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.

3,191 results found
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Anterior talofibular ligament

The anterior talofibular ligament (ATFL) is part of the lateral collateral ligament complex of the ankle. Its role is to stabilize the talus. It is also the weakest of the lateral collateral ankle ligaments.  Gross anatomy The ATFL is an intracapsular flat two-banded ligament that arises from ...
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Anterior talofibular ligament injury

Anterior talofibular ligament (ATFL) injury is the most common of the ligament injuries that can occur as part of the lateral ligament complex injuries 2. The injuries can comprise either soft tissue tears, avulsion fractures or both. Pathology ATFL injuries typically occur with an inversion i...
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Anterior tibial translocation sign

The anterior tibial translocation sign or anterior drawer sign (a.k.a. anterior translation of tibia) is seen in cases of complete rupture of the anterior cruciate ligament, and refers to anterior translocation (anterior tibial subluxation) of the tibia relative to the femur of >7 mm 1. 
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Anterior tibial vein

The anterior tibial veins, continuations of the venae comitantes of the dorsalis pedis artery, leave the anterior compartment of the leg between the tibia and fibula and pass through the proximal end of the interosseous membrane. They unite with the posterior tibial veins to form the popliteal v...
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Anterolateral ligament of the knee

The anterolateral ligament of the knee (ALL) is a ligament that is thought to aid with rotational stability of the knee joint. Some think that its presence (or reconstruction) may result in better outcomes from ACL stabilization surgery 2. The ligament has also been implied in Segond fractures 3...
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Anterolisthesis

The term anterolisthesis refers to anterior displacement (forward slip) of a vertebral body relative to the one below. Its severity can be graded by the Meyerding classification and its etiology classified according to the Wiltse classification.
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Antibiotic beads

Implanted antibiotic beads are a form of microbiological treatment inserted during orthopedic procedures to aid with the treatment of chronic infection. They are also used as a local treatment for osteomyelitis. The beads are radiopaque, thus lending themselves to visualization on all imaging m...
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Anti melanoma differentiation associated gene 5 (MDA5) antibody positive clinically amyopathic dermatomyositis

Anti-MDA5 antibody-positive amyopathic dermatomyositis is a subtype of dermatomyositis where there is positivity to an anti-melanoma differentiation-associated gene 5 (MDA5) antibody. It has been reported to be associated with rapidly progressive interstitial lung disease (RP-ILD) resulting in h...
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Antley-Bixler syndrome

Antley-Bixler syndrome (ABS), also known as trapezoidocephaly-synostosis syndrome, is a rare autosomal dominant or recessive condition characterized by craniosynostosis and extra-cranial synostoses. Mid-facial hypoplasia is also common. Epidemiology It is a very rare condition with only 50 cas...
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AO classification of distal clavicle fractures

The AO classification of distal clavicular fractures along with the Neer classification system is one of the more frequently used classification systems when assessing distal clavicular fractures. The classification system, broken into three categories focuses on the displacement and pattern of ...
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AO classification of proximal humeral fractures

The AO classification of proximal humeral fractures, along with the Neer classification, is one of the most frequently used systems for classifying proximal humeral fractures.  The AO classification divides proximal humeral fractures into three groups, A, B and C, each with subgroups, and place...
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AO classification of sacral injuries

The AO classification of sacral injuries aims to simplify and universalise the process of classifying sacral injuries and improve interobserver and intraobserver reliability. The AO sacral classification is broken into three subsections that follow a hierarchical structure similar to the AO cla...
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AO classification of subaxial injuries

The AO classification of subaxial injuries aims to simplify and universalise the classification of subaxial cervical spine fractures and improve interobserver and intraobserver reliability. Usage Although its existence is widely known among the relevant subspecialty groups, its day-to-day use ...
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AO classification of upper cervical injuries

The AO classification of upper cervical injuries aims to simplify and universalise the process of classifying upper cervical injuries and improve interobserver and intraobserver reliability. Usage Although in routine clinical practice, at least in many institutions, injuries will be described ...
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AO spine classification of thoracolumbar injuries

The AO spine classification of thoracolumbar injuries is one of the more commonly used thoracolumbar spinal fracture classification systems and aims to simplify and universalise the process of classifying spinal injuries and improve interobserver and intraobserver reliability 3. Unlike the othe...
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AO Spine classification systems

The AO Spine classification systems is a group of imaging morphology-based classification system, combined with clinical factors for injury of spinal trauma. It is designed to be a simple and reproducible method of describing injury patterns. At the time of writing (Oct 2018), the four publishe...
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Apert syndrome

Apert syndrome (also known as type I acrocephalosyndactyly) is a syndrome that is predominantly characterized by skull and limb malformations. Epidemiology The estimated incidence is 1 case per 65-80,000 pregnancies. Risk factors increased paternal age has been proposed 6 Associations CNS ...
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Apodia

Apodia is a rare non-syndromic transverse terminal lower limb defect characterized by the congenital absence of the foot and ankle. The remainder of the lower limb is present including both the tibia and fibular epiphyses. It can be unilateral or bilateral. See also acheiria hemimelia
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Apophyseal avulsion fractures of the pelvis and hip

Apophyseal avulsion fractures of the pelvis and hip are relatively common among physically active adolescents and young adults. Epidemiology Pelvic and hip apophyseal injuries typically occur in the 14 to 25 year age range. Mechanism Kicking sports, such as soccer, and gymnastics are frequen...
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Apophysis

The apophyses (singular: apophysis) are the normal bony outgrowths that arise from separate ossification centers and eventually fuse with the bone in time. The apophysis is a site of tendon or ligament attachment, as compared to the epiphysis which contributes to a joint. When unfused, they can...
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Apophysis of the proximal 5th metatarsal

The apophysis of the proximal 5th metatarsal (plural apophyses) lies laterally and is oriented longitudinally parallel to the shaft. Apophysis of the fifth metatarsal base appears on plain radiographs at age 12 for boys and 10 for girls. Fusion of the apophysis to the metatarsal base usually oc...
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Appendicular films (early clinical)

This is a basic article for medical students and other non-radiologists Appendicular films are x-rays taken of the bones and joints of the arms and legs. I've used this term to separate the x-rays taken as part of an assessment of non-acute disease from trauma films which represent x-rays taken...
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Appendicular skeleton

The appendicular skeleton is the portion of the bony skeleton that includes and supports the limbs (the appendages). It includes the pectoral girdle and the bony pelvis, connected to the axial skeleton centrally and is composed of 126 bones in total.  Appendicular bones form from cartilage, by ...
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Apple core sign (disambiguation)

The apple core sign has been described in two different scenarios: apple core sign (colon) apple core sign (femur)
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Apple core sign (femur)

The apple core sign has been used to describe the circumferential erosion of the femoral neck seen in synovial chondromatosis. Although this is the most common process that may lead to an apple core erosion of the femoral neck, this has also been observed with: pigmented villonodular synovitis ...
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Arachnodactyly

Arachnodactyly refers to the physical finding of elongated, thin "spider-like" fingers, which are a classic feature of Marfan disease, but by no means pathognomonic 1. Radiographic features The metacarpal index was historically-used as a radiographic criterion for arachnodactyly. To obtain it,...
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Arcade of Frohse

The arcade of Frohse (pronounced "\ˈfʁoːzə \") is also known as the supinator arch. The arcade is formed by a fibrous band between the two heads of the supinator muscle. The deep branch of the radial nerve passes beneath the arcade accompanied by vessels known as the leash of Henry. Radiograph...
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Arcuate foramen

The arcuate foramen (foramen arcuate atlantis, ponticulus posticus or posterior ponticle, or Kimerle anomaly) is a frequently encountered normal variant of the atlas and is easily appreciated on a lateral plain film of the craniocervical junction. Epidemiology Incidence is ~8% (range 1-15%) an...
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Arcuate ligament

The arcuate ligament is part of the posterolateral ligamentous complex of the knee that is variably present, being found in ~65% (range 47.9-71%) of knees. It is a Y-shaped thickening of the posterolateral capsule, which arises from the fibular styloid and divides into two limbs: medial limb: c...
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Arcuate line

The arcuate line or semicircular line of Douglas is located at roughly one-third of the distance from the pubic crest to the umbilicus. It is the demarcation where the internal oblique and transversus abdominis aponeuroses of the rectus sheath start to pass anteriorly to the rectus abdominis mus...
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Arcuate sign (knee)

The arcuate sign is often a subtle but important finding on knee x-rays and represents an avulsion fracture of the proximal fibula at the site of insertion of the arcuate ligament complex, and is usually associated with cruciate ligament injury (~90% of cases) 2. The fracture fragment is attache...
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Arm

The arm (also known as the upper arm) is part of the upper limb below the pectoral girdle and above the forearm, comprising the humerus.  The elbow joint is inferior and the glenohumeral joint is superior. Arm flexion, extension, abduction, adduction, internal rotation and external rotation occ...
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Arm abduction

Arm abduction represents movement of the arm away from the midline of the body in the coronal plane and, in most cases isolated abduction can be achieved to 160-180°. It is the opposite of arm adduction and contributes to the combined movement of shoulder circumduction. It is produced by: delt...
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Arm adduction

Arm adduction represents movement of the arm towards from the midline of the body in the coronal plane. Most individuals can manage 40° of isolated adduction. It is the opposite of arm abduction and contributes to the combined movement of shoulder circumduction. It is produced by: pectoralis m...
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Arm extension

Arm extension represents the opposite movement to arm flexion where the arm moves posteriorly. Only about 40° of movement posteriorly from the anatomic position is achievable in most individuals. It is the opposite of arm flexion and contributes to the combined movement of shoulder circumduction...
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Arm external rotation

External or lateral rotation of the arm represents the movement of the humerus when an arm flexed to 90° at the elbow is externally rotated around the longitudinal plane of the humerus such that the hand moves away from the midline of the body. It is the opposite of arm internal rotation. As wi...
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Arm flexion

Arm flexion represents rotation in the anatomic plane such that the distal humerus moves ventrally. Is represents raising the arm and isolated flexion can achieve approximately 150-170° of movement. The opposite movement is arm extension and contributes to the combined movement of shoulder circu...
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Arm internal rotation

Internal or medial rotation of the arm represents the movement of the humerus when an arm flexed to 90° at the elbow is internally rotated around the longitudinal plane of the humerus such that the hand moves towards the midline of the body.   The degree of rotation is dependent on the degree o...
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Arnold-Hilgartner classification of haemophilic arthropathy

Arnold-Hilgartner classification is a plain radiograph grading system for haemophilic arthropathy of the knee 1,2: stage 0: normal joint stage I: no skeletal abnormalities, soft-tissue swelling is present stage II: osteoporosis and overgrowth of the epiphysis, no cysts, no narrowing of the ca...
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Arrested pneumatization of the skull base

Arrested pneumatization of the skull base is an anatomical variant that most commonly occurs in association with the sphenoid sinus. It is known that the sphenoid bones undergo early fatty marrow conversion antecedent to normal pneumatization. However, for unclear reasons, some individuals exper...
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Arthogram (anesthetic)

An arthrogram injection is a procedure in which a solution is administered into a joint under imaging guidance.  These procedures are more accurately named direct arthrogram injections, although they are routinely known as arthrograms.  Fluoroscopy, ultrasound, and CT can be used for image guida...
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Arthrofibrosis

Arthrofibrosis is a complication of injury or trauma to a joint. It can also be iatrogenic e.g. post knee surgeries. It consists of excessive scar tissue formation within the joint capsule, resulting in pain, stiffness, and swelling, that are greater than expected in the given clinical scenario....
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Arthrogram

An arthrogram (or arthrography) is a commonly used term in musculoskeletal radiology, which can refer to both an injection into a joint, and cross-sectional imaging after a joint is injected. Indications Arthrograms are performed for a variety of indications including:  labral tear after shou...
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Arthrogram (CT)

A CT arthrogram is a CT performed after a joint is injected with a solution containing iodinated contrast.  They are not commonly abbreviated to CTA, which will be confused with CT angiography. An arthrogram also refers to the procedure of injecting a joint. Indications shoulder - instability/...
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Arthrogram (MRI)

An MR arthrogram is an MRI performed after a joint is injected with a solution containing gadolinium. Sometimes abbreviated to MRA, which can be confused with MR angiography.  MRI can also be performed after an injection is not directly administered into the joint, via an indirect arthrogram.  A...
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Arthrogryposis

Arthrogryposis (multiplex congenita) is a clinical or imaging descriptor that denotes congenital non-progressive joint contractures involving two or more body regions.  Epidemiology Mostly reported in individuals of Asian, African and European descent with equal incidence in males and females ...
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Articularis cubiti muscle

The articularis cubiti muscle lies in the posterior compartment of the arm: origin: posterior surface of the distal humerus insertion: posterior surface of the elbow joint capsule innervation: radial nerve action: tenses the posterior elbow joint capsule during elbow extension
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Articularis genu muscle

The articularis genu is a small flat muscle of the anterior knee. During knee extension it acts to tighten the synovial membrane superiorly thereby preventing impingement of the synovial folds between the femur and the patella. Summary origin: anterior distal femoral shaft insertion: knee joi...
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ASAS sacroiliitis classification system

First published in 2009 with a revised consensus in 2016, the Assessment in SpondyloArthritis International Society (ASAS) classification system utilizes imaging features of the sacroiliac joints on MR imaging to assist in characterizing the presence of sacroiliitis. The ASAS classification is ...
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Aseptic loosening of hip joint replacements

Aseptic loosening is considered relatively common complication of hip joint replacements. It is usually considered a long-term complication and is often considered as the most common complication 3. Pathology Aseptic loosening can occur as a result of inadequate initial fixation, mechanical lo...
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ASIA impairment scale for spinal injury

The American Spinal Injury Association Impairment Scale was developed by the American Spinal Injury Association (ASIA) in 2006, was revised in 2011, and remains the most widely used neurologic classification of spinal cord injury. Classification The scale divides spinal cord injuries into 5 ca...
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Astronomical inspired signs

Many signs in radiology have been inspired by astronomical phenomena: comet tail (disambiguation) comet tail artifact (ultrasound) color comet tail artifact comet tail sign (chest) comet tail sign (phleboliths) earth-heart sign galaxy sign (chest) loss of half-moon overlap sign milky wa...
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Atelosteogenesis

Atelosteogenesis (AO) refers to a group of lethal skeletal dysplasias. Pathology Sub types atelosteogenesis type I atelosteogenesis type II atelosteogenesis type III 4
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Athletic pubalgia

Athletic pubalgia is a clinical syndrome of chronic lower pelvic and groin pain, usually encountered in athletes. It is either a musculotendinous or osseous injury that involves the insertion of abdominal muscles on the pubis and the upper aponeurotic insertion of the adductor muscles. Although ...
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Atlanto-axial subluxation

Atlanto-axial subluxation is a disorder of C1-C2 causing impairment in rotation of the neck. The anterior facet of C1 is fixed on the facet of C2. It may be associated with dislocation of the lateral mass of C1 on C2. Pathology Etiology congenital os odontoideum Down syndrome (20%) Morquio...
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Atlanto-occipital assimilation

Atlanto-occipital assimilation is the fusion of the atlas (C1) to the occiput and is one of the transitional vertebrae.  Epidemiology Atlanto-occipital assimilation occurs in approximately 0.5% (range 0.08-3%) of the population 2-5,. It is thought to affect males and females equally. Clinical...
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Atlanto-occipital dissociation injuries

Atlanto-occipital dissociation injuries are severe and include both atlanto-occipital dislocations and atlanto-occipital subluxations. Pathology The tectorial membrane and alar ligaments provide most of the stability to the atlanto-occipital joint, and injury to these ligaments results in inst...
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Atlas (C1)

The atlas (plural: atlases) is the first cervical vertebra, commonly called C1. It is an atypical cervical vertebra with unique features. It articulates with the dens of the axis and the occiput, respectively allowing rotation of the head, and flexion, extension and lateral flexion of the head. ...
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Atraumatic fracture

Atraumatic fractures, as the name suggests, occur with no trauma or minimal trauma that would not normally be expected to result in a fracture 1. They can be: stress fractures fatigue fracture insufficiency fracture atypical fractures, e.g. bisphosphonate-related proximal femoral fractures ...
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Atypical cervical vertebrae

Of the cervical vertebrae, the atlas (C1), axis (C2) and vertebra prominens (C7) are considered atypical cervical vertebrae. The atlas (C1) lacks a body or spinous process. It has anterior and posterior arches with lateral masses. Its superior articular surfaces articulate with the occiput at t...
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Atypical femoral fracture

Atypical femoral fractures,  also known as bisphosphonate-related proximal femoral fractures, are an example of insufficiency fractures, although the direct causative link remains somewhat controversial 2. The atypical fracture pattern occurs in the femur shaft and may be unilateral or bilateral...
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Atypical fibroxanthoma

Atypical fibroxanthomas are well-circumscribed mesenchymal skin tumors that mainly manifest in the head and neck Epidemiology Atypical fibroxanthomas are rapidly growing tumors associated with excessive sun exposure, i.e. UV exposure, and usually occur in elderly patients. There is also an ass...
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Atypical lumbar vertebrae

Of the five lumbar vertebrae, L5 is considered atypical due to its shape. The remaining lumbar vertebrae are largely typical. For a basic anatomic description of the structure a generic vertebra, see vertebrae.
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Atypical ribs

Owing to their features, the first, eleventh and twelfth ribs are considered atypical ribs. Of all ribs, the first is the strongest, broadest and most curved. Ribs eleven and twelve are unique, among other reasons, by not being attached to the sternum.
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Atypical thoracic vertebrae

T1 and T9 - T12 are considered atypical thoracic vertebrae. T1 bears some resemblance to low cervical vertebrae. T9 has no inferior demifacet. T10 often, but not always, shares features with T11 and T12.  For a basic anatomic description of the structure a generic vertebra, see vertebrae.
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Autosomal dominant osteopetrosis

Autosomal dominant osteopetrosis is the less severe type of osteopetrosis and should be considered and compared with the other subtype autosomal recessive osteopetrosis. The autosomal dominant (AD) type is less severe than its autosomal recessive (AR) mate. Hence, it is also given the name "beni...
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Autosomal recessive osteopetrosis

Infantile autosomal recessive osteopetrosis is a subtype of osteopetrosis, a bone disease of dysfunctional osteoclasts that results in the overgrowth of bone. It is a more severe form that tends to present earlier. Hence, it is referred to as "infantile" and "malignant" compared to its autosomal...
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Avascular necrosis

Avascular necrosis (AVN), or more correctly osteonecrosis, is a generic term referring to the ischemic death of the constituents of bone. AVN has a wide variety of causes and can affect nearly any bone in the body. Most sites of involvement have an eponym associated with avascular necrosis of th...
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Avascular necrosis causes (mnemonic)

Mnemonics for the causes of avascular necrosis (AVN) or more correctly osteonecrosis: STARS PLASTIC RAGS ASEPTIC Mnemonics STARS Most common causes: S: steroids T: trauma (e.g. femoral neck fracture, hip dislocation, scaphoid fracture, slipped capital femoral epiphysis 2) A: alcohol exc...
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Avascular necrosis of the hip

Avascular necrosis of the hip is more common than other sites, presumably due to a combination of precarious blood supply and high loading when standing.  Clinical presentation The most common presenting symptom is a pain in the region of affected hip, thigh, groin, and buttock. Although few p...
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Aviator astragalus

Aviator astragalus is an antiquated reference to a pattern of isolated fracture/dislocation injury of the talus. Fractures included under this name include compression fractures of the talar neck, fractures of the body, posterior process or fracture-dislocation injuries. More specifically the t...
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Avulsion fracture of the 5th metatarsal styloid

Avulsion fracture of the 5th metatarsal styloid, also known as a pseudo-Jones fracture or a dancer fracture, is one of the more common foot avulsion injuries and accounts for over 90% of fractures of the base of the 5th metatarsal. Despite what should be a simple entity, controversy exists, as ...
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Avulsion fractures of the knee

Avulsion fractures of the knee are numerous due to the many ligaments and tendons inserting around this joint. They include 1: anterior cruciate ligament avulsion fracture posterior cruciate ligament avulsion fracture avulsion of the medial collateral ligament origin of MCL avulsion fracture...
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Avulsion injuries

Avulsion injuries or fractures occur where the joint capsule, ligament, tendon or muscle attachment site is pulled off from the bone, usually taking a fragment of cortical bone. There are numerous sites at which these occur. Being familiar with them is important as subacute/chronic injuries can ...
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Axial skeleton

The axial skeleton is the central portion of the bony skeleton comprising the head, neck and trunk (80 bones in total). It has many functions including housing and protecting the central nervous system as well as the organs of the chest, abdomen and pelvis. It enables movement and supports the u...
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Axilla

The axilla is a space located between the upper limb and thorax, which permits the passage of the major neurovascular structures. Gross anatomy The axilla is pyramidal in shape with its apex opening superiorly towards the base of the neck between the subclavius muscle, first rib, and clavicle....
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Axillary nerve

The axillary nerve is one of five terminal branches of the brachial plexus, supplying motor and sensory branches to the shoulder.  Summary origin: posterior cord of the brachial plexus course: passes out of axilla through the quadrangular space to the upper arm major branches: superior later...
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Axis (C2)

The axis is the second cervical vertebra, commonly called C2. It is an atypical cervical vertebra with unique features and important relations that make it easily recognisable. Its most prominent feature is the odontoid process (or dens), which is embryologically the body of the atlas (C1) 1,2. ...
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Baastrup syndrome

Baastrup syndrome (also referred to as kissing spines) results from adjacent spinous processes in the lumbar spine rubbing against each other and resulting in hypertrophy and sclerosis with focal midline pain and tenderness relieved by flexion and aggravated by extension.  Epidemiology It tend...
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Babcock triangle

Babcock triangle is a relatively radiolucent triangular area seen in the subcapital region of the femoral neck on an anteroposterior radiograph of the hip. In this region, the trabeculae are loosely arranged and surrounded by more radiodense normal bony trabeculae groups. It may be the initial s...
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Bacillary angiomatosis

Bacillary angiomatosis is an infective complication in those with the acquired immunodeficiency syndrome (AIDS) 3. Amongst other widespread multi-organ manifestations, the infection causes skin lesions which can be similar to those of Kaposi sarcoma. Pathology Characterized by a non-neoplastic...
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Bado classification of Monteggia fracture-dislocations

The Bado classification is one of the more widely used classifications for Monteggia fracture-dislocations and mainly focuses on the radial component. Four types are recognized and are generally based on the principle that the direction in which the apex of the ulnar fracture points is the same ...
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Baker cyst

Baker cysts, or popliteal cysts, are fluid-filled distended synovial-lined lesions arising in the popliteal fossa between the medial head of the gastrocnemius and the semimembranosus tendons via a communication with the knee joint. They are usually located at or below the joint line. They repre...
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Ball and socket ankle joint

A ball and socket ankle joint is a variant affecting the ankle where there is a rounded or spherical configuration to the talar dome with the corresponding concavity of the tibial plafond. The distal fibula may or may not be involved. Pathology The etiology has been debated with two theories p...
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Ball and socket joint

Ball and socket joints are a type of synovial joint where the spheroid articular surface of one bone sits within a cup-like depression of another bone. Movements The ball and socket configuration allows for movement with 3 degrees of freedom, which is more than any other type of synovial joint...
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Bamboo spine (ankylosing spondylitis)

Bamboo spine is a radiographic feature seen in ankylosing spondylitis that occurs as a result of vertebral body fusion by marginal syndesmophytes. It is often accompanied by fusion of the posterior vertebral elements as well.  A bamboo spine typically involves the thoracolumbar and/or lumbosacr...
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Banana fracture

A banana fracture refers to a complete, horizontally oriented pathological fracture seen in deformed bones affected by Paget disease. This term is often used to describe incremental fractures that occur in Paget disease as well, which represent a type of insufficiency fracture. The former of th...
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Bankart lesion

Bankart lesions are injuries specifically at the anteroinferior aspect of the glenoid labral complex and represent a common complication of anterior shoulder dislocation. They are frequently seen in association with a Hill-Sachs lesion.  Terminology Strictly speaking, a "Bankart lesion" refers...
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Bannayan–Riley–Ruvalcaba syndrome

Bannayan–Riley–Ruvalcaba syndrome (BRRS or BRR syndrome) is a very rare autosomal dominant hamartomatous disorder caused by a mutation in the PTEN gene. It is considered in the family of hamartomatous polyposis syndrome. There are no formal diagnostic criteria for this disease, but characterist...
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Bannayan-Zonana syndrome

Bannayan-Zonana syndrome, also known as Bannayan-Riley-Ruvalcaba syndrome, is a rare hamartomatous disorder.  Epidemiology Male predominance is reported 1. Clinical presentation Bannayan-Zonana syndrome is characterized by: macrocephaly  multiple lipomas hemangiomas 1 Other findings that...
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Barton fracture

Barton fractures are fractures of the distal radius. It is also sometimes termed the dorsal type Barton fracture to distinguish it from the volar type or reverse Barton fracture. Barton fractures extend through the dorsal aspect to the articular surface but not to the volar aspect. Therefore, i...
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Basal cell carcinoma

A basal cell carcinoma (BCC) is one of the commonest non-melanocytic types of skin cancer.  Epidemiology Typically present in elderly fair skinned patients in the 7th to 8th decades of life. There may be an increased male predilection. Associations Multiple basal cell carcinomas may be prese...
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Base of the skull

The base of the skull (or skull base) forms the floor of the cranial cavity and separates the brain from the structures of the neck and face. Gross anatomy The base of the skull is a bony diaphragm composed of a number of bones - from anterior to posterior: frontal bone ethmoid bone sphenoi...

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