Background: Congenital clubfoot (talipes equinovarus) is a common condition in pediatric orthopedic surgery. However, there is still disagreement over the best surgical approaches and age indications.

Methods: Surgical treatment was carried out by early operation, achieving dynamic muscle balance in 926 congenital clubfeet of 644 patients who had been followed up for 6 months to 33 years, with reference to unsuccessful treatment because of failure to achieve dynamic muscle balance. Muscle biopsy specimens were taken from the calf muscles in patients with congenital clubfoot for histochemical studies.

Results: Excellent and good results were achieved in 90.9% of the involved feet. Histochemical studies of calf muscle biopsy specimens showed hypertrophy and predominance of type I fibres, grouping of fibre types, and loss of fibre direction in the posteromedial muscles, but no evidence of active denervation and degeneration in the involved calf muscles.

Conclusions: Our findings support the theory of muscle imbalance in the etiology of congenital clubfoot. It is advocated that surgical treatment of congenital clubfoot be carried out immediately after 6 months of age by an operation achieving dynamic muscle balance for the maintenance of satisfactory correction and the 3rd cuneiform be the most appropriate site for a new insertion of transferred tendon.