The American Association for the Surgery of Trauma (AAST) injury scoring scales are the most widely accepted and used system of classifying and categorising traumatic injuries. Injury grade reflects severity, guides management, and aids in prognosis. At the time of writing (mid 2016), 32 differe...
The American Association for the Surgery of Trauma (AAST) renal injury scale 3-4 is the most widely used grading system for renal trauma at the time of writing (late 2016). Severity is assessed according to the depth of renal parenchymal damage and involvement of the urinary collecting system a...
The 1994 revision of the AAST (American Association for the Surgery of Trauma) liver injury scale is the most widely used liver injury grading system at the time of writing (late 2016).
haematoma: subcapsular, <10% surface area
laceration: capsular tear, <1 cm parenc...
The 1994 revision of the American Association for the Surgery of Trauma (AAST) splenic injury scale is the most widely used grading system for splenic trauma at the time of writing (late 2016).
subcapsular haematoma <10% of surface area
capsular laceration <1 cm depth...
Abdominal aortic injuries are a very rare form of traumatic aortic injury and are much less common than thoracic aortic injury.
Aortic injury occurs in <1% of blunt trauma patients, with abdominal aortic injury representing only ~5% of all aortic injuries 1. Males are more freque...
Abdominal trauma is usually divided into blunt and penetrating trauma.
Findings of abdominal trauma
splenic trauma: most common
gastrointestinal tract (bowel) trauma:
proximal jejunum is most commonly affected by blunt trauma,...
Acromioclavicular joint injuries are common and range from a mild sprain to complete disruption of the acromioclavicular joint (ACJ) and injury to surrounding structures.
Acromioclavicular joint injuries usually occur from a direct blow or following a fall onto the should...
Acute aortic syndrome (AAS) describes the presentation of patients with one of a number of life threatening aortic pathologies that give rise to aortic symptoms.
The spectrum of these aortic emergencies include:
aortic intramural haematoma
penetrating atherosclerotic ulcer
Adrenal gland trauma most commonly results from blunt force trauma.
Adrenal gland trauma is present on 1-2% of CT imaging in blunt trauma although the occurrence is thought to be much higher as injury has been demonstrated at 28% in one autopsy series 1-4.
The right adrenal glan...
Allen and Ferguson classification is used for research purposes to classify subaxial spine injuries. It is based ofn the mechanism of injury and position of the neck during injury. This classification was proposed by Allen and Ferguson in 19823 and at the time of writing (July 2016) remains the ...
The American Academy of Orthopedic Surgeons classification of periprosthetic hip fractures divides the femur into three separate regions:
level I: proximal femur distally to the lower extent of the lesser trochanter
level II: 10 cm of femur distal to level I
level III: femur distal to level...
The term amputation refers to the disconnection of all or part of a limb from the body. Specifically amputation is defined as removal of the structure through a bone. This is in contrast to disarticulation, which is removal of the structure through a joint.
When due to trauma, trau...
The Amsterdam wrist rules are validated clinical decision rules for determining which patients require radiographic imaging (wrist radiography) for acute wrist pain following trauma. The initial study evaluated 882 patients and were published in 2015 1. The decision rules assessed different clin...
The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists.
Head and neck anatomy
Abdominal and pelvic anatomy
The Anderson and D'Alonzo classification is the most commonly used classification of fractures of the odontoid process of C2.
fracture of the upper part of the odontoid peg
above the level of the transverse band of the cruciform ligament
usually considered stable...
Ankle fractures account for ~10% of fractures encountered in trauma, preceded only in incidence by proximal femoral fractures in the lower limb. They have a bimodal presentation, involving young males and older females. Ankle injuries play a major part in post multitrauma functional impairment t...
Anterior cruciate ligament (ACL) avulsion fractures or tibial eminence avulsion fractures are a type of avulsion fracture of the knee. This typically involves separation of the tibial attachment of the ACL to variable degrees. Separation at the femoral attachment is rare 5.
It is ...
Anterior hip dislocation is much less common than a posterior hip dislocation. It constitutes for only 5-18% of all hip dislocations.
While the posterior dislocation is often associated with fractures, the anterior dislocation is mostly an isolated injury 1.
It can be clas...
Anterior shoulder dislocation is by far the commonest type of dislocation and usually results from forced abduction, external rotation and extension 1.
Broadly speaking, anterior shoulder dislocations occur in a bimodal age distribution. The first, and by far the more prevalent a...
Anterior subluxation of cervical spine (also known as hyperflexion sprain) is a ligamentous injury to the cervical spine.
Patient presents with neck pain. There may be symptoms due to spinal cord oedema.
It results from ligamentous injury, however, there may b...
Anterior superior iliac spine (ASIS) avulsion injuries typically occur in athletes during forceful muscular contraction. ASIS is the site of attachment for sartorius and tensor fascia latae muscles.
ASIS avulsion, like other pelvic avulsion injuries, is a stable fracture.
Implanted antibiotic beads are a form of microbiological treatment inserted during orthopaedic 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 visualisation on all imaging ...
The aortic isthmus is the part of the aorta just distal to the origin of the left subclavian artery at the site of the ductus arteriosus.
This portion of the aorta is partly constricted in the fetus because of the lack of flow within the aortic sac and ascending aorta. It marks the partial sepa...
Aortic pseudoaneurysms typically occur as a result of trauma, a subset of traumatic aortic injury. They can be acute or chronic.
Aortic pseudoaneurysms are contained ruptures of the aorta in which the majority of the aortic wall has been breached, and luminal blood is held in only by...
Apophyseal avulsion fractures of the pelvis and hip are relatively common among physically active adolescents and young adults.
Pelvic and hip apophyseal injuries typically occur in the 14 to 25 year age range. Kicking sports, such as soccer, and gymnastics are frequently to blame...
Arthrofibrosis is a complication of injury or trauma to a joint. 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.
It has been most extensively studied in the knee, w...
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.
Down syndrome (20%)
Atlanto-occipital dissociation (AOD) injuries are severe and include both atlanto-occipital dislocations and atlanto-occipital subluxations.
The tectorial membrane and alar ligaments provide most of the stability to the atlanto-occipital joint, and injury to these ligaments results i...
The aubergine sign (also known as egg-plant sign or deformity) is a clinical sign of a fractured penis. Haemorrhage beyond the tunica albuginea produces swelling and bruising of the penis simulating the appearance of an aubergine.
An aviator fracture is a coronal-plane fracture of the neck of the talus resulting from forced dorsiflexion of ankle. It is the second most common talar fracture, after talar dome fractures.
In 20% of cases a fracture of the medial malleolus is also present 1.
These fractures are at risk of av...
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 ...
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...
Avulsion injuries, where a portion of cortical bone is ripped from the rest of the bone by the attached tendon, are common among those who participate in sports, and there are numerous sites at which these occur. Being familiar with them is important as chronic injuries can appear aggressive.
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 recognised and are generally based on the principle that the direction in which the apex of the ulnar fracture points is the same ...
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...
Bankart lesions are a common complication of anterior shoulder dislocation and are frequently seen in association with a Hill-Sachs lesion.
They result from detachment of the anterior inferior labrum from the underlying glenoid as a direct result of the anteriorly dislocated humeral ...
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...
Basilar fractures of the skull, also known as base of skull fractures, are a common form of skull fracture, particularly in the setting of severe traumatic head injury, and involve the base of the skull. They may occur in isolation or often in continuity with skull vault fractures or facial frac...
Benign post-traumatic pseudopneumoperitoneum is the presence of ectopic gas typically between the 5th-10th intercostal spaces after high-energy trauma in the absence of other causes of pseudopneumoperitoneum such as pneumomediastinum 9.
Occurs with an incidence of 5% post-trauma...
A Bennett fracture-dislocation is a fracture of the thumb resultant of forced abduction of the first metacarpal. Defined as an intra-articular two-part fracture of the base of the first metacarpal bone.
two piece fracture dislocation of the base of the t...
The Biffl scale or grade illustrates the spectrum of blunt cerebrovascular injury (BCVI) seen on angiography (both CTA and DSA). Some authors refer to the grading scale as the Denver scale, which is not to be confused with the Denver criteria, a series of clinical indications and risk factors fo...
A bilateral facet dislocation is a flexion distraction type of dislocation of the cervical spine, often a result of buckling force.
It has been thought to result from hyperflexion, however, recent studies suggest a buckling force to be the cause 1.
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.
Blunt cerebrovascular injury (BCVI) is an uncommon but serious consequence of blunt trauma to the head and neck.
It is often part of multi-trauma with a significant series of blunt trauma CTA reporting an incidence of approximately 1% 3. A large systematic review and meta-analysis...
Blunt traumatic neck injury is uncommon because it is usually protected by the head, shoulders, and chest. This term is generally used to refer to injuries of the neck besides to cervical spine injuries, which are common.
Blunt injury to the neck is most commonly from motor vehicle ...
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), orthopaedic surgeon f...
Bowel and mesenteric trauma can result from blunt force, penetrating and iatrogenic trauma.
The bowel and mesentery are injured in ~2.5% (range 0.3-5%) of blunt force abdominal trauma 1,3,5,8. However not surprisingly, bowel and mesenteric injuries are more frequent after penetrat...
Bowing fractures are incomplete fractures of tubular long bones in paediatric 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 re...
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...
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 ...
A mnemonic for the features of a bronchial fracture on a chest radiograph is:
P: progressive or
P: persistent pneumothorax or
Bucket handle fracture may refer to:
bucket handle fracture - non-accidental injury
bucket handle fracture of the pelvis
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...
Butterfly fragments are large, triangular fracture fragments seen commonly in comminuted long bone fractures. The term is commonly used in orthopaedic surgery, and results from two oblique fracture lines meeting to create a large triangular or wedge-shaped fragment located between the proximal a...
Calcaneal fractures are the most common tarsal fracture, and can occur in a variety of settings.
The calcaneus is the most commonly fractured tarsal bone and accounts for about 2% of all fractures 2 and ~60% of all tarsal fractures 3.
Calcaneal fractures can be divided...
Avulsion fractures of the calcaneal tuberosity are rare, accounting for only 3% of all calcaneal fractures. There is a strong association with diabetes, where they may occur spontaneously, and are thought to be due to peripheral neuropathy. They also occur in osteoporosis and hyperparathyroidism...
The Canadian CT head rule (CCTHR) is a validated clinical decision rule to determine the need for CT head in adult emergency department patients with minor head injuries.
Patient has suffered minor head trauma with resultant:
loss of consciousness
Caroticocavernous fistulas (CCF) represent abnormal communication between the carotid circulation and the cavernous sinus. They can be classified as direct or indirect which are separate conditions with different aetiologies.
Direct CCFs are often secondary to trauma, and as suc...
Carpometacarpal (CMC) joint dislocations are an uncommon dislocation of the hand.
There is a strong younger male predominance in the dominant hand.
The most common mechanisms of injury are punching followed by a fall.
The patient may present with ulnar dev...
Central cord syndrome is the most common type of incomplete spinal cord injury, accounting for ~10% of all spinal cord injuries. As the name implies, this syndrome is the result of a contusion of the central portion of the cervical spinal cord.
Most often central cord syndrome occ...
Cerebral haemorrhagic contusions are a type of intracerebral haemorrhage and are common in the setting of significant head injury. They are usually characterised on CT as hyperdense foci in the frontal lobes adjacent to the floor of the anterior cranial fossa and in the temporal poles.
Cerebral herniation, also referred to as acquired intracranial herniation, refers to shift of cerebral tissue from its normal location, into an adjacent space as a result of mass effect.
There are a number of different patterns of cerebral herniation which describe the type of herni...
Convenient mnemonics for the causes of cerebral ring enhancing lesions are:
MAGIC DR or DR MAGIC
DR MAGIC L
MAGIC DR or DR MAGIC
I: infarct (subacute phase)
D: demyelinating disease
R: radiation necrosis or re...
A floating pillar, also referred as pedicolaminar fracture-separation injury, is characterised by fractures through the pedicle and lamina of a cervical spine vertebrae creating a free-floating articular pillar fragment. It is an unstable cervical spine fracture that results from hyperflexion–la...
There are several cervical spine fracture classification systems:
Anderson and D'Alonzo classification (odontoid fracture)
Roy-Camille classification (odontoid fracture)
Levine and Edwards classification (for traumatic injuries to axis)
Allen and Ferguson classification (subaxial spine injur...
Cervical spine fractures can occur secondary to exaggerated flexion or extension, or because of direct trauma or axial loading.
The cervical spine is susceptible to injury because it is highly mobile with relatively small vertebral bodies and supports the head which is both heavy and...
Cervical spine injuries can involve the cervical vertebral column, intervertebral discs and cervical spine ligaments, and/or cervical spinal cord. The cervical spine accounts for ~50% of all spinal injuries.
5-10% of patients with blunt trauma have a cervical spine injury 1.
The Children’s Head injury ALgorithm for prediction of Clinically Important Events (CHALICE) clinical decision rule was developed to predict clinically important brain injuries in children with head trauma. This rule identifies high-risk criteria and divides them into history, examination and me...
Chalk stick or carrot stick fractures are fractures of the fused spine, classically seen in ankylosing spondylitis.
Some authors define the chalk stick fracture as a fracture through a Pagetoid long bone (see Paget disease).
They usually occur through the disco-vertebra...
Chance fractures, also referred as seatbelt fractures, are flexion-distraction type injuries of the spine that extend to involve all three spinal columns. These are unstable injuries and have a high association with intra-abdominal injuries.
They tend to occur from a flexi...
Chauffeur fractures (also known as Hutchinson fractures or backfire fractures) are intra-articular fractures of the radial styloid process. The radial styloid is within the fracture fragment, although the fragment can vary markedly in size.
These injuries are sustained eit...
Chopart fracture is a fracture/dislocation of the mid-tarsal joint (Chopart joint) of the foot, i.e. talonavicular and calcaneocuboid joints which separate the hindfoot from the midfoot. The commonly fractured bones are the calcaneus, cuboid and navicular.
The foot is usually dislocated mediall...
This classification of gamekeeper's thumb (also known as skier's thumb) was proposed by Hintermann et al. 1 in 1993 and is based on whether a fracture is present and whether the injury is stable:
fracture present, which is non-displaced and stable in flexion
typically treated with a sp...
There are several classification systems for sacral fractures, but the most commonly employed are the Denis classification and subclassification systems, and the Isler classification system. These classification systems are important to understand as proper classification can impact management.
Clavicular fractures are common and account for 2.6-10% of all fractures 2-3. They usually require minimal treatment, which relies on analgesia and a collar-and-cuff. However, in some cases open reduction and internal fixation is required.
Fractures can occur at any part of the clavi...
Clay-shoveler fractures are fractures of the spinous process of a lower cervical vertebra.
Often these injuries are unrecognised at the time and only found incidentally years later when the cervical spine is imaged for other reasons.
Acutely they tend to be associated wi...
Colles fractures are very common extra-articular fractures of the distal radius that occur as the result of a fall onto an outstretched hand. They consist of a fracture of the distal radial metaphyseal region with dorsal angulation and impaction, but without the involvement of the articular surf...
Comminuted fractures are fractures where more than 2 bone components are created.
The problem with the term is that it includes a very heterogeneous group of fractures from a 3 part humeral head fracture to a multi-part fracture of the femur following a high-energy road traffic accident.
Complete fractures are fractures where the parts of the bone that have been fractured are completely separated from each other. There is complete separation of the cortex circumferentially.
Complete fractures can be classified as:
transverse: straight across the bone
oblique: oblique line acr...
Complex midfacial fractures consist of multiple facial fractures that cannot be classified as any of the defined complex facial fracture (e.g. Le Fort fracture, zygomaticomaxillary complex fracture, naso-orbital-ethmoid fracture).
A handy mnemonic to recall the complications of transverse and longitudinal petrous temporal bone fractures is:
listen carefully to something funny
listen carefully = longitudinal / conductive hearing loss
to something funny = transverse / sensorineural hearing loss and facial nerve...
Condylar process fractures are fractures of the condylar process of the mandible. The condylar process of the mandible is involved in around 30% of all mandibular fractures.
Condylar fractures are classified according to the location of the fracture and the direction displacement of the condyle...
Congenital insensitivity to pain (CIP) refers to group of rare hereditary sensory and autonomic neuropathies (HSANs) characterised by an inability to feel pain 1.
Although not clearly defined in the literature, CIP is not one specific diagnosis, but describes symptoms common to man...
The Cooke and Newman classification of periprosthetic hip fractures is a modification of the Bethea classification proposed several years earlier.
explosion type fracture, comminuted around the stem of the implant
the prosthesis is always loose and the fracture is inherently unstable
Coracoclavicular (CC) ligament injury is common with shoulder trauma. It is considered part of the spectrum of acromioclavicular joint injuries 2 and is not often an isolated injury. It is also often injured with clavicular fractures.
This injury is easy to miss, especially with presence of an...
Coracoid process fractures are an uncommon type of scapular fracture. They do not often occur in isolation and are often associated with acromial, clavicular, or scapular fracture, as well as humeral head dislocation.
In general, the coracoid process tends to fracture at its base and be minimal...
Costal cartilage fractures are fractures of the cartilage connecting the ribs anteriorly to the sternum.
There is little published data on costal cartilage fractures. Most reported cases are in males and resulted from blunt trauma or a fall 1-2.
In young ch...
The costal hook sign is a chest x-ray features seen in some cases of flail chest. It represents the rotation of a fractured rib along its long axis, something that is only possible if a second fracture is present along its length, even if the second fracture is not visible 1.
A coup-contrecoup injury is a term applied to head injuries and most often cerebral contusions and traumatic subarachnoid haemorrhage. It refers to the common pattern of injury whereby damage is located both at the site of impact (often less marked) and on the opposite side of the head to the po...
CT abdomen is an increasingly common investigation that is used to help make diagnoses of a broad range of pathologies. A CT abdomen in its simplest form is a CT from diaphragm to symphysis performed 60 seconds after pump-injection of iodinated contrast intro a peripheral vein. However, dependin...
The CT comma sign is a characteristic sign seen in head trauma. It is the presence of concurrent epidural and subdural haematomas, which gives the characteristic appearance of this sign as a "comma" shape.
CT cystography is a variation of the traditional fluoroscopic cystogram. Instead of anterograde opacification of the urinary collecting system (as with CT urography), contrast is instilled retrograde into the patient's bladder, and then the pelvis is imaged with CT.