Anesthesiologists can significantly reduce loss of muscle strength in anterior cruciate ligament (ACL) knee surgery patients by using a new technique called an adductor canal block instead of a conventional femoral nerve block, according to a study published online ahead of print March 3 in Anesthesiology. Unlike the previously used femoral nerve block, the adductor canal block targets the distal branches of the femoral nerve in the mid-thigh.
Researchers randomly assigned 100 patients undergoing surgery for ACL repair to femoral nerve block or adductor canal block. They used a dynamometer to assessed patients’ muscle strength in patients for 45 minutes after receiving a nerve block. They then followed patients for 24 hours postop to gauge their pain severity and pain medication needs, and also recorded the incidence of falls or readmissions.
Patients who received the new mid-thigh adductor block experienced a 22% loss of muscle strength in the quadriceps, compare to a 71% loss for those who received the femoral nerve block. Those who received the new block reported no falls or accidents requiring readmission, compared with three falls or near-falls in the other group.