Biomechanical comparison of indirect and direct arthroscopic excision of the distal clavicle.

The purpose of this study was to compare the stability and force of ultimate failure of the acromioclavicular joint (ACJ) after direct arthroscopic distal clavicle excision (DCE) through superior portals and indirect arthroscopic DCE through inferior portals in paired cadaveric shoulders. Ten paired saline-embalmed cadaveric shoulders were operated alternatively using the indirect and direct technique. Biomechanical testing was performed in the horizontal plane, testing displacement at 15N and 30N and finally failure strength was measured testing the constructs until failure occurred. There was a significant difference in failure strength with the direct DCE being stronger: 766.6 N (SD 233.5) against 5403 N (SD 239.1) for the indirect DCE, p = 0.01334). There was no statistical difference for the displacement measured at 15N and 30N. A direct DCE will result in a postoperative ACJ with greater ultimate failure strength compared to indirect DCE because the inferior ACJ capsule can be better preserved.