What is knee replacement surgery, and how does it work?
Knee replacement involves removing parts of the bones that make up the knee joint and replacing them with artificial implants. It is primarily used to treat osteoarthritis-related knee pain and stiffness.
The majority of persons who have this surgery have advanced knee arthritis. The cartilage in the knee has worn away, and the surface has become pitted, degraded, and uneven. Pain, stiffness, instability, and a shift in body alignment are all symptoms of this condition. Some persons who have a weaker knee joint due to an injury or another ailment may benefit from knee replacement surgery.
What is the procedure for a total knee replacement?
The orthopaedic surgeon first cuts the knee and then shifts the patella (kneecap) to the side. Bone spurs (small bony growths) will be removed if they are present, common in osteoarthritis.
The anterior cruciate ligament (ACL) and, in certain situations, the posterior cruciate ligament (PCL) are then removed from the femur and tibia (PCL). The PCL is kept in some types of knee replacements.
The surgeon cuts and removes cartilage and some bone from the upper part of the tibia and lower parts of the femur during the major portion of the procedure. The femoral condyles are two knobby protuberances that are removed from the femur. Metal implants are then used to cap the tibia and femur, creating new surfaces for the joint. The femoral component's surface is shaped like the original femoral condyles. If the bottom of the kneecap has degenerated, the surface may be taken away and replaced with a polyethylene implant.
Finally, dissolvable sutures are used to restore the various layers of tissue, and the skin incision is closed with sutures or surgical staples. The patient will be brought to recovery with a bandage put over his knee.
Partial Knee Replacement
In uni-compartmental knee replacement/ or partial knee replacement or unicondylar knee replacement, only one part of the knee surfaces is replaced in comparison to the other procedure, total knee replacement, where both inner and outer part of the damaged bones are replaced with metal implants. The damaged bone and cartilages might need a replacement for most of the cases, but in certain cases where the disease is limited to just one area of the knee, the total replacement might not be required.
Also, because partial knee replacement is done using a short incision, patients tend to spend lesser time and tend to return to normal activities sooner than in total knee replacement. This, decision, however, is case specific. There is a range of treatments for knee osteoarthritis and you must consult doctor for advice regarding considering a complete or partial knee replacement surgery.
Total Knee Replacement
A total knee replacement surgery is also known as knee Arthroplasty or even knee resurfacing because only the surface of the knee is replaced. The damaged region of the upper and lower bone is removed slightly. The removed cartilage and bones are replaced with metal implants that mimic the surface of the joints. The patella might also be resurfaced depending on the surgical necessity. Finally, a medical grade plastic spacer for smooth gliding is inserted between the metal components. This completes the process.
Post-operatively we make the pt stand and walk within 24 hours of surgery with a help of a walker. Post-operatively 5 days are dedicated for physio, so that by the time you are discharge you should be able to go to washroom and sit on a commode with the help of a walker independently, able to stair climb, and take care of most of your daily routine activities.
What are the components of knee replacement implants?
Each patient's choice of design and materials for a knee replacement prosthesis is unique. Metal is used to make the major implant components, which are commonly titanium or chrome-cobalt alloys. The implants are either cemented or osseointegrated, which involves a porous metal stem extending into the tibia and the patient's natural bone growing into it. Between the tibial and femoral implant surfaces, a plastic platform or spacer will be introduced. Polyethylene is used to make the spacer.
Metal alloys (cobalt-chromium) or metal-ceramic alloys make up most femoral components (oxidized zirconium). Plastic makes up the patellar component (polyethylene). The tibial implant is similarly made of plastic (polyethylene). The following materials can be used to make the tibial tray component:
- Cobalt-chromium (metal alloy) (metal alloy)
- Polyethylene terephthalate (plastic)
After a knee replacement, how long does it take to walk?
Within two or three days of surgery, most patients use a straight cane, walker, or crutches. The distance and frequency of walking will increase as the days continue.
Patients can normally drive a car three to six weeks after surgery and return to all other normal activities by or before that time. It could take up to four months to fully recover and regain full strength and mobility. However, in many situations, patients are much more mobile one month after surgery than they were before their knee replacement.
Dr. Manu Bora – Leading Orthopaedic in Mumbai
As per Dr. Manu Bora, 8/10 knee related injuries can be cured without any surgery. He has helped plethora of his patients and some very leading sportspeople to bounce back after just a few days post the knee replacement surgery.