A comparison of two techniques for tungsten carbide ring removal

Emergency physicians may have difficulty removing modern rings made of hard metals such as titanium and tungsten carbide. These metals are exceptionally difficult or impossible to remove using standard ring cutters. Numerous alternative techniques for removal have been described, including the "umbilical tape" or "string technique" and, in the case of tungsten carbide, breaking the ring using locking pliers.

We sought to compare the speed and effectiveness of tungsten carbide ring removal using these two techniques.

Ten tungsten carbide rings were placed upon the finger of a standard medical simulation mannequin. The rings chosen were one-half size smaller than the mannequin's finger. Edema distal to the ring was simulated using foam tape. A single novice operator performed 10 trials using each of the techniques after a 10-minute orientation session. The success or failure of the technique and the time for removal were recorded for each trial. The mean removal times for the trials were compared using a paired t test.

All trials were successful. The rings were removed substantially faster using the locking pliers method (mean 23.1 seconds [95% CI 15.4-30.8] vs. mean 135.4 seconds [95% CI 130.2-150.6]). However, the locking pliers technique destroyed all rings and caused sharp ring fragments to be thrown up to 37 in.

Both the umbilical tape or string technique and the locking pliers technique successfully removed tungsten carbide rings in our model. The locking pliers technique is significantly faster but destroys the ring and creates potentially harmful shrapnel.