Features of hindfoot 3D kinetics in flat foot in ankle-joint maximal dorsiflexion and plantarflexion

• Published in: Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 16; no. 5; pp. 638 - 643
• Main Authors: Imai, Kan, Ikoma, Kazuya, Maki, Masahiro, Kido, Masamitsu, Tsuji, Yoshiro, Takatori, Ryota, Kubo, Toshikazu, Tokunaga, Daisaku, Inoue, Nozomu
• Format: Journal Article
• Language: English
• Published: Japan Elsevier B.V 01.09.2011; Springer Japan; Springer Nature B.V
• Subjects: Adult; Ankle Joint - diagnostic imaging; Ankle Joint - physiopathology; Biomechanical Phenomena; Calcaneus - diagnostic imaging; Calcaneus - physiopathology; Female; Flatfoot - diagnostic imaging; Flatfoot - physiopathology; Humans; Imaging, Three-Dimensional - methods; Male; Medicine; Medicine & Public Health; Middle Aged; Original Article; Orthopedics; Range of Motion, Articular; Rheumatology; Talus - diagnostic imaging; Talus - physiopathology; Tomography, X-Ray Computed - methods; Talar Head; Segmental Motion; Deltoid Ligament; Talonavicular Joint; Navicular Bone
• ISSN: 0949-2658; 1436-2023
• DOI: 10.1007/s00776-011-0103-x

It is difficult to evaluate the kinematics of flat foot from 2D images, and no definitive methods have so far been established to diagnose flat foot. This study evaluated hindfoot kinetics through the progression of posterior tibial tendon dysfunction (PTTD) in patients with stages II and III PTTD flat foot compared with those in normal patients under dorsiflexion and plantarflexion conditions using 3D computed tomography (CT) reconstruction images. CT images were taken of 26 normal and 32 flat feet in neutral, plantarflexion, and dorsiflexion positions of the ankle joint, from which 3D virtual models were made of each hindfoot bone. The 3D bone motion of these models was calculated using volume merge methods in three major planes. Tibiotalar-joint motion in ankle-joint plantar-flexion became less plantarflexed (normal –41.2°, stage II –33.5°, stage III –25.3°) and less adducted (normal –13.9°, stage II –10.7°, stage III –5.6°) as the stage progressed. Talocalcaneal-joint motion in stage III became more plantarflexed (normal –0.8°, stage II –3.0°, stage III –8.7°) and more adducted (normal –0.3°, stage II –4.7°, stage III –10.3°) as the stage progressed. Talonavicular-joint motion in stage III became more plantarflexed (normal –7.2°, stage II –7.6°, stage III –14.9°) and more adducted (normal 1.0°, stage II –7.3°, stage III –17.9°) as the stage progressed. Tibiotalar-joint plantarflexion decreased and talocalcaneal and talonavicular-joint adduction increased in the maximal ankle-joint plantarflexion in stage II in comparison with normal cases. Tibiotalar-joint plantarflexion and adduction were decreased and of the talocalcaneal and talonavicular joints increased in stage III in comparison with stage II cases.