Superficial bursae are those bursae that are located superficial to the fibrous fascia. They form in the months to years following birth, as a result of direct pressure or friction 1. An example is the olecranon bursa.
In contrast, deep bursae are located deep to the fibrous fascia.
The superficial inguinal nodes are located in the superficial fascia of the upper thigh near the inguinal ligament and great saphenous vein. They number around 10 and drain lymph from the gluteal region, inferior anterior abdominal wall, perineum and superficial lower limbs. They drain into the ...
The superficial peroneal (fibular) nerve is one of two terminal branches of the common peroneal nerve.
origin: arises as a terminal branch of the common peroneal nerve in the lateral compartment of the leg
course: passes between peroneus longus muscle and the fibula proximally and per...
The superficial posterior compartment of the leg is one of the four compartments in the leg between the knee and foot. Muscles within this compartment primarily produce ankle plantarflexion as all 3 muscles form the Achilles tendon. Of the two posterior compartments, the superficial compartment ...
The superficial radial nerve, also known as the superficial branch of the radial nerve, is a sensory cutaneous nerve that arises from the radial nerve. It supplies the skin on the dorsum of the hand as well as providing articular branches to joints in the hand.
As a branc...
The superior gemellus muscle is a small triangular muscle in the gluteal region that together with the inferior gemellus and obturator internus muscles form the tricipital (three headed) triceps coxae which occupies the space between the piriformis muscle (superiorly) and quadratus femoris muscl...
The superior gluteal nerve is formed from posterior divisions of L4, L5 and S1 nerve roots of the sacral plexus. The nerve supplies branches to the gluteus minimus and medius muscles and terminates by innervating the tensor fasciae latae muscle.
The superior gluteal nerve...
Superior labral anterior posterior (SLAP) tears are injuries of the glenoid labrum, and can often be confused with a sublabral sulcus on MRI.
SLAP tears involve the superior glenoid labrum, where the long head of biceps tendon inserts. Unlike Bankart lesions and ALPSA lesions, they ...
The superior lumbar triangle, also known as the triangle of Grynfeltt-Lesshaft, is one of the locations for a lumbar hernia.
medially: the quadratus lumborum muscle
superiorly: twelfth rib
laterally: internal oblique muscle
floor: transversalis fascia and the ap...
Superior peroneal retinaculum (SPR) injuries refer to a spectrum of acute and chronic injuries to the superior peroneal retinaculum in the ankle. They are one of the causes of lateral ankle pain and instability.
One method of grading is the Oden's classification 1,7...
The superior tibiofibular joint is a synovial joint between the superior aspects of the tibia and fibula and is one of the multiple sites of cartilaginous and fibrous articulation carrying the name of the tibiofibular joint.
fibula: flat facet of fibular head
The superior sublabral sulcus is a normal variant of the superior sublabral recess, which is normally present at the attachment of the biceps tendon to the glenoid labrum.
The superior sublabral sulcus has been described as being shallow or deep and may be continuous with a sublabral foramen if...
Supernumerary ribs occur most commonly as a cervical rib or arising from the lumbar vertebra. In extremely rare situations, there can be sacral, coccygeal, intrathoracic, or aberrant lumbar ribs 3.
trisomy 8 syndrome
Superscan is intense symmetric activity in the bones with diminished renal and soft tissue activity on a Tc99m diphosphonate bone scan.
This appearance can result from a range of aetiological factors:
diffuse metastatic disease
transitional cell carcinoma (...
The supinator muscle is, as its name suggests, a supinator of the forearm. It is located in the deep layer of the posterior compartment of the forearm and together with brachialis, forms the floor of the cubital fossa.
origin: posterior proximal shaft of ulna; lateral epicondyle of hum...
A supra-acetabular fossa, also known as pseudodefect of acetabular cartilage, is an anatomic variant whereby a focal defect is evident within the subchondral bone of the acetabular roof. It is seen in as many as 10% of hips and is typically located at the 12 o'clock position both in the coronal ...
The supraclavicular foramen is a normal variant and typically found as an incidental finding on radiographs. It occurs in ~4% (range 2-6%) of the population.
Supraclavicular foramen appear as an osseous tunnel or tunnels, with the most typical position at the superior aspect of the junction of...
This is a basic article for medical students and other non-radiologists
Supracondylar fractures are the commonest fracture at the elbow in paediatric patients. They result from force applied across the elbow, usually following a fall. The supracondylar region is the weakest point in the develop...
Supracondylar humeral fractures, often simply referred to as supracondylar fractures, are a classic paediatric injury which require vigilance as imaging findings can be subtle.
Simple supracondylar fractures are typically seen in younger children, and are uncommon in adults; 90% a...
A supracondylar spur, supracondylar process, supratrochlear spur, or avian spur of the distal anteromedial humeral cortex is an anatomical variant present in ~1% 1,2 of the population.
The supracondylar spur is typically located on the anteromedial humeral cortex, 5 cm proximal ...
The supraorbital foramen or notch is the small opening at the central edge of the superior orbital margin in the frontal bone just below the superciliary arches that transmits the supra-orbital nerve, artery and vein.
It is lateral to the supratrochlear foramen, where the supratrochlear nerve, ...
The supraorbital ridge, also known as the supraorbital margin or superciliary arch is the superior margin of the bony orbit. Part of the frontal bone, the supraorbital ridge contains the supraorbital foramen (or notch). The corrugator supercilii muscles arise from the medial end of the supraorbi...
The suprapatellar bursa, also known as the suprapatellar recess, is one of several bursae of the knee. It is located proximal to the knee joint, between prefemoral and suprapatellar fat pads. As with all bursae, its purpose is to reduce friction between moving structures.
In most (~85%) people,...
Suprapubic cartilaginous cysts (SPCC) are rare cystic lesions arising from the symphysis pubis thought to be degenerative in origin. They have also been called retropubic or subpubic cysts.
In the small number of cases in the literature, all bar one patient, have been female. The ...
The suprascapular nerve is the only branch of the upper trunk (C5 and C6) of the brachial plexus, supplying the supraspinatus and infraspinatus muscles and sensation to the acromioclavicular and glenohumeral joints.
The suprascapular nerve arises from the upper trunk of t...
Suprascapular neuropathy or suprascapular nerve entrapment occurs if the suprascapular nerve is compressed as it passes through the suprascapular notch or spinoglenoid notch.
Non-specific posterior shoulder pain and weakness.
masses (e.g. ganglion ...
The suprascapular notch is located on the superior aspect of the scapula, at the scapula's anterolateral aspect.
The suprascapular notch separates the superior border of the scapula from the anterior coracoid process.
Relations and/or boundaries
The suprascapular nerve passes ...
Supraspinatus is one of the four muscles that make up the rotator cuff, the others being: infraspinatus, teres minor and subscapularis.
origin: supraspinous fossa of the scapula
insertion: greater tuberosity of the humerus
innervation: suprascapular nerve (C5-6)
arterial supply: sup...
Suprasternal tubercle is a sternal normal variant which forms when a suprasternal ossicle fuses with manubrium 1. It can be unilateral or bilateral. It usually appears as triangular or pyramidal bony projection in continuity with the superior margin of manubrium. It is better depicted in coronal...
The supratrochlear foramen is the small opening at the medial edge of the superior orbital margin in the frontal bone that transmitts the supratrochlear nerve, artery and vein. When incomplete, it forms a notch. It is variably present, and when absent the neurovascular bundle will simple exit th...
The sural nerve is a sensory nerve of the lower limb formed by the union of branches from the tibial nerve as well as common fibular nerve supplying sensation to the lower lateral aspect of the calf and foot.
It travels within subcutaneous tissue adjacent to the small saphenous v...
The sustentaculum tali is a horizontal shelf that arises from the anteromedial portion of the calcaneus. The superior surface is concave and articulates with the middle calcaneal surface of the talus. The inferior surface has a groove for the tendon of flexor hallucis longus.
There are many sutures of the skull, which are where skull bones meet. In general, sutures don't fuse until brain growth is complete, therefore allowing the skull to increase in size with the developing brain.
Sutures are fibrous joints with the periosteum externally and outer la...
Swan neck deformity is a deformity of the digits that consists of:
hyperextension of the proximal interphalangeal (PIP) joints
compensatory flexion of the distal interphalangeal (DIP) joints
Swan neck deformity is seen in 3,4:
rheumatoid arthritis (classical association)
The Swischuk line is helpful in differentiating pathological anterior displacement of the cervical spine from physiological displacement, termed pseudosubluxation.
the line is drawn from anterior aspect of posterior arch of C1 to anterior aspect of posterior arch of C3
There are a large number of causes for a symmetrical periosteal reaction 1,2:
chronic venous insufficiency
physiologic periosteal reaction of the newborn (Caffey disease), most common cause before 6 months old
juvenile idiopathic arthritis
Symphalangism refers to ankylosis of the interphalangeal joints (i.e. fusion of the phalanges) in either the toes or the fingers. Less commonly, the metacarpophalangeal joints may be affected.
One study reports symphalangism of the fifth toe in ~55% (range 40-75%) of the populatio...
Symphyses are secondary cartilaginous joints composed of fibrocartilage. They are considered amphiarthroses, meaning that they allow only slight movement and are all found at the skeletal midline.
symphysis pubis between the pubic bones medially
manubriosternal joint between the ste...
Synarthroses are a functional class of joint that permit very little or no movement under normal conditions.
fibrous joints such as cranial sutures
synchondroses (primary cartilaginous joints) such as growth plates
Synchondroses are primary cartilaginous joints mainly found in the developing skeleton, but a few also persist in the mature skeleton as normal structures or as variants.
Synchondroses are cartilaginous unions between bone composed entirely of hyaline cartilage. Most exist between os...
Syndactyly refers to a congenital fusion of two or more digits. It may be confined to soft tissue (soft tissue syndactyly / simple syndactyly) or may involve bone (bony syndactyly / complex syndactyly).
The overall estimated incidence is at ~1 per 2,500 to 5,000 live births 6,8. T...
Syndesmophytes are calcifications or heterotopic ossifications inside a spinal ligament or of the annulus fibrosus. They are seen in only a limited number of conditions including:
Appearance on plain radiographs comprises v...
Syndesmoses are a type of fibrous joint where strong collagen rich connective tissue holds two portions of bone together allowing very little movement. They consist of an interosseous membrane and ligamentous thickenings.
distal tibiofibular syndesmosis
Synovial chondromatosis (or Reichel syndrome) is a disorder characterised by loose cartilaginous bodies which may, or may not be calcified or ossified.
It is classified under two main types:
Primary synovial chondromatosis: predominantly monoarticular disorder of unknown aetiology.
Synovial chondrosarcoma refers to a very rare malignant cartilaginous neoplasm arising from the synovium.
There can be a wide spectrum in age of presentation from from 25-75 years of age. A slight male predilection may be present.
It can either as a primary lesion (p...
Synovial cysts are para-articular fluid-filled sacs or pouch-like structures containing synovial fluid and lined by synovial membrane. They can occur around virtually every synovial joint in the body and also around tendon sheaths and bursae. Communication with the adjacent joint may or may not ...
Synovial enhancement is an imaging feature typically observed on MRI imaging. It can occur in various forms and can be focal or diffuse.
transient synovitis of the hip
tuberculous septic arthritis...
Synovial haemangiomas are rare benign vascular malformations that occur in relation to the joint. It is sometimes considered a subtype of soft tissue haemangiomas.
The lesions typically present in children and young adults. Occasionally patients can have recurrent haemarthroses 8....
Synovial joints are a type of joint with an articular capsule, consisting of an outer fibrous layer and an inner synovial membrane, which surrounds a fluid-filled synovial cavity. The articulating surfaces are covered by hyaline cartilage, designed to slide with little friction and to absorb com...
Synovial plicae are folds of synovium, thought to represent embryologic remnants. They are common, present in ~90% of arthroscopies 3.
They have been implicated in anterior knee pain and possibly in chondromalacia patellae although their role remains controversial 1,3.
Synovial sarcomas are relatively common intermediate-to-high grade malignant soft tissue tumours, often with an initial indolent course, affecting young patients, and most commonly involving the soft tissue surrounding the knees.
Synovial sarcomas typically present in adolescents ...
Syphilis is the result of infection with the gram negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately.
Despite the discovery of penicillin...
Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multisystem involvement. It is also sometimes classified as a vasculitis.
There is an overall increased female predilection. In adults, women are affected 9-13 times more than males. In children, this ratio i...
Musculoskeletal manifestations in patients with systemic lupus erythematosus are common and often symptomatic. Characteristic manifestations are seen in approximately 80% of patients, but many less characteristic manifestations are important to be aware of. Multiple different presenting complain...
T11 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a single costal facet that articulates with the atypical eleventh rib. There are no facets on the transverse processes.
T12 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a single costal facet with no facets on transverse processes.
T1 rho, also referred to as T1ρ or "spin lock", is an MRI sequence that is being developed for use in musculoskeletal imaging. At the moment it is mostly investigational and does not yet have widespread clinical use.
The "rho" in the sequence name refers to a "ro"tating frame and the sequence h...
T1 is an atypical thoracic vertebra. In contrast to typical thoracic vertebrae, it contains a complete facet for the 1st rib and a demifacet for the 2nd rib. It contains lips on the upper surface of the body. T1 also has a spinous process more horizontal than other thoracic vertebrae.
The talar beak sign is seen in cases of tarsal coalition, and refers to a superior projection of the distal aspect of the talus. It is most frequently encountered in talocalcaneal coalition. It is thought to result from abnormal biomechanic stresses at the talonavicular joint.
The talar declination angle is drawn on the weightbearing lateral foot radiograph between the mid-talar axis and the supporting surface. It should usually measure approximately 21°.
If the first metatarsal axis is steep, the mid-talar axis approaches the horizontal and is projected above the fi...
There are many types of talar dislocation given its multiple articulations:
total talar dislocation
Talar fractures are an uncommon injury, accounting for <5% of all foot fractures. Recognition of the unique talar anatomy is important for correct diagnosis.
talar head fractures
talar neck fractures
talar body fractures
talar dome osteochondral fracture
Talar head fractures most commonly result from a compressive force with a plantar flexed foot.
Talar head fractures almost always involve the talonavicular joint, and associated dislocation/subluxation is common.
Two types of talar fractures are described 3:
compression fracture, o...
Talar neck fractures extend through the thinnest cross-sectional portion of the talus, just proximal to the talar head. They represent one of the most common types of talus fracture (~30-50%), along with chip and avulsion fractures of the talus (~40-49%). These fractures are commonly associated ...
The talocalcaneal angle, also known as the kite angle, refers to the angle between lines drawn down the axis of the talus and calcaneus measured on a weightbearing DP foot radiograph. This angle varies depending on the position of the calcaneus under the talus and the stiffness of the ligaments ...
Talocalcaneal coalition is one of the two most common sub-types of tarsal coalition, the other being calcaneonavicular coalition. It accounts for 45% of all tarsal coalitions, and although all three facets of the talocalcaneal joint can be involved, the middle facet is most commonly involved.
The talocalcaneal joint, also called the anatomical subtalar joint, is an important and complex joint in the hindfoot that allows articulation of the talus and calcaneus.
It comprises three articulations between talus and calcaneus 1:
anterior: head of talus with anterior facet ...
Talonavicular coalition is one of the less common subtypes of tarsal coalition, the most commons being talocalcaneal coalition and calcaneonavicular coalition. As with other forms of coalition it can be osseous, cartilaginous or fibrous.
Uni-or bilateral. Most patients ar...
Talonavicular dislocations are a rare injury, and is caused by forced extreme abduction or adduction of the forefoot. They are often associated with calcaneocuboid dislocation (often transient) and calcaneal fractures (and are then called transcalcaneal talonavicular dislocations).
The talonavicular joint is an important joint of the hindfoot and forms the clinical subtalar joint with the talocalcaneal joint.
The talonavicular joint primarily consists of the articulation between the head of the talus and the concavity produced by the posterior aspect of th...
The talus is a tarsal bone in the hindfoot that articulates with the tibia, fibula, calcaneus, and navicular bones. It has no muscular attachments and around 60% of its surface is covered by articular cartilage.
The talus has been described as having three main components: head,...
The "tam o' shanter" is a Scottish hat, named after the character in Robert Burns' 1 poem of the same name. The appearances of advanced Paget disease of the skull are similar in appearance to the hat.
Paget involvement of the skull, with widening of the diploic space and an overall enlargement...
The tarsal bones are the seven bones of the foot excluding the metatarsals and phalanges. They are collectively known as the tarsus. The seven bones are:
There are several mnemonics for the tarsals.
Mnemonics of the tarsal bone are numerous and useful for memorising the order and location of tarsal bones. They usually describe the position of the tarsal bones from superior to inferior, medial to lateral in a right foot:
The Cab in New Mexico Is Land Cruiser
The Cure of Nemaline Myopathy I...
Tarsal coalition describes the complete or partial union between two or more bones in the midfoot and hindfoot. Tarsal coalition refers to developmental fusion rather than fusion that is acquired secondary to conditions such as rheumatoid arthritis, trauma or post-surgical.
The tarsal sinus (or sinus tarsi) is a cylindrical cavity located between the talus and calcaneus on the lateral aspect of the foot. MRI is the investigation of choice for evaluating the tarsal sinus structures.
The tarsal sinus is situated on the lateral side of the foot; distal...
The tarsal tunnel is a fibro-osseous canal found in the medial aspect of the ankle.
roof: flexor retinaculum
floor: medial surfaces of the tibia, talus and calcaneus 1, 2
From anterior to posterior:
tibialis posterior tendon
flexor digitorum longus tend...
Tarsal tunnel syndrome refers to an entrapment neuropathy of the tibial nerve or of its branches within the tarsal tunnel. This condition is analogous to carpal tunnel syndrome.
The most common symptoms are pain and paresthesia in the toes, sole, or heel and the main find...
The ankle teardrop sign is one of the radiological signs of an ankle joint effusion. It represents the presence of excess fluid in the inferior part of the anterior compartment of the ankle.
Technetium 99m-methyl diphosphonate (99mTc MDP) is a radiotracer used in nuclear medicine especially for bone scans. Any disease process which results in extracellular fluid expansion will lead to accumulation of this tracer.
photon energy: 140 keV
physical half life: 6 h...
Telangiectatic osteosarcomas (TOS) are an uncommon variant of osteosarcoma that represent 2.5-12% of all osteosarcomas.
TOS have similar demographics to that of conventional osteosarcoma and typically presents in adolescents and young adults (reported age range of 3-67 years with...
A telephone receiver deformity is a characteristic bowing of the shaft of the long bones, usually the humeri or femora, seen in thanatophoric dysplasia.
The temporalis muscle is one of the muscles of mastication. It is responsible for both closing the mouth and retraction (posterior fibres).
origin: temporal fossa between the infratemporal crest and inferior temporal line
insertion: coronoid process and ramus of mandible
The temporomandibular joint (TMJ) is an atypical synovial joint located between the condylar process of the mandible and the mandibular fossa and articular eminence of the temporal bone. It is divided into a superior discotemporal space and inferior discomandibular space by the TMJ disc (or meni...
The temporomandibular joint (TMJ) disc (or meniscus) is made of fibrocartilage and divides the joint into two compartments.
The disc is composed of fibrocartilage, with crimped collagen, thought to better absorb impacts. It has a biconcave shape with a thicker periphery attached...
Temporomandibular joint (TMJ) dysfunction is characterised by an abnormal relationship between the disc and the adjacent articular surfaces (condyle below with mandibular fossa and articular eminence above).
TMJ dysfunction is far more common in women (F:M 8:1).
Temporomandibular joint (TMJ) effusions are unusual in asymptomatic patients, and thus should trigger a careful search for underlying pathology. It usually precedes osteoarthritis of the TMJ. Effusions are seen in:
rheumatoid arthritis (RA)
Temporomandibular joint (TMJ) inflammation may occur as a result of an inflammatory arthropathy or secondary to TMJ dysfunction. Since the TMJ is a synovial joint, it is susceptible to inflammatory arthropathies that affect other joints.
rheumatoid arthritis (RA) : is by far the most common
Temporomandibular joint (TMJ) pathology encompasses three main entities:
temporomandibular joint dysfunction: relating to abnormal TMJ disc relationship to condyle and temporal bone, which can lead to osteoarthritis.
temporomandibular joint inflammation
temporomandibular joint trauma
Tendon and ligamentous ossification has a relatively narrow differential, including:
diffuse idiopathic skeletal hyperostosis
ossification posterior longitudinal ligament (OPLL)
Idiopathic Achilles tendon ossification - isolated finding
post-traumatic - rand...
A number of processes can affect tendons.
Literally means a disease or disorder of a tendon and typically used to describe any problem involving a tendon. While many define tendinopathy as an umbrella term to describe all tendon pathology, others may use it to descr...
Mnemonics for remembering the three conjoined tendons that make up the pes anserinus include:
Say Grace before Tea
From anterior to posterior, the tendons are:
Say Grace before Tea
Tennis leg represents a myofascial or tendinous injury of the lower limb and, not surprisingly, is seen most frequently in tennis players.
Although classically seen in people who play tennis, it can also be induced by playing squash, skiing, and athletics. Therefore, it typically ...