RT Journal Article SR Electronic T1 Adductor Canal Block Can Result in Motor Block of the Quadriceps Muscle JF Regional Anesthesia & Pain Medicine JO Reg Anesth Pain Med FD BMJ Publishing Group Ltd SP 170 OP 171 DO 10.1097/AAP.0000000000000053 VO 39 IS 2 A1 Junping Chen A1 Jonathan B. Lesser A1 Admir Hadzic A1 Wojciech Reiss A1 Francesco Resta-Flarer YR 2014 UL http://rapm.bmj.com/content/39/2/170.abstract AB Objective The block of nerves in the adductor canal is considered to cause a sensory block without a motor component. In this report, we describe a case of significant quadriceps muscle weakness after an adductor canal block (ACB).Case Report A 65-year-old female patient for ambulatory knee surgery was given an ACB for postoperative pain management. The block was performed under ultrasound guidance at the midthigh level using the transsartorial approach. Twenty milliliters of 0.5% ropivacaine was deposited adjacent to the anterior and posterior areas of the femoral artery. On discharge from the hospital, the patient realized that her thigh muscles were weak and she was unable to extend her leg at the knee. A neuromuscular examination indicated that the patient had no strength in her quadriceps muscle, along with sensory deficit in the medial-anterior lower leg and area in front of knee up to the midthigh. The weakness lasted 20 hours, and the sensory block lasted 48 hours before complete recovery. The optimal level and amount of local anesthetic for adductor canal block are currently not well defined. Proximal spread of local anesthetic and anatomical variation may explain our observation.Conclusions Several studies have reported that ACB involves no motor blockade. However, our case report illustrates that the ACB can result in clinically significant quadriceps muscle paralysis. This report suggests that patients should be monitored vigilantly for this occurrence to decrease the risk of falls.