Background: Hook plate fixation is popular fixation methos for the acromioclavicular (AC) joint injuries. However, there are various complications related to the stress concentration at the hook were reported. The purpose of the present study was to analysis the clinical outcomes of hook plate fixation with additional anchor fixation for AC joint injuries in comparison with isolated hook plate fixation without additional anchor fixation.

Methods: The study included 90 patients with acute AC joint injuries who underwent surgery. The patients were divided into 43 patient groups with hook plate fixation and additional anchor fixation and 47 patient groups without additional anchor fixation. For clinical assessments, the American Shoulder and Elbow Surgeons (ASES) score, constant score, and time for hardware removal were recorded. The coracoclavicular (CC) distance and the CC distance ratio were used for the assessment of reduction. Typically reported complications, such as secondary dislocation, peri-implant fracture, postoperative acromioclavicular joint arthrosis, implant failure or loosening, and acromion osteolysis were also analyzed.

Results: There was no statistically significant difference in the clinical result between the two groups. The last follow-up CC distance ratio was significantly low in the hook and anchor fixation group than in isolated hook fixation groups (106.6 ± 12.5% vs 126.3 ± 39.7, respectively, p < 0.05). Time for hardware removal was significantly shorter in the hook plate and anchor fixation group than in the isolated hook plate fixation group. The complication rate was also significantly low in the hook and anchor fixation group than in isolated hook fixation groups (37.0% vs 63.8%, respectively, p < 0.05).

Conclusion: The hook plate with additional anchor fixation was better for maintenance of reduction and minimizing complication than the hook plate fixation without additional anchor fixation. Although, there was no difference in clinical results between the two groups.