| In vivo 3D Kinematics of Axis of Rotation in Malunited Monteggia Fracture Dislocation |
| Eugene Kim, Se Jin Park, Haw Jae Jeong, Jin Whan Ahn, Hun Kyu Shin, Jai Hyung Park, Mi Yeon Lee, Murase Tsuyoshi, Ikemototo Sumika, Sugamoto Kazuomi, Young Min Choi |
1Department of Orthopedic Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea. dreugene0809@gmail.com
2Department of Orthopedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan. |
|
|
| Abstract |
BACKGROUND: Normal elbow joint kinematics has been widely studied in cadaver, whilst in vivo study, especially of the forearm, is rare. Our study analyses, in vivo, the kinematics of normal forearm and of malunited forearm using a three-dimensional computerized simulation system.
METHODS
We examined 8 patients with malunited Monteggia fracture and 4 controls with normal elbow joint. The ulna and radius were reconstructed from CT data placing the forearm in three different positions; full pronation, neutral, and full supination using computer bone models. We analyzed the axis of rotation 3-dimentionally based on the axes during forearm rotation from full pronation to full supination.
RESULTS
Axis of rotation of normal forearm was pitch line, with a mean range of 2 mm, from full pronation to full supination, connecting the radial head center proximally and ulnar fovea distally. In normal forearm, the mean range was 1.32 mm at the proximal radioulnar joint and 1.51 mm at the distal radioulnar joint. However in Monteggia fracture patients, this range changed to 7.65 mm at proximal and 4.99 mm at distal radoulnar joint.
CONCLUSIONS
During forearm rotation, the axis of rotation was constant in normal elbow joint but unstable in malunited Monteggia fracture patients as seen with radial head instability. Therefore, consideration should be given not only to correcting deformity but also to restoring AOR by 3D kinematics analysis before surgical treatment of such fractures. |
| Key Words:
Forearm; Monteggia fracture; Axis of rotation; Kinematics |
|
PDF Links
Full text via DOI
Download Citation
