[Parameters to judge the stability of wrist after the four-corner arthrodesis].
OBJECTIVE
To find out some parameters to judge the stability of the wrists after tour-corner arthrodesis and to explore the strategy for improving the range of motion (ROM) of the wrist after four-corner arthrodesis.


METHODS
After the simulated four-corner arthrodesis was performed in both wrists of 8 men and 4 women cadaver, the wrists were fixed on the wrist motor simulator; and wrist movement including flexion, extension, radial deviation, ulnar deviation was simulated. The standard posteroanterior and lateral radiographs were taken for measuring the change of capitolunate angle (alpha), radiolunate angle (beta), capitolunate posteroanterior angle (theta), the height (H) and width (W) of the fused four carpal bone bloc.


RESULTS
There were statistically significant differences in alpha, beta, theta angles (P<0.01) in the case of 50 degrees flexion or 40 degrees extension, and in H and W values (P<0.05) in the case of 25 degrees ulnar deviation or 15 degrees radial deviation when compared with before movement.


CONCLUSIONS
Capitolunate angle, radiolunate angle, capitolunate posteroanterior angle, the height and the width of the fused four carpal bone bloc can be used to judge the stability of the wrists after four-corner arthrodesis.
Liu
Tao
T
Department of Orthopaedics, the First People's Hospital of Zhenjiang City, Zhenjiang Jiangsu, PR China.
Liu
Fan
F
Huang
Yong
Y
D001174:Arthrodesis / Q000379:methods*; D051224:Capitate Bone / Q000033:anatomy & histology*; D050824:Carpal Joints / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D011859:Radiography