Malformation of the toes in infancy and early childhood are rarely symptomatic. The complaints of parents are more cosmetic in nature. However, as the child matures these deformities progress from a flexible deformity to a rigid deformity and become progressively symptomatic. Many of these deformities are unresponsive to conservative treatment. Common digital deformities are underlapping toes, overlapping toes, flexed or contracted toes and mallet toes. Quite often a prolonged course of digital splitting and exercises may be recommended but generally with minimal gain. As the deformity becomes more rigid surgery will most likely be required if correction of the deformity is the goal.
Underlapping toes are commonly seen in the adult and pediatric population. The toes most often involved are the fourth and fifth toes. A special form of underlaping toes is called clinodactyly or congenital curly toes. Clinodactyly is fairly common and follows a familial pattern. One or more toes may be involved with toes three, four, and five of both feet being most commonly affected.
The exact cause of the deformity is unclear. A possible etiology is an imbalance in muscle strength of the small muscles of the foot. This is aggravated by a subtle abnormality in the orientation on the joints in the foot just below the ankle joint called the subtalar joint. This results in an abnormal pull of the ligaments in the toes causing them to curl. With weight bearing the deformity is increased and a folding or curling of the toes results in the formation of callus on the outside margin of the end of the toe. Tight fitting shoes can aggravate the condition.
The age of the patient, degree of the deformity and symptoms determine treatment. If symptoms are minimal, a wait and see approach is often the best bet. When treatment is indicated the degree of deformity determines the level of correction. When the deformity is flexible in nature a simple release of the tendon in the bottom of the toe will allow for straightening of the toe. If the deformity is rigid in nature then removal of a small portion of the bone in the toe may be necessary. Both of these procedures are common in the adult patient for the correction of hammertoe deformity. If skin contracture is present a derotational skin plasy may be required.