Total knee replacement (TKR) is a surgical procedure where worn, diseased or damaged surfaces of the knee joint are removed and replaced with artificial surfaces.
Understanding your knee joint
The healthy knee : the healthy knee joint is a remarkable mechanism. It is formed by the bottom end of the femur (thigh bone), the top of the tibia (shin bone) and the patella (knee cap). A healthy knee joint has cartilage between the bones that acts as padding. This padding helps assure a gliding movement of the knee that is both effortless and smooth. The healthy knee joint also has a joint capsule which houses the synovial membrane. This membrane produces lubricating fluid which contributes to the smooth movement of the knee.
The human knee is designed to withstand a lifetime of stressful activity. However, sometimes arthritis intrudes, interfering with the knee’s ability to cushion the body from stress, and eventually causing the pain that dramatically erodes your quality of life.
All you need to know about knee Replacement surgery
- Osteoarthritis resulting from “wear and tear” of the knee is the most common reason individuals need to undergo knee replacement surgery.
- Rheumatoid Arthritis, injury and infection may also lead to a need for knee replacement surgery.
- The decision to have a knee replacement is based on whether the painful destroyed knee is significantly affecting a person’s day to day living.
- Total knee replacement (TKR) is designed to provide painless and unlimited standing, sitting, walking, and other normal activities of daily living.
- Improved surgical tools & procedures have led to artificial joint replacement for arthritis of the hip and knee as two of the most successful surgeries of the last century.
- The choice of surgical procedure and the type of implant depends on the surgeon’s preference and the individual patient’s requirements.
- Materials used for resurfacing of the joint are not only strong and durable but also optimal for joint functions they produce as little friction as possible.
- The artificial joint or ‘prosthesis’ generally has two components, one made of metal which is usually cobalt – chrome or titanium. The other component is a plastic material called polyethylene.
- The artificial implant is fixed to bone by either a cemented procedure or non-cemented procedure. This will usually affect whether one can fully weight bear or only toe-touch for the first six weeks following surgery.
- Some of the most common complications following knee replacement are deep venous thrombosis (DVT), infection, stiffness and loosening of the implant.
- Postoperative care begins with a team approach of the health professionals within the hospital which include nurses, physical therapists, respiratory therapists and occupational therapists.
- Once the postoperative total knee patient has progressed to a point where they are no longer homebound from their surgery, the patient may be a candidate for outpatient physical therapy services.
- With proper care, individuals who have undergone total knee replacement can expect a greater than ninety-five percent chance of success for at least 15 years.
The procedure has been proven to help individuals return back to moderately challenging activities such as golf, bicycling, and swimming. Total knees are not designed for jogging, or sports like tennis and skiing (although there certainly are people with total knee replacements that participate in such sports).
Indications for total Knee Replacement
- Deterioration of the knee joint cartilage (osteoarthritis).
- Inflammation in the lining of the knee joint (rheumatoid arthritis).
- Physical injury to the knee joint resulting in arthritis (traumatic arthritis).
- Moderate valgus (knock-kneed), varus (bowlegged), or flexion (bending) deformities.
- A loss of blood supply to the lower portion of the upper leg bone (femoral condyle) which leads to tiny breaks within the bone and possible collapse (avascular necrosis).
- To correct problems caused by previously failed surgeries.
- Certain breaks in the knee joint bones (fractures).
If You Are Considering Total Knee Replacement Surgery
If you have been told you have a severely damaged knee joint and would benefit from a TKR, the questions you need to ask yourself are:
- Have all of the appropriate non-surgical treatments been tried.
- Is my painful knee significantly restricting my day to day activities and not allowing me to do the things I need to do and the things I enjoy doing?
If the answers to these questions are yes, you may be a candidate for a new knee.
Types of Knee Joints Available and Recommendations
- The fixed bearing knee surfaces where the top of tibal (leg bone) and lower end of femur (thigh bone) are approximating are fixed by bone cement. There is no movement of the bearing surface viz a viz the bone platform. This type of joint is time tested and has been used world over for more than 25 years and is generally successful.
- Mobile bearing or rotating platform is a variety where the top of leg-bone provides mobile surface and this joint is considered to be having less wear & tear and therefore longer life. The last word about the authenticity of the tall claim is yet to come. The implant is otherwise successful.
- Third variety is high flexion knee which is supposed to provide more bending of the knee i.e. up to 150-160 degrees. This happens because of its construct but in practice many a times it may not be realized. This knee is more expensive than the earlier two knees. As a matter of wisdom in scientific world it has been established that flexion of knee post operatively depends more on its preoperative range of movement and technique and postoperative physiotherapy. The make per say is not all.
- The constrained knee variety is meant for unstable knee where deformity is more i.e. the leg is bent on one or the other side excessively and support of side-bands (collateral ligaments) is not good enough. Also this knee is used for revision of failed primary knee replacements. Its cost is almost double the amount of primary knee implant.