Pain and snapping along the outside border of the knee can be caused by a variety of problems. It could be iliotibial friction syndrome, meniscus tear, degenerative joint disease, or even a loose fragment in the joint.
In this report, the case of a 21-year-old female with a painful snapping of the left knee is presented. She had the symptoms for seven years. Evaluation and treatment by a variety of doctors and physical therapists were not helpful.
She had to give up all sports and recreational activities. Any activity involving knee flexion or extension seemed to set it off. Even walking became a painful process. Her goal to return to running seemed impossible.
She was seen by the authors of this case report (an orthopedic surgeon and a physical therapist). After a thorough examination, it was determined she should try another round of physical therapy treatment. The therapist used a trial of manual therapy, taping, icing, and a knee immobilizer.
Conservative (nonoperative) care was unsuccessful. Pain was relieved but only temporarily. As soon as the treatment was stopped, the pain returned. The surgeon performed an arthroscopic exam followed by open surgery to find out what was causing the symptoms. He found that the snapping was caused by the popliteus muscle as it moved over a tubercle (bump on the bone).
The popliteus is a muscle between the femur (upper leg) and the tibia (lower leg). It crosses the knee and helps rotate the tibia on the femur when the foot is planted on the ground. It also unlocks the extended knee when walking.
The surgeon removed the tubercle and moved the popliteus tendon to a new attachment. The new location of the tendon helped decrease how much the tendon moved during knee flexion and extension. The surgeon checked during the operation to make sure that the tendon was no longer snapping as the knee joint moved.
The painful snapping was eliminated with surgery. After completing a rehab program, the young woman was able to resume all activities. Conservative care is always recommended first before considering surgery. Three out of four patients with this problem are helped by nonoperative care. For that one patient who does not respond to physical therapy, surgery may be needed.
David A. Krause, PT, MBA, DScPT, OCS, and Michael J. Stuart, MD. Snapping Popliteus Tendon in a 21-Year-Old Female. In Journal of Orthopaedic & Sports Physical Therapy. April 2008. Vol. 38. No. 4. Pp. 191-195.'