Extra bone fragment on the metatarsal bone

Accessory navicular bone syndrome, also known as navicular syndrome or os tibiale externum, is a condition in which an extra piece of bone grows on the navicular bone in the arch of the foot; this occurs during embryonic development. This metatarsal bone is located on the inner side of the arch of the foot (the part that protrudes the most). This protrusion can frequently cause symptoms; it often affects adults, 80 per cent of whom are women.

The symptoms usually worsen after (sporting) activity or may be caused by an injury. You feel the pain on the inside of your foot.

Treatment depends on the cause and duration of the symptoms. The focus is on pain relief and increasing activity and participation. A temporary supportive therapy may be applied in the form of felt therapy, whereby the painful area is positioned within the shoe so that it is relieved of pressure. Taping can be used to provide temporary corrective therapy that stabilises the foot under load. Where there is an incorrect foot position, corrective podiatric insoles can be made. In addition, advice on (sports) footwear is provided. Shoe modifications may also be possible, such as reshaping or stretching the shoe on the spot.

The expected outcome is freedom from symptoms. If the above treatments do not help, you should consider surgery.