Pain found at the knee joint can be a symptom of plica syndrome. Anatomically the plica is thin layer of vascular synovial tissue found within the joint line of the knee. The plica is remnant tissue from the fetal stage of development that diminished in size, also known as a synovial fold. Due to the location of the plica, it can often be misdiagnosed with a meniscus tear, patellar tendinitis, or a stress fracture of the tibia.
The main function of the plica is to provide glide of the knee joint. In a knee joint with previous swelling, the plica can become quiet irritated due to the synovial tissue and become inflamed. Those who have difficulty running may have a restricted joint in the lower extremity, but a majority is due to poor biomechanics from a previous overuse injury of the soft tissue. The plica can be more prominent in some people than others, and is exposed when the knee is in the flexed position. The medial plica is found on the inside of the knee and is more commonly involved in joint irritation. In those patients who have had a few knee surgeries the quality of the plica tissue evolves and becomes thickened and more fibrotic causing it to be caught along the medial femoral condyle. The plica has an attachment to the genu articularis muscle and an indirect attachment to the quadriceps muscle. Therefore, plica irritation is more commonly found in those with weak quadriceps muscles, tight hamstrings- causing stress to the anterior knee, and have problems with joint muscle balance around the knee. Some may complain of pain with ascending/descending stairs, squatting, bending, or getting up from a chair after sitting for an extended period of time.
Symptoms of plica syndrome:
Pain dull and achy in at the medial knee joint, increase with activity
Catching or clicking of the knee upon flexion and extension
Swelling of the knee joint
When observing the knee for motion, the patient may experience pain with flexion and extension, which is a good indicator that there is some sort of restriction in the soft tissue or in the joint. To fully diagnose a plica and the degree, a thorough patellofemoral exam must be done and in some cases imaging may be necessary. The choice of imaging for a plica is arthroscopy, due to the intraarticular location of the tissue. For palpation, the examiner should use the plantar surface of the fingers and roll them along the medial joint line, feeling for a fold in tissue, possible tenderness may be noted. Valgus and varus stress may be put on the joint to rule out any ligamentous injuries, and traction of the patella. Location and palpation of the bursae of the knee should also be identified to rule out any inflammation of those structures.
Possible treatments for plica syndrome:
RICE (rest, ice, compress, elevate)
Surgery based on the severity of the inflammation of the plica tissue
Addressing the scar tissue formation
Rehabilitative strengthening exercises
Addressing the scar tissue and rehabilitation of the knee is very important. Skipping out on stretching can lead to further advanced conditions. A misconception that many runners have is, a tight muscle indicates a strong muscle- this is incorrect! Although a tight muscle can be strong, it is more common that the muscle is weak and spasming in hopes of remaining stable, but probably on the verge of an injury. Warm up of the quadriceps is important before beginning any strengthening protocol and should also be done with stretching of the hamstrings. An example of a hamstring stretch would be a simple sit and reach, without putting any strain on the low back.
Exercises to strengthen the quadriceps muscles:
Straight leg raise
Approximately 4-6 weeks of treatment will be needed, depending on the severity of the injury, to decrease the pain and strengthen the muscles.
At Performance Place Sports Care, we approach injuries in a conservative manner that will give the patient the most weighted benefits. Our providers are board certified chiropractors and certified in full body Active Release Technique. Too read more…