What is Knee Replacement?
Knee replacement, also called as Knee arthroplasty is a surgical process that helps to resurface the knee joint. This procedure involves replacing a totally worn, damaged odiseased knee with an artificial joint to reduce pain and functional disability.
Overview of knee joint
Knee joint is one of the strongest and most important joints of our human system. It is a synovial hinge joint which allows lower leg to move in relation to the thigh to support the weight of the body.
This joint helps us in performing the following activities -
Parts of Knee Joint:
Tibia-Shin bone or larger bone of lower leg
Cartilage-Function is to reduce friction during the joint movement
Synovial membrane -for lubrication
Ligaments & tendons -Elastin connective Tissue
Meniscus- Shock Absorber
When is knee replacement DONE?
A knee replacement is major surgery and is mostly recommended if other treatments, such as physiotherapy or steroid injections, haven't helped in reducing pain or improve mobility. Most common reasons for undergoing this surgery are:
Osteoarthritis-This is age related arthritis which develops due to inflammatory breakdown of cartilage of the knee joint.
Rheumatoid Arthritis- This is a chronic arthritis which results in soreness and stiffness of the knee joint.
Post traumatic Arthritis- Caused due to severe knee injury.
Candidate for Knee Replacement Surgery
Age and Gender are not a criteria kept into consideration if someone is going for a knee replacement. Generally the only reason for surgical replacement depends on the degree of severity and disability. It is mostly recommended for the older people, but teenager or adult may undergo knee replacement if there is excess wear tear of the knee joint.
Knee replacement surgery is performed when a patient has:
Severe knee pain and stiffness
Chronic Knee inflammation and swelling
Chronic Knee deformity
Failure of Medical treatments
Knee replacement procedure
The key indication for knee arthroplasty is to provide relief from pain caused by severe arthritis. Two type of knee replacement surgery are performed:
Before the procedure
Before the procedure a complete physical examination as well as several diagnostic tests including blood test will be done. Medical history (such as hemophilia, blood pressure, diabetes, and pregnancy), any medications (aspirin) and drug allergy if any should be informed to the doctor prior to the surgery. The patient is advised to stop smoking for as long as possible prior to the surgical procedure.
The types of used prostheses include the following:
Rotating platform and mobile bearing
Posterior cruciate ligament (PCL)-retaining
Surgery is usually performed under general, spinal or epidural anesthesia. The procedure usually take 1-2 hours, the orthopedic surgeon with excise the damaged cartilage or bone and replace it with a metal or plastic implant for restoration of function and alignment.
Incision: an incision is made over the knee cap area to gain access. The incision is usually 8 to 10 inches long
Rotating the Patella (knee cap): once the knee is open, the doctor rotates the patella outside the knee area.
Preparing the femur (thigh bone): The 1st bone to be resurfaced is the femur (thigh bone).The damaged bone and cartilage from the femur is cut and is resurfaced to fit the end part of the artificial prosthesis. Then the femur is implanted and sealed with bone cement.
Implantation of the femoral component: The metal femoral component is attached to the end of the femur and then bone cement is used to seal it into place.
Preparing the Tibia (Shin bone) & implanting it into the tibial component: After that tibia is resurfaced and attached with a metal or plastic prosthesis. The bottom part of the implant is called the tibia tray and is fitted to the tibia. After the tibia tray is placed a polyethylene (medical grade plastic) is inserted in between the tibia tray and femur component, this act as a buffer and will support the joint in case of bend and flex the knee.
Re-adjusting the Knee cap (Patella) & completing the procedure: The knee cap (patella) is readjusted according to the implant to ensure a proper fit. The knee is then bended and flex to ensure proper positioning and movement. The procedure is completed by closing the incision with the help of sutures.
After the surgery
Once the procedure is done, patient will be taken to an observation room. Blood pressure, heart rate, pulse are all monitored and assured that they are stable. Knee transplant surgery usually requires an in hospital stay for a few weeks. It is important to begin moving the joint after the surgery. A physiotherapist will plan the exercise and the pain killer will be prescribed to provide relief from pain.
Post hospital care
After discharge, the patient will be advised to walk with the help of a walker or crutches and will eventually move to a cane in 6 weeks.
Surgical area needs to be kept clean and dry.
Use support handle for stair cases, raised toilet seat, shower bench or chair.
Suture are dissolvable but if not then they must be removed in 10 days.
Bending of knee is variable, but by six week it must bend to 90 degrees. The goal is to obtain 110-115 degree movement.
Once the wound is healed the patient is allowed to shower. By the end of 6 weeks the patient is allowed to drive & walk at moderate levels. Sports and vigorous activities may take up to three months to do them comfortably.
Follow-up checkup will be done after six week. One should continue to see the surgeon for the rest of the life to access the position of the implant.
Some general complications that can arise as a result of the surgery include:
Deep venous thrombosis ( Blood clot)- It can form in calf muscle and can travel up to lung (pulmonary thrombosis)
Stiffness in the knee
Wear- Plastic liner usually wears over the period of time.
Cosmetic appearance- the knee may look different as it was
Inequality in leg length –This may be due to the fact that the corrected knee is more straight
Patella problem- patella (knee Cap) can get dislocate
In extremely rare chances - Congestive heart or Hemorrhage problems
Recovery after the surgery
Recovery times can vary depending on the individual and the type of surgery carried out. For an early recovery it is important to follow the doctor’s advice.
Most of the patients can stand and begin basic movement right after the surgery.
Patient can expect to start walking with support before they leave the hospital.
1st post-op visit is 4-6 weeks from date of surgery.
Swelling is normal (for as long as 6 months), but can reduced by regular application of ice packs.
Patient might have blood accumulation after the surgery that results in a bruised area around your knee. This is normal and will disappear with time.
What are the results of total knee replacement?
Knee-replacement surgery has a high rate of success in eliminating pain and restoring the normal day to day activity.
When should a person undergo knee replacement surgery?
Doctor will be able to decide if you are a candidate for the surgery or not. The decision will be based on the patient’s history, examination, X-rays and response to conservative treatment.
How long will the surgery take?
Surgery will take approximately 2-3 hrs.
How long & where will the scar be present?
The scar will be approximate 6-8 inches long & it will be present on the center of the knee.
What are the six weeks blues?
Approximately 5-6 weeks after the surgery most of the patients begin to feel both depressed and frustrated. It is normal to be in such an emotional state during the period. During the first 6 weeks the patient may get great strides in the reduction of pain and with the range of motion. After 6 weeks, the patient starts feeling completely normal. This 6 week phase is known as “Six weeks blues”.
For how long a patient will require the bandage after the knee replacement surgery?
Patients need to wear the bandage for approximately 1 week or until the wound is completely dry. This bandage should be changed daily to a new dry, sterile gauze.
Will a patient require blood transfusion?
A patient may require blood transfusion.
What are the good positions for knee & what positions should be avoided?
Patient is advised to do straightening of the knee (extension) as well as bending the knee (flexion) on daily basis. A good way to work on :
Extension: is to place a towel roll underneath the ankle while lying down.
Flexion: is to sit on a chair or stationary bicycle and bend your knee.
For how long a patient will a patient be on a blood thinner?
Generally a patient will be kept on a blood thinner for up to 1 month. Approximate duration will be determined by the doctor.
What activities should be avoided after knee replacement?
All impact activities, such as running and downhill skiing, and vigorous racquet sports, such as singles tennis or squash should be avoided.
Should a patient wear compression stockings after the surgery?
Compression stockings are not required after the surgery.
Can a patient use stairs after the surgery?
Yes. Initially the patient with start with the non-operated leg when going up stairs and lead with the operated leg when going down the stairs. Once the leg gets stronger (after about 1 month), the patient can use the stairs in a more regular pattern.
How long will the knee replacement last?
This will vary from patient to patient. It has been seen that over 90% of knee replacements functions well at 10 to 15 years post-op.
Why do knee replacements fail?
Common reasons for failure is loosening of the artificial surface from the bone. Wearing of the plastic spacer may also result in the need for a new spacer.
What is the cost of Knee Replacement Surgery in India?
Cost of Single Knee Replacement (Unilateral) in India ranges between USD4000 to USD6000. Cost of Both Knee Replacement (Bilateral) ranges between USD8000 to USD12000. For an assessment from leading doctors and quotation from hospitals you can write us on [email protected] or submit enquiry.