Prosthesis of the knee joint: indications and the essence of the operation

The life of any person is connected with constant movement. Such seemingly elementary things as going to the store, going down the stairs, running to the bus for some people become impossible due to illness of the knee joints. But even out of the worst situation there is always a way out. Thanks to modern medicine, a person who can not move due to pain or deformities in the knee joint can again feel the joy of independent movement. And prosthetic knee replacement will help in this.

The essence of the operation

Prosthetics, or endoprosthetics, of the knee joint is an operation to replace an abnormal knee joint or some of its structural elements with an artificial endoprosthesis( internal) that owns all the anatomical characteristics of a healthy joint and will allow the knee to return its motor function.

Modern prosthetic knee joints are made of completely biocompatible, hypoallergenic and high-strength materials, to which manufacturers make a number of stringent requirements, among which:

  • bioinertivity - the material should not interact with the body;
  • minimal risk of allergic reactions;
  • high strength;
  • long service life of the prosthesis( 15-30 years).
Artificial knee joint
For damaged knee joints, damaged biological tissues are replaced with artificial material

For the manufacture of modern designs for prosthetic knee replacement, materials such as metals and their alloys( mainly noble metals such as cobalt, titanium, chromium), ceramics, polyethylene, bone cement( polymethylmethacrylate), as well as complex products from these materials.

Prosthesis is a very complex procedure, during which the future endoprosthesis is subjected to detailed testing and control. All products are manufactured individually and have a quality certificate and a warranty period. In the event that a defective prosthesis is installed, the patient will be replaced absolutely free of charge. Of course, the artificial knee joint can not completely replace natural, even if its cost is colossal, and the operation was performed by the most brilliant orthopedic surgeon in the world. Criteria for successful endoprosthetics are the patient's relief from chronic pain and the ability to move independently, albeit with additional support. Many patients after such an operation even return to physical work and sports, but to ensure that the prosthesis serves a long time, it is better to avoid heavy loads.

The service life of the endoprosthesis varies and varies between 12-30 years. It depends on the material and type of knee prosthesis, the quality of rehabilitation and compliance with all the doctor's recommendations for using a new knee.

Types of knee arthroplasty

Depending on the severity of pathological changes, prosthetic knee replacement is partial( when replacement is only part of the joint) and complete, or total( when the knee is changed completely).

In this regard, identify the main types of knee endoprostheses.

Partial( single-pole) implant

Applied when only one condyle( inner or lateral) is destroyed in the knee and the posterior cruciate ligament is retained. This type of prosthetics is considered more physiological, as during the operation, as much as possible of the patient's own tissue is preserved. Rehabilitation is faster, and the cost of endoprosthetics is much less.

Total prosthesis with movable platform

This prosthesis consists of 3 components - a tibial, femoral and movable polyethylene insert inside the tibial component. This design allows rotation in the knee joint, which significantly increases the amplitude of movements. But this prosthesis also has negative sides - it wears out quickly, in addition, for its high-grade functioning, a good development of the supporting apparatus of the knee joint( muscles and ligaments) is necessary.

Total knee joint endoprosthesis
The structure of the total knee arthroplasty

Total prosthesis with a fixed platform

This is the most common type of knee endoprosthesis. In this case, the central polyethylene component is fixed on the tibial metal, and the femoral glides along this fixed cushioning platform. If the patient does not follow the recommendations of a specialist in the use of the prosthesis( excessive loads, overweight), the design quickly loosens and pain occurs. And this requires repeated endoprosthetics.

Indications and prohibitions for the replacement of the knee joint

Knee replacement begins with the last stage of chronic knee diseases, injuries, congenital anomalies, when the knee function is almost or completely lost.

List of diseases that lead to surgery:

  • deforming knee osteoarthritis( gonarthrosis);
  • arthritis of the knee joint;
  • Bechterew's disease;
  • aseptic necrosis of bones that form the joint;
  • congenital underdevelopment or knee deformation;
  • trauma( false joint, intra-articular fracture);
  • purulent melting of the joint.

It is important to remember that the cause of the number one operation to replace the knee joint is deforming osteoarthritis. Therefore, the prevention of this disease is an urgent issue and should be used by all patients with risk factors for such pathology.

Contraindications to knee endoprosthetics:

  • fever and acute infectious disease;
  • is an allergy to the prosthesis material;
  • is a severe stage of somatic pathology, for example, cardiac, renal, pulmonary insufficiency;
  • age under 25 years;Obesity 3 and 4 stages;
  • pathology of blood clotting;
  • malignant neoplasms of any stage;
  • endocrine diseases, which are accompanied by a violation of bone tissue metabolism( osteoporosis, hyperparathyroidism).
Deforming osteoarthritis of the knees
Deforming osteoarthritis of the knee often leads to the need for endoprosthetics

Preparation for knee replacement

Knee endoprosthesis is a very serious, long, voluminous and dangerous operation. Therefore, the preparation before it must be the most thorough to minimize the risk of complications during and after surgery.

Basic recommendations for the patient on preparation:

  1. It is mandatory to undergo a full medical examination before the operation, hand over all the prescribed tests and visit all specialists, including a therapist and an anesthesiologist. On the basis of the results obtained, the doctor will decide whether to allow surgical intervention or prohibition if contraindications are present.
  2. Control your weight. If you have excess weight, the specialist will "force" to go on a diet. This is extremely necessary, since every extra kilogram is a reduction in the chance of success of the intervention.
  3. Before the operation, you need to do gymnastics and practice walking on crutches, because in the first time after the operation you will move this way.
  4. You also need to buy crutches yourself and other necessary items for post-operative care. Also, you need to take care of the arrangement of your housing, for example, hang the handrails in the bathroom and toilet.
  5. Stop taking certain medications, as detailed in the expert.
  6. Consider the need to donate your own blood or find a suitable donor, since blood loss during such an operation is quite voluminous.
Before the operation it is necessary to prepare your house and install handrails in the bathroom

Operation and possible complications

As a rule, the operation itself lasts 1-3 hours, sometimes longer, only under general anesthesia. The surgeon performs a large incision along the front surface of the knee and releases the joint, after which it conducts a detailed audit. Only after the examination the doctor makes the final choice of the type of prosthesis and the method of its installation.

All pathological tissues are removed, the bones are prepared for the installation of prosthetic elements. First, the orthopedist puts a test prosthesis, which comes complete with the original. He tries to work constructively. If everything is in order, the surgeon sets up a permanent endoprosthesis.

Also you can read: Endoprosthetics of the knee joint Total knee replacement

After this wound is sutured, drainage tubes and bandage are installed. The operated leg is temporarily immobilized.

Among the possible complications of endoprosthetics, most often occur:

  • bleeding;
  • PE;
  • Fat embolism;
  • pathological reaction to anesthesia;
  • infection of a postoperative wound;
  • damage to the neurovascular bundle;
  • poor fitting of the prosthesis.

Rehabilitation period

Rehabilitation after knee replacement is a long period, which requires a lot of strength and patience, but further function of the leg will depend on it.

In the first hours after the operation, you can not move your foot, but already on day 2 you can start passive gymnastics and breathing exercises under the guidance of a physiotherapist.

The first steps should be done with crutches, but too long to use them is prohibited, as this gives psychological uncertainty about the work of the prosthesis, which can prolong your recovery.

Metal knee prosthesis
  • Operation essence
  • Types of
  • endoprostheses Indications and inhibitions
  • Preparation for operation
  • Operation and complications
  • Rehabilitation period