Lateral column lengthening with calcaneocuboid fusion: range of motion in the triple joint complex.

Lengthening the lateral column of the foot has been shown to correct flatfoot deformity. In adults, however, lengthening leads to calcaneocuboid arthritis. Lateral column lengthening with calcaneocuboid fusion, which lengthens the lateral column of the foot and prevents calcaneocuboid arthritis, was investigated in a cadaver model to determine the remaining range of motion in the talonavicular and subtalar joints. Inversion/eversion motion was produced by tendon pulls and the range of motion was measured in three dimensions using a magnetic space tracker. After lateral column lengthening with calcaneocuboid fusion, 48% of talonavicular and 70% of subtalar joint range of motion were preserved. Analysis of the inversion and eversion ranges of motion suggests that the lengthening fusion limits eversion more than inversion. These findings demonstrate the need for clinical investigation of this procedure, which could preserve motion in the talonavicular and subtalar joints, correct deformity, and obviate calcaneocuboid arthritis.