From Chapter 5, The MindBody Prescription, by John Sarno:
“Knee Tendonitis
While virtually any tendon in the body may be the target for TMS, some are more frequently involved than others. The knee is one of the most common sites. The pain may be anywhere in the front or back of the knee; a great many tendons attach around that joint. The largest is the patellar tendon, containing within it the patella (kneecap); it is the tendon of the quadriceps muscle, the weight-bearing muscle that keeps the knee from buckling during walking or running. The pain is usually in only part of the tendon, either above or below the kneecap. There are many others, including the hamstring tendons and those from muscles below the knee. The ligaments around the joint are important structures that help support it and may be a target for pain. All of this is easily ascertained on physical examination; the involved tendon hurts when you press on it. The problem does not involve the knee joint but the tendons attached to bones around the joint. Knee pain is often blamed on a condition known as chon-dromalacia. It is a roughening on the underside of the kneecap, diagnosed by X ray and, in my experience, painless. Once more we have a situation in which an X-ray abnormality is blamed for pain because the doctor is unaware of the existence of TMS. Pain may also be attributed to an unstable patella, or that old standby, arthritis. Occasionally a small tear in a meniscus (cartilage) is said to be the cause of the pain. Meniscus tears can be seen on imaging studies and are very often painless but will be blamed for pain really caused by TMS tendonitis. Not uncommonly these patients have arthroscopic surgery. I saw such a patient recently. After the arthroscopic procedure he continued to have pain, so the surgeon did a second one on the grounds that a fold of tissue was causing the pain. But the pain continued. Though this patient came to see me for his back, I informed him of the true nature of his knee pain and he was able to solve both problems simultaneously. Although it is less common, swelling of the knee may accompany tendonitis. When I first became aware of this I felt a little insecure about advising the patient that it was part of TMS. In the light of consistent success in treatment, I am now quite comfortable with that diagnosis.”