1. In congenital absence of the fibula, the fibrous strip that replaces the bone, abnormal insertions of fibular muscles, and disturbances in the formation and growth of the tarsal bones all go to cause the valgus deformity of the foot and the complete or partial dislocation of the talo-tibial joint.

2. Conservative treatment is justified only for children less than a year old and then only as preparation for operation.

3. Between the second and seventh year of life operations upon the soft tissues are indicated, to eliminate the contractures occurring on the posterior and lateral sides, to restore the proper position of the foot in line with the axis of the tibia, and to restore the normal shape of the foot and muscular equilibrium. At the same time favourable conditions are created for operative reconstruction of the lateral malleolus.

4. Arthrodesis of the talo-tibial joint or reconstruction of the lateral malleolus by a bone graft with the aim of stabilising the foot in the axis of tibia is not advisable in the growing limb.

5. The results obtained in three cases described support the conclusion that the bifurcation operation recommended by Gruca produces a new lateral malleolus with an epiphysis that grows at the same rate as the remainder of the lower epiphysis of the tibia, does not affect the rate of growth of the tibial epiphysis, prevents the recurrence of the deformity, and preserves the mobility of the talo-tibial joint.

6. In early cases this reconstructive operation may be done at the same time as soft-tissue deformities are corrected and subluxation reduced.

7. It is probable that the bifurcation operation should be done on children aged between two and seven years in order to give the limb the best chance to develop normally.