Adductus of the forefoot is the most common foot deformity. It is characterized by a convexity to the lateral aspect of the foot or a dynamic abduction of the great toe. The deformities fall into four categories.
Metatarsus adductus is a common intrauterine positional deformity. Because it is associated with hip dysplasia in 2% of cases, a careful hip evaluation is essential. Metatarsus adductus is common, flexible, benign, and resolves spontaneously.
Metatarsus varus does not produce disability and does not cause bunions, but it does produce cosmetic and occasionally shoe-fitting problems.
Skewfoot is discussed on the next page.
Great toe abduction is a dynamic deformity due to overactivity of the great toe abductor. It is sometimes called a “searching toe.” The condition improves spontaneously. No treatment is required.
Evaluate by performing a screening examination, test for stiffness, and consider the child’s age. Manage metatarsus adductus by documentation and observation.
Manage metatarsus varus by serial casting or bracing. Long-leg bracing is useful in the toddler. Serial casting is most effective. The deformity yields much more rapidly when the cast is extended above the flexed knee.
The following technique is useful to about age 5 years. Apply a short-leg cast first. As the cast sets, mold the forefoot into abduction and the hindfoot in slight varus-inversion. Finally, while holding the short-leg cast in neutral rotation and with the knee flexed about 30°, extend the cast to include the thigh. This long-leg cast allows both walking and effective correction.
In the older child, it may be best to accept the deformity, as it does not cause disability. If operative correction is selected, correct by opening wedge cuneiform and closing wedge cuboid osteotomies. Avoid attempting correction by capsulotomy or metatarsal osteotomies, as early and late complications are frequent.