What is knee replacement surgery?
If you have been advised to have a knee replacement surgery, it means that you have a knee joint degeneration such that it is no longer possible to lead a healthy life without a transplant. We will discuss and briefly understand what knee prosthesis is, how many types exist and what involves surgery of this kind.
Knee prosthesis (knee arthroplasty) involves replacing the surfaces lining the knee joint.
The pathological conditions that can lead to a situation for which knee arthroplasty is required are numerous –
- Primary arthrosis
- Post-traumatic arthrosis or secondary to various types of trauma
- Rheumatoid arthritis
- Juvenile rheumatoid arthritis
- Autoimmune arthropathies
- Primitive bone tumors
- Arthritis outcomes (e.g., osteomyelitis and bone tuberculosis)
Being an intervention that in most cases is carried out for problems related to osteoarthritis, it goes without saying that the people most exposed to risk are those between 50 and 90 years old.
Types of knee prosthesis
It is essential to know that when we talk about knee prosthesis, we mean a wide range of possibilities that the surgeon can utilize –
- Total knee replacement surgery – Complete lining of the articular surfaces of the tibia and femur, with or without the sacrifice of the anterior and posterior cruciate ligaments. A patella prosthesis may also be associated.
- Single-compartment knee replacement surgery – The knee is made up of three compartments – medial compartment, lateral compartment and patellofemoral compartment. In the uni-compartmental prosthesis, the surgeon treats one of these three compartments.
- Prosthesis revision surgery – In this case the surgeon will modify or replace an already implanted prosthesis, possibly removing it and inserting a new one.
Single compartment prosthesis are popular
Although most of the surgeons implant a total knee prosthesis, the mono-compartmental knee prosthesis is increasingly taking hold.
Considered initially as a niche solution, the unicompartmental prosthesis is increasingly used by surgeons, when the arthritis damage involves only a part of the knee. Furthermore, in selected cases in which the damage includes two of the three compartments of the knee, and the ligaments are intact, it is also possible to implant a bi-monocompartmental prosthesis (i.e., two unicompartmental prostheses in the same knee).
One of the advantages of the unicompartmental prosthesis is that, by replacing only one part of the knee, the movement of physiological sliding of the articular surfaces between them is not altered. In essence, the tibia and femur will continue to act as in a healthy knee, which is no longer the case when the prosthesis is total. In the latter case, the knee will develop an artificial movement, given by the prosthesis, which is different from the original one.
What makes up the prosthesis
The knee prosthesis consists of various elements that have the task of replacing the physiological components of the joint: the tibial component, the femoral component, and the insert.
The tibial component is mainly constituted by a metal support plate which will anchor on the suitably prepared tibial surface and by a polyethylene insert.
The femoral component is entirely metallic. It too, like the tibial component, will anchor on the appropriately prepared surfaces and slide on the polyethylene insert.
The choice of the type of prosthesis, its size and the means used for its fixation are influenced by various parameters including the quality of the bone, the structure of the joint components and the age of the subject who must undergo surgery.
Post surgery recovery
If there are no complications, the main objective to be achieved is to walk again; for this purpose, it is necessary to undertake a physiotherapy program aimed at restoring strength to the muscles and mobility to the joint.
Often the patient after 6-8 hours of the operation can walk with crutches.
Knee replacement surgery is performed at nearly every specialty hospital in India. It is considered as a reasonably easy procedure and total knee replacement costs INR 300,000 or less, i.e. USD 4,200. Thos cost of partial knee replacement is half that. In state-run facilities, the price is as low as INR 60,000 or USD 840. Since it occurs widely and is treated with a relatively simple procedure, every large city in India has multiple hospitals which offer knee replacement packages including cost of physiotherapy for a month to build strength.