Continuous Loop Double Endobutton Reconstruction for Acromioclavicular Joint Dislocation

Abstract

Background: Current anatomic methods for reconstruction of the dislocated acromioclavicular (AC) joint show improved clinical results but continue to be associated with significant rates of fixation loss and complications, limiting more widespread use. Purpose: To determine the long-term clinical and radiologic outcomes of a novel surgical technique using a closed-loop double Endobutton device to reconstruct both acute and chronic dislocations. Study Design: Case series; Level of evidence, 4. Methods: Between 2003 and 2012, a total of 35 patients (31 men, 4 women) at a mean age of 42 years (range, 25-70 years) were surgically treated for a Rockwood type III or greater AC joint dislocation with the described technique (26 chronic, 9 acute). Imbrication of the AC joint capsule and deltotrapezial fascia was performed in all patients. Biological bridging across the coracoclavicular (CC) interval was performed in all patients by use of coracoacromial (CA) ligament transfer in 28 patients and primary repair of the CC ligament in 7 patients. Complete follow-up information was obtained for 31 of 35 patients. Results: At a mean follow-up of 5.2 years (range, 27-144 months), the construct remained stable in all but 1 patient. The mean CC interval difference was 1.1 mm (range, –2.5 to 4.0 mm) and was <2 mm in 87% of patients. The mean Constant score was 98; the mean University of California, Los Angeles Shoulder Rating Scale score was 34; and the mean American Shoulder and Elbow Surgeons Shoulder Score was 98. Follow-up MRI evaluation in 10 patients consistently demonstrated a wide band of dense scar tissue between the coracoid and clavicle. No infections, fractures, or perioperative complications occurred. Conclusion: Excellent results were obtained and maintained over long-term follow-up. The continuous loop device eliminated the possibility of knot slippage or breakage. MRI confirmed a robust healing response. The described technique resulted in outcomes that were significantly superior to historical reports of nonsurgical outcomes, and the technique can be recommended both for acute and chronic dislocations.