An accessory navicular is a congenital anomaly in which the tuberosity of the navicular bone develops from a secondary ossification center.
An accessory navicular is a congenital anomaly in which the tuberosity of the navicular bone develops from a secondary ossification center. It is a relatively common anatomical variant, with an estimated incidence ranging from 2% to 14% in the population. While often asymptomatic, this condition can cause pain and functional issues in some individuals, particularly when associated with overuse, trauma, or footwear irritation.
The post focuses on patients who present with symptoms related to the accessory navicular. (A) Image of right foot showing localized erythema and swelling over the medial aspect of the right mid-foot (arrow) and (B) X-ray of right foot showing accessory navicular bone (circle)The accessory navicular, one of the most common accessory ossicles in the foot, can be classified into three anatomical types.
Type I is a small ossicle located within the distal fibers of the posterior tibialis tendon near its insertion on the navicular tuberosity. Type II, the most common form, consists of a larger fragment connected to the main navicular by a cartilaginous or fibrous synchondrosis. Type III appears as a cornuate-shaped bone or a partially fused enlargement of the navicular’s medial tuberosity.
"Genetic influence on accessory navicular bone in the foot: a Korean twin and family study." Twin Research and Human Genetics 20.3: 236-241.[/ref]Symptoms of an accessory navicular typically arise from tension, shearing, or compression forces transmitted through the posterior tibial tendon to the fibrocartilaginous interface, as well as from direct shoe pressure on the accessory bone. These symptoms often follow trauma, with studies showing that 74% of athletes and 39% of non-athletes report a preceding injury such as a twisting motion or abnormal midfoot biomechanics. Posterior tibial tendon pathology may also contribute.
Associated conditions include pes planus, though its relationship remains debated with reported incidences between 15% and 34%, as well as Achilles tendon and gastrocnemius contractures. Accessory navicular pain most commonly affects younger athletes, presenting as discomfort along the medial arch that worsens with walking, running, or training. Pain may be aggravated by direct shoe or cleat pressure and is often associated with trauma or sprain mechanisms, occurring in about 35% of cases.
If you are experiencing symptoms that may be related to accessory navicular syndrome, it is important to see a sports medicine physician. Early evaluation and treatment typically lead to better outcomes. Do not ignore pain or symptoms that are limiting your activity.
*This article is for educational purposes only and does not substitute for professional medical advice. Always consult a qualified healthcare provider.*
Connect with a doctor, physical therapist, or imaging center near you.
Find a Provider Near You →