Tourniquet-induced enmg changes in arthroscopic anterior cruciate ligament reconstruction. A comparison of low and high-pressure tourniquet systems.

BACKGROUND AND AIMS: The use of a tourniquet during surgery is associated with a risk of neurological disorders. We compared whether a new tourniquet system using low pressure (250 mmHg) is safer than a standard tourniquet system using higher inflation pressure (350 mmHg).

MATERIALS AND

METHODS

Thirty-one patients (ASA I-II), ages 16-48 years, were studied with ENMG preoperatively and 3 weeks postoperatively following arthroscopic anterior cruciate ligament reconstruction. Tourniquet times varied 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 H-reflex latencies. The sensory amplitude of the sural nerve decreased. Vastus medialis of the quadriceps femoris muscle showed a reduced interference pattern 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 the use of both tourniquet systems is safe within the limit of tourniquet times of less than 2 h.