S1022 THERMAL SHRINKAGE FOR TREATMENT OF MULTIDIRECTIONAL INSTABILITY OF THE SHOULDER

Abstract

Thermal capsular shrinkage presents the prospect of reducing redundant capsule, and therefore may be a suitable method of treating capsular-type instability. A prospective study of fifty-four consecutive patients (58 shoulders) treated exclusively with radiofrequency capsular shrinkage for atraumatic instability. The mean Rowe score improved from 33.1 to 74.1 points at followup of up to 48 months. Twenty of the fifty-eight shoulders had recurrence instability. Recurrent instability was related to the type of instability: 76.9% for voluntary instability, 30.3% for involuntary instability and none of 12 shoulders for instability/impingement pain. Recurrence was related as well to previous instability surgery (70%). The outcome was not related to the direction of instability, type of radiofrequency probe used, age of patient or ligamentous laxity. Twenty-two (57.9%) of thirty-eight patients returned to their pre-instability level of sporting activity. By using repeated RF treatments for the failed thermal shrinkage cases the failure rate was reduced from (20/58) 34.5% to (13/58) 22.4% and cumulative changes were seen on electron microscopy. These results are comparable to some of the results for open inferior capsular shift for patients with multidirectional instability with substantial less morbidity. The application of the minimal effective energy is controlled according to the tissue response without any charring or burning effect to the tissue. No scar was seen in repeated arthroscopies, or in electron microscopy studies. Thermal shrinkage does not negatively affect a later open stabilisation, but rather may provide better conditions for secure open surgery. We have found significant improvement in proprioception following thermal shrinkage treatment. We believe that by re-tensioning the proprioceptors they begin to fire off at lesser degrees of movement, and that there is a greater dynamic muscular contribution to shoulder stability. When using the correct technique for the right indications, Radiofrequency thermal shrinkage is a viable alternative to open inferior capsular shift in patients with capsular type of instability.