To study the long-term utility of transfer of the tibialis anterior
tendon to the heel in patients who have a myelomeningocele, we reviewed the
cases of twenty-five patients who had reached maturity. Forty-six transfers
had been performed in these patients, and all of the patients had been
followed for at least twelve years. At follow-up, four of the forty-six
transferred muscles were functioning in a foot that was plantigrade, eleven
were functioning but the foot had a persistent calcaneal deformity, and
seventeen transferred muscles had never functioned. Of the fourteen
remaining feet, eight had required a release of the transferred tendon
because of progressive equinus deformity after the transfer and six had a
minor degree of the same deformity but additional surgical treatment was
not deemed necessary for them. Patients who had been operated on after the
age of five years generally benefited more from the operation, in that
additional surgical procedures were not necessary and the transfer was
functional at the time of our review. Most of the patients in whom an
equinus deformity developed after the procedure were later found to have
spasticity in some of the muscles of the leg. It is likely that these
patients originally had unrecognized spasticity in the transferred
muscles.