The Total Knee Replacement Surgery is an operation to replace a severely impaired knee joint with an artificial joint. The main purpose of the surgery is to relieve the person from pain and mostly restore the function of the joint.
How does the knee joint work?
In a healthy knee, smooth cartilage covers the ends of the thighbone (femur) & the shinbone (tibia). It acts as a cushion between these weight-bearing surfaces and allows the bone ends to breathe and glide easily over one another, allowing for painless and free movement. Muscles and ligaments further provide a side-to-side stability. A synovial membrane lines the joint and produces a clear lubricating fluid in order to lubricate the joint for an easy movement.
What can cause an impaired knee joint?
There can be several factors that cause a knee pain and stiffness, such as injury, which can cause the progressive degeneration of cartilage (osteoarthritis) reducing its ability to serve as a cushion. The bone ends then become roughened and irregular due to the friction caused in between them. This further causes pain and limits our movement. Rheumatoid arthritis (inflammatory arthritis) can even cause inflammation and swelling that might further damage the cartilage. Other problems with the knee joint, including poor alignment of the leg bones and where the blood supply to the knee joint is poor can also lead to acute knee pain.
However, only an orthopedic surgeon can assess the need for a knee replacement taking into account the medical history, physical examination (especially knee motion, stability, strength, and alignment), blood tests and finally, the x-rays of the damaged knee. A knee replacement is a major surgery and there are many things to be discussed with a surgeon, including the risks and benefits of it.
Things To Ask Your Doctor Before Going For A Surgery:
- What are the newest knee replacement procedures available?
- Do I need to go for a partial knee procedure or a total knee arthroplasty?
- When is the time for knee replacement?
- How many times can you have a total knee replacement?
- The average time for knee replacement surgery
- What is the time duration for a knee replacement surgery take?
Total Knee Replacement Surgery Procedure, How is it done?
An artificial knee joint commonly knows as a ‘prosthesis’ has smooth surfaces which replace the degenerated cartilages within the knee joint. The artificial knee joint is however made of metal and hard plastic components that fit together during surgery. Each individual requires their own prosthesis design, which is made by the surgeon.
There are three main factors to keep in mind while designing an artificial knee joint – the femoral component (to supersede the end of the femur), the tibial component (to supersede the end of the tibia) and the patellar component (to replace the back of the kneecap). All of these components play a key role in a knee joint surgery.
The knee joint replacement surgery can be performed under a general or spinal anesthetic. This is to be discussed with the surgeon and anesthetist prior to surgery, for an appropriate judgment.
The complete procedure usually takes around 2 hours. The operation begins with an incision being made over the front of the knee joint. The surgeon has to expose the knee joint, then loosen the muscles and ligaments surrounding it, and take the kneecap out of its place. The worn cartilages within the joint, including the back part of the kneecap, are removed and the ends of the bones are precisely reshaped and restructured. The components of the prosthesis are then attached to the bone ends using a specialized bone cement, and attached together. The ligaments and muscles are repositioned and, if necessary, the ligaments are then readjusted to for better functioning of the knee.
Finally, at the completion of the surgery, a drainage tube is inserted to drain excess fluids from and around the new joint. The surgeon will then close the layers of tissue and the skin with stitches, followed by a dressing around the knee.
Several surgeons suggest antibiotics during and after the operation to prevent the development of infection in the new joint. If required, the surgeon will also discuss blood transfusion before the surgery and will ask to make arrangements well in advance.
The surgeon prescribes several measures to prevent the blood-clot formation and reduce leg swelling. These may include compression stockings, inflatable leg coverings (compression boots), and also sometimes, blood thinning medication.
Steps To Be Taken After The Surgery :
After the operation, your surgeon and a physiotherapist will work together to set recovery and movement guidelines for your knee joint. Most of the time, this includes passive exercises, before progressing to gentle knee-bending exercises and then finally walking. Ongoing exercises are further designed to increase the range of movement of the new joint and to strengthen the surrounding muscles and cartilages, particularly the thigh muscle (quadriceps). Strength in the quadriceps will further keep the knee joint stable and strong, therefore protecting the new joint.
The success of the Total Knee Replacement Surgery depends on following the recovery and movement instructions prescribed by the surgeon and the physiotherapist, while in the hospital or even at home.
The time spent in the hospital can vary from about 6 to 9 days. The healthcare team (surgeon, physiotherapist or physical therapist and nurses) will make an ongoing assessment of recovery of the knee and will then recommend when going home would be appropriate. The healthcare team’s assessment also states if special equipment needs to be installed to assist the patient at home or if home help needs to be arranged.
The patient needs to use crutches for up to six weeks after the operation. By 6 weeks, the majority of people returns to a range of normal activities, including driving.
Risk Of The Process
As with any surgical procedure, there are several risks involved with total knee joint replacement. With the general risks of blood infection and risks associated with anesthesia; Here are a few risks that are specific to this surgery:
- The prosthetic leg might differ in size and shape compared to your other leg.
- The knee prosthesis might become loose and require a further operation.
What are the follow-up steps after the surgery?
It is usually advised to see the surgeon or the physiotherapist two to six weeks after surgery to assess recovery. Long-term follow up may also be recommended in order to assess the fitting of the artificial knee joint. It may be that replacement of the artificial knee joint is required if it loosens and becomes painful.
Most of the modern knee replacements last for around 15 years if properly cared for and not subjected to too much stress or exertion.