Background: There are several surgical treatment options for acromioclavicular joint dislocation including clavicular hook plate and TightRope fixation, both of which are capable of achieving satisfactory outcomes. However, there is no single procedure of choice and there have been no randomized controlled trials of alternative procedures.

Objective: To evaluate and compare the functional outcomes of the clavicular hook plate fixation and the TightRope fixation techniques for acute acromioclavicular joint dislocation in adults.

Materials and Methods: Forty-four patients presenting with acute acromioclavicular joint dislocation Type TTT to V who met the criteria for operative treatment were randomized and allocated to undergo either clavicular hook plate or TightRope fixation within one month after injury. This randomized controlled trial recorded Constant Shoulder Scores at three months post-operation to compare functional outcomes as well as operative time, early and late
surgically-related complications, and percentage of remaining joint displacement.

Results: The mean Constant Shoulder Score was 81.6+5.7 for the clavicular hook plate group and 90.4+3.5 for the TightRope group. The mean difference, -8.8+1.4 (95% CT; -11.6, -5.9), was statistically significant (p = 0.005). The clavicular hook plate group also achieved a significantly lower percentage of remaining joint displacement compared with the TightRope group (0.9+1.9% and 5.3+5.0%, respectively (p<0.001). There was no difference in operative times or in incidence of early or late surgically-related complications.

Conclusion: The TightRope fixation is more effective than the clavicular hook plate fixation for patients with acute acromioclavicular joint dislocation (Type TTT to V) as evidenced by a higher Constant Shoulder Score three months post- surgery. However, clavicular hook plate fixation achieve a greater quality of joint reduction.

Keywords: Acute acromioclavicular joint dislocation, Clavicular hook plate, TightRope