MUA TKA (Manipulation Under Anesthesia Total Knee Replacement): A Complete Look

This article on manipulation under anesthesia total knee replacement was reviewed and co-authored by Dr. David Halley, MD.

It is not uncommon to have some stiffness in the knee after knee replacement surgery. However if that stiffness persists, you will need to take some action to avoid the condition becoming a permanent problem.

A Manipulation Under Anesthesia (MUA) is often the “go to” solution that surgeons turn to, to fix knee stiffness and range of motion issues. In about 75% of cases it makes a difference and improves knee range of motion (ROM).  For the 25% who need a second MUA or other treatment (like Arthroscopy) ongoing aggressive physical therapy and compliance on physical therapy simply does not solve their knee stiffness. They suffer from ongoing stiffness and do not reach good knee flexion for everyday living.

This may sound like what you are going through. If knee stiffness is impacting you, a Manipulation Under Anesthesia (MUA) may be recommended.

Knee stiffness as a diagnosed complication that requires MUA is not as uncommon as you may think. Studies indicate the incidence of MUA to be as high as 7% after a total or partial knee replacement.

What is a Knee Manipulation Under Anesthesia (MUA)?

A Manipulation Under Anesthesia is used to improve knee range of motion (extension and flexion). The MUA is a second procedure after a knee replacement. During the approximately 10 minute procedure the surgeon will break-up the scar tissue, fibrous materials and adhesions that are causing stiffness. The procedure is non-invasive.

After you are put under anesthesia, the surgeon will move your leg to several different positions, applying pressure and breaking up the scar tissue. It is possible to see and hear the tissue breaking up. Finally, the leg will be flexed and extended to its maximum range.

All of this will be performed while you are under anesthesia (usually general anesthesia). You will not feel any pain during the procedure.

A manipulation under anesthesia (MUA) for knee surgery is most common and effective around the 4-12 week mark after surgery. Surgeons are much more reluctant to do the procedure beyond this window of time as they are concerned about doing damage to the tendons and muscles surrounding the knee.

Benefits of a Knee MUA

Successful MUA: Allen’s Story

Allen had an MUA that was not delivering the results he had expected. A few week after the procedure when his knee was still not performing as expected he was very concerned. Approximately 25% of MUA patients require a second MUA and that seemed to be Allen’s fate. He tells his story of how he solved the MUA recovery in this video.

The MUA treats the complication of stiffness, addressing problems with range of motion and flexion. Sometimes may be a necessary and very worthwhile secondary procedure for patients who are experiencing the complication of stiffness. Here are the main important benefits of a MUA:

  • Improves knee movements and range of motion. In a controlled study that measured 21 MUA patients, the average arc of motion improved from 60.2° pre-MUA to 91.9° post-MUA.
  • Excellent, immediate results. Almost every patient, had significantly improved range of motion after MUA. Patients initially swell up and may not see a benefit in the immediate days after the procedure, however they notice a difference in the days to follow.
  • A second chance after surgery. While not a guaranteed solution, if physical therapy is not improving range of motion, at-home rehab exercises are delivering the results you expect, a MUA is a chance to restart your rehabilitation.
  • A restart. Be vigilant and communicate with your surgeon’s office early and often. If truly needed, you want to have the procedure earlier than later. Having this secondary procedure will mean additional recovery time. It is possible to catch up to others who had their knee replacement around the same time.

Downsides of a Knee MUA

Unsuccessful MUA: Lois’ Story

Unfortunately the surgeon tore Lois’ Patellar Tendon in the MUA procedure. She was in a cast for about five weeks afterwards and her recovery simply stalled after that. Lois then needed an Arthroscopy to clean up the scar tissue three months later. She tells her story in this short interview.

  • Bone breakage. Applying pressure to break-up adhesions around your knee joint requires a lot of force. Applying this force without breaking any bones requires a skillful surgeon. If your bones are weak, or too much force is applied, they could break. This is a risk you should be aware of. The risk increases for those who have osteoporosis, weak bones, are older.
  • Added risk factors. Going under anesthesia is very low risk, but is a risk to be aware of. Anesthesia is taxing on your body and comes with mild-moderate side effects. If you have any secondary conditions (like high blood pressure, diabetes, obesity, challenges with alcohol abuse) then anesthesia may be more risky. Talk to your doctor about the different types of anesthesia that may be available to you.

A Manipulation Under Anesthesia is not the sole cure for larger complications that could be caused by a technical surgical error. An MUA alone may not cure all stiffness and pain in the knee.

Avoiding a Manipulation After Knee Surgery

How to Avoid the MUA Completely

One way to avoid the MUA from 4-10 weeks after surgery is The X10 Knee Recovery System™ Learn more in this video.

There are many surgery and recovery factors that are out of your control. But all is not lost if you are experiencing stiffness.

Here’s how to avoid a manipulation (MUA) after a knee replacement

Pre-hab (rehabilitation) before a knee replacement allow you to achieve a better outcome and recovery. The best indication of knee range of motion and stiffness after surgery is what your range of motion was like before you surgery. Those with poor range of motion, flexion and extension going into surgery will have the toughest recovery afterwards.

Pre-SURGERY-Email Series for Knee Surgery Recovery

Follow Best Recovery Practices: RICE (Rest, Ice, Compression, Elevate)

After a knee replacement it is absolutely crucial to work your knee for 30 minutes 3x per day. This means regular physical therapy complimented by an at-home rehab program like with the X10.

In addition to following the best exercises at the right frequency, you must remember to ice your knee several times a day. You should be icing daily for several weeks after surgery (for 60-90 days). Pair icing with elevation to cut down swelling, pain, and stiffness. Compression hose are usually recommended by your surgeon as well.

Best Icing Practices After a Knee Replacement

  • Elevate and ice for 10-15 minutes at a time.
  • There are many tools to consider to help your icing regimen. Click here for a full look at icing options.
  • Repeat icing after exercise, 3-4 times a day.

Other Techniques to Improve Post-Operative Stiffness

  • Make your knee recovery your vocation. Do not get frustrated about post-op knee stiffness. The more you work and pay attention to your body, the better.
  • Get some sleep. If you are mentally and physically exhausted, your body is not able to recovery the way it should.

Let’s Not ‘Sugar-Coat” this Problem

A stiff knee can truly derail a knee recovery and leave a patient very disappointed with their knee surgery. If you are in the 7% of knee patients who are stuck we are more than willing to discuss your situation. Just schedule a free consultation with one of our Recovery Coaches.

Can You Avoid an MUA?

You may be able to avoid an MUA with The X10 Knee Recovery System™. In 10 to 14 days our patients see marked improvements in their ROM and oftentimes can avoid the MUA completely.

To help you determine if the X10 can help you avoid an MUA take this online assessment by clicking on the AVOID MUA? image here.


  • Alejandro González Della Valle, MD, Alejandro Leali, MD, and Steven Haas, MD, “Etiology and Surgical Interventions for Stiff Total Knee Replacements”
  • Ingmar Ipach, Falk Mittag, Julia Lahrmann, Beate Kunze and Torsten Kluba, “Arthrofibrosis after TKA – Influence factors on the absolute flexion and gain in flexion after manipulation under anaesthesia”
  • I. Ipach, R. Schäfer, J. Lahrmann, T. Kluba, “Stiffness after knee arthrotomy: Evaluation of prevalence and results after manipulation under anaesthesia”
  • Sean E. Fitzsimmons, MD, Edward A. Vazquez, BS, and Michael J. Bronson, MD, “How to Treat the Stiff Total Knee Arthroplasty?: A Systematic Review”
  • X10 Knee Recovery System™ Proprietary Research, 2012-2019, Dr. David Halley, Dr. Carl Freeman
  • Physical Impairments and functional limitations: A comparison of individuals 1 year after Total Knee Arthroplasty with control subjects. Walsh M. Woodhouse LF, Thomas SG, Finch E. 
  • How often is functional range of motion obtained by manipulation for stiff total knee arthroplasty? Ho-Rim Choi & John Siliski & Henrik Malchau & Andrew Freiberg & Harry Rubash & Young-Min Kwon
  • Manipulation Under Anesthesia After Total Knee Arthroplasty is Associated with An Increased Incidence of Subsequent Revision Surgery Brian C. Werner, MD, James B. Carr, MD, John C. Wiggins, BS, F. Winston Gwathmey, MD, James A. Browne, MD
  • Clinical, Objective, and Functional Outcomes of Manipulation Under Anesthesia to Treat Knee Stiffness Following Total Knee Arthroplasty Kimona Issa, MD, Bhaveen H. Kapadia, MD, Mark Kester, PhD, Harpal S. Khanuja, MD, Ronald E. Delanois, MD, Michael A. Mont, MD
  • Continuous Passive Motion After Knee Replacement Surgery, Cochrane Collaboration Musculoskeletal Group Harvey LA, Brosseau L, Herbert RD
  • Manipulation Under Anaesthesia for Stiffness Following Knee Arthroplasty Riazuddin Mohammed, Royal Orthopaedic Hospital, Birmingham B31 2AP, UK E: