A new kinematics method of determing elbow rotation axis and evaluation of its feasi-bility
10.3969/j.issn.1671-167X.2016.02.007
- VernacularTitle:1种新的肘关节外固定旋转轴的定位方法及其可行性评估
- Author:
Wei HAN
;
Jian SONG
;
Guangzhi WANG
;
Hui DING
;
Guoshen LI
;
Maoqi GONG
;
Xieyuan JIANG
;
Manyi WANG
- Publication Type:Journal Article
- Keywords:
Elbow;
External fixation;
Rotation center positioning
- From:
Journal of Peking University(Health Sciences)
2016;48(2):218-223
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study a new positioning method of elbow external fixation rotation axis,and to evaluate its feasibility.Methods:Four normal adult volunteers and six Sawbone elbow models were brought into this experiment.The kinematic data of five elbow flexion were collected respectively by opti-cal positioning system.The rotation axes of the elbow joints were fitted by the least square method.The kinematic data and fitting results were visually displayed.According to the fitting results,the average moving planes and rotation axes were calculated.Thus,the rotation axes of new kinematic methods were obtained .By using standard clinical methods,the entrance and exit points of rotation axes of six Sawbone elbow models were located under X-ray.And The kirschner wires were placed as the representatives of rotation axes using traditional positioning methods.Then,the entrance point deviation,the exit point de-viation and the angle deviation of two kinds of located rotation axes were compared.Results:As to the four volunteers,the indicators represented circular degree and coplanarity of elbow flexion movement tra-jectory of each volunteer were both about 1 mm.All the distance deviations of the moving axes to the ave-rage moving rotation axes of the five volunteers were less than 3 mm.All the angle deviations of the mo-ving axes to the average moving rotation axes of the five volunteers were less than 5 °.As to the six Saw-bone models,the average entrance point deviations,the average exit point deviations and the average angle deviations of two different rotation axes determined by two kinds of located methods were respective-ly 1.697 2 mm,1.838 3 mm and 1.321 7°.All the deviations were very small.They were all in an ac-cep-table range of clinical practice.Conclusion:The values that represent circular degree and coplanari-ty of volunteer's elbow single curvature movement trajectory are very small.The result shows that the elbow single curvature movement can be regarded as the approximate fixed axis movement.The new method can replace the traditional method in accuracy.It can make up the deficiency of the traditional fixed axis method.
