Bedside ultrasound‐guided aspiration and corticosteroid injection of a baker's cyst in a patient with osteoarthritis and recurrent knee pain

Baker's cyst accompanying knee osteoarthritis represents a common cause of knee pain presenting to the emergency department. In this case report, a 56‐year‐old male presented with atraumatic left knee pain and swelling. Radiographically, he had tricompartmental osteoarthritis and was found to have a baker's cyst on duplex ultrasound. Using point‐of‐care ultrasound, the cyst was aspirated and corticosteroids were injected. The patient tolerated the procedure well and was discharged with a compression wrap and orthopedic follow‐up. Baker's cyst aspiration with corticosteroid injection represents a safe alternative treatment option for patients. In some cases, this treatment may be definitive. Orthopedists currently use this procedure to reduce pain and improve function for patients with chronic knee ailments related to baker's cysts. As demonstrated in this case report, implementing this bedside procedure in the emergency department with orthopedic follow‐up expands non‐surgical, non‐narcotic treatment options for patients with chronic knee pain secondary to Baker's cysts with osteoarthritis.