Meralgia paresthetica-like symptoms following epidural analgesia after total knee arthroplasty

Meralgia paresthetica (MP) is generally caused by entrapment of the lateral femoral cutaneous nerve (LFCN), and presents with pain and paresthesia in the anterolateral thigh. This paper describes a patient who had MP-like symptoms as a result of continuous epidural analgesia after total knee arthroplasty. The patient with pre-existing left foraminal stenosis at L3-L4 and disc herniations at L4-5 did not complain of paresthesia or pain during the combined spinal-epidural anesthetic procedure. However, during epidural analgesia on the second post-operative day, he complained of paresthesia and pain in the anterolateral thigh of the contralateral leg. Electromyography showed a neurogenic lesion at the level of L3. Although an ultrasound-guided diagnostic block of the LFCN was performed twice post-operatively, the patient's symptoms persisted. The symptoms gradually resolved 12 months after the surgery. In our case, we suggest that the continuous epidural infusate caused neural ischemia of the L3 nerve root by a compressive effect.