Parameniscal cysts are a very common finding on a knee MRI.  The word parameniscal means “next to the meniscus”.  A cyst is simply a fluid-filled space or sack. These are different than the more common Bakers Cyst we tend to get in the back of our knee.

The meniscus is a c-shaped cartilage disc inside the knee.  The meniscus helps to absorb stress to minimize the risk of developing arthritis.  Meniscus tears are very common.  In this popular post, we talk about whether or not a meniscus tear can heal on its own.

parameniscal cyst


What is a parameniscal cyst?

If a meniscus tear has been present for a while then the fluid in our knee joint can leak out through the tear.  The fluid will form a cyst.  That fluid filled area is now called a “parameniscal cyst”.  Sometimes these cysts can become quite large.  Cysts that form on the inner part of the knee tend to be larger than cysts on the outer or lateral aspect of the knee.

Lateral meniscus cysts tend to be smaller than medial meniscus cysts because the very tight ITB tendon limits the growth of the cysts on the outside of our knee.

Lateral meniscus cysts also tend to hurt more than medial meniscus cysts because of the pressure they put on the ITB tendon.

Are parameniscal cysts dangerous?

A parameniscal cyst is not dangerous.  They rarely need to be removed.  In some patients, a parameniscal cyst will become very large.  In those cases, the way to treat the cyst is to repair the meniscus tear.  If the tear is repaired then fluid from within the knee can no longer enter the cyst.  Surgery to remove a parameniscal cyst is very rarely needed.  Once the tear is treated the cyst will usually go away on its own.

Disclaimer:  this information is for your education and should not be considered medical advice regarding diagnosis or treatment recommendations. Some links on this page may be affiliate links. Read the full disclaimer.

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About the author:

Howard J. Luks, MD

Howard J. Luks, MD

A Board Certified Orthopedic Surgeon in Hawthorne, NY. Dr. Howard Luks specializes in the treatment of the shoulder, knee, elbow, and ankle. He has a very "social" patient centric approach and believes that the more you understand about your issue, the more informed your decisions will be. Ultimately your treatments and his recommendations will be based on proper communications, proper understanding, and shared decision-making principles – all geared to improve your quality of life.

22 comments on “Parameniscal cysts and meniscus tears

  • Hi Doc Howard,
    I have a baker’s cyst & a mild arthrosis in my right knees. The size of the cyst is 6.8 x 1.7 cm, my question is do i need to go for a surgery, coz i have to much pain if i bend my knees. God bless you for helping people.
    Thank you,

    • Thanks Eliza …
      If a Bakers cyst bothers you it can be aspirated (fluid removed). The risk is that the cyst might come back.
      We almost never operate on a Bakers cyst. Only in very rare circumstances.

  • Hi Dr Howard,

    I have had two left knee arthoscopies (7 weeks apart) to fix meniscal tear causing huge lateral meniscal cyst (looked like a tennis ball on the outside of my knee).
    After the first operation, the cyst site swelled again after one week. Surgeon recommended second operation.
    After the second operation (to fix the problem again) my cyst has again swollen up one week post surgery and is extremely squishy.
    I am absolutely confused at this situation, as if the tears have been fixed, then I dont see how the cyst can keep swelling up! I have been extremely careful post surgery and followed recommendations perfectly.

    • These cysts are caused by a unique tear called a horizontal cleavage tear. In order to get the cyst to stop filling with fluid we need to close the tear together with sutures inside the knee. That way the fluid from the knee can not exit the knee joint any more and cause a cyst.
      If that was done then perhaps all you need is an aspiration (taking the fluid out of the cyst with a needle), or time (it can take many weeks for the cyst fluid to be absorbed by the body. Perhaps you should wait a bit… and if that doesn’t work talk to your doctor again.

      • Thanks Dr Howard!
        Sorry to ask another question, but do you think that if I continue appropriate physiotherapy to increase strength and range of movement in the knee that this could ‘move’ the fluid out of my knee? (In a positive way)
        I really appreciate your reply! I have read the information on your website over the past months and it has helped me greatly!
        Thanks again

  • Hi.. my MRI report of left knee says…. Septated paramensical cyst of size 14 x 8 mm, seen along anterolatreal aspect of the anterior horn of the lateral meniscus.

    Mild thining and surfaces irregularlity seen in the anterior horn of the lateral meniscus, possibly sequelate to chronic tear..

    Slight lateral subluxation of patellae noted..

    My doctor say if pain doesn’t go with physiotherapy with in 20 days.. then u need aurthoscopy operation.. I dont want to do operation.. please let me know is it possible to cure it only with physiotherapy?… please reply

    • Surgery on the lateral side of the knee is not well tolerated at all. Many knees that are operated on for a lateral meniscus tear will go on to degenerate or become more arthritic very rapidly. Many experienced sports surgeons do not like operating on lateral meniscus tears for this reason. The surgery may not help… and it could make things worse.

  • Hello
    My niece is only 15 years old and has a degenerate horizontal cleavage tear lateral meniscus that she has had diagnosed in March 2017. She has just had an mri done yesterday and it says that the tear is unchanged in size but there is now a prominent perimeniscal cyst approx 15mm in the lateral gutter of the knee. The cyst last March was 3mm. We really hope she doesn’t need surgery. Can you kindly pls share your advice? With many thanks, Carolyn

    • On occasion these will require surgery… not common, but at her age these tears might bother her more than an adult with the same tear. The cyst is not a worry, it is a normal consequence of these tears. Over the last 5-10 years we have been repairing these tears. Many will heal after a suture repair. That way she will not lose any meniscus tissue and the cyst will go away if the repair is successful.
      I would avoid having the torn piece trimmed out….

  • My husband has been diagnosed with parameniscal cyst. The surgeon saw the cyst 9 months ago when repairing a tear but thought it would dissolve. It hasn’t and my husband now has worsening pain. Our surgeon said he would need surgery to correct. Other than surgery is there any treatment/cure for this cyst?

    Thanks in advance

    • These cysts do usually resolve after the meniscus is repaired and the hole to the cyst is closed. Very few of these cysts cause pain. It may be difficult to say whether or not the cyst is the cause of the pain in your husbands case. One useful way to determine if the cyst is the cause of pain is to remove the fluid from the cyst. If it feels better afterwards then it is the cause of pain. If it doesn’t feel better then your surgeon will need to determine what the cause of pain is.

      Good Luck

  • Hello,
    I had a small parameniscal cyst aspirated and injected with steroid about 8 days ago. I was told that the cyst immediately shrunk and for the first two day, I had no pain. Now, I am in more pain than before the procedure, especially after any physical activity. Is this kind of pain normal post aspiration? And is it expected to decrease on its own? I was told to take ibeprophen and ice it — but it’s not reducing the pain / burning in my knee.

    • Painful parameniscal cysts will usually not go away unless the meniscus tear associated with it is fixed. We are often able to repair these tears by suturing the tear together so the hole which allows the fluid to exit the knee and create the cyst is closed.

  • I am 21 and just found out from an MRI that I have a parameniscal cyst caused from a tear in my right meniscus on my right knee from when I was aged anywhere from 9-16 years of age. I’ve been in many accidents and have had pain with my knee for ever. I had it x-rayed with no answers but a knee brace for those majority years. I learned to live with not much control of my knee without a brace. I am waiting for an apt with the specialist for consultation because of how bad the tear is and how long I have been in pain. The cyst is what finally got doctors to believe me to get an MRI. What happens if I end up having my meniscus trimmed or nothing is left to salvage, how well will I be able to move my knee without the meniscus? They say are going to remove the cyst as well but now I see in previous comments most don’t get removed, what will benefit me from having it removed? They said stem cell would not benefit me at this point but I want as many opinions as possible on treatment and the best recovery to living as a 21 year old should.

    • HI Julia …
      Most of these cysts do not require an additional open removal. Once the tear is repaired (sutured) or removed (surgeons call during surgery) then the cyst should go away on its own.
      At your age you want to try and find someone who is willing to repair the tear. Any loss of meniscus tissue at a young age can lead to arthritis later on.

  • Hi
    As of 2017 i was diagnosed with a complex lateral meniscus tear on my right knee and was on a cat 3 waiting list and as of 2019 mri results stated it was a large lateral meniscus tear with a parameniscal cyst still there, im currently have moved up to a cat 2 and waiting for my appointment in a week and wondering if they are likely to operate? . I go regularly to physio and over the past year and half of this injury had times of pain when i have taken strong anti- inflammatory drugs such as Tramadol . I think the tear is degenerative.

    • Horizontal cleavage tears with a lateral parameniscal cyst is a common cause of pain on the outer side of the knee. IT only needs surgery if your pain persists after a course of PT. It is a quality of life procedure. Most of these tears are repairable. That means we can suture them together and expect them to heal most of the time. Many docs might just cut the torn pieces out. Try to figure out which your surgeon plans on doing. The more meniscus you keep the less your chance of developing arthritis.

  • Hi Dr Luks
    I am currently 10 months post injury and got a new MRI today. It was reported that I have partial ACL tear with tear on the medial meniscus (4.9×3.3mm) which may represent meniscus cyst. Currently I have occasional pain while walking and cannot stand or walk long due to muscle weakness. I am 26 and will be an intern in a hospital soon which require lots of standing and walking , what is your opinion for the best course of treatment?

    • HI … Often times resistance exercises will help you overcome the discomfort. These small cysts and most partial ACL tears should not require surgery. Consider working with a solid physical therapist or a certified trainer.

  • Dear Dr. Luks,
    I got MRI result, and it showed “Horizontal tear of the entirety of the medial meniscus with anterior parameniscal cysts measuring up to 6mm. Cartilage surface irregularity without focal full-thickness defect…” I am very active (hiking, biking, skiing, diving,…) and the knee is functional but hurts a lot (even at night). Can it be fixed with arthroscopic surgery? What is a long term prognosis for such tear ? I will appreciate your expert advise. Thank you.

    • Hi… Many “horizontal cleavage” tears can be fixed or repaired. In the past surgeons simply cut out the torn pieces, but over the last decade, we have found that suture repairs actually work well in many people. The benefit of that is simply the fact that you do not lose any meniscus.
      Anyways.. before considering surgery, you should go through a period of non-surgical management (6-8 weeks). That means physical therapy. It is very often effective at minimizing the pain due to a meniscus tear.

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