You don’t need a heart attack to change your life

It just goes to show you that you don’t need a heart attack to change your life. Sometimes it may be just a sore knee. Our third case is knee pain in a 60-year-old female homemaker who has had bilateral knee pain, worsening over the past year. Constant pain, especially at night. Pain with stairs, rising from a chair. She hurts to stand for more than 30 minutes. On exam both knees were slightly warm with small effusions. She did have focal tenderness distal to the medial joint line and had tri-compartmental crepitus both knees, femoral both weight-bearing surfaces. X-rays confirmed that she had moderate OA in both knees, particularly the medial compartment.

Now what this person has in addition to osteoarthritis is focal tenderness distal to the joint line, medial aspect. Most rheumatologists know to look for tenderness there. What resides there is the pes anserina bursa and pes anserina bursitis, if it really exists, can be a source of pain where the large bursa that sits underneath the insertion of the sartorius gracilis and the semimembranosus tendons. Although we seldom have occasions to image it, it does exist and we see the three muscles here, sartorius gracilis, semimembranosus and this descended structure on T2 is an engorged pes anserina bursa. It can cause pain by several different mechanisms, and some of the more severe pain may derive from its relationship to the saphenous nerve, which runs right next to it. In fact, the patient who complains of pain in their knee and down the shin may have it from irritation of the saphenous nerve by the bursitis. Saphenous nerve serves sensation also to the anterior two-thirds of the knee, so much of the knee pain can derive from that irritation.

Does that mean we should charge our pes anserine bursitis injections as nerve blocks? I’m not sure.