Anteroposterior Translational Malalignment of Ankle Arthrodesis Alters Foot Biomechanics in Cadaveric Gait Simulation

Abstract

Tibiotalar arthrodesis is a common surgical treatment for end-stage ankle arthritis. Proper ankle alignment is important as malalignment can lead to complications that may require revision surgery. This study aimed to determine how anteroposterior (AP) translational malalignment of ankle arthrodesis affects distal foot joint kinematics and plantar pressure. Ankle arthrodesis was performed on ten cadaveric foot specimens using a custom fixture that could fuse the ankle neutrally and induce discrete malalignments (3, 6, and 9 mm) anteriorly and posteriorly. Gait was simulated under each alignment with a robotic gait simulator, and foot bone motion and plantar pressure were quantified. AP translational malalignment did not substantially affect plantar pressure or joint range of motion, but there were several significant differences in joint position throughout stance phase. Differences were seen in five joints (talocalcaneal, talonavicular, calcaneocuboid, fifth tarsometatarsal, and first metatarsophalangeal) and in the position of the first metatarsal relative to the talus. The most extreme effects occurred when the talus was displaced 6 mm or more posteriorly. In vivo, this may lead to aberrant joint loading, which could negatively impact patient outcomes.

Reconstruction of the Supple Flatfoot with the Concept of Planal Dominance

“…Bruce Sangeorzan, MD and colleagues only recently discussed the "forward movement of the talus" moving like a screw [6]. This factor of the talus sliding forward on the calcaneal facets correlates to radiographic findings that will be discussed.…”

Die Arthrodese des oberen Sprunggelenks und Rückfußes

“…Biomechanisch konnte gezeigt werden, dass eine anterior-posteriore Translation zu signifikanten Veränderungen in den angrenzenden Gelenken (talokalkaneal, talonavikular, kalkaneokuboidal, 5. tarsometatarsal und 1. tarsometatarsal) führt, insbesondere ab einer posterioren Translation des Talus von 6 mm [32].…”

Radiographic Sagittal Tibio-Talar Offset in Ankle Arthrodesis—Accuracy and Reliability of Measurements

“…Reliable measurement methods are therefore needed to objectively assess the tibio-talar alignment. Several studies focused on the sagittal alignment and tibio-talar offset in the native ankle joint, the arthritic ankle, and in total ankle replacement with regard to component placement [2,7,[11][12][13][14][15][16][17][18]. Literature on reliable measurement methods for fused ankles is scarce [3,[19][20][21].…”