A knee prosthesis can be used for partial or complete replacement knee joint, damaged cartilage which no longer provides joint mobility and pain-free support.
When is surgery indicated? When there is incurable wear and tear of the knee joint, which leads to severe pain during exercise and at rest, and this pain significantly limits daily life, the knee joint can be surgically replaced with a prosthesis, which helps reduce pain and improve function.
Surgery technique Under partial or general anesthesia, the knee joint is exposed and the damaged surface of the joint is removed. Depending on the size of the damage, a naturally shaped metal cap replaces the entire surface of the joint or only the most affected part. Fixation can occur with or without bone cement. Sometimes, to eliminate pain, it is necessary to replace the lateral side of the kneecap. For more severe cases, various special prostheses are available.
How is the operation performed? The operation is performed under partial or general anesthesia. The knee joint is released through an incision on the front side, and the diseased parts of the joint surface are removed with special instruments. Then, using special templates, the femur and tibia are prepared one by one and trial prostheses are installed, with which the expected result is checked. Only then are the final components of the prosthesis installed and strengthened. A synthetic attachment (polyethylene) is used as a shock absorber and sliding plane between the main components of the prosthesis. The parts of the prosthesis themselves consist of special, very high-quality metal alloys. With cementless prostheses, the parts adjacent to the bone are made of titanium.
When should you choose a total or partial denture?
During knee arthroplasty, the surgeon may choose to install a total (3-compartment) or partial (1-compartment) prosthesis depending on the condition of the knee joint and ligaments.
- 3-compartment prostheses: Replace all of the damaged knee cartilage (eg, arthrosis) and sometimes require removal of some of the cruciate ligaments. This can be the entire femoral cartilage, and sometimes the patella. There are three-compartment dentures with sliding or hinged joints, the latter being less common.
- Single-compartment dentures: Also known as hemoprostheses or partial dentures, these replace only part of the cartilage of the damaged compartment without touching other knee compartments or ligaments. This may be the internal or external femortobial compartment. They are used for osteoarthritis limited to one compartment. Other compartments and ligaments must not be damaged.
Rice. Single compartment knee joint
Results of knee replacement
Functional results are excellent in 90% of cases; The criteria for their assessment are pain, joint mobility and the ability to use the knee, especially when walking. The first goal of installing an endoprosthesis is to reduce pain. In 60% of cases, complete disappearance of pain is achieved, in 30% of cases, episodic pain persists, often associated with changes in weather, however, these pains are not severe and do not require any analgesic therapy. In 10% of cases, the pain is slightly stronger, while there is no defect in the area of the prosthesis.
How to choose between a fixed and movable earbud?
The tibial liner is one of the components of total or three-compartment knee prostheses. There are knee prostheses with a fixed liner and knee prostheses with a movable liner.
Movable earbuds have become very popular in recent years and theoretically have certain advantages over fixed earbuds, such as greater comfort during movement and a longer service life.
However, to date there is no concrete evidence of clinical benefits associated with the use of mobile inserts.
Rice. Knee prosthesis with movable insert
Service life of the knee endoprosthesis
Currently, over a more than 20-year observation period, we can say that the service life of endoprostheses reaches this period. However, the risk of damage to the prosthesis is proportional to the service life as well as the weight of the patient; this damage usually manifests itself as wear or loosening, that is, the mobilization of the elements of the prosthesis in relation to the bone on which they rest. 10-year statistical studies show that during this period another 80% - 90% of endoprostheses remain in place. Consequently, not all prostheses have a 20-year service life, but a small bone resection performed during their installation makes it possible to replace them in good technical conditions.
What type of fastening should I choose?
When implanting a prosthesis, there are three types of anchorage to choose from: neutral mechanical alignment, kinematic hinge, or hybrid anchorage. What are their differences:
- Neutral mechanical alignment : Bone cuts and components are aligned to the mechanical axis of the lower extremity (femur + tibia). Previously, this technique was considered the only correct one; it helped to avoid premature failure of the prosthesis and the need for its early replacement. But this was true in the early years of knee arthroplasty, when the quality of implants and fixation techniques were less advanced than they are today. Kinematic or hybrid fastening methods are also now accepted and widely practiced.
- Kinematic hinge : cuts match the kinematics of the knee in motion, maintaining the alignment of the limb in its original deformity. The alignment angle is determined individually for each patient.
- Hybrid fixation : One part of the incisions is aligned with the mechanical axis of the lower extremity, and the other part is aligned with the kinematics of the knee.
Gender implants
Manufacturers design implants based on average sizes. This usually narrows the choice down to 2-3 suitable prostheses. However, some companies, such as Zimmer and Biomet, make gender-specific models. According to them, the products allow us to take into account and correct anatomical differences between men and women.
An example of a “female” knee implant from the company [email protected] There are no visual differences from the usual one.
There is no convincing evidence that gender-specific endoprostheses are more effective. Many experts are confident that this approach is nothing more than a marketing ploy designed to increase sales.
What are the possible complications?
Three types of complications can occur during knee replacement surgery: intraoperative complications, primary complications, and secondary complications. They are related to the nature of the procedure itself and exclude possible risks associated with anesthesia or risks associated with the age and medical history of the patient.
Three types of complications:
- Complications arising during surgery : these are exceptional and can be caused, for example, by injury to a large artery of the lower limb (popliteal artery) or a nerve (external popliteal sciatic nerve) during surgery.
- Primary complications : The main complication of this type is infection. This is a serious complication, but it is rare. Monitoring for several weeks after surgery allows infection to be identified and treated with appropriate antibiotics. Often a new operation is required to clean out the joint and prosthesis. Primary complications also include phlebitis, hematoma, knee stiffness, etc.
- Secondary complications : These include mechanical complications related to the functioning of the prosthesis, delayed infection, which may be caused by the prosthesis becoming infected with an infection outside the knee (tooth abscess, urine infection, etc.), or knee stiffness that occurs over time after operation.
How does postoperative treatment occur? Therapeutic gymnastics exercises begin already on the first day after surgery. In this case, mobile movements on mobile splints, as well as active exercises to strengthen strength, are combined individually. In addition, walking on crutches and later climbing stairs are trained. Inpatient treatment is usually followed by rehabilitation, which, based on need and agreement with the relevant health insurance fund, can be carried out either on an outpatient or inpatient basis.
Where is knee replacement performed in Kyrgyzstan?
Today, knee replacement is performed in the following hospitals in Kyrgyzstan in the arthrology department:
1. “ City Clinical Hospital No. 4” (Bishkek)
2. “Kyrgyz Research Institute of Balneology and Rehabilitation Treatment” (Tash-Dobo village (Vorontsovka))
Surgeons of hospitals in Kyrgyzstan, such as City Clinical Hospital No. 4 and the Kyrgyz Research Institute of Balneology and Rehabilitation Treatment (Tash-Dobo village (Vorontsovka)) recommend hip joint endoprostheses from Aesculap.
Aesculap is one of the leaders in the medical products market. It produces not only endoprostheses, but also surgical instruments, equipment for laparoscopic surgery, extracorporeal blood purification, and infusion systems.
Risks and positive aspects of endoprosthetics.
Pain the
main symptom when visiting an orthopedist. The doctor should provide information about the positive results that can be hoped for, but also explain the risks of this operation, which increase due to age or pre-existing medical conditions. One should be suspicious of surgical indications that are only prophylactic in nature: for example, one should not decide to undergo such an operation only because of the fear that it will be needed as one gets older. Also, it should not be done too early for fear that arthrosis will progress while the functional state is still tolerable.
Age
- an important factor when deciding on surgery. Installing an endoprosthesis in a young patient increases the risk of wear and loosening, since a young and active patient will use this prosthesis for a long time and a lot. For this reason, surgeons do not recommend such an operation at too young an age. Thus, it is advisable to perform arthroplasty as late as possible. Considering that it is impossible to determine age limits, they take into account the severity of pain, the degree of arthrosis and deformation, the cause of joint damage... Finally, at a young age, osteotomy is preferred in all cases where this is possible.
Advantages of Aesculap prostheses
When using endoprostheses produced by Aesculap, it is possible to restore full mobility of the damaged joint. Implants do not affect muscle fibers, tendons or blood vessels.
Main characteristics of Aesculap products
- sustainability;
- strong fixation;
- Full compatibility with bone.
Increased resistance to wear makes it possible to re-replace the prosthesis much less frequently compared to lower quality products. The material does not cause allergic reactions in patients. After the operation, joint mobility is restored as soon as possible.
Types of Aesculap endoprostheses
The company's products are divided into categories depending on the functions they perform.
- Recovery systems. This includes artificial joints used to work on the hip joints.
- Partial replacement. Implants are used in operations on the knee joint and for reconstruction of its structure.
- Systems for the treatment of fractures of the humerus and femur. Damaged areas heal and restore functionality thanks to the use of rods.
The company's products can completely replace a damaged joint even with very poor bone tissue condition. Aesculap endoprostheses will restore the ability to move in cases where other prostheses cannot cope. Innovative developments of various coatings significantly reduce the wear of the prosthesis. When creating each implant, numerous tests are carried out to reduce friction between the parts.
You can purchase Aesculap® endoprostheses at BOSTI offices in Bishkek, Osh and Jalal-Abad. Also, all Aesculap® products are available for order throughout Kyrgyzstan.
If you have any questions about knee replacements, you can consult with Dr. BOSTI by calling 0551717713. We look forward to your call!
Endoprosthesis replacement technique
Replacing a worn-out joint with an artificial one is a difficult and quite lengthy operation, which is performed under general anesthesia. Total endoprosthetics involves removing cartilage from the articular surfaces of bones and then attaching an implant to them.
Total knee replacement in Germany is performed under combined anesthesia: to eliminate severe pain in the postoperative period, specialists use two methods at once - general anesthesia and conduction anesthesia, which “freezes” the sensitivity of the leg for 48 hours.
The choice of anesthesia for partial arthroplasty is entirely dependent on the complexity and scale of the upcoming operation. Minor manipulations are performed using an endoscope under computer supervision, and local administration of drugs is sufficient for pain relief.
Knee replacement in Germany takes at least two hours. The specialist will inform you of the exact time after receiving the MRI results and indicating the progress of the upcoming operation.
Oncological endoprosthesis
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The femur and tibia often become sites for the development of tumors and oncological diseases. Previously, such a diagnosis was considered a clear contraindication to the endoprosthesis procedure, but manufacturers have developed oncological endoprostheses that provide outstanding results even in the presence of extensive bone defects.
The essence of oncological endoprostheses is a more extensive method of fixation in the bone, so they are more voluminous.
The bone sections are resected and replaced with artificial implants. If the patient’s disease is malignant, the devices can save his life and restore mobility.