Chronic acromioclavicular dislocations repaired by modified Weaver-Dunn technique with two EndoButtons: retrospective review of twenty three cases.

PURPOSE: Chronic acromioclavicular joint instability (ACJI) remains challenging, and the optimal surgical technique is debated. Weaver-Dunn reconstruction is widely used, but modifications have been made to improve horizontal and vertical stability. This study addressed the clinical outcomes of a modified Weaver-Dunn procedure reinforced with a double EndoButton construct.

METHODS

This retrospective single-center study included 23 patients undergoing modified Weaver-Dunn reconstruction for chronic ACJI between 2012 and 2024, with a minimum follow-up of 12 months. Indications included symptomatic Rockwood grade 3 or higher after failed conservative management. Surgery was performed arthroscopically in most cases; five cases used an open approach. Clinical assessment included Constant-Murley score, Subjective Shoulder Value (SSV), Visual Analog Scale (VAS) for pain, ROM, piano-key sign, and clavicular drawer test. Radiographic evaluation included coracoclavicular distance, alignment, and loss of reduction. Complications and revisions were documented.

RESULTS

At a mean follow-up of 79 months, pain improved significantly (VAS 2.9 to 0.4, p = 0.001). Constant score increased from 60 to 87 (p = 0.001), and SSV improved significantly. Forward flexion improved from 159° to 175° (p = 0.015), and abduction from 163° to 175° (p = 0.03). Clinical stability improved, with disappearance of the piano-key sign and drawer sign in 82% and 91% of cases. Four patients (17%) showed recurrent grade 3 or higher dislocation. Complications occurred in five patients (22%), including one coracoid fracture and one EndoButton migration.

CONCLUSION

Modified Weaver-Dunn reconstruction using two EndoButtons provided significant improvements in pain, function, ROM, and clinical stability with acceptable recurrence and complication rates.