Knee Pain After Total Knee Surgery: A Physical Therapist’s View

This article discusses the pain a total knee replacement patient will have after surgery, the contributing factors, and how to minimize that pain.

As a physical therapist, I have seen thousands of patients over the last 40 years who have had total knee replacement surgery.

I can tell you that the surgical procedure has improved dramatically, and the amount of pain a patient experiences after total knee replacement surgery has significantly decreased over the years.

As a past Chief of Physical Therapy in a hospital setting, I have seen patients immediately after surgery (even during the surgery) and bedside until they’re discharged from the hospital.

As the owner of Buena Physical Therapy, Inc., an outpatient physical therapy office for 40 years, I saw a multitude of patients who were about a month post total knee replacement surgery.

For the past several years, I have been exclusively seeing total hip and total knee replacement patients for Home Health Care Physical Therapy until they are ready to initiate the outpatient Physical Therapy portion of their rehabilitation.

Here are a couple of tips I give my patients to help them understand and control their post-surgical pain:

Tip 1: Apply Cold Therapy Before Going To Bed.

All of my total knee surgery patients are using either Ice Packs or Cold Therapy Machines (Amazon affiliate links) multiple times daily to help control pain levels. Applying cold therapy for 40 minutes just before going to bed will reduce your pain while sleeping
See my article: Ice After Total Knee Replacement: A PT’s Complete Guide.

This is the sum of my experience with total knee replacement pain.

How much pain will I have after total knee replacement surgery?

  • 0 to 5 days: pain should not exceed 6/10 with pain medications.
  • 6 to 21 days: pain should decrease from 5/10 with meds to 1/10 without prescription pain medications.
  • 3 months: pain should be 0/10 to 1/10 without medications.
  • 6 months after surgery, there should be no pain.

The above guidelines are what I expect to see in my patients who have had their total knee replacement surgical site closed with biological glue and Steri-Strips.

The expected pain levels above are pain levels at rest before we start the physical therapy session. I expect the resting pain levels to drop by about a point after the physical therapy session is completed.

Surgical sites closed with stitches or staples may remain at the above pain levels a few days longer than surgical sites closed with biological glue.

Surgical sites closed with stitches or staples will cause more pain when trying to increase flexion of the knee, and the range of motion will come more slowly.

Pain Guidelines

No pain, no gain may work fine in a gym, but it is absolutely not true when recovering from total knee replacement surgery.

Pain is one of the primary indicators that tells the patient if they are doing too much. That rule applies to any activities of daily living they may be doing, as well as for the physical therapy home program.

The patient is allowed to push to pain but not through pain.

For Activities of Daily Living pushing to pain but not through pain means when the patient begins to feel an increase in knee pain, they need to stop that activity and sit down with the leg elevated.

If the pain persists for longer than five minutes after sitting down with the leg elevated, whatever the activity the patient was doing is too much. They need to either eliminate that activity or substantially decrease the amount of time doing that activity.

As for the Physical Therapy Home Exercise Program, I expect the patient to be able to push the range of motion portion of the home exercise program all the way up to their pain tolerance, which may be in the 7/10 pain range, but I expect the patient’s pain level to return to the pre-range of motion exercise level within a few seconds after the exercise.

The muscle-strengthening portion of the home exercise program should not cause pain. If it does cause pain I find a different way to strengthen the targeted muscle so that the exercise does not cause pain.

Does the total knee replacement surgical technique affect pain levels?

How the total knee replacement surgical incision is “closed” makes a difference in pain levels once discharged from the hospital.

  • Surgical sites closed with biological glue have the least pain.
  • Surgical sites closed with stitches have some increase in pain levels.
  • Surgical sites closed with staples have the most pain.

The pain level differences at rest are not nearly as noticeable; however, I see a significant difference once the patient starts trying to bend the knee to regain range of motion.

When interviewing potential surgeons for a total knee replacement, how the surgeon closes the surgical site would be a question I would ask to help me pick the best surgeon for me.

Biological Glue

For the patients I see that have their surgical site closed with biological glue, the main feedback I receive from them is a feeling of stretching beyond their comfort level. Sometimes they express concerns the surgical site may split open.

I have never seen a TKR surgical site split open when biological glue was used to close the site!

The biological glue technique also uses Steri-Strips as supports against the surgical site splitting open.

Biological Glue TKR cropped
The surgical wound was sealed with biological glue, and then steristrips were applied.

Using biological glue also allows for earlier removal of the protective bandages. I feel early removal of the bandage is a deterrent for infections. Too often I see stained bandages left on the new total knee replacement surgical incision until 3 or 4 weeks after the surgery, when the patient has their first post-surgical visit with the surgeon.

When I feel my patient’s bandage is concerning, I take a picture and text it to the home health care nurse case manager. The nurse case manager then forwards it to the surgeon’s office, and the surgeon either tells nursing to change the bandage or leave it as is.

Some surgeons feel more comfortable with discolored or stained bandages than I do. Many times, when I would demand a bandage change if it were my knee, the surgeon is fine leaving the stained bandage instead of changing the bandage.

Since infection is such a serious complication, I probably have a lower tolerance for potential infection than some surgeons. I have seen the effects of a knee infection after total knee replacement, and it can add months to the rehabilitation process.

One of my referring surgeons using this biological glue technique removes the bandage 7 days after surgery, and he has the lowest infection rate in the entire United States (and he does 15 to 23 surgeries per day, 3 days per week).

This surgeon also operates in a hospital that has an extremely low infection rate. He also requires the patient to do extensive body decontamination BEFORE arriving at the hospital on the day of the surgery.

You can check out your doctor and hospital infection rating here.

In recent years, the vast majority of total knee replacements I have seen use this effective biologic glue and Steri-Strip technique to close the surgical site; however, most of my recent home health care total knee replacement patients have come from 4 or 5 top surgeons in teaching hospitals in the Los Angeles area using cutting-edge techniques and doing a LOT of surgeries.

I know there are many good surgeons throughout the country (and even in my area) who still use the stitch or staple techniques to close the surgical site.

Stitches

Closing a total knee replacement with stitches is still a pretty common practice throughout the United States.

Patients I see who have their total knee replacement surgical site closed with stitches almost always complain about the stitches “pulling and hurting” as they try to bend the knee.

Pulling on these stitches, in my opinion, causes the “stitch puncture hole” to remain open longer than if it were closed with biological glue.

It is kind of like twirling the earring in a newly pierced ear to keep the piercing open.

This open stitch punch hole can act like a wick to pull pathogens into the joint and cause an infection.

Most surgeons using stitches to close the surgical site keep the surgical site covered with bandages for about 3 weeks. I think they keep the site covered to protect against the possibility of infection being wicked into the knee through the stitches.

Total knee patients that I have seen for home physical therapy with stitches almost always have more pain than biologic glue, and their ability to bend the knee is slower to gain flexion until the stitches are removed.

Staples

Staples are the least common method of closing total knee replacement surgical sites that I see.

Staples has the same issues as stitches for increased pain and increasing the time required to regain range of motion, (but on steroids)!

Staples are pretty large and leave a much bigger punch hole than stitches (and biological glue has no punch holes).

Patients I see with staples are much more reluctant to bend their knee because of the increased pain from pulling on the staples.

Staples TKR cropped
The surgical wound was closed with staples.
Extra insulation will be needed if freezer cold packs are applied!

Final Thoughts: Three Kinds Of Patients

Over the years, I have seen so many patients with total knee replacements that I can divide them into three groups:

  • Those patients that I have to push to get them to do the full physical therapy home exercise program they are instructed to do on their own between physical therapy visits.
  • Those patients that stay in the lane and do exactly what their home exercise program tells them to do each day.
  • Those patients that I have to keep pulling back into the lane because they think if they are told to do 10 repetitions of an exercise, 20 or 30 repetitions would be better. Some get away with this non-compliance, but my experience is that more than 50% of these patients set themselves back 7–10 days in their rehabilitation because they overdid it.

My hope is that after reading my thoughts regarding pain after total knee replacement, you will have a more informed perspective of the expected pain levels and duration of pain after surgery.

Total knee replacement surgery has made the possibility of a senior citizen’s ability to age in place a reality for thousands of people.

Read my other articles about Total Knee Replacement

Happy Aging In Place With Quality Of Life

Paying It Forward

Perhaps you are approaching or already retired and wondering how you could earn extra money in retirement.
One option would be to do as I am doing.
Read my article How To Generate Retirement Income: Cash In On Your Knowledge.

Dr. Robert Donaldson

Dr. Donaldson is dually licensed; physical therapy in 1975 and doctor of chiropractic in 1995. He held credentials of Orthopedic Clinical Specialist in physical therapy for 20 years, QME in California, and taught at USC. He owns and operates an orthopedic physical therapy practice. See "About Me" page.

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