A painful condition causing medial foot pain may be due to a painful accessory navicular. An accessory navicular is a large extra bone that is present adjacent to the medial side of the navicular. Most cases are asymptomatic but can be the cause of painful tendinosis due to the traction between the ossicle, the navicular and tibialis posterior tendon.
There are 3 types of accessory Navicular:
Type 1: Lies within the distal portion of the tibialis posterior tendon
Type 2: Connected to the navicular tuberosity by a layer of cartilage
Type 3: Fused to the navicular bone itself
The patient typically presents with medial foot pain located over the navicular tuberosity, when large it can protrude medially and rub against footwear. The pain can be aggravated by walking, running and any weight-bearing activities. When acute there can be localised erythema and oedema and severe pain.
Acute pain is managed with immobilisation of the foot for 2-3 weeks duration in a cam boot. After this, adequate support for the foot especially during growth is recommended with appropriate footwear and orthotic therapy.
An accessory navicular can be seen on a plane film x-ray, best seen on a lateral-oblique view. However, when acutely symptomatic an MRI is best to review whether bone marrow oedema is present.
Research reports that an accessory navicular occurs in about 10% of the population. More common in females and typically first appears in adolescence. This has been our experience with the cases in the clinic being females between the ages of 11-14 when first presenting.
Sure Step Podiatry are well placed to manage this condition as we keep cam boots in stock and specialise in the after care of orthotic therapy and footwear advice.
Accessory navicular: Radiopedia by Mostafa El-Feky and A. Prof Frank Gailard
The painful asseccory navicular Lawson, J.P., Ogden, J.A., Sella, E. et al. Skeletal Radiol (1984) 12: 250. httpsContact Us Today