Reconstruction of the medial talonavicular joint in simulated flatfoot deformity.

BACKGROUND

Reconstructing the ligamentous constraints of the medial arch associated with adult acquired flatfoot deformity remains a challenge. The purpose of this study was to test the efficacy of several reconstruction techniques of the medial arch. We hypothesized that an anatomic reconstruction of the spring ligament complex would correct the deformity better than other techniques tested.

METHODS

Three reconstructions of the medial support structures were performed on each specimen to recreate the different lines of action and insertions of the medial ligamentous complex in 12 specimens with a simulated flatfoot deformity. Talonavicular and tibiocalcaneal (hindfoot) orientations were measured in the axial, sagittal, and coronal planes in the intact, flatfoot, and reconstructed conditions.

RESULTS

While each reconstruction technique corrected the deformity (P < .05), proximal fixation of the graft corrected the greatest amount of talonavicular deformity while also correcting hindfoot valgus (P < .05).

CONCLUSION

The fixation points and lines of action of a medial arch reconstruction have important implications on deformity correction in a flatfoot model. Despite its fidelity to the native structure, the anatomic spring ligament reconstruction provided the least amount of correction. These findings suggest that other ligamentous structures of the medial arch are critical in supporting the midfoot.

CLINICAL RELEVANCE: Reconstruction of the ligamentous supports of the medial arch might be able to correct substantial amounts of deformity without osseous procedures like calcaneal osteotomies or midfoot fusions.