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Foot Bone or Joint Injury

Accessory Navicular (Os Naviculare)

Minute Read


Posted 9 months ago


Last updated: 04/03/2023


by James McCormack


The navicular bone is a wedge-shaped bone that sits in the foot’s medial arch and plays a vital role in the structural integrity of the foot’s arch. There are two ossification points on the navicular bone during childhood; in a small proportion of the population, these two points do not fuse. In these cases, a small piece of additional bone or cartilage remains, known as the accessory navicular bone or Os Naviculare. When the accessory navicular bone becomes irritated, it is known as Accessory Navicular Syndrome.


The symptoms of an accessory navicular syndrome are pain along the medial arch of the foot. There may be some mild localised swelling in the area, and it is tender to palpate the navicular bone with a visual bony prominence on the arch of the foot.

It can be painful when walking, running or standing for long periods, and there may be a throbbing sensation in the foot after use.


The causes of Accessory Navicular syndrome include having a flat foot, which places extra strain on the foot’s medial arch. Tight or ill-fitting footwear can lead to excess friction on the Os Naviculare, causing pain.

Repetitive foot overuse can cause navicular pain syndrome and a history of ankle sprains.

Ethnicity does play a role in this condition; there is a prevalence of accessory navicular syndrome of approximately 10% in the general public, while there is a prevalence of up to 45% in the Asian Population.

Classification of Accessory Navicular Syndrome


  • Type 1: A sesamoid bone is found in the Posterior Tibial tendon, 3mm or less from the Navicular.
  • Type 2: An accessory bone of up to 1.2mm that is attached to the navicular with hyaline cartilage.
  • Type 3: The accessory bone is fused to the navicular


If you have the symptoms of Accessory Navicular syndrome, your clinician will likely refer you for an x-ray in the initial instance, as this is an easily accessible and cheap form of imaging. If the diagnosis is confirmed on an x-ray, you may be referred for an MRI or Ultrasound scan to identify any swelling in the area or other soft tissue injuries.

Treatment for Accessory Navicular Syndrome

A Physical Therapist is in the best position to provide treatment for Accessory Navicular syndrome. Treatments such as taping, joint mobilization and massage can provide pain relief alongside home treatments such as resting, anti-inflammatories and icing.

A physical examination will identify muscular imbalances and weakness that can contribute to your pain, and a comprehensive programme of strengthening, balance and stretching exercises will be formed.

Footwear advice is essential as the correct shoe can provide significant pain relief alongside insoles and orthotics.

An injection may be required for symptoms that fail to settle with Physical Therapy, usually in the form of an ultrasound-guided corticosteroid injection. Depending on the consultant, 1-2 weeks in a walking boot may be recommended before recommencing Physical Therapy.

In a minimal number of cases, this treatment is unsuccessful, and surgery is required. Arthroscopic surgical excision of the accessory navicular is the most common form of surgery for this condition which has a high success rate.

Picture of Insoles for Accessory Navicular Syndrome

Physiotherapy with James McCormack

This is not medical advice. We recommend a consultation with a medical professional such as James McCormack. He offers Online Physiotherapy Appointments.

Related Article: Best Shoes for Accessory Navicular Syndrome

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