Three-dimensional motions of distal syndesmosis during walking.
BACKGROUND
The motion of the distal syndesmosis correlates highly with the instability, while an accurate kinematic description of the distal tibiofibular joint during normal gait has not previously been presented.


METHODS
Sixteen healthy syndesmoses of sixteen living subjects (8 male and 8 female) were studied during stance phase of the normal gait. Data of CT scanning were collected first and used to create the 3D models of the distal tibia and fibula. The lateral X-ray images of the syndesmosis were captured by fluoroscopy when the subject was walking. Seven key-pose images were selected for subsequent 3D to 2D bone model registration and six degrees-of-freedom (DOF) motions of syndesmosis were then calculated. A validation experiment was also conducted to confirm the accuracy of the 3D/2D technique for the syndesmosis.


RESULTS
During the stance phase, the distal tibiofibular joint exhibited with 2.98 ± 1.10° of dorsi/plantarflexion, 5.94 ± 1.52° of inversion/eversion, and 5.99 ± 2.00° of internal/external rotation; 2.63 ± 1.05 mm on medial/lateral, 3.86 ± 1.65 mm on anterior/posterior, and 4.12 ± 1.53 mm on superior/inferior translation. From heel strike to mid-stance, the syndesmosis demonstrated 1.69° of dorsiflexion, 3.61° of eversion, and 3.95° of external rotation. Likewise, from mid-stance to heel-off, the syndesmosis presented 1.04° of plantarflexion, 4.95° of inversion, and 5.13° of internal rotation.


CONCLUSIONS
During the stance phase of normal gait, internal/external rotation and vertical motion play dominant roles in terms of rotation and translation, respectively.
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Chen
C
Wang
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Junsheng
J
Yang
Harvard Medical School, Boston, MA, USA.|Key Laboratory of Exercise and Health Science, Ministry of Education, Shanghai University of Sport, Shanghai, China.
Shaobai
S
Wang
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China. maxin@sh163.net.
Xin
X
Ma
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Xu
X
Wang
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Jiazhang
J
Huang
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Chao
C
Zhang
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Li
L
Chen
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Jian
J
Xu
Department of Orthopedics, Huashan Hospital, Fudan University, NO.12 Middle Wulumuqi Road, Jingan District, Shanghai, China.
Xiang
X
Geng
Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
Kan
K
Wang
D000328:Adult; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D001696:Biomechanical Phenomena; D005260:Female; D005360:Fibula / Q000000981:diagnostic imaging / Q000502:physiology*; D005471:Fluoroscopy / Q000379:methods; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology; D012399:Rotation; D013977:Tibia / Q000000981:diagnostic imaging / Q000502:physiology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016138:Walking / Q000502:physiology*; D055815:Young Adult