SELECTIVE HINDFOOT ARTHRODESIS FOR THE TREATMENT OF ADULT ACQUIRED FLATFOOT DEFORMITY - AN IN-VITRO STUDY

An acquired flatfoot deformity with significant laxity at the transver se tarsal joint was created experimentally and the amount of correctio n that was obtained with selective hindfoot fusions was measured radio graphically. Results showed that the talonavicular, double (talonavicu lar and calcaneocuboid), and triple arthrodeses were able to fully cor rect the deformity, including correction of hindfoot valgus with just a talonavicular fusion, Subtalar and calcaneocuboid fusions failed to completely correct the deformity. This study provides experimental evi dence that although the triple joints are interconnected, they differ with respect to their ability to correct malalignment. We conclude tha t talonavicular or double arthrodesis will correct deformity in a flat foot with considerable laxity through the transverse tarsal joint, but that a subtalar fusion will not provide consistent correction.