Effect of graft shape in lateral column lengthening on tarsal bone position and subtalar and talonavicular contact pressure in a cadaveric flatfoot model.

Lateral column lengthening (LCL) has been used for correction of flatfoot deformity. The purpose of this study was to determine the effect of LCL graft shape on tarsal bone position and talonavicular and subtalar joint pressure. A flatfoot model was created in 6 cadaveric specimens. Corrective LCL was performed using a rectangular graft or a trapezoidal graft with the broad surface oriented dorsally, laterally, or plantarly. Bony surface markers were digitized to calculate angular parameters used in the evaluation of flatfoot deformity. Contact pressure and area in the subtalar and talonavicular joints were also recorded. All measurements were carried out under multiple axial loads in the intact and flatfoot conditions, and following LCL with each graft shape. Flatfoot creation resulted in significant changes in arch collapse and forefoot abduction. LCL with a rectangular graft best corrected these parameters, while a laterally oriented trapezoidal graft provided some correction. Talonavicular contact pressure was unchanged after flatfoot creation, and was significantly less than intact after LCL. Subtalar contact pressure decreased in some conditions after flatfoot creation, and decreased further after LCL. LCL with a rectangular graft best restored tarsal bone orientation in a cadaveric flatfoot model. The decreases in talonavicular pressure likely represent redistribution of force from the medial to lateral foot. When performing LCL for flatfoot deformity, increased bone graft volume medially better restores tarsal bone position. One way of achieving this is through the use of a rectangular graft as opposed to a trapezoidal graft.

Campbell ST ，Reese KA ，Ross SD ，McGarry MH ，Leba TB ，Lee TQ ... -  《-》

Sensitivity of plantar pressure and talonavicular alignment to lateral column lengthening in flatfoot reconstruction.

Oh I ，Imhauser C ，Choi D ，Williams B ，Ellis S ，Deland J ... -  《-》

Graft shape affects midfoot correction and forefoot loading mechanics in lateral column lengthening osteotomies.

Adult acquired flatfoot deformity is characterized by midfoot abduction and collapse of the medial longitudinal arch. Lateral column lengthening osteotomies primarily correct the abduction deformity, but the effects of graft shape on deformity correction and forefoot loading are unclear. Therefore, the purpose of this study was to demonstrate the effect of graft shape and taper on deformity correction and forefoot loading mechanics in a cadaveric flatfoot model. Flatfoot deformity was simulated in 18 cadaveric specimens. A lateral column lengthening osteotomy was performed using a triangular, trapezoidal, and rectangular graft for each specimen. During each testing condition, talonavicular joint angles and forefoot plantar pressures were measured. Each graft shape corrected abduction and dorsiflexion deformity at the talonavicular joint. Coronal plane correction was affected by graft shape, and the less tapered trapezoidal and rectangular grafts overloaded the lateral forefoot compared to the intact condition. The more tapered triangular graft did not cause a lateral shift in forefoot pressures. Forefoot plantar pressures were strongly correlated with talonavicular abduction correction (R (2) = .473, P < .001). Graft shape had no effect on the correction of talonavicular abduction or dorsiflexion but did influence coronal plane motion and forefoot loading mechanics. Also, overcorrecting the abduction deformity was predictive of increased lateral plantar pressures. Although overcorrection of the abduction deformity at the midfoot remains the primary determinant of lateral forefoot overload, utilizing a graft with a larger taper may lower the incidence of lateralized forefoot pressure following correction.

Baxter JR ，Demetracopoulos CA ，Prado MP ，Gilbert SL ，Tharmviboonsri T ，Deland JT ... -  《-》

Lateral column calcaneal lengthening, flexor digitorum longus transfer, and opening wedge medial cuneiform osteotomy for flexible flatfoot: a biomechanical study.

Benthien RA ，Parks BG ，Guyton GP ，Schon LC ... -  《FOOT & ANKLE INTERNATIONAL》

Biomechanical Analysis of Cuboid Osteotomy Lateral Column Lengthening for Stage II B Adult-Acquired Flatfoot Deformity: A Cadaveric Study.

Zhou H ，Ren H ，Li C ，Xia J ，Yu G ，Yang Y ... -  《-》