19 Mar Brachymetatarsia
This condition refers to an abnormally shortened metatarsal bone. This is generally caused by a premature closure of the growth plate of the metatarsal. While the remaining metatarsals continue to grow at a normal rate, the affected bone will remain the same size. With time, this causes a visible difference in the appearance of the toes around the time of early puberty.
Most commonly, the fourth metatarsal is affected, resulting in a the appearance of a short forth toe.
Shortened fourth metatarsal
Tension Stress Effect
We owe a great deal of acknowledgment to the work done by the Russians regarding ground breaking work in the area of treating severe structural abnormalities utilizing a concept known as the the “tension stress effect.” This concept, developed by Dr. Ilizarov, focused on the bodies ability to “grow” new bone in a widening distraction gap under controlled mechanical means.
Mechanism of Action
Utilizing the these principles, it is possible to lengthen bones which are abnormally short and restore the appropriate length. In the forefoot this technique can be applied both to congenitally short bones as well as shortening due to surgical complications.
Elongated forth metatarsal
- Alleviate pain
- Restore a functional metatarsal parabola
- Establish a cosmetically acceptable foot
Proper communication between the podiatric surgeon and the patient is critical. The patient will play an active role in the surgical outcome and commitment to perform daily distraction is critical. Nicotine use has been shown to impede bone healing. Since this procedure involves a complex biological cascade of events with each step dependent on the preceding, smoking cessation is required.
A mini external fixator is place over the bone to be lengthened. A small surgical cut in the bone is performed. After 7-14 days, the patient will turn a tiny wheel on the mini fixator twice a day. Turning the wheel will slowly move the bone. The gap that is created will fill in with newly grown bone. The number of days required to distract the bone is dependent on the amount of lengthening required. For example, if the metatarsal needs to be lengthened 20 mm, it will take 40 days of lengthening (based on 0.5 mm per day).