Abstract: BACKGROUND: At present, there are few reports on the postoperative efficacy of arthroscopic coracoid tunnel-free suspension fixation and coracoid single tunnel fixation in the treatment of acromioclavicular joint dislocation at home and abroad. The specific clinical efficacy of the two procedures and whether there are other risks need to be explored.
OBJECTIVE: To compare the short-term postoperative clinical efficacy of arthroscopic TightRope band plate fixation with single tunnel fixation of the coracoid process and tunnel-free suspension fixation of the coracoid process in the treatment of acute type III-V acromioclavicular joint dislocation.
METHODS: A retrospective analysis was performed in 45 patients with acromioclavicular joint dislocation who met the inclusion criteria admitted to the Sixth Affiliated Hospital of Xinjiang Medical University from June 2019 to September 2022, and were divided into coracoid single tunnel fixation group (20 cases) and coracoid tunnel-free suspension fixation group (25 cases) according to the surgical treatment plan. Operation time, incision length, blood loss, Constant-Murley score, visual analogue scale score, the American Shoulder and Elbow Surgeons (ASES) score and intraoperative and postoperative complications of the shoulder joint before operation, 3 months after surgery and the last follow-up were compared between the two groups.
RESULTS AND CONCLUSION: All patients successfully completed the operation, and there was no important nerve or blood vessel damage during the operation. The operation time of the coracoid tunnel-free suspension fixation group was significantly shorter than that of the coracoid tunnel-free suspension fixation group (P < 0.05). There was no significant difference in intraoperative blood loss and incision length between the two groups (P > 0.05). All patients were followed up for 12 to 24 months, with an average of (15.29±2.73) months. In the coracoid single tunnel fixation group, at 3 months after operation and the final follow-up, the visual analogue scale score was significantly lower than the preoperative score (P < 0.05); Constant-Murley score and ASES score were significantly increased compared with the preoperative values (P < 0.05). In the coracoid tunnel-free suspension fixation group, at 3 months after operation and the final follow-up, the visual analogue scale score was significantly lower than the preoperative score (P < 0.05); the Constant-Murley score and the ASES score were both significantly higher than the preoperative scores (P < 0.05). At 3 months after operation, the Constant-Murley score of the coracoid tunnel-free suspension fixation group was higher than that of the coracoid single tunnel fixation group (P < 0.05), while there was no significant difference in visual analogue scale and ASES scores between the two groups (P > 0.05). There was also no significant difference in the visual analogue scale, Constant-Murley, and ASES scores between the two groups at the corresponding time points before surgery and at the final follow-up (P > 0.05). Intraoperative and postoperative complications: In the coracoid single tunnel fixation group, there was one case of coracoid cortical rupture and fracture during the tunnel drilling during the operation, and one case of a loss of reduction at 3 months after operation, which was repositioned and fixed with hook plate transposition of the coracoacromial ligament. All patients had good acromioclavicular joint function recovery and no re-dislocation at the final follow-up. All patients in the coracoid tunnel-free suspension fixation group did not suffer from coracoid fractures, loss of reduction and other complications during surgery, postoperatively and at the last follow-up. To conclude, these two arthroscopic treatments for acute type III-V acromioclavicular joint dislocation have the advantages of less trauma, reliable reduction and fixation, and good recovery of shoulder joint function after operation. However, compared with the coracoid single tunnel technique, the coracoid tunnel-free suspension fixation requires shorter time, faster recovery of shoulder joint function in the short term, and avoids the establishment of bone tunnels on the coracoid process, which reduces the probability of iatrogenic fracture of the coracoid process during operation and provides a higher degree of safety.

Key words: acromioclavicular dislocation, shoulder arthroscopy, coracoclavicular ligament, single tunnel fixation, coracoid tunnel-free suspension fixation