular retraction describes the backward movement of the scapula about the thoracic wall (scapulothoracic joint). As the scapula moves towards the midline it can also be referred to as scapular adduction. The opposite motion is scapular protraction.
The muscles that act as primary movers are ...
Article
Scapular protraction
Scapular protraction describes the forward movement of the scapula about the thoracic wall (scapulothoracic joint). As the scapula moves away from the midline it can also be referred to as scapular abduction. This motion usually occurs in conjunction with some scapular lateral rotation. This mov...
Article
Scapular depression
Scapular depression refers to the caudal motion of the scapula (scapulothoracic joint). In most instances, depression of the scapula is a passive process (due to gravity) that is facilitated by movement at the acromioclavicular joint. Occasionally some muscular attachments serve as active depres...
Article
Scapular elevation
Scapular elevation refers to the cranial motion of the scapula (scapulothoracic joint), commonly described as “shrugging the shoulders”. This movement is facilitated by several muscles and it is useful to distinguish these as primary movers and stabilizers. It is important to note that no one mo...
Article
Subseptate uterus
A subseptate uterus is a mild form congenital uterine anomaly (often considered as a normal variant) where there is a presence of a partial septum within the uterus not extending to the cervix and with the central point of the septum at an acute (<90°) angle. The external uterine contour is unif...
Article
Deep artery of the penis
The deep artery of the penis, also known as cavernosal artery, is one of the two terminal branches of the internal pudendal artery.
Gross anatomy
Origin
The internal pudendal artery bifurcates terminally into the deep artery of the penis and the dorsal artery of the penis at the anterior marg...
Article
Dorsal artery of the penis
The dorsal artery of the penis is one of the two terminal branches of the internal pudendal artery.
Gross anatomy
Origin
The internal pudendal artery bifurcates into the deep artery of the penis and the dorsal artery of the penis at the anterior margin of the perineal membrane 1.
Terminatio...
Article
Artery to the bulb
The artery to the bulb of the penis (male) or vestibule (female) is a branch of the internal pudendal artery. It differs slightly in males and females.
Artery to the bulb of the penis
Origin: internal pudendal artery, distal to the perineal artery1.
a common penile artery, serving as the or...
Article
Pes anserinus (disambiguation)
The pes anserinus (rare plural: pedes anserini) is the name given to two different anatomical structures:
pes anserinus (facial nerve): a.k.a. parotid plexus
pes anserinus (knee)
Both structures are so named due to their similarity to a goose's foot, which is what 'pes anserinus' means in Lat...
Article
Marginal mandibular nerve
The marginal mandibular nerve (TA: ramus marginalis mandibularis nervi facialis) is a branch of the extratemporal (terminal) segment of the facial nerve. It supplies the depressor anguli oris, depressor labii inferioris and mentalis muscles. It is of greater clinical importance than the other fa...
Article
Mentalis muscle
The mentalis muscles (TA: musculus mentalis) are paired muscles, one on each side of the mouth, important as elevators of the chin and lower lip; the muscles are one of the facial muscles.
Summary
origin: incisive fossa of the mandible
insertion: skin of the chin
innervation: facial nerve
...
Article
Common iliac lymph nodes
The common iliac lymph nodes are found surrounding the common iliac artery and vein which is located above the bifurcation of the external and internal iliac vessels and distal to the aortic bifurcation (in a majority of patients at the L4 level and a minority at the L3 or L5 level) and medial t...
Article
Antebrachial fascia
The antebrachial fascia or deep fascia of the forearm is a thick connective tissue fascia investing the forearm muscles. It also forms the lateral intermuscular septum, which divides the forearm muscle into the anterior and posterior compartments together with the radius, ulna, and interosseous ...
Article
Perineal artery
The perineal artery arises from the internal pudendal artery and supplies some of the perineal musculature and external genitalia.
Summary
Origin: branches off the internal pudendal artery, arising at the level of the posterior angle of the perineal membrane
Branches: it has two branches:
a ...
Article
Middle genicular artery
The middle genicular artery (MGA) is one of the arteries of the knee joint and is a major supplicant of the anterior and posterior cruciate ligaments.
Summary
location: knee
origin: popliteal artery
supply: cruciate ligaments
Gross anatomy
The middle genicular artery originates from the an...
Article
Cystic vein
The cystic veins (TA: venae cysticae) are the main venous drainage of the gallbladder. They subsequently drain into the portal vein.
Gross anatomy
The cystic veins begin as venules running over the surface of the fundus and body of the gallbladder merging proximate to the neck of the gallbladd...
Article
Development of the heart
The heart is one of the first organs in the developing embryo to form and function. By the start of week 4, a primitive heart has begun to pump blood and by week 7 most of the gross development of the heart is complete. Its development is complex, with several events occurring simultaneously.
T...
Article
Superior medial genicular artery
The superior medial genicular artery (SMGA) is the medial counterpart of the superior lateral genicular artery and participates in the supply of the superomedial structures of the knee and the vascularization of the patella.
Summary
location: knee
origin: popliteal artery
branches: anterior ...
Article
Superior lateral genicular artery
The superior lateral genicular artery (SLGA) is the lateral counterpart of the superior medial genicular artery and supplies the superolateral structures of the knee and participates in the vascularization of the patella.
Summary
location: knee
origin: popliteal artery
branches: anterior and...
Article
Inferior medial genicular artery
The inferior medial genicular artery (IMGA) is the medial counterpart of the inferior lateral genicular artery and supplies the inferomedial structures of the knee including the medial tibial condyle and participates in the supply of the patella.
Summary
location: knee
origin: popliteal arter...
Article
Inferior lateral genicular artery
The inferior lateral genicular artery (ILGA) is the lateral counterpart of the inferior medial genicular artery and supplies the inferolateral structures of the knee and the patella.
Summary
location: knee
origin: popliteal artery
branches: cutaneous perforating branches
supply: inferolater...
Article
Sphincter (disambiguation)
A sphincter (TA: musculus sphincter) is a term used in anatomy to refer a ring of muscle which narrows a tube or closes off a bodily orifice 1.
anal sphincter
external anal sphincter
internal anal sphincter
hepatic sphincter
esophageal sphincter
lower esophageal sphincter
upper esophagea...
Article
Buccolabial muscles
The buccolabial muscles form a subgroup of the facial muscles.
Elevators, retractors and evertors of the upper lip:
levator labii superioris alaeque nasalis (LLSAN) muscle
levator labii superioris muscle
zygomaticus major muscle
zygomaticus minor muscle
malaris muscle
levator anguli oris...
Article
Crural fascia
The crural fascia or deep fascia of the lower leg is a thick connective tissue fascia that invests the muscles of the lower leg and divides them into the four compartments of the lower leg 1,2:
anterior compartment
lateral or peroneal compartment
deep posterior compartment
superficial poster...
Article
Thyrolinguofacial trunk
A thyrolinguofacial trunk is a very rare pattern of branching of the anterior branches of the external carotid artery. Rather than the facial artery, lingual artery, and superior thyroid artery having their own distinct origins, all three vessels originate from a common trunk of the external car...
Article
Linguofacial trunk
A linguofacial trunk is a rare variation of the anterior branches of the external carotid artery. The lingual artery and facial artery share a common trunk rather than branching independently from the external carotid artery 1. Unlike the thyrolingual or thyrolinguofacial variations in which the...
Article
Thyrolingual trunk
A thyrolingual trunk is an anatomical variant in which the superior thyroid artery and lingual artery share a common trunk 1. This is in contrast to the typical pattern of both vessels emerging independently from the external carotid artery. Other variations of origin include a linguofacial trun...
Article
Submental artery
The submental artery is the largest branch of the facial artery. The vessel supplies the floor of the mouth and sublingual gland while also connecting the circulation of the tongue and the floor of the mouth 1,3.
Summary
origin: facial artery 2
course: emerges from the facial artery at the s...
Article
Submasseteric space
The submasseteric space, also known as the masseteric space, is the inferolateral subcompartment of the masticator space located between the mandible and masseter muscle.
Gross anatomy
Relations and/or Boundaries
The submasseteric space has the following boundaries 1:
medially: mandible (ram...
Article
Pterygomandibular space
The pterygomandibular space is the inferomedial subcompartment of the masticator space located between the mandible and pterygoid muscles.
Gross anatomy
Contents
The pterygomandibular space contains loose areolar tissue, the sphenomandibular ligament, and the following named neurovascular str...
Article
Coronary microcirculation
The coronary microcirculation comprises several anatomically and functionally different coronary vascular compartments with a small diameter (<500 µm) that play a crucial role in the regulation of myocardial perfusion.
Summary
location: epicardium, myocardium, endocardium
blood supply: epicar...
Article
Dual stream language processing models
The dual stream language processing models (dorsal and ventral) have replaced the historic model that only included the Broca's and Wernicke's areas and the arcuate fasciculus 1.
Function
The dorsal stream is responsible for phonological processing and language production (sound/sign to actio...
Article
Levator anguli oris muscle
The levator anguli oris muscle, also known as caninus or triangularis labii superioris muscles, is a buccolabial muscle, a subdivision of the facial muscles.
Gross anatomy
Summary
origin: canine fossa of the maxilla
insertion: modiolus and merges with depressor anguli oris muscle
innervati...
Article
Tubercle of Assaki
The tubercle of Assaki, also known as the tubercle of Asskay 3, is a small bony protuberance of the central part of the glenoid fossa with accompanying thinning of articular cartilage in this location 1.
Pathology
It is presumably caused by the constant pressure of the humeral head exerted on ...
Article
Lesser palatine artery
The lesser palatine artery is a small branch of the descending palatine artery (branch of the 3rd part of the maxillary artery). The vessel supplies the soft palate with small branches to the palatine tonsils 1,2. The vessel emerges through the lesser palatine foramen before traveling posterior ...
Article
Descending palatine artery
The descending palatine artery is a branch of the maxillary artery that supplies both the soft palate and hard palate as well as the palatine tonsils 1.
Summary
origin: 3rd part of the maxillary artery
course: descending through the pterygopalatine fossa before its branches enter either the ...
Article
Ascending palatine artery
The ascending palatine artery is a branch of the facial artery that supplies part of the soft palate. In addition, the vessel also supplies the tensor veli palatini, uvular muscle, palatine tonsils, and palatopharyngeus 1,2. The posterior branch supplies the posterior and inferior soft palate es...
Article
Aerodigestive tract
The aerodigestive tract is a non-TA descriptive collective term for the respiratory tract and proximal portion of the digestive tract. As it is a non-standard term, its precise components vary somewhat with the context in which the term is being employed.
Terminology
Definitions of what precis...
Article
Frontalis muscle
The frontalis muscle (TA: musculus frontalis) is a paired muscle extending from the supraorbital region to the level of the coronal suture. Flat and quadrilateral in shape, it is one of the facial muscles. Along with the occipitalis muscle, it forms the occipitofrontalis muscle due to a common t...
Article
Anterior tarsal tunnel
The anterior tarsal tunnel is a fibro-osseous canal found in the anterior aspect of the ankle.
Gross anatomy
Boundaries
The anterior tarsal tunnel is beneath the inferior extensor retinaculum of the foot and bordered by the following structures 1,2:
roof: inferior extensor retinaculum
media...
Article
Risorius muscle
The risorius muscle (TA: musculus risorius) is one of the muscles of the mouth, a subset of the facial muscles. It is often absent and has been described as an accessory muscle.
Summary
origin: fascia overlying the parotid, masseter and/or platysma muscles
insertion: modiolus at the angle of...
Article
Glenoid bare spot
Glenoid bare spot, also known as glenoid bare area, is a small central or slightly eccentric area of the inferior glenoid fossa, where the articular cartilage is markedly thinner or completely absent 2. It is considered to be a normal aging-related phenomenon 1.
Epidemiology
The glenoid bare s...
Article
Levator labii superioris muscle
The levator labii superioris (LLS) muscle (TA synonym: musculus levator labii superioris) is one of the elevators of the upper lip, a subset of the facial muscles.
It is not to be confused with the levator labii superioris alaeque nasalis muscle, which has a very similar name, at least partiall...
Article
Medial capsuloligamentous complex of the knee
The medial capsuloligamentous complex of the knee is comprised of three layers 1-3:
superficial layer (layer 1)
deep crural fascia
sartorius muscle
intermediate/middle layer (layer 2)
superficial medial collateral ligament
posterior oblique ligament
medial patellofemoral ligament
medial ...
Article
Interossei muscles of the hand
The interosseous (or interossei) muscles of the hand are a group of intrinsic hand muscles that lie near the metacarpals.
There are two sets:
dorsal interossei muscles (hand)
palmar interossei muscles (hand)
Article
Palmar aponeurosis
The palmar aponeurosis is the thickened strong part of the palmar fascia in the hand which is continuous with the flexor retinaculum and the tendon of palmaris longus tendon. It is superficial to the long flexor tendons and is an inverted triangle in shape, fanning over the palm and thinning med...
Article
Muscles of the hand
Muscles of the hand can be divided into:
extrinsic muscles whose tendons, which attach to structures within the hand, arise from muscle bellies from the forearm or distal humerus
intrinsic muscles (mnemonic) whose muscle bellies and tendons are located solely within the hand
Article
Central vein
A central vein refers to a major vein close to the center of the circulation, i.e. the heart. It originally referred to those large veins in which the distal tip of a catheter could lie for central venous pressure monitoring. To accurately measure the central venous pressure, which is the pressu...
Article
Skeletal muscle
Skeletal muscles, skeletal striated muscles or plainly muscles are integral to the locomotor system responsible for movements. The human body's musculoskeletal system has more than 600 muscles 1 making up around 40% of the body weight. They are heterogeneous and have different architectures and ...
Article
Non-recurrent laryngeal nerve
A non-recurrent laryngeal nerve is an uncommon anatomical variant in which the laryngeal nerve does not descend into and return from the thorax, instead directly entering the larynx from the cervical vagus nerve.
Epidemiology
Incidence is rare and varies by study but has been indicated to be a...
Article
Additional radial wrist extensor muscles
Additional radial wrist extensors are normal anatomical variants and accessory muscles of the forearm and the wrist. The following additional wrist extensors have been described 1-6:
extensor carpi radialis intermedius
extensor carpi radialis accessorius
extensor carpi radialis tertius
Epid...
Article
Accessory flexor carpi ulnaris muscle
The accessory flexor carpi ulnaris (AFCU) is a rare accessory muscle of the forearm and wrist and a normal anatomical variant that can be found in addition to a normal flexor carpi ulnaris muscle.
Epidemiology
The accessory flexor carpi ulnaris muscle is considered very rare 1,2.
Associations...
Article
Flexor carpi radialis brevis vel profundus
The flexor carpi radialis brevis (FCRB) vel profundus muscle is an accessory muscle of the forearm and wrist and a normal anatomical variant.
Epidemiology
The flexor carpi radialis brevis vel profundus muscle has been found in 2-8% of anatomical dissections 1-3.
Summary
origin: anterior...
Article
Anterior meniscofemoral ligament (of Humphrey)
The anterior meniscofemoral ligament (aMFL) or ligament of Humphrey) is one of two variably present bands of the meniscofemoral ligament.
Gross anatomy
The anterior meniscofemoral ligament inserts to the lateral aspect of the medial femoral condyle and runs between the anterior cruciate ligam...
Article
Ligament
Ligaments are connective tissue structures that arch over joints connecting one bone to another bone with primary functions as stabilizers of articulations. The scientific study of ligaments is called syndesmology.
In the abdomen, a ligament is formed by two folds of peritoneum that enclose an ...
Article
Posterior sacroiliac ligament
The posterior (a.k.a. dorsal) sacroiliac ligament (TA: ligamentum sacroiliacum posterius) is a very strong ligament important in stabilizing the sacroiliac joint.
Gross anatomy
Some texts state that the posterior sacroiliac ligaments have two components; a more superior part, the short posteri...
Article
Paraspinal muscles
The paraspinal muscles (PSM) , also known as paravertebral muscles, is a descriptive term given to those muscles that closely surround the spine, primarily the thoracolumbar spine. There has been great research interest in using the cross-sectional area of these muscles as a measure of overall m...
Article
Accessory muscles of the forearm, wrist and hand
Accessory muscles of the forearm, wrist and hand are muscular, usually asymptomatic, anatomical variants that might be encountered on imaging studies and confused with pathologic conditions.
The following accessory muscles around the forearm, wrist and hand have been described 1-6:
elbow
acc...
Article
Accessory flexor digitorum superficialis indicis muscle
An accessory flexor digitorum superficialis indicis muscle is an unusual accessory muscle of the hand and wrist and a normal anatomical variant.
Summary
origin: flexor digitorum superficialis tendon near the transverse carpal ligament
insertion: metacarpal head of the index finger near the A1...
Article
Os sustentaculi
The os sustentaculi or os sustentaculum is a rare accessory ossicle of the ankle and a normal anatomical variant.
Epidemiology
The estimated prevalence is approximately 0.3-0.4% 1.
Associations
It has been found in up 24% of talocalcaneal coalitions 2.
Gross anatomy
The os sustentaculi is ...
Article
Accessory extensor digiti secundus muscle
The accessory extensor digiti secundus muscle is a rare accessory muscle or tendon of the ankle and an anatomical variant.
Summary
origin: extensor hallucis longus tendon or muscle
insertion: medial phalanx of the second toe adjacent to the second tendon of the extensor digitorum longus muscl...
Article
Anterior fibulocalcaneus muscle
The anterior fibulocalcaneus muscle is a rare accessory muscle of the ankle and an anatomical variant.
Summary
origin: the proximal third of the fibula, peroneus tertius muscle fascia, anterior crural intermuscular septum
insertion: lateral calcaneus anterosuperior to the peroneal tubercle ju...
Article
Extensor hallucis capsularis tendon
The extensor hallucis capsularis tendon, also known as secondary extensor hallucis longus, accessory extensor tendon of the first metatarsophalangeal joint, extensor ossis metatarsi hallucis or extensor ossis primi internodii hallucis is an accessory tendon or muscle of the ankle and an anatomic...
Article
Tibiocalcaneus internus muscle
The tibiocalcaneus internus muscle is a rare accessory muscle of the ankle and an anatomical variant with an unknown prevalence.
Summary
origin: medial crest of the lower third of the tibia
insertion: medial surface of the calcaneus approximately 1-2 cm anterior to the Achilles tendon
Gross ...
Article
Peroneocalcaneus internus muscle
The peroneocalcaneus internus muscle, also known as fibulocalcaneus internus muscle of MacAlister, is a rare accessory muscle of the ankle and an anatomical variant with an estimated prevalence of about 1%. It is often bilateral if present.
Summary
origin: the medial surface of the distal...