The throwing shoulder in pitchers frequently exhibits a paradox of glenohumeral joint motion, in which excessive external rotation is present at the expense of decreased internal rotation. The object of this study was to determine the role of humeral head retroversion in relation to increased glenohumeral external rotation. Glenohumeral joint range of motion and laxity along with humeral head and glenoid version of the dominant versus nondominant shoulders were studied in 25 professional pitchers and 25 nonthrowing subjects. Each subject underwent a computed tomography scan to determine bilateral humeral head and glenoid version. The throwing group demonstrated a significant increase in the dominant shoulder versus the nondominant shoulder in humeral head retroversion, glenoid retroversion, external rotation at 90 degrees, and external rotation in the scapular plane. Internal rotation was decreased in the dominant shoulder. Total range of motion, anterior glenohumeral laxity, and posterior glenohumeral laxity were found to be equal bilaterally. The nonthrowing group demonstrated no significant difference in humeral head retroversion, glenoid retroversion, external rotation at 90 degrees or external rotation in the scapular plane between shoulders, and no difference in internal rotation at 90 degrees, total motion, or laxity. A comparison of the dominant shoulders of the two groups indicated that both external rotation at 90 degrees and humeral head retroversion were significantly greater in the throwing group.

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A prospective study was completed on 25 baseball players with medial side elbow pain. They were evaluated preoperatively with both computed tomography arthrogram and magnetic resonance imaging examinations of the elbow to assess the ulnar collateral ligament. At surgery, 16 of 25 patients had an abnormal ulnar collateral ligament and 9 patients had a normal ulnar collateral ligament. The computed tomography arthrogram detected abnormalities in 12 of the 14 patients with ulnar collateral ligament tearing (sensitivity, 86%). The magnetic resonance imaging scan indicated abnormalities in 8 of 14 patients (sensitivity, 57%). The specificity of the computed tomography arthrogram was 91% and the magnetic resonance imaging was 100%. A newly described "T-sign" was seen on the computed tomography arthrogram in the patients with an undersurface tear of the ulnar collateral ligament. This represented the dye leaking around the detachment of the ulnar collateral ligament from its bony insertion but remaining contained within the intact superficial layer of the ulnar collateral ligament and capsule. Both the computed tomography arthrogram and the magnetic resonance imaging scan were accurate in diagnosing a complete tear of the ulnar collateral ligament preoperatively in all cases. The main advantage of the computed tomography arthrogram was in evaluating the partial undersurface tear.

The functional results of this reconstruction method are similar to those reported for debridement and subacromial decompression alone and are satisfactory, despite magnetic resonance imaging arthrogram evaluation demonstrating failure of the structural integrity of the allograft. Allograft reconstruction carries increased risk of infection and rejection and is technically more difficult than other less expensive treatment options with similar functional results. Therefore, we do not recommend allograft reconstruction of massive and otherwise irreparable rotator cuff tears.