What is Type 2 Naviculare?
Type II is a secondary ossification center of the navicular bone and is also referred to as “prehallux”, accounting for approximately 50-60% of accessory navicular bones. It is seen over the medial pole of the navicular bone at between nine and 11 years of age (3).
What is Type 3 OS Naviculare?
Type III, also known as cornuate or gorilliform navicular, is characterized by a very prominent navicular tuberosity resulting from bony fusion of the accessory ossification center with the tuberosity. Most cases are asymptomatic, but ANB may cause pain and tenderness in a small proportion (<1%).
What is a Naviculare?
Medical Definition of navicular (Entry 1 of 2) : a boat-shaped bone: a : the one of the seven tarsal bones of the human foot that is situated on the big-toe side between the talus and the cuneiform bones. — called also scaphoid.
How common is OS Naviculare?
However, these accessory ossicles can occasionally become fractured, dislocate or undergo degenerative changes, resulting in pain and reduced range of motion. The os naviculare is one of the most common accessory ossicles in the foot, and has been reported to be present in 4% to 21% of the population (1, 2, 3, 4).
What is a Type 1 accessory navicular?
Type I: is a sesamoid bone in the posterior tibialis tendon. There is a small gap of approximately 3mm or less between the sesamoid and the navicular. Type II: consists of an accessory bone, up to 1.2cm in diameter, where synchondrosis develops between it and the navicular.
What is os trigonum syndrome?
The Os Trigonum Syndrome refers to pain posterior of the ankle and reduced plantarflexion caused by “the nutcracker-phenomenon”. When an os trigonum is present, this accessory ossicle together with surrounding soft tissues can become wedged between the tibia, talus and calcaneus.
Is accessory navicular rare?
In summary, an accessory navicular is a fairly uncommon condition which is rarely symptomatic. Oftentimes nonsurgical treatment is successful. In the minority of cases, surgical intervention is required. Patients typically do very well with conservative and surgical treatment.
What is the extra bone in your ankle called?
Os Trigonum forms when one area of bone fails to fuse with the rest of the bone. during growth. In the ankle, this extra bone forms behind the talus bone. Approximately 1 in 5 of the general population has an Os Trigonum.
What is human navicular?
The navicular is an intermediate tarsal bone on the medial side of the foot, which articulates proximally with the talus. Distally it articulates with the three cuneiform bones. In some individuals it also articulates laterally with the cuboid. The tibialis posterior tendon inserts into the navicular bone.
What is distal navicular?
The foot is the region distal to the ankle and consists of three main parts: the tarsus, the metatarsus and the phalanges. However, in the tarsus there is also an intermediate bone interposed between the distal and proximal row on the medial side, referred to as the navicular bone.
Can you have 2 ankle bones?
The presence of an os trigonum in one or both feet is congenital (present at birth). It becomes evident during adolescence when one area of the talus does not fuse with the rest of the bone, creating a small extra bone. Only a small number of people have this extra bone.
Does accessory navicular syndrome go away?
What are the types of navicular bone?
Also known as Prehallux, Os Tibiale Externum and Navicular Secundum. Type II: consists of an accessory bone, up to 1.2cm in diameter, where synchondrosis develops between it and the navicular. Type III: is the fused accessory navicular resulting in a large cornuate shaped navicular.
What is a type 2 navicular?
Type II: consists of an accessory bone, up to 1.2cm in diameter, where synchondrosis develops between it and the navicular. Type III: is the fused accessory navicular resulting in a large cornuate shaped navicular. The navicular is an intermediate tarsal bone on the medial side of the foot, which articulates proximally with the talus.
What are the different types of navicular projections?
The accessory navicular has 3 morphologic types. (Grogan, Gasser et al. 1989) Type 1 is a small oval to round ossicle within the tendon of the TPT. Type 2 is a larger lateral projection from the medial aspect of the navicular with a clear separation from the base of the navicular. Type 3 is a connected “horn” shaped prominence.
What is an accessory navicular?
An accessory navicular is a large accessory ossicle that can be present adjacent to the medial side of the navicular bone.