Abstract: BACKGROUND: There is no uniform standard for acromioclavicular dislocation. Clavicular hook plate fixation is a commonly used fixation method clinically, but minimally invasive ligament reconstruction technology and arthroscopic surgery have become a research hotspot.   
OBJECTIVE: To observe the application value of suture bridge with thread anchor under arthroscopy in the treatment of acromioclavicular dislocation. 
METHODS: Patients with Tossy type III acromioclavicular dislocation who were admitted to Department of Orthopedic Surgery of General Hospital of Jizhong Energy Xingtai Mining Group between January 2016 and April 2018 were selected as the subjects. The patients were randomly divided into two groups. The patients in the arthroscopy group were treated with arthroscopic suture bridge technique with suture anchor for reduction and fixation, while those in the clavicle hook plate group were treated with clavicular hook plate for internal fixation. The length of surgical incision, duration of surgery, hospitalization time and time to return to work of both groups were recorded. The shoulder function was evaluated according to the Lazzcano criterion of curative effect at 3, 6 and 12 months after surgery. The visual analogue scale score of shoulder pain, abduction and raising, forward bend and raising were compared between the two groups. All patients were followed up for 1 year to record the occurrence of complications. This study was approved by the Medical Ethics Committee of General Hospital of Jizhong Energy Xingtai Mining Group. All subjects signed the informed consent.  
RESULTS AND CONCLUSION: (1) There was no significant difference in the duration of surgery between the two groups (P > 0.05). The surgical incision, hospitalization time and time to return to work of the arthroscopy group were significantly better than those of the clavicle hook plate group (P < 0.01). (2) According to the Lazzcano criterion of curative effect, the excellent and good rate of curative effect in the arthroscopy group (84%) was significantly better than that in the clavicle hook plate group (66%) at 3 months after surgery (P < 0.05). The excellent and good rates of curative effect in the arthroscopy group at 6 and 12 months after surgery were higher than those in the clavicle hook plate group (P > 0.05). (3) Visual analogue scale scores of the two groups showed a decreasing trend at 3, 6 and 12 months after surgery (P < 0.01). The visual analogue scale score of arthroscopy group was significantly lower than that of the clavicle hook plate group at the same time point (P < 0.01). (4) Angles of abduction and raising, forward bend and raising of both groups showed an increasing trend at 3, 6 and 12 months after surgery (P < 0.01). The angles of abduction and raising, forward bend and raising of the arthroscopy group were larger than those of the clavicle hook plate group at the same time point (P < 0.01). (5) The 1-year follow-up results showed that the incidence of complications in the arthroscopy group (6%) was significantly lower than that in the clavicle hook plate group (63%) (P < 0.01). (6) Compared with clavicular hook plate fixation, the technique of suture anchors under arthroscopy has the advantages of small trauma, quick recovery, fewer complications and no need to remove endografts again. Meanwhile, the surgery can also clearly diagnose the concomitant lesions in the joints and treat them when necessary, so as to improve the treatment effect. 

Key words: bone, acromioclavicular joint dislocation, arthroscopy, suture anchor, suture bridge, Tossy type III, hook plate, internal fixation, coracoclavicular ligament