Ultrasound-guided treatment of common peroneal neuropathy caused by Baker’s cyst: a clinical note - A case report -

BACKGROUND: Baker’s cysts are usually located in the posteromedial side of the knee and seldom cause neuropathy. CASE: We describe the rare case of a 57-year-old woman with a popliteal cyst who presented with limping gait and pain in her lower leg. She was electronically diagnosed with common peroneal neuropathy and transferred to our pain clinic. On ultrasound examination, about 2.0 × 1.2 cm sized popliteal cyst was found to extend to the fibular head, compressing the common peroneal nerve. Therefore, ultrasound-guided aspiration of the cyst and a common peroneal nerve block were performed. Immediately after the procedure, the pain, dysesthesia, and limping gait were relieved. Although her pain and dysesthesia were relieved, she underwent the surgery because of limping gait. CONCLUSIONS: In this case, we found the Baker’s cyst, the cause of the common peroneal neuropathy, and treated it immediately by just simple ultrasound examination and aspiration.