Treatment of subungual exostosis
A subungual exostosis is a bone spur that forms beneath the great toe nail. The spur is found equally in men and women and usually presents with an onset between the ages of 30 and 50 years of age. Diagnosis is made with a lateral x-ray of the foot that shows a pronounced bone spur on the dorsal, distal tip of the distal phalanx of the great toe.
The symptoms of a subungual bone spur include pain with direct pressure to the toe nail. A subungual bone spur is often difficult to differentiate from a chronic ingrown nail. A subungual exostosis presents with no swelling or redness and is typically diagnosed by placing direct pressure to the nail. A slight discoloration of the nail may be seen in severe cases where the nail bed has been disrupted.
The most common contributing factor to pain with a subungual exostosis is a tight toe box on the shoe. Hyperextension of the great toe at the interphalangeal joint may make the tip of the toe prone to rub against the toe box. Symptoms of a subungual exostosis may be improved or made worse by the type of shoe worn. For instance, steel-toed boots would contribute to the symptoms of a subungual exostosis while an open toe sandal would improve symptoms.
Conservative care of a subungual exostosis includes modification of shoes to avoid direct pressure to the toe. Padding can be used to cushion the toe. Examples of pads used to protect the toe include Gel toe Protectors, Lambs Wool, Foam Toe Caps, Gel Toe Caps or Tube Foam.
Surgical correction of a subungual exostosis includes filing down the spur (resection) and occasionally interphalangeal joint fusion.
Jeffrey A. Oster, DPM