Triradiate cartilage

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Triradiate cartilage
Acetabulum (model).jpg
The acetabulum
Anatomical terminology

The triradiate cartilage (in Latin cartilago ypsiloformis) is the 'Y'-shaped epiphyseal plate between the ilium, ischium and pubis to form the acetabulum of the os coxae.


Human development

In children, the triradiate cartilage closes at an approximate bone age of 12 years for girls and 14 years for boys. [1]

Clinical use

Evaluating the position of the triradiate cartilage on an AP radiograph of the pelvis with both Perkin's line and Hilgenreiner's line can help establish a diagnosis of developmental dysplasia of the hip.

Related Research Articles

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Larynx Voice box, an organ in the neck of amphibians, reptiles, and mammals

The larynx, commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about 4–5 centimeters in diameter. The larynx houses the vocal cords, and manipulates pitch and volume, which is essential for phonation. It is situated just below where the tract of the pharynx splits into the trachea and the esophagus. The word larynx comes from a similar Ancient Greek word.

Cartilage Resilient and smooth elastic tissue in animals

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The acetabulum is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint.

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Coxa vara Medical condition

Coxa vara is a deformity of the hip, whereby the angle between the head and the shaft of the femur is reduced to less than 120 degrees. This results in the leg being shortened and the development of a limp. It may be congenital and is commonly caused by injury, such as a fracture. It can also occur when the bone tissue in the neck of the femur is softer than normal, causing it to bend under the weight of the body. This may either be congenital or the result of a bone disorder. The most common cause of coxa vara is either congenital or developmental. Other common causes include metabolic bone diseases, post-Perthes deformity, osteomyelitis, and post traumatic. Shepherd's Crook deformity is a severe form of coxa vara where the proximal femur is severely deformed with a reduction in the neck shaft angle beyond 90 degrees. It is most commonly a sequela of osteogenesis imperfecta, Pagets disease, osteomyelitis, tumour and tumour-like conditions.

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Epiphyseal plate

The epiphyseal plate is a hyaline cartilage plate in the metaphysis at each end of a long bone. It is the part of a long bone where new bone growth takes place; that is, the whole bone is alive, with maintenance remodeling throughout its existing bone tissue, but the growth plate is the place where the long bone grows longer.

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In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone of the skull. It is connected to the temporal bones by the temporomandibular joints.

Hilgenreiner's line is a horizontal line drawn on an AP radiograph of the pelvis running between the inferior aspects of both triradiate cartilages of the acetabulums. It is named for Heinrich Hilgenreiner.

Perkin's line is a line drawn on an AP radiograph of the pelvis perpendicular to Hilgenreiner's line at the lateral aspects of the triradiate cartilage of the acetabulum.

X-rays of hip dysplasia are one of the two main methods of medical imaging to diagnose hip dysplasia, the other one being medical ultrasonography. Ultrasound imaging yields better results defining the anatomy until the cartilage is ossified. When the infant is around 3 months old a clear roentgenographic image can be achieved. Unfortunately the time the joint gives a good x-ray image is also the point at which nonsurgical treatment methods cease to give good results.


  1. Dimeglio, A (2001). "Growth in Pediatric Orthopaedics". J Pediatr Orthop. 21 (4): 549–555. doi:10.1097/01241398-200107000-00026. PMID   11433174.

See also