Arthroscopic rotator interval closure: effect of sutures on glenohumeral motion and anterior-posterior translation.

Abstract

The effect of arthroscopic rotator interval closure on glenohumeral motion and translation is not well understood, nor is the ideal location or number of sutures required for closure. The number of arthroscopic rotator interval closure sutures and their placement will have a significant effect on glenohumeral range of motion and anterior-posterior translation. Controlled laboratory study. Using a custom testing apparatus, the authors measured range of motion in 12 fresh-frozen cadaveric shoulders; anterior-posterior translation in adduction and neutral rotation was measured in 9. Specimens were initially tested without sutures and then tested after 3 interval closures using a random sequence of (1) an isolated medial suture at the level of the glenoid, (2) an isolated lateral suture 1 cm lateral to the glenoid, or (3) both sutures followed by removal of all sutures. Analysis of variance demonstrated that interval closure had a significant effect on decreasing flexion (mean, 6 degrees), external rotation (mean, 10 degrees), and anterior translation (mean, 3 mm) of the adducted shoulder. There was no significant difference between the 3 interval closures in any of the tests. Arthroscopic interval closure produced significant decreases in range of motion and anterior-posterior translation. The effects of single lateral or medial suture closures were similar to the use of 2 sutures. This study suggests that the initial effect of arthroscopic rotator interval closure on anterior translation of the shoulder will be similar whether 1 or 2 sutures are used. In vivo studies are necessary to determine if the effect of these 2 methods would be the same over time.