Items tagged “bone”
27 results found
Article
Os acromiale
Os acromiale is an anatomical variant and represents an unfused accessory center of ossification of the acromion of the scapula.
Epidemiology
Os acromiale is relatively common, seen in ~8% (range 1-15%) of the population 1,2 and can be bilateral in 60% of individuals 5.
Clinical presentation
...
Article
Os odontoideum
Os odontoideum (plural: ossa odontoidea) is an anatomic variant of the odontoid process of C2 and needs to be differentiated from persistent ossiculum terminale and from a type 2 odontoid fracture. It can be associated with atlantoaxial instability.
Although it was originally thought to be a c...
Article
Accessory navicular
An accessory navicular is a large accessory ossicle that can be present adjacent to the medial side of the navicular bone. The tibialis posterior tendon often inserts with a broad attachment into the ossicle. Most cases are asymptomatic but in a small proportion, it may cause painful tendinosis ...
Article
Acetabular foramen
The acetabular foramen is formed by the bony margins of the acetabular notch and completed by the transverse ligament of the hip. From its margins (both transverse ligament and acetabular notch) arises the ligamentum teres. Through it pass nutrient vessels to the femoral head epiphysis.
Article
Fluid-fluid level containing bone lesions
Fluid-fluid level containing bone lesions are best seen on MRI, although with narrow window width they can also be appreciated on CT.
Epidemiology
Their prevalence is estimated at ~3% of bone and soft tissue tumors 1.
Differential diagnosis
Their presence is non-specific, as they are seen in...
Article
Os peroneum
An os peroneum is a small accessory bone of the foot located at the lateral aspect of the cuboid within the substance of the fibularis longus tendon as it arches around the cuboid.
Epidemiology
It is a very common anatomical variant, seen in up to 26% of feet 1.
Differential diagnosis
It sho...
Article
Os trigonum
The os trigonum (plural: ossa trigona) is one of the ossicles of the foot and can be mistaken for a fracture.
It sits posterior to the talus on the lateral foot radiograph and represents a failure of fusion of the lateral tubercle of the posterior process. It is estimated to be present in ~7% ...
Article
Os calcaneus secundarius
An os calcaneus secundarius is an accessory ossicle of the anterior calcaneal process present in up to 5% of the population at cadaveric examination. The ossicle can be a cause of ankle pain and may mimic bifurcate ligament avulsion fracture of the anterior calcaneal process.
Differential diagn...
Article
Bipartite patella
A bipartite patella (two-part patella) is a patella with an unfused accessory ossification center, typically at the superolateral aspect.
Epidemiology
The superolateral accessory ossification center of the patella is usually present by 12 years of age and may persist into adult life. Bipartite...
Article
Bone island
Bone islands, previously known as enostoses, are common benign sclerotic bone lesions that usually represent an incidental finding. When occurring in the head they are called osteomas. Bone islands are considered one of the skeletal “don’t touch” lesions.
Terminology
Enostosis is not a recomme...
Article
Accessory sutures
The parietal and occipital bones in particular are common regions for accessory sutures because of their multiple ossification centers.
It is important to know these anatomic variations, mainly on the head trauma image studies in children, where it could be difficult to differentiate non-depres...
Article
Os subfibulare
Os subfibulare is an accessory ossicle that lies at the tip of the lateral malleolus of the ankle and is rarely reported 1.
Clinical presentation
Os subfibulare are usually asymptomatic although they may eventually cause painful syndromes or degenerative change in response to overuse and traum...
Article
Os subtibiale
An os subtibiale is a rare, genuine accessory ossicle and normal variant related to the posterior colliculus of the medial malleolus 1. It is present in ~1% of the population 5.
Clinical presentation
They usually are asymptomatic although they may eventually cause painful syndromes or degener...
Article
Accessory superior acetabular notch
An accessory superior acetabular notch is a normal variant of the acetabulum, which can be seen on radiographs. It may lead to diagnostic confusion, especially in younger patients.
Radiographic features
MRI
appear as bilateral symmetric fluid-filled pits in the roof of the acetabulum with sh...
Article
Os hamuli proprium
The hook of the hamate has its own ossification center, which may fail to fuse with the body of the hamate, creating an ossicle. This ossicle is referred to as an os hamuli proprium or unfused hamulus
In some instances, this can be difficult to distinguish from a fracture of the hook, but is s...
Article
Accessory ossicles of the wrist (mnemonic)
The accessory ossicles of the wrist can be easily recalled with the mnemonics:
LOTTEO 1
HOTELS
Mnemonics
LOTTEO
L: lunula
O: os styloideum (carpal boss)
T: (os) triangulare
T: (os) trapezium secondarium
E: (os) epilunate
O: os hamuli proprium
HOTELS
H: (os) hamuli proprium
O: os tri...
Article
Accessory ossicles of the wrist
Accessory ossicles of the wrist are commonly seen on plain radiographs of the wrist and associated cross-sectional imaging. Over 20 were originally described 2, although the more common include 1:
lunula: between TFCC and triquetrum
os styloideum (carpal boss): on dorsal surface of 2nd or 3rd ...
Article
Multipartite hallux sesamoid
Multipartite hallux sesamoids are a commonly seen normal variant, present in up to 33% of hallux sesamoids. They are more commonly bipartite than tripartite.
The medial (tibial) sesamoid is more likely to be multipartite than the lateral (fibular) sesamoid because it more commonly has more tha...
Article
Angiosarcoma (bone)
Angiosarcoma of bone is a malignant vascular bone tumor. These are rare and account for <1% of malignant bone tumors. The majority of these tumors arising in bone are primary; however, a tiny percentage are either radiation-induced or associated with bone infarction.
Epidemiology
Most common i...
Article
Tumors that metastasize to bone (mnemonic)
Tumors that metastasize to bone may be remembered using the mnemonic "PBKTL", rendered as "lead kettle", as "Pb" is the standard abbreviation for the chemical element, lead.
PB-KTL
Mnemonic
P: prostate
B: breast
K: kidney
T: thyroid
L: lung
For females, breast and lung are the most commo...
Unable to process the form. Check for errors and try again.