The effect of coracoacromial ligament excision and acromioplasty on the amount of rotator cuff force production necessary to restore intact glenohumeral biomechanics.

Hypothesis And Background: Coracoacromial ligament (CAL) excision and acromioplasty increase superior and anterosuperior glenohumeral translation. It is unknown how much of an increase in rotator cuff force production is required to re-establish intact glenohumeral biomechanics after these surgical procedures. We hypothesized that, after CAL excision and acromioplasty, an increase in rotator cuff force production would not be necessary to reproduce the anterosuperior and superior translations of the intact specimens.

Biomechanical study comparing biceps wedge tenodesis with other proximal long head of the biceps tenodesis techniques.

Purpose: The purpose of this biomechanical study was to compare the ultimate failure strength, stiffness, cyclic displacement, and failure displacement of 5 different proximal biceps tenodesis fixation techniques, specifically comparing wedge tenodesis with the other 4 techniques.

Methods: Forty cadaveric shoulders underwent 1 of 5 long head of the biceps tenodesis techniques and were cyclically tested to failure by use of tensile forces applied parallel to the longitudinal axis of the humerus. A preload at 5 N was applied for 2 minutes, followed by cyclical loading for 500 cycles from 5 to 70 N at 1 Hz and a pull-to-failure test at 1 mm/s.

Coronoid fractures.

Coronoid fractures are rarely isolated injuries; they are most commonly encountered in association with other elbow injuries as part of 3 major instability patterns. Type 1 fractures are usually associated with terrible triad injuries. Type 2 fractures are associated with varus posteromedial rotatory instability.

Posterosuperior displacement due to rotator cuff tears.

Purpose: To compare the effects of different-sized anterosuperior and posterosuperior rotator cuff tears (RCTs) and the effects of long head of the biceps tendon (LHB) loading on posterosuperior glenohumeral translation.

Methods: Ten cadaveric shoulders were subjected to posterosuperior loading in the intact state and with sequentially larger anterosuperior and posterosuperior RCTs. Glenohumeral translation was measured with and without LHB loading.

Analysis of wrist motion following vascularized bone graft to the proximal scaphoid.

Purpose: To determine whether there is any motion loss associated with the 1,2 intracompartmental supraretinacular artery (ICSRA) bone graft to the dorsal scaphoid. The null hypothesis is that placement of a vascularized bone graft in the dorsal scaphoid does not lead to a significant change in range of motion.

Methods: Seven fresh-frozen cadaveric upper extremities were examined.