Accessory Navicular Syndrome

Accessory navicular syndrome involves an extra piece of either cartilage or bone located on the medial side of the foot, on the navicular bone. The accessory navicular articulates with the navicular bone, while the navicular bone articulates with numerous bony structures. It articulates posteriorly with the talus, anteriorly with the cuneiform bones, and laterally with the cuboid bone. The joint associated with accessory navicuar syndrome is the talonavicular joint (Panchbhavi, V. K., 2015, December 11). The muscle involved in accessory navicular syndrome is the tibialis posterior, which originates on the upper half of the posterior shaft of the tibia and the upper half of the fibula between the medial nerve crest and the interosseous border.
The syndrome is congenital, meaning that the individual develops the bone or cartilage at birth (D'amico J., 2016, September). Pain may arise due to trauma to the ankle or foot. It is common for pain and other symptoms to appear in adolescence. Sometimes, however, the symptoms do not occur until adulthood. A patient with accessory navicular syndrome will have a visible bony prominence on the midfoot that is located on the navicular bone. The bony prominence may have redness and swelling that is associated with it, mainly due to friction from footwear. They may complain of vague pain or throbbing in the midfoot and arch that usually occurs during or after periods of activity. The patient may complain of mid food or arch pain, which may be apparent with or without trauma, pes planus, an inflamed bursa, complain of difficulty with footwear, have a tenderness over the prominence, and pain over the posterior tibialis tendon due to tendinitis and tightness of the tendoachillis in long standing cases (D'amico J., 2016,
The talonavicular, cuneiform, first metatarsal, and dorsal lalignment should be carefully palpated. (Buchanan, M., 2016, June 7). In order to determine the type of accessory navicular, one must palpate to determine the size of the accessory bone and to determine if it is attached or not. Differentiation of navicular prominence from talar head prominence in flat foot deformity is differentiated by palpating over the navicular bone while inverting and everting through the subtalar joint (Buchanan, M., 2016, June 7). Range of motion may be decreased and may cause pain when plantar flexion and inverting the foot. The patient would receive the tibialis posterior manual muscle test, while also using the navicular drop test to assess for flat foot (Accessory navicular, 2010). When palpating, an athletic trainer may be able to determine the type of determine what type of accessory navicular syndrome the patient has, type I is a sesamoid bone that is imbedded into the tendon and is less than 3mm, type II is a triangular ossification between 8 and 12mm and connected by a sysostosis, and type III is connected to the navicular and is an enlarged medial horn. (Accessory navicular,