cortical fixation ACL reconstruction anterior cruciate ligament biomechanics bone staples ligament reconstruction ACLR Acromioclavicular joint dislocation BCD Bipolar clavicle dislocation Bipolar clavicular instability Hoffa fracture Letenneur classification OCD Sternoclavicular joint dislocation Tape augmentation adjustable loop button anatomical dissection anterior cruciate ligament reconstruction anteromedial rotational instability articular surface bone bridge brace continuous loop button cyclic loading distal osteotomy of the superficial medial collateral ligament epicondyle osteotomy extended anteromedial approach fragment size-dependent screw trajectories graft fixation