For the evaluation of the result from McKay operation in the correction of rigid clubfoot, 71 patients (103 feet) were followed up postoperatively for 2 to 9 years. According to the criteria concerning the functional recovery of the foot, the external appearance of the foot after correction and the roentgenographic findings, the result was evaluated as excellent in 55 patients (78 feet), good in 11 patients (16 feet), fair in 5 patients (9 feet) and with no recurrence. It was considered that the favorable time for operation was when the child being 6 to 18 months old. In 7 patients (12 feet), there were morphological changes of the calcaneal and navicular bones in 12 feet, limitation of ankle movement in 9 patients and resultant flatfoot deformity in 5 patients (7 feet). The factors influencing the functional recovery of the foot and the relationship between the corrective result and the age of patient when the operation being given were discussed in details.
