Birth fractures of the clavicle occur in 0.5-1% of vaginal deliveries and are the most frequent birth-related fracture. They are most commonly seen following normal, uncomplicated births but there is recognised increased incidence with high birth weight babies, forceps delivery and shoulder dyst...
Birth trauma relates to those conditions caused by both physical/mechanical and hypoxic injuries.
Birth trauma occurs in ~5 per 1000 births 2.
Bizarre parosteal osteochondromatous proliferations (BPOP), also known as a Nora lesions, are benign exophytic osteochondral lesions which have an appearance similar to an osteochondroma and are typically seen in the hands and feet.
On imaging, BPOPs are shown to be continuous with the underly...
The Blackburne-Peel ratio is an alternative to Insall-Salvati ratio and is used to assess patellar height, and determine the presence of patella baja or patella alta.
A lateral radiograph of the knee with 30 degrees of flexion is obtained, and a horizontal line at the level of the tibial platea...
The blade of grass sign, also called the candle flame sign, refers to the lucent leading edge in a long bone seen during the lytic phase of Paget disease of bone.
The blade of grass sign is characteristic of Paget disease of bone. This is akin to osteoporosis circumscripta cranii seen in the s...
Blade plates, also known as angled blade plates, are a type of orthopedic hardware used for reconstructing subtrochanteric femoral fractures, including therapeutic fractures during derotational osteotomies.
Blade plates were an advance on earlier fixation nails such as the Y nail or the Zicker ...
Block vertebra is a type of vertebral anomaly where there is a failure of separation of two or more adjacent vertebral bodies. It is an anatomic variant.
In a block vertebra, there is partial or complete fusion of adjacent vertebral bodies.
Bloom syndrome is a rare autosomal recessive disorder characterized by short stature, brachydactyly, malar hypoplasia and facial telangiectasia, erythema and cafe au lait spots. Affected individuals have an increased risk of developing malignancies.
There is extreme chromosomal fragi...
Blount disease refers to a local disturbance of growth of the medial aspect of the proximal tibial metaphysis and/or epiphysis that results in tibia vara. The condition is commonly bilateral.
There is no recognised inheritance pattern.
Clinically, the chi...
Blow out bone metastases or expansile bone metastases are typically only encountered in a relatively small number of primary malignancies, including 1:
renal cell carcinoma
Occasionally the sclerotic metastases of prostate cancer may also be expansile ...
Blumensaat line is the line drawn along the roof of the intercondylar notch of the femur as seen on lateral radiograph of the knee joint. It can been used for:
indicating the relative position of the patella as normally this line intersects the lower pole of the patella
suggesting ACL injury a...
A Bochdalek hernia is a form of congenital diaphragmatic hernia. They occur posteriorly and are due to a defect in the posterior attachment of the diaphragm when there is a failure of pleuroperitoneal membrane closure in utero. Retroperitoneal structures may prolapse through the defect, e.g. ret...
The body of the sphenoid bone is the midline cubical portion of the sphenoid bone, hollowed by the sphenoid air sinuses.
The body has superior, inferior, anterior, posterior, and lateral surfaces.
The superior surface features:
ethmoidal spine: prominent spine that articulates...
Böhler angle, also written as Bohler angle or Boehler angle, is also called the calcaneal angle or tuber joint angle 1, and is the angle between two lines tangent to the calcaneus on the lateral radiograph. These lines are drawn tangent to the anterior and posterior aspects of the superior calca...
Bone age assessment is used to radiologically assess the biological and structural maturity of immature patients from the hand and wrist x-ray appearances. It forms an important part of the diagnostic and management pathway in children with growth and endocrine disorders. It is helpful in the di...
The bone age, hand and wrist PA is a commonly performed examination to determine the radiographic age of the patient via the assessment of growth centers
patient is seated alongside the table
the non-dominant hand is placed, palm down on the image receptor
shoulder, elbow, a...
Bone (marrow) contusion (also known as bone bruising) is an osseous injury which may result from compression of bone structures.
Bone contusions represent trabecular microfractures with hemorrhage and without a discrete fracture line or contour abnormality 4. They typically appear wi...
A mnemonic for bony cortical lesions is:
O: osteoid osteoma
S: stress fracture
Conditions associated with bone deformity from softening includes:
bowing of long bones
biconcave vertebral bodies / codfish vertebra
Bone-forming tumors are a subset of bone tumors that are characterized by their propensity to form excess osteoid. They can be further subdivided into benign and malignant tumors.
bone island (enostosis)
Bone infarction is a term used to refer to osteonecrosis within the metaphysis or diaphysis of a bone. Necrosis is a type of cell death due to irreversible cell injury, which can be recognised microscopically by alterations in the cytoplasm (becomes eosinophilic) and in the nucleus (swelling, py...
There are several bony lesions that can involve or depict a sequestrum.
brodie abscess: osteomyelitis
certain soft tissue tumors (with bony extension)
malignant fibrous histiocytoma
metastasis (especially from breast car...
Bone macroscopic structure allows a bone to be divided into regions based on position or morphology. This is important for a number of reasons including how growth may be affected by injury.
Bones can be separated into:
Normal bone marrow is divided into red and yellow marrow, a distinction made on the grounds of how much fat it contains.
Red marrow is composed of:
reticulum (phagocytes and undifferentiated progenitor cells)
scattered fat cells
a rich v...
Bone marrow edema is the term given to abnormal fluid signal seen within the bone marrow on MRI. It is a non-specific, yet important, finding usually indicating the presence of an underlying pathology.
There is a long (long) list of possible causes of this finding:
Bone mineral density (BMD) is defined as the amount of mineral (calcium hydroxyapatite) per unit of bone.
BMD can be measured by various methods with DEXA the most prevalent
gamma rays: replaced by radiographic methods
single-energy photon absorptiometry (SPA) was super...
Bone scans are a nuclear medicine (scintigraphic) study that makes use of Technetium 99m (commonly Tc99m-methylene diphosphonate (MDP)) as the active agent.
The study has three phases which follow intravenous injection of the tracer. Sometimes a fourth (delayed/delayed) phase is performed.
The bones in the lower limb can be divided into those within the thigh and leg (4) and those within the foot (26).
Bones of the thigh and leg
Bones of the foot
The bones in the upper limb can be divided into those within the arm and pectoral girdle (3), forearm (2) and wrist and hand (27). There are also a number of accessory ossicles, predominantly occurring at the wrist.
Bones of the arm and pectoral girdle
Bones of the...
There are many types of bone within the body:
long bones (longer than they are wide)
short bones (not long bones)
sesamoid bones (for within a tendon)
irregular bones (don't fit into a category)
The majority of the bones of the appendicular skeleton are long bones. However, the ...
There are a bewildering number of bone tumors with a wide variety of radiological appearances:
Bone within a bone is a descriptive term applied to bones that appear to have another bone within them. There are numerous causes including:
thoracic and lumbar vertebrae (neonates and infants)
growth recovery lines (after infancy)
cortical splitting and new periostitis
sickle cell d...
A useful mnemonic to remember the possible etiologies of a bone within a bone appearance is:
G: growth arrest lines
H: heavy metal, hypoparathryoidism, hypothyroidism
S: sickle cell anemia, scurvy, syphilis
T: thalassemia, tuberculosis
D: disease of...
Bony humeral avulsion of the glenohumeral ligament (BHAGL) lesion is just like its slightly shorter relative HAGL lesion, except as the name suggests a bony avulsion fracture is seen at humeral insertion of the inferior glenohumeral ligament.
It is often associated with a subscapularis tear, an...
A mnemonic to help remember bony lesions that have no pain or periostitis is:
F: fibrous dysplasia
U: unicameral bone cyst
N: non-ossifying fibroma
If periostitis or pain is present (assuming no trauma, which can be a foolhardy assumption), you can exclude E-...
The bony pelvis is formed by the sacrum and coccyx and a pair of hip bones (os coxae or innominate bones), comprising the ischium, pubis and ilium and are part of the appendicular skeleton.
Its primary function is the transmission of forces from the axial skeleton to the lower limbs as well as...
The radiological definition of a bony sequestrum refers to an image of calcification within a lucent lesion, completely separated from the surrounding bone and without referring to the histological nature and vascular status of the calcified tissue 1.
The pathological definition of a sequestru...
Mnemonics to help remember common causes of bony sequestrum include:
E: eosinophilic granuloma
I: infection (Brodie abscess)
L: lymphoma (skeletal)
M: malignant fibrous histiocytoma or metastasis (especially from breast carcinoma)
The skeleton is the complete set of bones that make up a human. There are 206 bones in total which can be divided into:
The proximal femur has four major groups of trabeculae, distributing the compressive and tensile forces from the femoral head into the femoral diaphysis through the femoral neck. Together these trabeculae create the Ward triangle. The individual trabecular groups include:
principal compressive ...
Boogard's angle is measured by drawing a line from basion to opisthion and another line along the plane of the clivus to the basion intersecting the first line - the angle between these two lines is measured .
The normal angle is 126° +/- 6°. If the angle measures more than 136° it is indicativ...
The boomerang sign is defined as a small displaced flap from a longitudinal horizontal type medial meniscal tear which is displaced inferiorly into the medial meniscotibial recess. The imaging diagnosis of this type of tear is crucial because it is normally hidden from the surgeon during routine...
Bornholm disease, also known as epidemic pleurodynia, is a virally-mediated condition presenting as recurrent episodes of acute severe pleuritic pain. It is usually self-limiting, and serious morbidity is rare.
Its true incidence is unknown and it is thought that it is underdiagno...
The term Bosworth fracture is no longer used. However, it was classically used to refer to a fracture-dislocation of the ankle in which there was fracture of the fibula and posterior dislocation of the talus.
History and etymology
Named after David M Bosworth (1897-1979), orthopedic surgeon fr...
This is a basic article for medical students and other non-radiologists
Both hands series (or both hands x-ray) is an investigation almost exclusively performed in the rheumatology service to assess patients with arthritis. It is not used in trauma.
This is a summary article...
A botryoid rhabdomyosarcoma is a type of embryonal rhabdomyosarcoma and accounts for 5-10% of all rhabdomyosarcomas 6.
It tends to occur in pediatric population, often between birth and 15 years of age 7.
Rhabdomyosarcomas generally have a nonspecific infiltrative app...
Bouchard nodes are a clinical sign relating to bony nodules of the the proximal interphalangeal joints, and are much less common than Heberden nodes. They generally (but not always) correspond to palpable osteophytes.
They are sometimes painful, and are typically associat...
Boutonniere deformity is one of the musculoskeletal manifestations of rheumatoid arthritis in the hand with:
flexion contracture of the proximal interphalangeal (PIP) joints
extension of the distal interphalangeal (DIP) joints
The defect appears in the tendon which splays open. The appearanc...
Bowdler spurs refer to transverse long bone midshaft spurs or osteochondral projections associated with hypophosphatasia. They typically occur in the fibulae and less commonly in the forearms.
Bowing fractures are incomplete fractures of tubular long bones in pediatric patients (especially the radius and ulna) that often require no intervention and heal with remodelling.
Bowing fractures are almost exclusively found in children. However, there have been several case rep...
Boxer fractures are minimally comminuted, transverse fractures of the 5th metacarpal and are the most common type of metacarpal fracture. They typically occur (as the name suggests) when punching and are a common sight in all emergency departments on Friday nights.
They should not be confused w...
Boxer knuckle (not to be confused with a Boxer fracture) refers to an appearance when there is a disruption to the sagittal bands involving the extensor hood. particularly the sagittal band over the metacarpophalangeal (MCP) joint.
It often tends to result when a clench fisted hand s...
Boyd amputation refers to amputation at the level of the ankle with preservation of the calcaneus and heel pad and consequent fixation of the calcaneus to the tibia. It allows for complete weight bearing and provides both stabilisation of the heel pad and suspension for a prosthesis.
The brachialis muscle (brachialis) is one of the three muscles of the anterior compartment of the arm. It is only involved in flexion at the elbow and therefore the strongest flexor at the elbow, compared with the biceps brachii which is also involved in supination because of its insertion on th...
Brachial plexitis refers to inflammatory change involving the brachial plexus. This is in contrast to a brachial plexopathy meaning any form of pathology involving the brachial plexus.
Brachial plexitis is more commonly seen in men between 30 and 70 years of age and is bilateral i...
The brachial plexus is a complex neural network formed by lower cervical and upper thoracic ventral nerve roots which supplies motor and sensory innervation to the upper limb and pectoral girdle. It is located in the neck extending into the axilla posterior to the clavicle.
Brachial plexus injuries are a spectrum of upper limb neurological deficits secondary to partial or complete injury to the brachial plexus, which provides the nerve supply of upper limb muscles.
Trauma, usually by motor vehicle accidents, involves severe traction on the ...
Mnemonics for brachial plexus terminal branches includes:
Most Alcoholics Must Really Urinate
Where the first letter of each word represents the terminal branches of the brachial plexus:M: musculocutaneous nerveA: axillary nerveM: median nerveR: radial nerveU: ulnar nerve
Brachioradialis is a flexor at the elbow and works with biceps brachii and brachialis. Is it located in the superficial layer of the posterior compartment of the forearm and is particularly useful in elbow stabilisation.
Despite the bulk of the muscle being visible from the anterior surface of ...
Brachycephaly refers to a calvarial shape where the bi-parietal diameter to fronto-occipital diameter approaches the 95th percentile. It can result from a craniosynostosis involving the coronal and lambdoid sutures.
Brachycephaly can be associated with numerous syndrom...
Brachydactyly (BD) essentially refers to short digits. It is often inherited as an autosomal dominant trait (all the types). The clinical spectrum can widely range from minor digital hypoplasia to complete aplasia. As a group, it most commonly involves the middle phalanx 2.
Single or multiple b...
Brachydactyly type A1 or Farabee type brachydactyly is a subtype of brachydactyly. It was the first human anomaly recognised to have a mendelian pattern of inheritance. The anomaly is characterized by hypoplasia or aplasia of middle phalanges of the second to fifth digits in hands and feet and p...
Brachydactyly type A2 or Mohr-Wriedt type is characterized by hypoplasia/aplasia of the second middle phalanx of the index finger, second toe and sometimes little finger. There is radial deviation of the index finger and tibial deviation of the second toe.
Type A2 brachydactyly can b...
Brachydactyly type A3 is characterized by shortening of the middle phalanx of the little finger with radial deviation of distal phalanx. Slanting of the distal articular surface of the middle phalanx leads to radial deflection of the distal phalanx. However it is not always associated with clino...
Brachydactyly type A4 or Temtamy type is characterized by brachymesophalangy (absent or hypoplastic middle phalanx) of the second and fifth fingers. Other less common features include club foot, clinodactyly, ulnar deviation of the second finger.
Like other brachydactyly, type A4 is ...
Brachydactyly type A5 is characterized by absence of the middle phalanges and nail dysplasia with duplicated terminal phalanx of the thumb with resultant bifid thumb. Inheritance is suggested as autosomal dominant.
Brachymetatarsia (a.k.a. congenital short metatarsus) is a rare condition that develops from early closure of the growth plate.
Females are almost exclusively affected 1.
It typically involves the fourth ray or, less frequently, more than one metatarsal bon...
Bridging (or fusion) of the pubic symphysis can be associated with various systemic and local causes, including 1-3:
The bright rim sign in anterior talofibular ligament injury refers to a sign seen on MRI. A cortical defect with a bright dot-like or curvilinear high-signal-intensity, usually at the fibular attachment site, is seen on MRI. It has been described as an indicator of ATFL injury 1.
The British athletics muscle injury classification is a five-point MRI-based system that is based on extent and site. It has been primarily based on hamstring injuries, but is used in other muscle injuries. The classification system has been shown to have moderate inter- and intra-rater agreeabi...
Brodie abscess is an intraosseous abscess related to a focus of subacute pyogenic osteomyelitis. Unfortunately, there is no reliable way radiographically to exclude a focus of osteomyelitis. It has a protean radiographic appearance and can occur at any location and in a patient of any age. It mi...
Brown adipose tissue (BAT) is one of two types of adipose tissue (the other one being white fat) important for producing thermal energy (heat, non-shivering thermogenesis) especially in the newborn. It constitutes ~5% of body mass in the newborn and tends to disappear in adulthood. It is importa...
Brown tumor, also known as osteitis fibrosa cystica and rarely as osteoclastoma, is one of the manifestations of hyperparathyroidism. It represents a reparative cellular process, rather than a neoplastic process. Histologically brown tumors are identical to giant cell tumor (both are osteoclasto...
Brucellosis is a global zoonotic infection secondary to any of the four Brucella spp. that infect humans. It can be focal or systemic, but has a particular affinity for the musculoskeletal system.
Brucellosis occurs worldwide but is particularly prevalent in Mediterranean regions...
Brunelli procedure is a surgical procedure aiming to reconstruct a torn scapholunate ligament by reconnecting the scaphoid and lunate using the flexor carpi radialis tendon 1. In the modified Brunelli technique the tendon is sutured upon itself, thereby preventing the crossing of the distal radi...
Bucket handle fracture may refer to:
bucket handle fracture - non-accidental injury
bucket handle fracture of the pelvis
Bucket-handle meniscal tears are a type of displaced longitudinal meniscal tear where the inner part is displaced centrally. They are more commonly occur in the medial meniscus and are often associated with anterior cruciate ligament tears.
Bucket-hand tears can man...
Buckle rib fractures are typical of an anterior compressive force to the chest, most commonly external cardiac massage, but can be seen following any such traumatic injury.
Buckle rib fractures occur in all ages, even very elderly patients. Thus ribs are not the same as most adult lo...
Buford complex is a congenital glenoid labrum variant where the anterosuperior labrum is absent in the 1-3 o'clock position and the middle glenohumeral ligament is thickened (cord-like) and originates directly from the superior labrum at the base of the biceps tendon and crosses the subscapulari...
Bullet-shaped vertebra refers to the anterior beaking of the vertebral body.
It is seen in the following conditions:
mucopolysaccharidosis (Morquio disease, Hurler disease)
weapons and munitions inspired signs
A bunionette, also known as a tailor's bunion, is a bony prominence at the lateral 5th metatarsal head. It is the lateral counterpart of the more common bunion of the first metatarsophalangeal joint.
Bunionettes are visible on clinical examination as an erythematous swel...
Bursae are small fluid-filled sacs lined by synovial membrane with an inner capillary layer of synovial fluid. It provides a cushion between bones and tendons and/or muscles around a joint. This helps to reduce friction between the bones and allows free movement. They may or may not communicate ...
Bursitis is inflammation of a bursa, a synovial membrane-lined space, present overlying a number of joints. The inflammation may be acute or chronic, in the later case calcification may be apparent on plain radiographs. MRI best illustrates the bursa and related pathology.
Burst fractures are a type of compression fracture related to high-energy axial loading spinal trauma that results in disruption of the posterior vertebral body cortex with retropulsion into the spinal canal.
They usually present as back pain and or lower limbs neurologi...
Buschke-Ollendorff syndrome (BOS) , also known as disseminated dermatofibrosis lenticularis 2, comprises of osteopoikilosis associated with disseminated connective tissue and cutaneous yellowish naevi, predominantly on the extremities and trunk 1.
Recent genetic work has linked this syndrome ...
Butterfly fragments are large, triangular fracture fragments seen commonly in comminuted long bone fractures. The term is commonly used in orthopedic surgery, and results from two oblique fracture lines meeting to create a large triangular or wedge-shaped fragment located between the proximal an...
Butterfly vertebra is a type of vertebral anomaly that results from the failure of fusion of the lateral halves of the vertebral body because of persistent notochordal tissue between them.
an anterior spina bifida, with or without an anterior meningocele
can be part of...
A button sequestrum is a small sequestrum of devascularised bone surrounded by lucency. Although classically described in osteomyelitis and eosinophilic granuloma it is also occasionally seen in fibrosarcoma and lymphoma.
C7, also known as the vertebra prominens, is the seventh cervical vertebra and looks like vertebra C3-C6, but has some distinct features making it one of the atypical vertebrae. The name vertebra prominens arises from its long spinous process, which is easily palpable.
Café au lait spots are a type of pigmented skin lesions which are classically described as being light brown in color.
Conditions associated with them include:
neurofibromatosis type 1 (NF1)
McCune-Albright syndrome: typically irregular which has been likened to t...
Caffey disease or infantile cortical hyperostosis is a largely self-limiting disorder which affects infants. It causes bone changes, soft-tissue swelling, and irritability.
A rare variant known as prenatal onset cortical hyperostosis is severe and fatal, though it is probably a separate entity ...
Caisson disease is an uncommon diving-related decompression illness that is an acute neurological emergency typically occurring in deep sea divers.
Diving-related decompression illness is classified into two main categories 3:
arterial gas embolism secondary to pulmonary decompression barotra...
Calcaneal apophysitis, also known as Sever disease, is the painful inflammation of the apophysis of the calcaneus.
It typically presents in active young children and adolescents, especially those who enjoy jumping and running sports.
Patients tend to prese...