Tourniquet-induced ENMG changes in arthroscopic anterior cruciate ligamentreconstruction - A comparison of low and high-pressure tourniquet systems

Background and Aims: The use of a tourniquet during surgery is associated w ith a risk of neurological disorders. We compared whether a new tourniquet system using low pressure (250 mmHg) is safer than a standard tourniquet sy stem using higher inflation pressure (350 mmHg). Materials and Methods: Thirty-one patients (ASA I-II), ages 16-48 years, we re studied with ENMG preoperatively and 3 weeks postoperatively following a rthroscopic anterior cruciate ligament reconstruction. Tourniquet times var ied between 30 and 146 min. Results: Postoperative slowing of motor and sensory conduction was observed , as well as an increase of the minimum peroneal F-response and tibial I-I- reflex latencies. The sensory amplitude of the sural nerve decreased. Vastu s medialis of the quadriceps femoris muscle showed a reduced interference p attern in ENMG in maximal voluntary effort postoperatively. No differences were found in measured results between the low and high pressure tourniquet systems. Conclusions: Slight postoperative ENMG alterations were demonstrated but th e use of both tourniquet systems is safe within the limit of tourniquet tim es of less than 2 h.