What is Brachymetatarsia?
Brachymetatarsia is a condition in which one of the bones in the front of the foot (metatarsals) is abnormally shorter than the others. Although it may affect any of the five metatarsals, the condition most commonly occurs in the fourth toe and is usually in both feet (bilaterally). Females are almost exclusively affected. If it affects more than one toe, the condition is called brachymetapody. Additionally, if it involves the first metatarsal, the condition is better known as Mortons Toe. .
Looking at the foot, it may appear that the fourth toe itself is shorter than the adjacent toes. Sometimes it may even appear as if the fourth toe is raised up, with the third and fifth toes touching each other below it.
Signs and Symptoms
The primary concern for most people with Brachymetatarsia is the toe’s appearance. Hiding their feet and avoiding being barefoot is common behaviour. Beyond the appearance, the shortened metatarsal may not contact the ground properly or carry its share of the person’s body weight. Consequently, the weight distribution of the ball of the foot can be altered and can cause pain and pressure calluses. Also, the shorten toe often sits higher up on the foot and can get irritated in shoes, making shoe selection difficult.
Causes of Brachymetatarsia
In most cases, brachymetatarsia results when the metatarsal growth plate closes too early. Once the growth plate closes, the bone can no longer grow. This can be caused by a genetic factor or by trauma to the foot at a young age which results in a metatarsal growth plate fracture.
Brachymetatarsia can also be related to several genetic conditions and syndromes which include:
- Aneuploidic anomalies
- Trisomy 21 / Down Syndrome
- Monosomy X / Turner syndrome
- other anomalies
- Albright’s syndrome
- Diastrophic dysplasia
Conservative Treatment of Brachymetatarsia
Treatment for brachymetatarsia is limited. The first treatment choice for most patients is non-surgical. Non-surgical treatment options include:
- Footwear Modification. Footwear that has extra depth to allow more room for the shortened toe.
- Padding. This can help protect the toe from pressure and friction from the top of the shoe, which may cause calluses, corns and ulcerations.
- Strapping and splinting. This can help maintain an ideal posture of the toe, to reduce the risk of pressure and friction.
- Orthotic therapy. Orthotics may be designed to relieve pressure under the other toes
Surgery for Brachymetatarsia
There are several types of toe lengthening procedures which can be performed for brachymetatarsia when conservative treatments have not resolved the issue. For metatarsals that only need to be lengthened up to 15 mm, single-stage lengthening procedures with a variety of biologic and synthetic implants can be used. Gradual lengthening procedures allow for greater length gain and natural lengthening of the soft tissues.