Clinical and Radiological Results of Hook Plate Fixation in Acute Acromioclavicular Joint Dislocations and Distal Clavicle Fractures

Background: The purpose of this study was to evaluate the clinical outcomes and complications of hook plate fixation in acromioclavicular (AC) joint dislocations and distal clavicle fractures. Methods: We retrospectively reviewed a series of 60 consecutive patients with hook plate fixation for AC joint dislocation (group I) and distal clavicle fracture (group II). Groups I and II had 39 and 21 patients, respectively. Clinical results were evaluated using the pain visual analogue scale (VAS), simple shoulder test, and Constant-Murley scores. In addition, subacromial erosion and stiffness were evaluated as complications. Results: At the removal, the pain VAS was $2.69{\pm}1.30$ and $4.10{\pm}2.14$ in groups I and II, respectively, which were significantly different (p=0.003). The simple shoulder test score was $9.59{\pm}1.60$ and $7.81{\pm}2.67$ in groups I and II, respectively, which were also significantly different (p=0.002). Subacromial erosion was significantly more frequent in group II (14/21 patients, 66.7%) than in group I (15/39 patients, 38.5%) (p=0.037), and stiffness was also higher in group II (17/21 patients, 81.0%) than in group I (22/39 patients, 56.4%), but it was not significant. Conclusions: Hook plate fixation showed good clinical and functional results for the treatment of acute unstable AC joint dislocation and distal clavicle fracture. But, in distal clavicle fractures, there are more subacromial erosion and stiffness compare with acute unstable AC joint dislocation.