Acquired flatfoot
Objectives- Discuss etiology(ies) for acquired flatfoot in children
- Discuss strategies for treatment of acquired flatfoot
The presence of an acquired flatfoot in a child warrants a thorough evaluation and search for an etilogy. Some conditions such as cerebral palsy, polio, and tarsal coalition, all associated with acquired flatfoot, have been discussed separately. Posterior tibial tendon dysfunction is a common cause of acquired flatfoot in the adult but rare in the child. Injury to the posterior tibial tendon can cause an acquired flatfoot in the child, manifested by the "toe many toes" test, a result of abduction of the foot. It has been noted that the toe flexors may substitute functionally for an injured posterior tibial tendon, but in this case, active dorsiflexion and plantarflexion of the toes cannot be performed when the foot is plantarflexed and inverted. There is some recent evidence that obesity may be associated with acquired flatfoot. Berg noted an increased number of flatfeet in infants who were treated with a Dennis Browne bar for metatarsus adductus. Whether orthotic misuse can produce a structural flatfoot has not been established. There has always been some suspicion that such a foot could result in use of twister cables for intoeing secondary to femoral anteversion; the foot being most subject to the external rotation forces would respond by abducting and pronating. Any neurologic imbalance favoring the foot evertors could produce an acquired flatfoot; the cavavarus foot is certainly much more associated with acquired neurologic dysfunction.
Obviously, the strategy of treatment must consider the underlying etiology. Spasticity, muscle imbalance, and contracture contribute to the deformity in the presence of cerebral palsy. If the foot is flexible, orthotic support may suffice; in older children with more fixed deformity, bony surgery is often necessary. The symptomatic rigid flatfoot associated with tarsal coalition is best treated by treatment of the coalition. Reconstructive procedures using a toe flexor have been effective for traumatic posterior tibial injury. Although the role of orthotics in production of the acquired flatfoot is still speculative, no harm can result from the judicious use of orthotics. If one only prescribes an orthotic when one can clearly articulate the objective of orthotic wear, iatrogenic orthotic mischief will be held to a minimum.
References
- Berg EE. A reappraisal of metatarsus adductus and skewfoot. Journal of Bone & Joint Surgery - American Volume 1986;68(8):1185-96.
- Citron N. Injury of the tibialis posterior tendon: a cause of acquired valgus foot in childhood. Injury 1985;16(9):610-2.
- Luhmann SJ, Rich MM, Schoenecker PL. Painful idiopathic rigid flatfoot in children and adolescents. Foot & Ankle International 2000;21(1):59-66.
- Sullivan JA. Pediatric flatfoot: evaluation and management. Journal of the American Academy of Orthopaedic Surgeons 1999;7(1):44-53.
May 16-19, 2012 in Denver, CO
