Knee Replacement Pain At Night | When To Worry + Treatments

Written By on June 20, 2022 — Medically Reviewed By Kris Ceniza (PT)

Written by on June 20, 2022 — Medically Reviewed By: Kris Ceniza (PT)

About 50% of patients experience extreme knee replacement pain. At night the symptoms can get worse, which is a huge problem on its own – adequate sleep is key for recovery. (1)

However, this acute postoperative pain should respond to medications and home treatments. If it doesn’t, it may be a sign that something’s wrong.

But don’t worry – you’ll learn what’s normal night pain after total knee replacement (TKR) and what isn’t. These are the topics we’ll discuss, tap on any of them to go straight to its section:

Normal night pain after knee joint replacement surgery

It’s completely normal to have pain at night after total knee replacement surgery.

See, this symptom acts as an alarm to let you know the tissue is damaged. It forces you to rest so that recovery can take place. And the inflammation associated with it brings cells that heal this major surgery.

Yet, the worst part should be during the first week after surgery. (2) There will be better days and bad ones for sure, but the trend should be towards improvement.

Related: How to relieve general knee pain at night

Normal acute postoperative symptoms include:

  • Moderate pain, or even severe.
  • Inflammation and bruising of varying degrees.
  • Stiffness and lack of range of movement.

Now, your surgeon will discuss pain management strategies with you before the procedure. They usually include (1):

These treatments should be enough to reduce the pain for most people.

But if they aren’t enough, that doesn’t necessarily mean something’s wrong.

Pain is an extremely subjective phenomenon that can be amplified by lack of sleep, anxiety, and even dehydration. Not to mention knee OA symptoms tend to worsen at night.

Knee Force Knee Sleeve

This is to say that if you’re experiencing severe symptoms at night, don’t go straight to the worst scenario – “the surgery failed!” Instead, pay attention to other associated symptoms and their causes.

See, common postoperative complications have specific signs. Learning about them will help you figure out if the pain is normal or if you should talk to your doctor straight away.

Related: Why is knee osteoarthritis pain worse at night?

5 Complications that cause nighttime pain after knee replacement

The most common complications that cause abnormal knee pain at night after TKR include (3):

1) Infection

A certain level of redness around the surgical incision is to be expected. But if it’s infected, the area will likely be red, tender, and painful to the touch.

The pain will be present all day, not only at night. It will probably get worse with both movement and rest as well.

Also, the symptoms will keep getting worse as time goes by. You may also experience other issues, like a fever, chills, or night sweats.

If you think you have an infection, notify your physician as soon as possible. You’ll need antibiotic treatment to get rid of it.

2) Blood clot

showing the veins and a zoom in with the blood clot

The risk of having a blood clot is high during the first 2-3 months after the procedure. (4)

Now, depending on your age and overall health, your doctor may prescribe a blood thinner to reduce this risk.

With that said, having a blood clot can be a life-threatening issue. Please go immediately to the ER if, apart from the nighttime pain, you also experience (4):

  • Shortness of breath.
  • Dull to severe pain in the calf area that doesn’t respond to medication.
  • A cramp-like feeling on the calf that doesn’t go away regardless of what you do.
  • Ankle and/or foot pain.

3) Fracture

A periprosthetic fracture is a rare complication that happens when the bone breaks close to the implant area. The most frequent site is on the thigh bone, followed by the shinbone and the kneecap.

They occur in 0.3%-2.5% of total knee replacement patients, usually within 2 to 4 years after the procedure. (5)

Sadly, one of the main causes is an inappropriate surgical technique during the procedure. Yet, several risk factors can make a patient prone to this complication, like (5):

  • A previous revision of total knee replacement.
  • Prolonged steroid use.
  • Osteoporosis.
  • Rheumatoid arthritis.
  • Being +80 years old.
  • Neurologic disorders like epilepsy or Parkinson’s.

It’s treated like any other fracture if the implant is still stable and the bone fragments are aligned. That means wearing a cast for a few weeks while the injury heals.

If that’s not the case, the treatment involves another surgery to stabilize the implant and/or realign the bone fragments. (5)

4) Dislocation

X-ray with a side view of a dislocated knee replacement

A TKR dislocation is another rare complication that happens when the upper and lower parts of the implant move out of place. The bones aren’t broken, but the joint surfaces don’t match anymore.

It happens in 0.15–0.5% of patients, and it’s easily preventable with the proper surgical technique. Another common cause is choosing the wrong type of implant. (6)

Before the dislocation itself, the patient may feel instability symptoms, like (6):

  • Feeling like your knee gives away under you.
  • Weakness.
  • Episodes of severe joint inflammation.
  • Problems climbing stairs.

The treatment is surgical and usually requires a period of immobilization, followed by physical therapy.

Knee Force Knee Sleeve

5) Implant migration

This is when the replacement moves out of place in relation to the bone. It can happen due to a trauma, like falling on the knees. Or, because the implant itself isn’t properly fixated in the bone. (7)

See, after surgeons remove the joint itself, they insert the prosthesis inside the bone and “glue” it with bone cement. If this isn’t done right, the implant can loosen down the road. (7)

Apart from this, certain patients have a higher risk of implant migration, including (7, 8):

  • Being female.
  • Having rheumatoid arthritis.
  • Having a posterior-stabilized implant.
  • Surgical procedure involving varus alignment.

Symptoms include persistent knee pain, swelling, and stiffness that doesn’t get better. This complication usually happens after a few months or even years following the procedure. (8)

How to treat knee replacement surgery pain at night

someone with their knee wrapped in bandage, lying on their side in bed. Include the pillows under the head and between the knees

First of all – take the pain medications your doctor recommends and don’t miss your physical therapy appointments. This is the bare minimum and will ensure you don’t develop chronic pain.

Now, other ways to prevent sleep disturbances after this surgery include (1, 9):

  • Changing your sleeping position with pillows to promote comfort.
  • Taking CBD after knee replacement may help you sleep and manage pain.
  • Wear a knee brace during the day to keep symptoms in check.
  • Rest, but not too much – a daily stroll can boost recovery and manage pain.

However, avoid using heat therapy after the surgery as it may worsen the symptoms.

Learn more: Should you use a heating pad after TKR? Do’s and don’ts


What helps pain at night after hip or knee replacement?

Taking pain medication, doing home remedies, and having a nighttime routine help for both hip and knee arthroplasty pain.

How long does night knee pain last after TKR?

Most knee replacement patients feel improvements after 4-6 weeks post-surgery. (10)

What causes stabbing pains in knees after TKR?

If it’s during the first 3 months after surgery, common reasons include normal pain and inflammation, infection, a blood clot, a fracture, and dislocation. Longer than that, it could also be implant migration.

Conclusion: Total knee replacement pain at night

It’s normal to have some degree of knee pain at night after replacement surgery. But it should respond to the treatments your physical therapist and doctor recommended.

If the pain doesn’t budge, you may want to check in with your surgeon. It may be an infection, a blood clot, or the implant got loose.

But, if the symptoms are severe and you have a visual deformity on the joint, it’s likely a fracture or a dislocation. These are medical emergencies and may require surgical treatment.

Finally, it’s wise to have an honest conversation with your surgeon. Ask what to expect, warning signs, and any other questions that will bring you peace of mind. This will make your recovery process much easier.


  1. Korean Knee Society. “Guidelines for the management of postoperative pain after total knee arthroplasty.” Knee surgery & related research vol. 24,4 (2012): 201-7. DOI: 10.5792/ksrr.2012.24.4.201
  2. Gupta, Anuj et al. “Clinical aspects of acute post-operative pain management & its assessment.” Journal of advanced pharmaceutical technology & research vol. 1,2 (2010): 97-108.
  3. Hsu H, Siwiec RM. Knee Arthroplasty. [Updated 2022 Apr 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
  4. “Avoiding a Blood Clot After Total Knee Replacement Surgery: A Patient Story.” National Blood Clot Alliance. Retrieved on May 2022 from:
  5. Yoo, Jae Doo, and Nam Ki Kim. “Periprosthetic fractures following total knee arthroplasty.” Knee surgery & related research vol. 27,1 (2015): 1-9. DOI: 10.5792/ksrr.2015.27.1.1
  6. Villanueva, Manuel et al. “Dislocation following total knee arthroplasty: A report of six cases.” Indian journal of orthopaedics vol. 44,4 (2010): 438-43. DOI: 10.4103/0019-5413.69318
  7. Pijls, Bart G et al. “RSA migration of total knee replacements.” Acta orthopaedica vol. 89,3 (2018): 320-328. DOI: 10.1080/17453674.2018.1443635
  8. van Hamersveld, Koen T et al. “Risk Factors for Tibial Component Loosening: A Meta-Analysis of Long-Term Follow-up Radiostereometric Analysis Data.” The Journal of bone and joint surgery. American volume vol. 103,12 (2021): 1115-1124. DOI: 10.2106/JBJS.20.01454
  9. American Academy of Orthopaedic Surgeons Management of Osteoarthritis of the Knee (Non-Arthroplasty) Evidence-Based Clinical Practice Guideline (3rd Edition). Published on August 31, 2021.
  10. Alipourian, Ali et al. “Improvement of sleep quality 6 months after total knee arthroplasty: a systematic review and meta-analysis.” Journal of orthopaedic surgery and research vol. 16,1 342. 28 May. 2021, DOI: 10.1186/s13018-021-02493-4
Mitch Torres (PT)
Mitch is a physical therapist, personal trainer, and nutrition coach. Fascinated with the knee joint, Mitch poured that passion into writing about knee pain and how to overcome it with movement. His goal is to teach you how to apply this knowledge into your daily life, so you can keep knee pain away for good.