Thermal Capsulorraphy for the Treatment of Acute or Chronic Shoulder Instability

Abstract

Shoulder instability resulting from over-used and/or damaged ligaments is a frequent problem for physically active individuals, especially professional athletes. This chronic ailment had been traditionally treated with open procedures in the past, but arthroscopic alternatives have become the new wave in orthopedic treatment. Thermal capsulorraphy utilizes a Radio Frequency (RF) probe that is inserted in the shoulder to shrink the ligaments by denaturing the fibers and letting them stiffen during the subsequent renaturation process, thereby curing the instability. Our goal in this project is to model the heating of the shoulder ligament to determine the optimal time, convective heat transfer coefficient (h), and the proper heat generation (Q) to generate the most uniform results, while limiting the unwanted heat that is delivered to the surrounding tissue. We concluded that computer simulation can be used to better understand the heat transfer in the shoulder during thermal capsulorraphy. We also found that the optimal Q was 60,000 kW/m3 , the optimal h was 50 W/m2-K, the optimal time was 600 seconds per ligament strip, and the optimal number of probe sweeps was three to get the most effective results.