A suprapatellar plica is a membrane - possibly an embryonic remnant - that stretches across the joint cavity in the pouch above the kneecap.

Page updated February 2024 by Dr Sheila Strover (Clinical Editor)

suprapatellar plica

Here the patella (kneecap) has been cut from its tendon and lifted up to show the region at the top of the joint. You can see the curved suprapatellar plica above the patella.

suprapatellar plica

MRI image from the side showing the position (yellow arrow) of the suprapatellar plica. The plica may easily be missed on X-ray but may show up as a thin structure if there is fluid in the knee (which shows as white).

suprapatellar plica being nipped between quads and femur

A traumatised and thickened suprapatellar plica can get trapped between the femur and the quadriceps tendon, where it can cause ongoing pain. Sometimes this is mistaken as quadriceps muscle or tendon injury.

 

Anatomy of the suprapatellar plica

suprapatellar plica

Commonly a supra patellar plica is a curved band along one wall of the capsule above the kneecap. This arthroscopic photograph is looking down on the plica from above, and you can just see the top of the patella at the bottom of the image and it enters the groove of the femur.

 

Rarely a suprapatellar plica may reach right across as a full membrane from one side of the supra patellar pouch to the other, dividing it in two, sometimes with a little window in the middle. Then it is called a suprapatellar septum. Although a septum can also be symptomatic, its real importance is that it often confuses the novice surgeon during arthroscopy.

  • Quote from peer-reviewed paper:

    The "(s)uprapatellar synovial plicae is a fold generally located above the proximal pole of the patella....Plicae are remnants synovial structures occurring due to the lack of septa reabsorption that divides the knee into three compartments....during embryonic development...."

    Citation: Akao M, Ikemoto T, Takata T, Kitamoto K, Deie M. Suprapatellar plica classification and suprapatellar plica syndrome. Asia Pac J Sports Med Arthrosc Rehabil Technol. 2019 Apr 22;17:10-15. doi: 10.1016/j.asmart.2019.03.001. PMID: 31044135; PMCID: PMC6477514.

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How the suprapatellar plica causes symptoms

As a plica the suprapatellar plica is quite common, but as a symptomatic disorder it is actually quite rare. In disorders of the suprapatellar plica patients may complain of pain in the area above the kneecap, generally related to a prior episode of blunt trauma to this region.

  • Quote from peer-reviewed paper:

    "Dull knee pain is a common symptom, and the pain is often aggravated during stair climbing...patients have tenderness over the upper edge of the patella. MRI examination is useful..."

    Citation: Akao M, Ikemoto T, Takata T, Kitamoto K, Deie M. Suprapatellar plica classification and suprapatellar plica syndrome. Asia Pac J Sports Med Arthrosc Rehabil Technol. 2019 Apr 22;17:10-15. doi: 10.1016/j.asmart.2019.03.001. PMID: 31044135; PMCID: PMC6477514.

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Management of a symptomatic suprapatellar plica

Often a suprapatellar plica becomes symptomatic only after a minor traumatic incident, because it is inflamed. Conservative management, with rest and anti-inflammatory medication, may be enough to help it settle.

If symptoms become chronic, then the plica can be excised during arthroscopic surgery.

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Synonyms: 
SPP
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Dr Sheila Strover (Editor)
BSc (Hons), MB BCh, MBA

See biography...

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eBook about plica problems in the knee

eBook - An overview of plica problems in the knee

An expert look at the various plical folds of the knee and the problems that can be caused by a troublesome plica.

by Dr Sheila Strover (Clinical Editor)