GLENOHUMERAL JOINT TRANSLATION AFTER ARTHROSCOPIC, NONABLATIVE, THERMAL CAPSULOPLASTY WITH A LASER

The purpose of this study was to determine whether there are changes i n anterior and posterior glenohumeral translation after arthroscopic, nonablative, thermal capsuloplasty with a laser. Two anteriorly and tw o posteriorly directed loads were sequentially applied to the humerus of nine cadaveric glenohumeral joints, and anterior and posterior tran slation of the humerus on the glenoid was measured. The glenoid was ri gidly fixed, and the glenohumeral joint was positioned simulating 90 d egrees of shoulder abduction and 90 degrees of external rotation. Usin g the holmium:yttrium-aluminum-garnet laser, thermal energy was then a pplied to the anterior capsuloligamentous structures and anterior and posterior translation measurements were then repeated. The results sho wed a significant reduction in anterior and posterior translation afte r laser anterior capsuloplasty. Anterior translation decreased from 10 .9 +/- 2.0 mm (mean +/- SEM) to 6.4 +/- 1.5 mm with the 15-N load; and from 13.4 +/- 2.1 mm to 8.9 +/- 1.8 mm with the 20-N load. Posterior translation decreased from 7.2 +/- 1.2 mm to 4.4 +/- 0.6 mm with the 1 5-N load and from 10.4 +/- 1.4 mm to 6.5 +/- 0.9 mm with the 20-N load . These results indicate that the holmium:yttrium-aluminum-garnet lase r can be used to decrease glenohumeral joint translation and may be an effective treatment for glenohumeral joint instability.