Articles
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16,923 results
Article
Ligamentum flavum
The ligamenta flava (singular: ligamentum flavum) are paired ligaments which run between adjacent laminae of the vertebral bodies and are present from C2/3 to the sacrum. Above the C2/3 level, the equivalent structures are known as the posterior atlanto-occipital membrane between the skull base ...
Article
Hockey stick sign (Creutzfeldt-Jakob disease)
The hockey stick sign refers to the hyperintense signal involving the head of the caudate and the putamen bilaterally on FLAIR, in cases of variant Creutzfeldt-Jakob disease, which has the shape of a hockey stick.
See also
pulvinar sign (Creutzfeldt-Jakob disease)
hockey stick sign (thyroid h...
Article
Popliteal artery
The popliteal artery is the direct continuation of the superficial femoral artery, at the point where it exits the adductor canal at the adductor hiatus, and passes into the popliteal fossa as the vessel courses posteriorly behind the knee.
Summary
origin: continuation of the superficial femor...
Article
Hemorrhagic transformation of ischemic stroke
Hemorrhagic transformation is a complication of cerebral ischemic stroke and can significantly worsen prognosis.
Terminology
The term hemorrhagic transformation is somewhat variably used and collectively refers to two different processes, which have different incidence, appearance and prognost...
Article
Hydrosalpinx
Hydrosalpinx is a descriptive term and refers to a fluid-filled dilatation of the fallopian tube. If the fluid is infected, i.e. pus, then it is a pyosalpinx; if bloody, then hematosalpinx.
Clinical presentation
Patients may be asymptomatic or may present with pelvic pain or infertility.
Path...
Article
Osteoid osteoma
Osteoid osteomas are benign bone-forming tumors that typically occur in children (particularly adolescents). They have a characteristic lucent nidus <1.5 or 2 cm and surrounding osteosclerotic reaction, which classically causes night pain that is relieved by the use of NSAIDs.
Epidemiology
Ost...
Article
Obesity
Obesity is defined as a body mass index (BMI) greater than or equal to 30 kg/m2. It is described as being a "modern epidemic" due to increased rates of metabolic syndrome and other complications in these patients, along with a high and increasing prevalence.
Terminology
Large body habitus is ...
Article
Tendinopathy
Tendinopathy has been defined as "persistent tendon pain and loss of function related to mechanical loading" 7 but is also used as a broad term used to describe any problem involving a tendon.
Epidemiology
The prevalence of tendinopathy in the general population is 2-5%. Active and sporting in...
Article
Calcaneal tendon
The calcaneal tendon, commonly known as the Achilles tendon, is the strongest and largest tendon of the human body. It is also one of the commonest tendons to become injured due to its high biomechanical load but poor vascularity 2.
Gross anatomy
The calcaneal tendon forms by the merging of fi...
Article
Paratenon
The paratenon is a membrane-like areolar structure consisting of loose connective tissue found around extraarticular tendons without a synovial sheath including Achilles tendon, quadriceps tendon, patella tendon, the distal biceps tendon, or the distal 1-2cm of the posterior tibial tendon. It al...
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Tenosynovitis
Tenosynovitis is a term describing the inflammation of the synovial membrane surrounding a tendon. It may be seen with or without tendinosis/tendinitis. The synovial membrane is part of a fluid-filled sheath that surrounds a tendon.
Clinical presentation
joint swelling
pain in the affected ar...
Article
Cartilage
Cartilage or cartilaginous tissue is a resilient and type of connective tissue of mesodermal origin that forms an integral part within the musculoskeletal system and as a structural component in other organs.
Cartilage can be generally classified into the following main types:
hyaline cartil...
Article
Cancellous bone
Cancellous, trabecular or spongy bone is one of the two macroscopic forms of bone, the other being cortical bone, and comprises 20% of skeletal mass.
Gross anatomy
Cancellous bone is located in the medullary cavity of bone, in particular tubular and short bones, and consists of dense trabecul...
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Cortical bone
The outer shell of compact bone is called cortical bone or cortex. It is formed by compact bone which is one of the two macroscopic forms of bone, the other being cancellous bone.
Gross anatomy
Cortical bone contains Haversian systems (osteons) which contain a central Haversian canal surround...
Article
Pathological fracture
Pathological fractures are fractures that occur in abnormal bone and occur spontaneously or following minor trauma that would not otherwise fracture biomechanically normal bone.
Terminology
The term pathological fracture is usually reserved for tumors, either benign or malignant, although it h...
Article
Periosteal reaction
Periosteal reaction is a nonspecific radiographic finding that indicates new bone formation in reaction to the abnormal stimulants. Periosteal reactions may be broadly characterized as benign or aggressive, or more specifically categorized by pattern.
Terminology
Periosteal reaction is the rec...
Article
Plexiform neurofibroma
Plexiform neurofibroma is an uncommon variant of neurofibroma, a benign tumor of peripheral nerves (WHO grade I), arising from a proliferation of all neural elements. Plexiform neurofibromas are essentially pathognomonic of neurofibromatosis type 1 (NF1). Unlike small sporadic localized neurofib...
Article
Split scar sign (rectal cancer response assessment)
The split scar sign has been described as a feature on rectal cancer MRI studies acquired following chemoradiotherapy. It is characterized by a high specificity and positive predictive value for a complete response 1. In a meta-analysis that observed an average complete response rate of 38%, the...
Article
Supratentorial lymphocytic inflammation with parenchymal perivascular enhancement responsive to steroids (SLIPPERS)
Supratentorial lymphocytic inflammation with parenchymal perivascular enhancement responsive to steroids (SLIPPERS) is a rare inflammatory disorder that shares pathoradiological similarities with chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPP...
Article
Aneurysmal bone cyst
Aneurysmal bone cysts (ABC) are benign expansile osteoclastic giant cell-rich bony neoplasms, composed of numerous blood-filled channels and cystic spaces 1.
ABC accounts for the 'A' in the popular mnemonic for lucent bone lesions FEGNOMASHIC.
Terminology
The terms 'giant cell reparative gran...