Epiphyseal spur refers to a spur seen in skeletally mature individuals arising at the level of closed epiphyseal line. It may be seen in any epiphysis.
The epiphyses (singular: epiphysis) are the rounded portions at the ends of a bone separated from the metaphysis by the physis. The epiphysis contributes to a joint, compared with an apophysis which is a site of tendon or ligament attachment. Once the growth plate has fused, the epiphysis and me...
Episternal (or suprasternal) ossicles are accessory bones and a normal variant of the sternum. They result from supernumerary ossification centers and are seen in ~4% (range 1-7%) of the population.
Episternal ossicles are usually located posterior or superior to the superior bor...
There are numerous eponymous fractures which are named after the people who first described their existence 1:
Bankart fracture: glenoid
Barton fracture: wrist
Bennett fracture: thumb
Bosworth fracture: ankle
Chance fracture: vertebral
Charcot joint: foot
Chopart fracture: foot
Erdheim-Chester disease (ECD) is a rare non-Langerhans cell, non-familial multisystemic granulomatosis, with widespread manifestations and of highly variable severity. The most common presenting symptom is bone pain.
Erdheim-Chester disease is a rare, non-inherited disease of midd...
The erector spinae group is the intermediate layer of the intrinsic muscles of the back. This group is made of three subgroups, with the group divisions occurring by location. The iliocostalis group occurs most laterally, followed by the longissimus group, and finally the spinalis as the most me...
There are multiple handy mnemonics to recall the erector spinae muscles. They usually describe the position from lateral to medial.
I Like Standing
I Love Sex
I Long for Spinach
I Like Siri
Erlenmeyer flask deformity (EFD) (also known as metaphyseal flaring) refers to a radiographic appearance typically on a femoral radiograph demonstrating relative constriction of the diaphysis and flaring of the metaphysis.
It has been classically used with reference to the distal ends of the fe...
Some of the causes of an Erlenmeyer flask deformity can be recalled with the following mnemonics:
C: craniometaphyseal dysplasias
sickle cell disease
N: Niemann-Pick disease
G: Gaucher dis...
Differential diagnosis of erosion of the superior aspects of the ribs include:
Erosion of the odontoid peg can result from a number of pathological entities:
rheumatoid arthritis: classic 1-2
systemic lupus erythematosus
calcium pyrophosphate arthropathy (CPPD): relatively common
non-inflammatory arthropathy: osteoar...
Erosive arthritis has a broad differential, including:
clinically an acute inflammatory attacks (swelling, erythema, pain) in postmenopausal woman
typically includes the DIPs, PIPs 1st CMC joint 6, but not the metacarpophalangeal (MCP) joints and large joints
Erosive (inflammatory) osteoarthritis (EOA) is a form of osteoarthritis (OA) where, as the name implies, there is an additional erosive/inflammatory component.
There is marked female predilection (F:M ~12:1), typically presenting in the postmenopausal patient.
Essex-Lopresti fracture-dislocations comprise of a comminuted fracture of the radial head accompanied by dislocation of the distal radioulnar joint. The force of trauma is transmitted down the forearm through the interosseous membrane causing disruption. The distal radioulnar joint injury may be...
Recurrent bone tumours are a common complication post curettage or resection.
Radiographs taken pre- and postoperatively are sufficient for evaluation of recurrence based on the following features:
matrix mineralisation (characterist...
Ewing sarcoma is the second most common highly malignant primary bone tumour of childhood after osteosarcoma, typically arising from medullary cavity with invasion of Haversian system. They usually present as moth-eaten destructive permeative lucent lesions in the shaft of long bones with large ...
Ewing sarcoma family of tumours (ESFT), also referred as Ewing sarcomas of the chest wall, are malignant tumours affecting children and young adults, originating either from the osseous structures or the soft tissues of the chest wall.
On imaging, they are usually characterised as a large extr...
Excessive lateral pressure syndrome (ELPS) or patellar compression syndrome is the abnormal lateral tilt of the patella without lateral translation and considered one of the relatively common causes of anterior knee pain.
It can affect both adolescents and adults.
Exostoses are defined as benign growths of bone extending outwards from the surface of a bone. It can occur in any bone and be triggered by a number of factors. There are a number of examples of exostoses that occur due to local irritant stimuli:
exostosis of the external audit...
Expansile lytic bone lesions without cortical destruction can result from various benign and malignant neoplastic pathologies, causes include 1:
unicameral bone cyst
aneurysmal bone cyst (eccentric)
chondromyxoid fibroma (eccentric)
non-ossifying fibroma (eccentric)
Extension teardrop fracture typically occurs due to forced extension of the neck with resulting avulsion of the anteroinferior corner of the vertebral body. Extension teardrop fractures are stable in flexion and unstable in extension as the anterior longitudinal ligament is disrupted. Extension ...
Extensor carpis radialis brevis (ECRB) is a muscle of superficial layer on posterior compartment of the forearm. It passes through the 2nd extensor compartment of the wrist. ECRB is one of the three muscles forming the mobile wad of Henry.
origin: lateral epicondyle of the humerus, ann...
Extensor carpis radialis longus (ECRL) is a muscle of the superficial layer in the posterior compartment of the forearm. It passes through the 2nd extensor compartment of the wrist. It is one of the three muscles forming the mobile wad of Henry.
origin: lateral supracondyle ridge of hu...
Extensor carpis ulnaris (ECU) is a muscle of the superficial layer of the posterior compartment of the forearm. It is separated from the extensor digitorum and the extensor digiti minimi muscles by a distinct intermuscular septum. It is the only forearm extensor that lies in its own fibro-osseou...
The extensor tendons at the level of the wrist are divided into six extensor compartments that are designated by Roman numerals from lateral to medial 1:
I: extensor pollicis brevis, abductor pollicis longus
II: extensor carpi radialis longus, extensor carpi radialis brevis
III: extensor poll...
Extensor digiti minimi (EDM) is a muscle of the superficial layer of the posterior compartment of the forearm, and with other extensor muscles arises from a common extensor tendon attached to the lateral epicondyle of the humerus. The EDM represents a medial group of superficial extensor muscles...
Extensor digitorum (ED), also known as extensor digitorum communis (EDC), is a muscle of the superficial layer of the posterior compartment of the forearm and with other extensor muscles arises from a common tendon attached to the lateral epicondyle of the humerus. ED represents a medial group o...
The extensor digitorum brevis manus (EDBM) muscle is an accessory muscle in the hand and is a normal anatomical variant.
origin: distal radius and posterior radiocarpal ligament
insertion: extensor hood of 2nd or 3rd digits (variable)
innervation: posterior interosseous nerve
The extensor digitorum brevis muscle is a muscle on the dorsal surface of the foot which helps extend digits 2 through 4.
origin: superolateral surface of calcaneus
insertion: lateral sides of the tendons of extensor digitorum longus of toes II to IV
action: extension of toes II to I...
Extensor digitorium longus (EDL) is a thin muscle situated in the anterior leg lateral to extensor hallucis longus and extends the lateral four toes.
origin: lateral tibial condyle, medial surface of the middle portion of the fibula and superior portion of the anterior surface of the i...
The extensor hallucis brevis is a muscle on the dorsal surface of the foot which helps to extend the big toe.
superolateral surface of calcaneus
base of proximal phalanx of great toe
extension of metatarsophalangeal joint of great toe
Extensor hallucis longus is a thin muscle in the anterior compartment of the leg between tibialis anterior and extensor digitorum longus.
origin: anterior surface of the middle portion of the fibula and the interosseous membrane
insertion: the dorsal side of the base of the distal pha...
The extensor indicis muscle is an accessory extensor of the 2nd digit. It is located in the deep layer of the posterior compartment of the forearm and its tendon passes through the 4th extensor compartment of the wrist.
origin: posterior surface of the ulna (distal to extensor pollicis...
The extensor mechanism of the knee comprises:
medial patellar retinaculum
lateral patellar retinaculum
extensor mechanism of the knee injuries
Extensor mechanism of the knee injuries include:
quadriceps muscle tears
quadriceps tendon rupture
patellar tendon rupture
patellar dislocation often with medial retinaculum tears
patellar sleeve fractures
Extensor pollicis brevis (EPB) is one of the muscles of the deep layer of the posterior compartment of the forearm, inserting into the base of the proximal phalynx of the thumb. Along with extensor pollicis longus, it is responsible for extension of the thumb. Along with abductor pollicis longus...
Extensor pollicis longus (EPL) is a muscle of the deep compartment in the posterior compartment of the forearm. It passes through the 3rd extensor compartment of the wrist, then continues laterally towards the thumb around Lister's tubercle. The tendon of EPL defines the ulnar border of the Anat...
The extensor retinaculum is located at the dorsal aspect of the foot and consists of the superior and inferior extensor retinacula.
The superior extensor retinaculum is located proximally to the dorsal aspect of the ankle joint and houses the tibialis anterior, extensor digitoru...
The external (or outermost) intercostal muscles are important muscles of respiration. They number eleven on each side and are located in the intercostal space, expanding the transverse dimension of the thoracic cavity during inspiration.
The external intercostal muscles are the o...
The external oblique muscle (EOM) is one of the muscles that forms the anterior abdominal wall. Its free inferior border forms the inguinal ligament, and its aponeurotic part contributes to the anterior wall of the inguinal canal.
origin: outer surface of the shaft of the lower 8 ribs...
Extra-articular lateral hindfoot impingement syndrome refers a non-traumatic cause of ankle impingement. This can include talocalcaneal, subfibular, and /or talocalcaneal-subfibular impingements.
It presents as the sequela of a pathological tibialis posterior tendon, which causes pes planus (fl...
Extraskeletal chondrosarcomas make up only 2% of soft-tissue sarcomas and only 1% of all chondrosarcomas.
They tend to be of higher grade than run-of-the-mill conventional intramedullary chondrosarcomas, with the majority being of the myxoid (most common) or mesenchymal varieties 3...
Extraskeletal Ewing sarcoma (EES) is included in the Ewing sarcoma family of tumors (ESFT) along with Ewing sarcoma of bone, primitive neuroectodermal tumor (PNET), peripheral neuroepithelioma, and thoracopulmonary PNET (Askin tumour). When compared with Ewing sarcoma of bone, extraskeletal Ewin...
extraskeletal myxoid chondrosarcoma
pigmented villonodular synovitis (PVNS)
Extraskeletal osteosarcoma (ESOS) is a rare mesenchymal malignant tumour that occurs in the retroperitoneum and soft tissue of extremities without any attachment to bone.
Extraskeletal osteosarcoma in contrast to other subtypes of osteosarcoma occurs infrequently in individuals un...
The fabella is an accessory ossicle typically found in the lateral head of the gastrocnemius. It occurs in ~20% (range 10-30%) of the population 1.
The fabella can also be fibrocartilaginous in nature and is occasionally found in the medial head of the gastrocnemius. The fabella articulates wi...
Facet dislocation refers to anterior displacement of one vertebral body on another. Without a fracture, the only way anterior displacement can occur is by dislocation of the facets.
Facet dislocation can occur to varying degrees:
The injury usua...
The facet (or apophyseal or zygapophyseal) joints are the articulations of the posterior arch of the vertebrae and form part of the posterior column.
They are symmetrical synovial-lined joints that have a fibrous capsule and connect the articular facets of the vertebrae. The sup...
Facet joint capsules are the fibrous capsule that surround the vertebral facet or zygapophyseal joints. They are particularly thin and loose, attached to the margins of articular facets on adjoining articular processes. The capsules merge medially with the ligamentum flavum.
In the cervical re...
The facial muscles enable facial expression and serve as sphincters and dilators of the orifices of the face. These muscles differ from those of other regions in the body as there is no fascia deep to the skin of the face; many of the facial muscles insert directly into the skin 1.
Facioscapulohumeral muscular dystrophy (FSHD) is a form of muscular dystrophy characterised by extremely variable degrees of facial, scapular and lower limb muscle involvement.
It is considered one of the more common hereditary muscular disorders with a prevalence of ~1 in 8,000.
Failed back syndrome refers to persistent leg and/or lumbar back pain after a surgical procedure. The pathophysiology of this syndrome is complex, as often the operation was technically successful.
Other names for failed back syndrome include failed back surgery syndrome, post-lam...
The fallen fragment sign refers to the presence of a bone fracture fragment resting dependently in a cystic bone lesion. This finding is said to be pathognomonic for a simple (unicameral) bone cyst following a pathological fracture. Although it has occasionally been reported with other cystic le...
Fall onto an outstretched hand (FOOSH) is a common mechanism for wrist-forearm fractures, in certain cases with involvement of elbow structures, particularly in children.
Some injuries that result from such a fall include:
Familial multiple lipomatosis (FML) is a hereditary syndrome of multiple encapsulated lipomas which are found on the trunk and extremities, with relative sparing of the head and shoulders.
It is clinically distinct from the similarly named multiple symmetric lipomatosis with which...
Fanconi anaemia is a rare disorder characterised by progressive bone marrow failure, various congenital abnormalities, and predisposition to malignancies (often acute myeloid leukaemia). It is considered the commonest type of inherited marrow failure syndrome 7.
Fanconi anaemia sh...
The fascial tail sign is the linear extension along the fascia/muscular aponeurosis from a deeper tumour.
It appears as a tail and is best appreciated on MRI, classically seen in desmoid tumours as T2 hypointense bands that progressively enhance particularly on delayed ph...
Fascicular sign is a finding on T2-weighted MRI images that suggests a lesion of neurogenic origin. It is characterised by multiple small ring-like structures with peripheral hyperintensity representing the fascicular bundles within the nerves.
It is found in various neurogenic tumours, includi...
Fatco syndrome is a syndrome consisting of
tibial campomelia and
It is a syndrome of unknown genetic basis and inheritance with variable expressivity and penetrance.
Fuhrmann syndrome and Al-Awadi syndrome are said to be similar to FA...
Fatigue fractures are a type of stress fracture due to abnormal stresses on normal bone. They should not be confused with an insufficiency fracture, which occurs due to normal stresses on abnormal bone. Plain films typically demonstrate a linear sclerotic region. MRI is the most sensitive and sp...
In fat-pad impingement syndromes the aetiologies are different for each knee fat pad.
In anterior suprapatellar fat pad impingment syndrome the cause is usually due to either a developmental cause related to the anatomy of the extensor mechanism, or may be related to abnormal mechanics. In this...
The fat redistribution syndrome (or HIV lipodystrophy syndrome) is seen in a number of AIDS patients on HAART. It is characterised by typical changes in body fat distribution.
Features include :
hypertrophy in the neck fat pad (buffalo hump)
increased fat in the abdominal region (protease pau...
Faulty fetal packing, also known as congenital vault depression, is a congenital concave depression of the skull in a newborn.
Occurs in 1 in 10,000 births 1.
This appearance is due to external compression on the skull from 1,2:
fetal limb or twin
The FBI sign is an acronym referring to the components that form a lipohaemarthrosis. It stands for:
FCD may refer to:
focal cortical dysplasia (of the brain)
fibrous cortical defect (of the bone)
The radiographic features of a Charcot joint can be remembered by using the following mnemonic:
6 Ds of Charcot joint
increased Density (subchondral sclerosis)
Debris (intra-articular loose bodies)
The causes of Charcot arthrop...
Feingold syndrome is characterised by the combination of:
alimentary tract atresias especially oesophageal atresia
Felty syndrome comprises of the combination of:
rheumatoid arthritis (RA)
It is thought to occur in ~ 1% of patients with rheumatoid arthritis 2.
rheumatoid factor (RF): Over 95% of FS patients are positive 5
Femoral anteversion refers to the orientation of the femoral neck in relation to the femoral condyles at the level of the knee. In most cases, the femoral neck is oriented anteriorly as compared to the femoral condyles. In the case of posterior orientation, the term femoral retroversion is also ...
The femoral canal, or the medial compartment of the femoral sheath, is the inverted cone-shaped fascial space medial to the femoral vein within the upper femoral triangle. It is only 1-2 cm long and opens superiorly as the femoral ring. It serves two purposes:
allows the femoral vein to expand ...
Femoral facial syndrome, also known as femoral hypoplasia-unusual facies syndrome, is a rare congenital syndrome characterized by varying degrees of femoral hypoplasia and facial dysmorphism 1.
Femoral facial syndrome can cause varying degrees of femoral malformation rang...
Femoral hernias are a type of groin herniation and comprise of a protrusion of a peritoneal sac through the femoral ring into the femoral canal, posterior and inferior to the inguinal ligament. The sac may contain preperitoneal fat, omentum, small bowel, or other structures.
Neck of femur fractures (NOF) are common injuries sustained by older patients who are both more likely to have unsteadiness of gait and reduced bone mineral density, predisposing to fracture. Elderly osteoporotic women are at greatest risk.
It is anticipated that the total number ...
The femoral nerve is a large nerve arising from the lumbar plexus and one of two major nerves supplying the lower limb.
It arises from posterior divisions of L2-L4 roots of the lumbar plexus.
emerges from the lateral border of the psoas muscle to descend between ...
Femoral nerve neuropathy occurs when the femoral nerve is compressed as it passes under the inguinal ligament, anterior to iliopsoas.
Causes include surgery (hysterectomy, pelvic, hip, femoral artery catheterization, arterial bypass).
Mass effect from iliacus or iliopsoas may be visualised and...
The femoral ring is the superior opening of the femoral canal. Its boundaries are:
medial: lacunar ligament
anterior: medial part of the inguinal ligament
lateral: femoral vein within the intermediate compartment of the femoral sheath
posterior: pectineal ligament overlying the pectineus and...
The femoral sheath is the funnel-shaped fascial space that extends from the abdomen, inferior to the inguinal ligament, into the femoral triangle. It has variable length and terminates by blending in with the adventitia of the femoral vessels. It is formed from the transversalis and psoas fascia...
Femoral torsion analysis is used to assess the alignment of a femur post surgery. If one side has been operated on it can be compared to the non-operated side.
Superimpose axial images of:
the neck of femurs
Draw a line from the centre of the femoral h...
The femoral triangle is found in the anterior upper thigh.
The major boundaries can be recalled with the mnemonic SAIL 1,2:
lateral border: medial border of sartorius
medial border: medial border of adductor longus
superior border: inguinal ligament
A mnemonic for the boundaries of the femoral triangle is:
This should be easy to remember because the femoral triangle is shaped like a sail.
A: adductor longus
IL: inguinal ligament
Mnemonics to recall the order of the femoral vessels and nerve as they emerge from beneath the inguinal ligament into the femoral triangle are:
From lateral to medial:
N: femoral nerve
A: femoral artery
V: femoral vein
Femoroacetabular impingement (FAI) refers to a clinical syndrome of painful, limited hip motion resulting from certain types of underlying morphological abnormalities in the femoral head/neck region and/or surrounding acetabulum. FAI can lead to early degenerative disease.
The femoroacetabular or hip joint is a large ball-and-socket synovial joint between the femoral head and the acetabulum.
articulation: ball and socket joint between the head of the femur and the acetabulum
ligaments: ischiofemoral, iliofemoral, pubofemoral and transverse acetabular li...
The femur (plural: femora) is the longest, most voluminous and strongest bone in the human body.
It is composed of the upper extremity, body and lower extremity and provides several muscular origins and insertions.
The upper extremity is composed of the head, neck, greater tr...
Femur sparing intrauterine growth restriction is considered by some authors as a particular type of intrauterine growth restriction (IUGR) 1. In this type, the femoral length is the only standard fetal biometric parameter unaffected while all others are reduced.
This is a basic article for medical students and other non-radiologists
A femur x-ray, also known as femur series or femur radiograph, is a set of two x-rays performed of the entire femur. It is performed to look for evidence of injury (or pathology) affecting the humerus. It may be performed a...
Fetal rib fractures can be caused by certain skeletal dysplasias. These include:
osteogenesis imperfecta: type II - one of the classical causes of fetal rib fractures
achondrogenesis: type Ia - Houston-Harris sub type
Fibrodysplasia ossificans progressiva (FOP), previously known as myositis ossificans progressiva (MOP), is a rare, inherited disorder characterised by progressive fibrosis and ossification of muscles, tendons, fasciae, aponeuroses, and ligaments of multiple sites. It is disabling and ultimately ...
A fibrolipomatous hamartoma of the nerve (also known as a neural fibrolipoma) is a benign neoplasm of nerves, resulting from anomalous growth of fibroadipose tissue of the nerve sheath.
Fibrolipomatous hamartoma may be related to hypertrophy of mature fat and fibroblasts in the epine...
Fibromatosis refers to a wide range of soft tissue lesions that share an underlying histopathologic pattern of fibrous tissue proliferation. They can occur in a variety of anatomic sites (e.g. musculoskeletal, abdominopelvic, breast, etc.) and also vary in their behaviour, ranging from indolent/...
Fibromatosis colli is a rare form of infantile fibromatosis that occurs within the sternocleidomastoid muscle.
There may be a slight male predilection. It typically presents a few weeks after birth.
Presentation is usually with torticollis and is most frequ...
Fibrosarcoma of the bone is a rare malignant bone tumour which may occur as a primary lesion, or secondarily after radiation treatment, dedifferentiation from other tumours 3 or pathologies such as Paget disease, bone infarction, or chronic osteomyelitis.
It is a distinct entity fr...
Fibrous cortical defects (FCD) are benign bony lesions and are a type of fibroxanthoma, histologically identical to the larger non-ossifying fibroma (NOF).
Fibrous cortical defects typically occur in children (usually 2-15 years), and indeed are one of the most common benign bony ...