Abstract:

BACKGROUND: The angle of the hook of the clavicular hook plate could not change in application of dislocation of acromioclavicular joint and or fracture of the clavicle distal end. But the angle of the acromioclavicular joint will change somewhat during the glenohumeral joint abduction.
OBJECTIVE: To investigate the normal acromioclavicular joint value and its relation to glenohumeral joint motion during abduction as well as their clinical significance.
METHODS: A total of 97 cases with their TOP images among the CT data containing the shoulder joints were selected, including 57 males and 40 females. The angle of acromioclavicular joint values on the screen of the CT monitor was measured. The angle of acromioclavicular joint is the included angle between the major axis of acromeon and the major axis of clavicle distal part. The glenohumeral joint angle is the major axis of humoros in abduction and vertical line.
RESULTS AND CONCLUSION: The average angle of the acromioclavicular joint was (162.04±10.53) ° when the glenohumeral joint angle at (16.06±11.87) ° (R=0.010, P < 0.000), suggesting the correlation between two angles. The average angle of the acromioclavicular joint was (174.34±10.14) ° when the glenohumeral joint angle at (137.64±14.48) ° (R=0.053, P < 0.01) suggesting the correlation between two angles. Results indicate that the acromioclavicular joint angle is changing during active humeral elevation. The acromioclavicular joint angle moves during glenohumeral joint angle change.