Diego H. Zanolli,Richard R. Glisson,James A. Nunley,Mark E. Easley

Background:  

Options for surgical correction of acquired flexible flatfoot deformity involve bone and soft-tissue reconstruction. We used an advanced cadaver model to evaluate the ability of key surgical procedures to correct the deformity and to resist subsequent loss of correction.

Methods:  

Stage-IIB flatfoot deformity was created in ten cadaver feet through ligament sectioning and repetitive loading. Six corrective procedures were evaluated: (1) lateral column lengthening, (2) medial displacement calcaneal osteotomy with flexor digitorum longus transfer, (3) Treatment 2 plus lateral column lengthening, (4) Treatment 3 plus “pants-over-vest” spring ligament repair, (5) Treatment 3 plus spring ligament repair with use of the distal posterior tibialis stump, and (6) Treatment 3 plus spring ligament repair with suture and anchor. Correction of metatarsal dorsiflexion and of navicular eversion were quantified initially and periodically during postoperative cyclic loading.

Results:  

Metatarsal dorsiflexion induced by arch flattening was initially corrected by 5.5° to 10.6°, depending on the procedure. Navicular eversion was initially reduced by 2.1° to 7.7°. The correction afforded by Treatments 1, 3, 4, 5, and 6 exceeded that of Treatment 2 initially and throughout postoperative loading. Inclusion of spring ligament repair did not significantly enhance correction.

Conclusions:  

Under the tested conditions, medial displacement calcaneal osteotomy with flexor digitorum longus tendon transfer was inferior to the other evaluated treatments for stage-IIB deformity. Procedures incorporating lateral column lengthening provided the most sagittal and coronal midfoot deformity correction. Addition of spring ligament repair to a combination of these three procedures did not substantially improve correction.