Knee Arthroplasty

Listed below is the step by step procedure of knee arthroplasty:

1. What is Knee Arthroplasty?
2. Why is Knee Arthroplasty Required?
3. Pre-operative Preparation
4. Day Before Surgery
5. Procedure Day
6. Methods/Techniques of Knee Arthroplasty Surgery
7. Post Procedure
8. Risks and Complications
9. FAQs

What is Knee Arthroplasty?

Knee arthroplasty or Knee Replacement Surgery are the terms to denote surgical treatment for people suffering from knee damage and the subsequent pain from it. Arthroplasty means “surgical repair of a joint.” Hence, knee replacement surgery is the surgical repair of joints in the knee. Knee replacement surgery involves replacing the malfunctioning joint with an artificial metallic one.

Why is Knee Arthroplasty Required?

A knee replacement is a pretty common surgery undergone today by not only people in their old age but also those who have lost their mobility due to knee damage, accidents or any other unforeseen incident. Following listed are the events that necessitate someone to undergo a knee replacement surgery:

• Osteoarthritis
  

  Osteoarthritis, a type of arthritis, is characterized by inflammation of joints in knees. It can happen as much to a person in his 50s as much as it could to individuals in their 20s and 30s. Joint swelling and aches are common to a person suffering from osteoarthritis. However, an arthroplasty or knee replacement is only an option when the inflamed knee is reducing quality of life of the person to a large extent.

  
• Rheumatoid arthritis
  

  Rheumatoid arthritis is not only an autoimmune disorder but also a systemic one. Which means, it affects the entire body. This disorder also has joint inflammation and its swelling and aches. If left untreated, this disorder has the capability to cause destruction which is irreversible to bones, cartilage, joint tissues. The doctor recommends surgery only when medications fail to have the expected outcome.

• Knee deformity
  

  Bowing out of knees which is noticeable may alert your doctor to prescribe surgery.

• Inactivity
  

  Inactivity or reduced mobility due to aching knee joints and also marked inability in doing everyday activities is also cause for concern. Knee replacement surgery is an option for people at such times.

Pre-operative Preparation

This stage entails, diagnostic testing before the big day. Based on the results, the day and date are decided for surgery. Following tests are required to be done in the preoperative evaluation:

• X-ray

  This imaging modality, along with Magnetic Resonance Imaging (MRI) is ordered by the orthopedic for understanding the status of the knee damage.

• Complete Blood Count

  This test is relevant for helping the doctor to know the status of hemoglobin, RBC and WBC.

• Electrocardiogram

  Heart health and its functioning is monitored through Electrocardiogram(ECG) test.

• Physical examination

  Physical fitness of patients is determined through this test.

• Anesthesia testing

  The anesthetic agent best suitable to your body (to be used during surgery) is found out. Also, coagulant test helps the doctor in determining how well the formation of blood clots happens naturally.

Day Before Surgery

Its importance stems from the fact that it decides the mobility of a person for the rest of his life and in turn the quality of life too.

Following are the measures one needs to follow in the period before the surgery and also on the day prior to the big day:

• Medication
  Prior to undergoing surgery, patients are usually prescribed certain medications. Antacids will be given to prevent development of acidity which can be an obstacle during surgery. Prophylactic pain killers and antibiotics may be given to the patient to combat pain and infection respectively, after surgery.
• Fasting
  The doctor may ask you to refrain from eating anything after midnight.

Procedure Day

On the day of procedure, following things happen before you are taken into the operation theater for knee replacement:

• Consent form
  Signing a consent form is a must, since that gives your written approval for the surgery.
• Sedative
  A sedative is given to you before the procedure to make you feel sleepy.
• Hospital gown
  You are made to change into a hospital outfit that is loose and comfortable.

Methods/Techniques of Knee Arthroplasty Surgery

An intravenous line is connected to your hand or arm. General anesthesia is administered for making you unconscious. A urinary catheter is placed inside the body for drainage of urine.
There are the two types of replacement procedures.

• Total Knee Replacement
• Partial Knee Replacement

Total Knee Replacement

The total knee replacement procedure lasts anywhere between 1-3 hours. An incision is made in the knee to alter the position of kneecap so as to expose the knee joint adequately for the duration of surgery. The incision helps in accessing the shin-bone and femur. Surfaces of the insides of knee are shaped so as they are able to hold the joint, fitted artificially during surgery. The prosthesis (artificial body part) is then fitted on the last end of femur bone. Bone cement is then used for making the prosthesis stay in place. A plastic spacer is then placed on tibial surface, once the prosthesis is fixed on the bone. The plastic spacer acts as a shock absorber. Thereafter, the surgeon flexes the knee to 110 degrees. After this, the incisional area of skin is stitched up.

Partial Knee Replacement

Partial Knee Replacement- Also known as unicompartmental knee replacement and unicondylar knee replacement, this type is a minimally invasive surgery for replacing damaged knee joints. Smaller incisions as compared to total knee replacement are made by the operating surgeon for working on the knee joint. The damaged portion of knee joint is surgically removed. An artificial prosthesis is fitted into its place. The surgeon makes sure, the prosthesis fits perfectly before concluding the surgery. A metallic knee cap is placed over the affected part of the knee. Bone cement is filled to make it stay in place. Subsequently, the incision is also stitched up. Ideally, you are likelier to get recommended for a partial knee replacement, if arthritis has damaged only a part of the knee and still the knee's range of motion is good, ligaments are stable and when you are old and not active.

Post Procedure

You will be moved to the recovery room after your knee is properly bandaged. A catheter tube is also attached to the joint for draining out fluid that builds up from surgery. When you are sleeping the knee will be connected to a continuous passive motion (CPM) machine for flexing your legs while you are resting. A catheter is also inserted to save you from trips to the washroom.

Additionally, you are also made to wear compression stockings for reducing chances of blood clots and improving blood circulation. An intravenous line will be attached to your vein for administering medications. Ask your doctor for medication if you experience diarrhea which is completely normal in the post operative period.

Dos and Don'ts after Knee Arthroplasty Surgery

There are certain measures one needs to follow to have a speedy and safe recovery post undergoing knee replacement. Few of the dos and don'ts to be followed are as below:

• While sleeping, always make sure to sleep straight and not in a way that could twist the knee.
• Avoid driving for the next 6-8 weeks following knee replacement. Start driving only when you feel the confidence.
• Make sure not to put pressure on your knees while going about your everyday activities.
• The incisional area should be kept clean and infection free. It is important for healing of the wound created during making incision.
• Try to be sure that you don't slip on the wet bathroom floor while having a bath.
• During the recovery period, avoid running, climbing and jumping and also engaging in other high impact activities. They are likely to give you stress injuries curbing early recovery.
• If you have a multi-storied house, avoid climbing stairs to go up. Make arrangements beforehand such that you are not required to use the upper portion of the house.
• Avoid sitting in one place for more than an hour, that could only increase stiffness in the knee region.
• Use ice packs for keeping the operated knee from swelling and aching.
• Learn to use crutches and walking aides few weeks prior to your knee replacement surgery.
• Exercising and walking daily as prescribed by the doctor and physiotherapist should not be compromised.
• Learn and implement exercises from the physiotherapy sessions that would reduce discomfort, stiffness and improve blood circulation in the operated area.
• Use the continuous passive motion machine as prescribed by the doctor. As it helps you to achieve maximum range of motion from the operated knee.
• At home, remove all rugs and carpets for the time being, as stepping on soft ones may make you trip and fall down.

Risks and Complications

A knee replacement is a life-altering surgery. However, just like other surgeries, this surgery also carries few risks which need to be discussed with the doctor before undergoing it. Few of the risks are as listed below:

• Deep vein thrombosis
  Deep vein thrombosis in simple terms means formation of blood clots in veins which run deep inside the body in thighs, calf or pelvis region. Blood clotting can be triggered by various factors. Antigens and fats that get released into the bloodstream also has the capacity to trigger blood clots.
• Fluid buildup
  It is a not very serious complication. Fluid buildup happens behind the back of the knee and can be cleared with the help of draining it out.
• Stiffness
  Patients may experience stiffness in their knees post a knee replacement surgery which is totally normal. The patient may not be able to bend his/her knees back and forth. This can be alleviated with the help of a physiotherapist. The normal range of motion of the knee can be achieved with the help of exercises.
• Infection
  Infection is not a negligible risk. If infection develops within the knee joint after surgery, it can be an extremely painful condition. The infection risk is likely to occur in few weeks of surgery and is dealt with the help of medication and antibiotics for the time ahead.
• Noisy implants
  A clicking sound coming out from implant is not uncommon. Since the implants are made out of plastic and metal, the clicking sound from the knee after some movement is common and not anything to lose sleep over.
• Blood vessel injury
  There is a very minor possibility of the nerves behind the knees getting damaged during surgery.
• Injury to the nerves
  In rare cases, it is possible that the nerves adjacent to the knee joint which is being operated upon, get accidentally damaged during surgery. This might affect the function of the nerves depending upon the degree of damage which is done. If the damage is severe, a neurologist can be consulted to restore nerve function.
• Dislocation
  Dislocation of the newly fit joint can also take place which can be treated by surgery.
• Wounds
  Wounds and the skin near the replaced knees need to heal properly. A skin graft may be done if the recovery does not take place as expected.
• Allergy
  The implant is made of metals like titanium and combination of other metallic alloys. Many people have allergies to certain objects and metals. The doctor needs to be notified of the same.
• Bone fracture
  Fracture and damage to surrounding bones during procedure because of surgical instruments and accidental damage is completely possible.

FAQs

1. What are the factors that decide whether you are a candidate for knee replacement?

   Following are the factors that decide whether you are a likely candidate for knee replacement surgery:

   • Age - The orthopedic is likely to recommend you for a knee replacement for your damaged knee if you are anywhere between 55-70 years of age.
   • Knee ache - Immobility and a lack of movement due to knee pain is also likely to make you get recommended for total knee replacement surgery.
   • Radiological imaging - If the MRI results show even a small amount of degeneration and wear and tear in knees, decision regarding the replacement type and surgery date needs to be made.
   • Functioning of knees - If any fault in knee functioning is observed by your orthopedic surgeon through the range of motion. That may be a green signal for surgery.
   • Ineffective medication - Also, if the line of treatment of medication decided by your orthopedic does not work out and knee pain persists, then it is time you undergo a total knee replacement.

2. How can one prevent problems with a knee joint replacement?

   Problems after a knee replacement surgery could be prevented with the help of proper diet, following physiotherapy exercises and being active maximum times instead of resting all the time. The replacement ideally should last for the next 15-20 years.

1. Information on Total Knee Replacement Surgery
2. Information on Partial Knee Replacement Surgery
3. Information on Knee Osteotomy