One of the intricate joints in the body is the knee.
It is composed of the femur's distal end (femoral condyles) and the tibia's proximal end (tibial plateau).
The femoral condyles move smoothly along the tibial plateau, making lower leg motions painless and even.
Osteoarthritis is the one of the most widely occurring diseases that damage the knee to such an extent that surgery is required to replace the joint.
This type of arthritis causes the knee bones and cartilage to wear away, leaving rough and uneven joint surfaces that result in pain and inflammation during movement.
Surgery to replace knee joints is required when:

• A knee suffering from Osteoarthritis is unaffected by conservative treatments like NSAIDs drugs for more 6 months.
  
• The knee functions are impaired or cease to work due to the disease
• The sufferer cannot work or do day-to-day activities because of pain.
  
• Sleep is impossible at night due to pain inn the affected knee.
  
• Walking a short distance becomes unattainable due to pain.
  
• Knee prosthesis becomes loose.
  
• The knee incurs fracture injury.
  

Surgery to replace the knee will be undertaken under general anesthesia by an orthopedic surgeon.
After incising an opening on the affected area, the knee cap, or patella is moved aside and the femur and tibia heads are shaved and rough surfaces are smoothed to make way for better prosthesis placement.
The prosthesis has two parts which are firmly fixed into the thigh and tibia bones with the aid of special bone cement.
Post-surgery bandages include a large dressing on the operation site.
There will also be a small drainage tube installed during surgery for draining excess joint fluids that may leak during the procedure.
The whole leg will be fastened with a CPM, or a Continuous Passive Motion device to help flex and extend the knee at a gradual post-operative rate.
The CPM, continually attached to the leg, will be adjusted to increase the rate and amount of flexion as much as the patient can tolerate.
It can help with faster recovery, lessen post-operative pain, bleeding and infection.
Patient-controlled analgesia (PCA) or epidural analgesics will help with the post-surgical pain which will be present for the first few days after surgery.
As the pain diminishes, oral analgesics may be prescribed after day 3.
It is recommended to take the painkillers about 30 minutes before attempting to walk, or after shifting position.
Intravenous feeding tubes will provide you with hydration and nourishment until you are able to start oral fluid intake.
To lower the risks of infection, prophylactic or preventive antibiotics may be prescribed.
This requires removal of the artificial joint to administer.
From surgery, your leg will be encased in an anti-embolism device known as inflatable pneumatic compression stockings.
These cuts down the risk of blood blot formation which can occur after surgery on the lower limbs.
Walking is encouraged after surgery as soon as you are able to move.
On the first day, post-op, you will be aided off the bed towards a chair.
While confined in bed, it is advised to perform mild ankle bending and straightening exercises to prevent blood clot formation.