Brachymetatarsia is a condition in which one of the five long bones of the foot (the metatarsals) is abnormally short, resulting in a shortened toe. This condition usually occurs in both feet (i.e., bilaterally) and in the fourth toe. If it affects more than one toe, the condition is called brachymetapody.
The most common cause of brachymetatarsia is when the growth plate of the bone stops growing too soon. This may be caused from trauma, infection or a genetic predisposition.
During Walking, The weight is normally distributed from the 5th toe to the 4th and so on until it reaches the 1st toe ( big toe). The weight and pressure gets distributed and transfered across the ball of the foot evenly. An abnormally short Metatarsal will disrupt this process . If there is a short 3rd metatarsal , this means that the weight goes from 5th to 4th and these to bones bear more weight than usual causing the pain and discomfort.
The treatment for brachymetatarsia is very limmited. Conservative treatment includes shoe modification ( more room in the toe box area) . Padding of the shoe to releive pain in the high pressure area . Orthosis may be used to distribute the weigh to other bones.
Surgical treatment is performed to lengthen the bone to its ideal lenght. This is done by surgically cutting the bone and either:
1. Grafting a bone between the two ends
2.Putting a device on the bone to lengthen the bone gradualy ( my preferred method).
I like the lengthening method because it give the surgeon more control of how much you can lengthen the bone. I usually have the patient lenghten the bone 1/2 mm a day which is done by turning a screw at home ( this process is totally pain free).
Problem with method #1: If the bone needs significant lengthening and the surgeon tries to graft a bone that is too long ,the tendons, arteries and veins might not cooperate and results can be loosing the blood supply to the bone and eventualy loosing the toe.