Review of Pedal Macrodactyly
Macro means larger than what is considered normal; pedal macrodactyly is a condition where the toe on a foot is growing more quickly than the other normally growing toes. It is a rare congenital disease, which means that you are born with it, although it doesn't seem to run in families. Because the toe is larger than the others, it has extra fibrous fatty tissue on the bottom (the plantar part of the toe, causing it to curl upwards, the dorsal or top. The authors of this article reviewed previous case reports to better understand the etiology or cause of the disease.
Macrodactyly falls into one of two types: static or progressive, the most common type. Patients with static macrodactyly have larger toes (or toe) when they are born. It then continues to grow proportionally to the other toes. The other type, progressive, the toe grows faster than it should, given the growth pattern of the child. The condition seems to affect slightly more boys than girls, and it can occur on one foot only, on both feet, and it can be symmetrical or asymmetrical. Macrodacytly isn't necessarily associated with any other type of deformity, although it can be found in people with some types of syndromes, such as Proteus syndrome, Banayan-Riley-Ruvalcabe, Maffuccin, Ollier's disease, and Milroy's disease.
Although the cause of macrocactyly isn't known, there are theories, which include one hypothesis of a defect in a cell that causes certain areas of the body to become supersensitive to growth. Another theory is that it may be caused by an interaction of genetic and environmental factors. There may be hemangiomas, which are benign (noncancerous) tumors made of a mass of blood vessels. These may also cause enlargement of the toes. Another cause could be damage in the nerves, causing rapid overgrowth of the area.
When the affected toes of children are examined, it is seen that the subcutaneous fat, the fat just below the skin, looks like adult fat, not a child's. As well, all the elements of the toe are larger (the tendons, nerves, blood vessels, fat, nails, skin and the bones in the toe. The exception is the bone in the foot that goes to the affected toe is not larger than normal. The skin on the affected toe is thicker than normal and the toe feels rubbery and soft.
Treatment for the disorder depends on several issues, particularly, if the toe or toes are causing pain or disability. If surgery needs to be done, the surgeon could destroy the growth part of the bone, along with removing as much as the excess tissue as is possible. This part, however, called defatting, is done in a two-step process. The first step involves reducing the thickness on the convex side of the toe by 10 to 20 percent. The second step involves doing the same to the other side, and shortening the bone and removing excess skin. Amputation could be considered, but this is not common and is usually only used as a last resort. As well, amputations of the smaller toes do not seem to have as big an effect on the foot as with the larger toes, so this is also taken into consideration.
In one case presented by the article's authors, a three-year-old had an affected fourth toe. The parents wanted to make the foot more normal-looking and to allow for wearing appropriate shoes. The surgeon removed a large piece of full-thickness skin and subcutaneous tissue. A k-wire was inserted to stabilize the toe. The child wore a walking cast for six weeks and there were no reports of complications. Although the surgery was a success, there will likely be more in the future.
In the second case, a 24-year-old patient wanted surgery to correct the look of her second toe and the practicality of no longer having to buy two different sized shoes, one in a larger size for the affected foot. She had no problems with mobility and was able to run and walk without pain or difficulty. Although the toe had been affected since she was a toddler, her parents did not seek treatment.
The affected toe was 15 mm longer and 15 mm thicker than the same toe on the opposite foot. Since the toe wasn't causing any physical problems, the surgeon used a nail graft after removing some of the bone and also removed some of the subcutaneous tissue. This was chosen over an amputation because it would leave the patient with a normal looking toe, while an amputation wouldn't.
The authors concluded that the number of people affected by this condition is unknown, but it is found more often in males. The cause of macrodactyly is unknown and treatment varies according to which toe is affected, what the surgeon prefers to do and what - if any - problems are being caused by the enlargement.
Ellise Natividad, DPM Candidate and Kinna Patel, DPM Candidate. A Literature Review of Pedal Macrodactyly. In The Foot and Ankle Online Journal. May 2010.