What Happens to the Ligaments With Total Knee Replacement

A common question regarding total knee replacement (also known as total knee arthroplasty) is what happens to the ligaments in the knee after surgery?

First, it is helpful to understand the location and function of these important soft-tissue structures.  There are four major ligaments in the knee joint.  Two of these ligaments act as “side-to-side” stabilizers in the knee:  the medial collateral ligament (MCL) and the lateral collateral ligament (LCL).  These ligaments connect the femur (thigh-bone) to the tibia (shin-bone).  They are located on the inside (medial) and outside (lateral) parts of the knee.

The other two ligaments, the anterior cruciate ligament and the posterior cruciate ligament (ACL and PCL) limit “front-to-back” or anterior-to-posterior movement of the knee.  These ligaments are named based on their attachment site on the tibia and are found roughly in the middle of the joint.  The PCL runs from the back or posterior part of the tibia to the front of the femur.  The ACL runs in the opposite way.  These ligament cross, hence the name “cruciate”.

So what happens to these ligaments as a result of total knee replacement?   The collateral ligaments (LCL and MCL) are left intact as they are important for proper function and longevity of a total knee replacement since the function of these ligaments is, for the most part, not replaced by the prosthetic components.

The ACL is removed since the portions of the bone where it typically attaches are removed and replaced by the implant components.  Often this structure is severely compromised in patients requiring total knee replacement.

What is done with the PCL is not as straightforward.  Depending on the particular patient as well as surgeon preference, the PCL may either be retained or sacrificed. Implants specific to either scenario are available for the surgeon’s use.

For more on types of implants see our section on this topic.

So in summary, in a standard total knee replacement..

  • The collateral ligaments (LCL and MCL) are preserved
  • The ACL is removed
  • The PCL is either retained or sacrificed.


15 Responses to “What Happens to the Ligaments With Total Knee Replacement”

  1. Your Ligaments and Total Knee Replacement « Total Knee Replacement on March 5th, 2010 4:58 am

    [...] view the rest of this story on your ligaments and knee replacement surgery [...]

  2. Andy on November 18th, 2011 9:19 pm

    Above it says ACL is removed during knee repalcement surgery than in the next paragraph it says it is retained, which is it?

  3. admin on November 20th, 2011 6:12 pm


    Thanks for the comment. Yes, sorry, that is a typo. It should read

    “The collateral ligaments (LCL and MCL) are left intact”

    We’ll correct the error.


    admin at http://www.totalkneeweb.com

  4. Bill on February 12th, 2012 3:29 pm

    In a total knee replacement, what replaces the functionality of the ACL & PCL? What keeps the joint from moving to far in either direction?

  5. Bill on February 12th, 2012 3:35 pm

    Of the 1% of recipients that get an infection, are there any demographics relative to who is more likely supseptable? I.e. age, health, gender, fitness, etc?

  6. Eli deal on August 28th, 2012 6:51 pm

    I am having much pain 19 months after TKR of slight knock left knee.
    new knee was install straight.
    I have read that slight knock knee anatomy should be maintained in some cases.

    if pain persist should I consider a custom TKR?

    Eli Deal
    Annapolis MD

  7. Janet on January 16th, 2013 11:36 pm

    I underwent total knee replacement on both knees and have done
    wonderfully well except a pocket of nerves have appeared on both knees and are extremely painful. The doc recommended a drug that people with fibromyalgia use. Has anyone experienced this?
    If so, please tell me what you did to rid your self of extreme pain.

  8. Karen on April 16th, 2013 4:07 am

    can a tkr mend after sending a shock through leg after landing heavily on missed step. Possible medial ligament strain other medial pain and a little instability. Tkr was post op 3 years and performing ok. I’m 57 and skinny.

  9. Freddie DiPlacido on May 19th, 2013 12:22 am

    Can the medial cruceate ligament be injured during TKR or subsequent manipulation? It has been 18 months since TKR and I have major instability. I cannot put weight on my knee when it is bent, I cannot go up or down steps, I can’t walk downhill without feeling like I might fall any minute. My knee is swollen all the time and even more so if I vacuum or walk a lot. I cannot turn over in bed without reaching down and helping my left leg. I am much worse than before my surgery and nothing helps the pain and swelling.

  10. Freddie DiPlacido on May 19th, 2013 12:25 am

    Can the MCL be injured during TKR or during manipulation of the knee at 6 weeks? I am very unstable and my knee is swollen all the time. It has been 18 months since my surgery and the knee is much worse than before the replacement. I cannot walk much and feel like I might fall whenever going downhill and steps are unbearable.

  11. Larry Estep on December 8th, 2013 11:44 pm

    Freddie I feel like I am walking down your path. I posted this on another site and my Facebook page………… Can a replace knee lead to damage to any of the ligaments? History….knee replace two years ago…. pulled knee first week after replacement….pain first year unable to strengthen leg without pain…..Surgery x-rayed and found kneecap pulled off location…. used medical cream for pain and water exercise…two years after surgery, no change surgeon x-rayed again and found my knee pulled 45 degrees off location, to the right. two months ago surgeon open knee up and clipped knee cap to relieve stress and let knee cap go back in place….. several days after surgery hopes were high with positive results until a week later when infection set in….8 days in hospital, 5 weeks with wound vac, Healing almost complete…..BUT, know I have extreme pain on both sides that is managed by pain pills, tylenol, and ice. I am using my cane and my surgeon is scatching his head… I have viewed knee photos and noted the pain I have is located were the medial collateral ligament connects at the tibia and on the other side lateral collateral ligament stretches from the lateral epicondyle of the femur. I also have some swelling. Can knee replacement effect the ligaments?

  12. Eli Deal on December 12th, 2013 10:09 pm

    I am having much pain 3 YEARS after a left TKR of slight knock left knee.
    new knee was install straight. Surgeon says they should be strait
    I have read that slight knock knee anatomy should be maintained in some cases.and replaced at the same angle

    My pain is at the fibula joint and down the outside of my left leg..

    The pain is bad after a nights sleep and the whole knee has a slight ache continually. If I walk more than 2/10 mile the oain is unbearable!
    Any comments will be appreciated,

    if pain persist should I consider a custom TKR?

    Eli Deal
    Annapolis MD

  13. Diane on October 25th, 2014 2:17 am

    I twisted my right knee almost 4 mos. after TKR. It will bend but hurts to put weight on it.I was able to walk without the cane, but now have to use it. I’m waiting for appt. with surgeon. It is swollen and hot on the outside. Does anyone have any ideas what has happened?

  14. TS on December 21st, 2014 1:16 am

    I had TKT performed at HSS in NY. 18 Months latter the femoral component had loosened. The cement on the cap to femur had shown to be missing on an ex ray and had degraded. I then had revision TKR at HSS in NY. This included a femoral post and attached cemented cap type of femoral component. Now – 9 months later I have pain upon exercise. I feel the pain on the outside of my knee and on the lower part of my knee cap. I like to ride bicycle. After exercise. I limp for days. I feel this is tendon, ligament, soft tissue as I am confident if the prostheses. I don’t know what to do.

  15. Allan Scott on September 17th, 2015 3:36 pm

    I am 71 years old and had TKR 18 months ago on my Right Knee. Everything seemed to be going OK. I play Golf twice a week normally and have recently experienced terrible pain on my Lateral Ligament after playing a few holes. .
    Would be grateful for some advice

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