Acromioclavicular joint reconstruction: an additional acromioclavicular cerclage does not improve horizontal stability in double coraco-clavicular tunnel technique

Abstract

Purpose: Horizontal instability—especially in the posterior plane—is a common problem after acromioclavicular joint injuries. The purpose was to compare the stability of a single coraco-clavicular tunnel technique and a double coraco-clavicular tunnel technique for coraco-clavicular ligament reconstruction and to examine the influence of an additional acromioclavicular cerclage on the horizontal stability in the acromioclavicular joint. Methods: 21 acromioclavicular joints of human cadaveric shoulders were randomly assigned to the following groups: single coraco-clavicular tunnel technique with horizontal augmented acromioclavicular cerclage (SCT + AC); double coraco-clavicular tunnel technique (DCT); double coraco-clavicular tunnel technique and acromioclavicular cerclage (DCT + AC). The specimens underwent cyclic horizontal testing and were recorded using a 3D optical measuring system. Results: The displacement and the increase in displacement in relation to the displacement after precondition for SCT + AC were significantly higher after every measured amount of cycles than for DCT (p10 = 0.0023; p5000 = 0.0012) and DCT + AC (p10 = 0.0006; p5000 = 0.0012). There was no significant difference in the total displacement, or in the increase in total displacement between double coraco-clavicular tunnel reconstructed groups with and without additional acromioclavicular cerclage. Conclusion: Double coraco-clavicular tunnel technique with and without additional acromioclavicular cerclage results in a significant higher stability regarding the horizontal plane in comparison to single coraco-clavicular tunnel technique with acromioclavicular cerclage. Based on the results of this biomechanical in vitro study, the use of an additional acromioclavicular cerclage with single coraco-clavicular tunnel technique may not be indicated in most cases. The effect of an additional acromioclavicular cerclage seems to be negligible, at least in presence of a double-coraco-clavicular tunnel technique reconstruction. Techniques of AC joint reconstruction should focus on the use of double coraco-clavicular tunnel devices.