Pain after knee surgery


Operations on the knee joint are very common. In Germany, around 175,000 new knee joints are inserted every year.
But even if a knee prosthesis is not installed, the knee is a joint that is often operated on, since it is easy to injure the menisci or the surrounding ligaments, especially in sports such as skiing or soccer.

The procedures performed are generally very safe procedures that are performed frequently. Nevertheless, it can never be ruled out that a complication that leads to pain does not arise during an operation. This can be secondary bleeding, infection or damage to nerves.

More information on this topic at: Post-operative complications


In general, knee pain in the phase immediately after a knee operation is nothing unusual or worrying. Pain is part of every wound healing process and is based on the fact that body structures are inevitably injured during every operation.

However, if the pain is exceptionally severe or persistent, accompanied by fever and excessive swelling or other complaints, then there is probably an unplanned complication. This can be secondary bleeding that can develop into a severe, painful bruise in the knee.

There may also be an infection with inflammation of the joint. Wound healing disorders can also occur, or nerves can be injured or irritated.

Wound pain

Wound pain refers to pain that occurs in the area of ​​a wound. The symptoms do not only exist immediately after the injury, but also during the healing process and, in rare cases, persist even after healing.

An operation on the knee joint can also trigger wound pain. The general rule is that the pain increases with the size of the wound. Therefore, the wound pain after minimally invasive measures is generally lower than after open operations with a lot of tissue damage.

In order to relieve wound pain, infection of the wound should be avoided at all costs. Anti-inflammatory pain relievers and cooling procedures also help with pain relief. The acute wound pain after knee surgery should decrease within a few days.

Further information on this topic can be found at: Phases of wound healing and Pain

Appointment with a knee specialist?

I would be happy to advise you!

Who am I?
My name is dr. Nicolas Gumpert. I am a specialist in orthopedics and the founder of .
Various television programs and print media report regularly about my work. On HR television you can see me every 6 weeks live on "Hallo Hessen".
But now enough is indicated ;-)

The knee joint is one of the joints with the greatest stress.

Therefore, the treatment of the knee joint (e.g. meniscus tear, cartilage damage, cruciate ligament damage, runner's knee, etc.) requires a lot of experience.
I treat a wide variety of knee diseases in a conservative way.
The aim of any treatment is treatment without surgery.

Which therapy achieves the best results in the long term can only be determined after looking at all of the information (Examination, X-ray, ultrasound, MRI, etc.) be assessed.

You can find me in:

  • Lumedis - your orthopedic surgeon
    Kaiserstrasse 14
    60311 Frankfurt am Main

Directly to the online appointment arrangement
Unfortunately, it is currently only possible to make an appointment with private health insurers. I hope for your understanding!
Further information about myself can be found at Dr. Nicolas Gumpert


If the knee is painfully swollen after an operation and also reddened and overheated, these are signs of an infection.

This means that either germs entered the knee joint during the operation or that the body has become susceptible to existing germs due to the slight immune deficiency after the operation. The colonization of the knee joint with germs triggers an inflammatory reaction and can cause lasting damage to the joint.

If the infection is advanced, a fever can occur. Once a bacterial infection is diagnosed, antibiotic therapy should be initiated as soon as possible. Depending on the source, the rate of infections after inserting a knee prosthesis is 0.3% to 5%.

More information on this topic at: Operation of a knee prosthesis

Injury to a nerve

During an operation, a nerve can be damaged by either a complete or partial severing of the nerve or by sustained pressure or tension.

In addition, nerve damage can also occur after the operation, if e.g. a heavy bruise forms that pinches the nerve. The nerve damage can show up either as a loss of sensory sensitivity in the knee or lower leg or as a muscle weakness below the knee and a reduced Achilles tendon reflex.

Further information on this topic can be found at: Nerve damage


With every knee operation there is a small loss of blood. However, if there is still bleeding after the operation and after the drainage has been removed, the blood will collect in the knee joint cavity.
Since the tissue can only expand to a limited extent there, painful swelling occurs. Such a bloody joint effusion is also called hemarthrosis.

The joint can also be restricted in its mobility due to the bruise. Small amounts of blood can easily be broken down by the body within several days. However, if the effusion is too large, the orthopedic surgeon can relieve it using a thin hollow needle as part of a joint puncture.

Circulatory disorders

Blood vessels can also be damaged during surgery. If these are large vessels, the damage is repaired directly during the operation and the vessel is repaired again.
Smaller vascular injuries usually do not lead to permanent circulatory disorders, since several small blood vessels can usually supply a region of the body with blood and compensate for the failure of a vessel.

However, in rare cases during the operation, small droplets of fat can pass from the fatty tissue of the surrounding tissue into the blood system. These can occlude blood vessels and thus lead to an arterial thrombosis with a consequent inadequate supply of the relevant part of the body.

Further information on this topic can be found at: Circulatory disorders


Thrombosis is one of the most feared complications after operations in general, and more particularly after operations on the legs and feet. This is a blood clot (=thrombus), which forms in a vein (a vessel that transports blood to the heart).

Movement plays a major role in blood transport, especially in the leg veins. By activating the muscles, for example in the calf, the blood is also pumped up towards the heart. If this activity is absent, for example because someone is not allowed to step on after knee surgery, the blood moves more slowly and more disorderly through the vein. This greatly increases the risk of thrombus formation.

If a thrombosis occurs, the affected leg swells up below the blood clot, it often becomes overheated, the skin becomes tense and the leg can be painful. The greatest danger is that the thrombus will loosen and enter the lungs through larger veins. There it can clog such large vessels that it leads to life-threatening shortness of breath.

Read more on the topic:

  • Detect thrombosis
  • embolism
  • Deep vein thrombosis

For prophylaxis (prevention) one receives the "thrombosis injection" after a knee operation. This contains a blood thinner (Heparin) and thereby prevents the formation of clots.

Read more on the topic:

  • Thrombosis prophylaxis start and duration
  • Measures for thrombosis prophylaxis

Water in the knee

Colloquially, water in the knee is any type of fluid that collects in the knee. Mostly it is a clear body-own fluid that occurs naturally in the joint, the synovial fluid.

During knee surgery, the joint is manipulated, which leads to an increased production of synovial fluid. This transports cells to the knee joint that are supposed to repair the tissue damage that has occurred. During the operation, small blood vessels can be damaged, which can increase the swelling in the knee.

Read more on the topic:

  • Joint effusion
  • Knee puncture

Pain therapy after knee replacement surgery

After the installation of a knee replacement surgery, a good pain therapy is started immediately, since only the relief of the pain enables the necessary movement exercises to be started directly on the first day after the operation.

The pain medication is taken according to the needs of the patient for about two to three weeks. The pain decreases steadily after a week and should generally not be very severe with good medication.

Since the pain sensation is very subjective and depends on many individual factors, it is not possible to generally define how long or how intense the pain therapy must be for all people. In general, however, pain must be treated long enough and sufficiently to reduce the level of suffering.

More information on this topic at: Pain with a knee prosthesis and pain therapy

Pain therapy after an arthroscopy

Arthroscopy of the knee joint is a gentler surgical technique than open surgery, as there are generally fewer tissue injuries.

The joint is also accessed through significantly smaller incisions. As a result, healing is faster and pain is less persistent.

In general, however, a distinction must be made between whether it is a purely diagnostic arthroscopy or whether therapy is also used, for example by removing disruptive tissue. In the latter case, the pain lasts a little longer.

Further information on this topic can be found at: Arthroscopy complications

Pain therapy after cruciate ligament surgery

The duration of pain after cruciate ligament surgery depends on how well the surgical area heals.

If there is a knee joint effusion, the pain will last at least until the space-filling effusion has reduced. In general, however, it is also true here that good pain therapy not only enables better movement training and thus accelerates recovery, but also means that the pain is kept as low as possible.

Often, pain medication is no longer necessary after five to seven days. Really pain-free movement is only possible after about four to six weeks.

Further information on this topic can be found at: Anterior cruciate ligament tear and posterior cruciate ligament tear

Concomitant symptoms

In general, bruises and swellings occur in the operating theater shortly after the operation. In addition, the knee joint can usually not be fully flexed or stretched. Depending on the complications, the pain after knee surgery can also be accompanied by various other complaints.

A knee joint effusion usually shows itself with severe swelling and restricted movement of the joint.

An infection of the joint, on the other hand, is associated with the classic signs of inflammation. In addition to painful swelling, these also include reddening and overheating of the joint. In this case, too, the knee is not fully functional. Severe infections can also lead to impaired general well-being and a fever.

If nerves were injured during the operation, sensation may be lost and muscle strength may be reduced. The muscle reflexes are also reduced in this case.

Numbness of the tibia

If there is a sensory disorder of the tibia, it is likely a nerve lesion.

The nerve does not necessarily have to be completely damaged, it can also be a temporary pressure lesion. This can e.g. as part of a strong effusion or swelling, constrict the nerve in its course.

The shin is supplied by two different nerves that are responsible for sensation. Therefore, if the numbness is due to a disorder of the nerves, either the right or left half of the tibia tends to be affected.

Pain in the calf

If there is pain in the calf after knee surgery, a deep vein thrombosis should always be excluded. Due to the restricted mobility after the operation, many patients spend more time lying down than usual. Despite preventive blood thinning with heparin syringes, this increases the risk of developing a thrombosis.

The signs of thrombosis are calf pain, bluish discoloration of the lower leg and paleness, and swelling of the affected leg. If these symptoms occur, a doctor should be consulted immediately to prevent the life-threatening complication of pulmonary embolism.


The answer to the question of whether the pain after knee surgery still belongs to the harmless pain that accompanies healing or whether there is a complication that intensifies the pain can best be given by a doctor.

In this case, the specialist is primarily the orthopedic surgeon who operated on the knee. He knows what the joint looked like during the operation and what reactions to expect. In addition to the physical examination, ultrasound can also be used to confirm the diagnosis, e.g. to determine the amount of effusion.

If a purulent infection is suspected, a puncture of the joint may also be useful.

Treatment and therapy

Pain therapy after knee surgery is usually first carried out with so-called non-steroidal anti-inflammatory drugs. These include ibuprofen, diclofenac and Novalgin®. The advantage of these drugs is that not only do they reduce pain, they are also anti-inflammatory.
Paracetamol can be used to lower fever.
If the pain becomes very severe, the medication can be combined with opioids.

In addition to pain therapy, it is important, if possible, to eliminate the cause of the pain.
For this purpose, e.g. a strong knee joint effusion can be punctured and thus relieved. This usually leads to pain relief and can also relieve stress on nerves irritated by pressure.
If the nerve is only slightly irritated, the numbness usually heals on its own. However, if the sensitive nerve has been completely severed, the feeling is unlikely to come back.

If there is a thrombosis, blood should be thinned with heparin and the leg should be compressed for at least three months using an elastic bandage or fitted compression stockings.

Duration of pain

After knee surgery, pain is completely normal up to a certain limit. Most operations are now carried out arthroscopically, so only small holes are cut in the skin through which instruments can be pushed forward to the knee. This means that there are no longer any large cuts in the skin, and the pain caused by the cuts on the skin is significantly reduced.

Read more on the topic: Arthroscopy of the knee joint

Large knee replacement operations, for example, are an exception, where larger incisions are still necessary to insert the knee prosthesis into the bone. In knee operations, however, not only superficial cuts are made, injured structures in the knee are either cut out or possibly sewn back together. All of this initially leads to pain, which, however, can be treated with painkillers post-operatively. It is therefore typical that pain medication (often Ibuprofen®) is also given in a slightly higher dose for a few days or weeks after knee surgery.

Read more on the topic: Operation of a knee prosthesis

Depending on the size of the operation, the pain should subside after one to several weeks.