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Abstract
One fresh-frozen cadaveric shoulder will undergo a multitude of force tests of superoinferior translation with a sequence of conditions for a Type III acromioclavicular (AC) joint injury repair. The sequence of conditions compared consists of a nonoperative Shamus taping technique and one operative technique, the modified Weaver-Dunn procedure. The fresh-frozen cadaveric shoulder will be tested on the Instron in the Orthopaedic Surgery Department with cyclic loading on all conditions to test for increase in superior laxity; load-to-failure testing will be performed on the operative technique, the modified Weaver-Dunn Procedure. First, the cyclic loading will mimic 10% of a mild postoperative physical therapy stress protocol; 70N will be applied cyclically for 1000 cycles at 1 Hz in a superior direction. For each condition, the maximum displacement at the first cycle and the 1000th cycle will be measured, and the difference will indicate the laxity after cyclic loading. Second, applied load and measured displacement will be recorded separately for the modified Weaver-Dunn procedure to test load to failure. Static superior load will be added at a rate of 120 mm/min, and load to failure is defined by Nüchtern et al. as a “20mm superior dislocation or fracture, insufficiency, or material failure occurrence." Ultimately, this project has the potential to identify the most restorative therapeutic options, via the delivery of a surgical fixation technique or the conservative management of the Shamus Taping Technique.