Knee Replacement

Knee Replacement

knee replacement surgery
knee replacement surgery

Who needs Knee Replacement Surgery?

Knee replacement surgery is performed in the following situations:

  • Osteoarthritis with severe damage to the knee, as it causes the joint cartilage to break down
  • Other types of arthritis, such as rheumatoid arthritis (the synovial membrane becomes inflamed and the excessive synovial fluids accumulated in the joint leads to pain and stiffness) or psoriatic arthritis
  • Injuries or trauma to the knee, affecting the mobility of the joint (traumatic arthritis)
  • Rare diseases of the joint in which the destruction is rapid and progressive
  • Tears in the meniscus or the ligaments
  • Defects of the knee cartilage
  • Severe destruction of the knee, with progressive levels of pain and impaired functionality (recommendation for total knee replacement)
  • Impossibility to practice daily activities, including walking and climbing stairs
  • Stiffness and limited range of motion, associated with pain when lying or sitting down


knee replacement surgeryThe knee replacement surgery is performed in the hospital, under general anesthesia. Before the procedure, your medical history will be reviewed and you will have to undergo a blood test and other diagnostic tests to make sure that you are prepared for the surgery. You will have to mention whether you are allergic to certain medication, as this is very important for the anesthesia.

Immediately before the surgery, you will be positioned on the operating table and the area for surgery will be prepared. The skin will be cleansed with an antiseptic solution and if there is a lot of hair in that area, it will be removed. After making an incision in the area, the doctor will remove the damaged part of the joints from the surface of the bone or the entire joint if the damage is too extensive.

After the removal process, prosthesis or an artificial joint will be placed in the affected area, being made either from plastic or metal. The joint will be attached to the thigh bone, the shin and the knee cap, using cement or other special materials. Today, uncemented artificial joints are not that common and surgeons prefer to use surgical cement for better results of the procedure. After the artificial joint has been placed and attached to the three components, the incision will be closed and the doctor might decide to also apply a drain to remove the excessive fluid. Dressing will be applied to the recently operated area.

How long does knee replacement surgery take?

The knee replacement surgery should not take more than half an hour but this depends on the complexity of the procedure and the possible complications that may appear. Generally, the procedure itself takes half an hour but the whole prepping and anesthesia phase will add up, being on the whole somewhere around two or two and a half hours.


The overall costs for the knee replacement surgery are dependent on a number of factors and they can vary considerably from one clinic or hospital to the other. Below, you will find the most common factors that affect the cost of this kind of surgery:

  • Number of hospital days – this number depends on whether the knee replacement was total or partial, whether the surgery went fine or there were any complications
  • Type of prosthesis and surgical method – the costs are determined by the materials of the prosthesis and the instruments or technology used for the actual surgery (specialized computers, surgical tools that have been customized)
  • Pre-existing conditions that might increase the number of hospital days and medical treatment provided
  • Duration of the actual surgical procedure
  • Complications arising during or after the procedure (costs are viewed in terms of care and equipment)
  • Average price for total knee replacement is of $50.000
  • Average price for partial knee replacement is of $40.000 (fewer hospital days)
  • Surgical treatment fees
  • Operating room staff fees, including anesthesia
  • Pre and post-operative physical therapy


These are the most common complications that can occur with knee replacement surgery:

Common side-effects of the anesthesia during the surgical procedure:

  • Vomiting
  • Dizziness
  • Chills
  • Sore throat
  • Pain and discomfort
  • State of drowsiness

More serious adverse or negative reactions of the anesthesia:

  • Throat swelling with difficulty breathing or swallowing
  • Wheezing
  • Injuries of the vocal chords
  • Digestive problems
  • Heartbeat changes (irregular rhythm)

Blood clots – deep vein thrombosis (legs) or pulmonary embolism (lungs)

Infection – only in very rare situations

Transfusion complications – rare hemolytic transfusion reaction (very rare)

Allergy to metal components of the prosthesis – titanium or cobalt-chromium based alloy

Slow healing and bleeding of the wound

Baker’s cyst – fluid builds up behind the knee and it might require drainage

Injury to the arteries – damage will be repaired by the vascular surgeon

Injury to the nerves – the nerve will repair on its own in time

Scarring can reduce the mobility in the knee – physical therapy can improve the range of motion or an additional surgery might be required to remove the scar tissue

Implant failure – improper placement or implant malfunction

Recovery time

The general recovery period after the knee replacement surgery lasts somewhere around twelve weeks.

In the first day, right after the surgery, will be taught by the physical therapist how to stand and even walk using assisting devices. The exercises demonstrated by the physical therapist are meant to help you strengthen your muscles around the knee. He or she might also recommend that you use a continuous passive motion machine, in order to maintain your range of mobility and prevent immobility caused by stiffness.

In the second day after the surgery, you will walk for a larger distance using         any of the following assistive devices: walker, crutches or cane. You will still continue to use the continuous passive motion machine, be recommended to go to the toilet and even climb a few steps.

In the third day after the surgery, you will climb a flight of stairs and come down, try to make transfers without assistance and reduce the amount of time in which you will use the assistive devices. These are the three days you will spend in the hospital and you should be able to get out of the bed and perform transfers yourself, using only minimally the assistive devices.

After these three days, you will be recommended to undergo physical therapy for better recovery. The first of week of rehabilitation will be the one in which you will learn to rely less and less on assistive devices. The physical therapist will prescribe a set of exercises that you will have to perform on a daily basis.

For the following two weeks, you will continue to become more powerful in the knee and increase your range of motion. Thanks to the physical therapy program, you will be able to walk for longer distances, to perform activities of daily living without assistance and the inflammation will be reduced to a minimum.

The next month will be dedicated to increasing the strength of the knee by performing daily activities. You might be recommended by the physical therapist to do toe and heel raises, partial knee bends, abductions of the hip and even bicycling (stationary). The last weeks of rehabilitation will be concentrated on engaging in sports that are useful for the knee joints, such as swimming.

Alternatives to knee replacement surgery

These are the most common alternatives recommended before considering knee replacement surgery:

  • Anti-inflammatory drugs for the symptoms (oral administration)
  • Topical anti-inflammatory creams and ointments
  • Corticosteroids injections into the joint
  • Injections with hyaluronic acid to improve joint mobility
  • Injections with platelet rich plasma reduces the pain experienced in the damaged joint
  • Physical therapy to strengthen the muscles around the joint
  • Walking using assistive devices (walker, cane, crutches)
  • Weight loss programs (losing weight can reduce the pressure on the knees and delay the need for surgery)
  • Supplements for the joints (glucosamine, chondroitin)
  • Vitamin D supplements
  • Supplements of omega fatty acids
  • Warm compresses to the knee to stimulate the blood flow in the area
  • Arthroscopic washout and debridement – the damaged cartilage is made smooth and any debris accumulated in the joint is taken out
  • Microfracture – holes are made in the exposed surface of the bone in order to stimulate the growth of new cartilage
  • Osteotomy – the shin bone is cut crosswise and a wedge is created to shift the load away from the area in which the joint is damaged
  • Autologous chondrocyte therapy – new cartilage is grown in the lab and then applied to the damaged area
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