2022 Volume 29 Issue 4 Pages 56-59
Although the site of pain in knee osteoarthritis is generally assumed to be within the joint, soft tissues outside the joint may also be involved. The patient was a 73-year-old woman who visited our clinic because intra-articular injection had no effect on her knee pain. We diagnosed medial collateral ligament edema via ultrasound and early osteoarthritis of the knee and gastrocnemius lateral head bursitis via MRI. Ultrasound identified the gastrocnemius lateral head bursitis, and the pain improved after injection of a local anesthetic. Extra-articular lesions may cause pain in osteoarthritis of the knee, and ultrasound may be useful in their identification and treatment.
