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Michael J Fitzpatrick

Publications and source records attributed to Michael J Fitzpatrick.

4 recordsLinked to original sources
PubMedDate not supplied

Development of cadaveric models of a thrower's shoulder.

Two novel cadaveric models of a thrower's shoulder were evaluated. Both models included the capsuloligamentous and osseous components of the glenohumeral joint. In model 1 the coracohumeral ligament was retained and the glenoid was positioned parallel to the ground whereas the humerus was positioned at 60 degrees of glenohumeral elevation in the scapular plane. In model 2 the coracohumeral ligament was resected and the glenoid was positioned vertically at 30 degrees of scapular elevation whereas the humerus was positioned at 60 degrees of glenohumeral elevation in the scapular plane. Each specimen was sequentially tested under 3 conditions: intact, after nondestructive anterior capsular stretch, and after simulated posterior capsular contracture. Measurements included rotational range of motion and relative glenohumeral position from neutral to maximum external rotation of the humerus. In model 2 the glenohumeral forces were also measured by use of a 6-degree-of-freedom load cell. The stretching of the anterior capsule in model 1 was performed while the humeral head was constrained in the glenoid and in model 2 while the humeral head was unconstrained. Both models showed increased humeral external rotation and decreased humeral internal rotation similar to that seen in throwing athletes. Both models also showed an increased humeral shift inferiorly after anterior capsular stretching. Model 1 demonstrated a subsequent humeral shift superiorly after posterior capsule plication. Unconstrained specimens of model 2 dislocated posteriorly and inferiorly after posterior capsule plication when the humerus was rotated to maximum external rotation. On the basis of these findings, for future studies, constrained capsular stretching models will be further investigated.

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PubMedDate not supplied

Biomechanical analysis of isolated type II SLAP lesions and repair.

The effects of type II superior labrum anterior-posterior (SLAP) lesions on glenohumeral rotation and translation were studied in 6 cadaveric shoulders before and after repair. Glenohumeral translation with the application of 15 N and 20 N in the anterior, posterior, superior, and inferior directions was measured with the joint in 60 degrees of abduction and 90 degrees of external rotation. Data were recorded for intact shoulders, shoulders with arthroscopy portals, shoulders with arthroscopically created anterior type II SLAP lesions, shoulders with arthroscopically created anterior and posterior type II SLAP lesions, and shoulders that had undergone arthroscopic repair. With the creation of a SLAP lesion, significant increases in total range of motion (P = .028), external rotation (P < .0001), internal rotation (P < .01), anterior-posterior translation (P < .0001), and inferior translation (P < .01) were observed. After arthroscopic repair, total range of motion, internal rotation, external rotation, and translation significantly decreased, returning to expected values. These findings suggest that type II SLAP lesions cause significant glenohumeral instability, which can be effectively treated with current arthroscopic techniques.

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