Types of hip and knee endoprostheses

Hip replacement is a total or selective replacement of parts of the joint that are in direct contact with each other during movement.

Total hip replacement is a complete replacement of the head and neck of the femur and acetabulum with artificial ones.

Hip pain is most often the result of osteoarthritis and can seriously affect your ability to lead a full and active life. Osteoarthritis of the hip joint is medically called coxarthrosis.

Hip replacement will help you get rid of pain and return to a full life. Over the past 20 years, thanks to the introduction of new materials and techniques into practice, the results of endoprosthetics operations have significantly improved.

This type of surgery is becoming more and more common as the world's population ages. Currently, hip replacement surgery is the most frequently performed in the world.

The hip endoprosthesis consists of four components:

• cup (acetabular component)
• fixed inside the liner
• legs
• head of the hip joint

The most common type of arthroplasty is total hip arthroplasty. During this operation, both the neck with the head of the femur and the acetabulum are replaced with artificial ones (bipolar or total endoprosthetics).

When may endoprosthetics be required??

The main indications for hip replacement are:

• arthrosis of the hip joint (coxarthrosis);
• fracture of the femoral neck;
• aseptic necrosis of the femoral head

With arthrosis, degenerative changes occur in the articular cartilage, which ultimately leads to wear and tear of the cartilage. Bone growths (osteophytes) form around the joint.

Due to wear and tear of the cartilage, a decrease in its thickness, a significant decrease in smoothness, as well as a change in the shape of the articular surfaces, friction in the joint increases, which leads to pain and progressive impairment of movement in the joint.

Aseptic necrosis of the femoral head is another cause of hip joint destruction. In this disease, the head of the femur loses its blood supply and is actually destroyed.

A femoral neck fracture is also an indication for joint replacement surgery. When the femoral neck is fractured, the blood supply to the head is disrupted, resulting in its gradual destruction.

There are a large number of models of hip joint endoprostheses, because... there is no ideal model. Each model has its own advantages and disadvantages. It is important for the patient that an experienced doctor selects a model individually for each patient. The cost and quality of endoprostheses from well-known manufacturers are approximately the same, but each doctor, after many years of work, has his own preferences. Even the most expensive model, if it is not installed professionally, will not stand and will begin to loosen. The most important thing for a patient is to make sure of the doctor’s professionalism.

Endoprosthesis femoral head

The femoral head of the endoprosthesis is mounted on the upper cone of the endoprosthesis stem and slides in the cup (acetabulum).

Such a sliding friction pair can consist of various materials with different hardness and surface texture. Today, the most commonly used combinations are ceramics with plastic, metal with plastic and metal with metal.

Selection of the type of endoprosthesis: Which hip joint endoprostheses are for which patients?

The type of endoprosthesis is selected depending on the patient’s age, anatomical features of the joint structure, body weight, as well as the wishes of the patient himself.

The ceramic-ceramic friction pair is the best in terms of wear, because Ceramics have high rigidity and a low coefficient of friction. But ceramics, like glass, is a fragile material. So, in the event of a fall, which can happen to any patient, the endoprosthesis may split into many fragments, which are very difficult to remove from the tissue.

A metal-to-metal friction pair is also a good combination because... consists of a hard and unbreakable material.

A metal-high-polymer polyethylene friction pair is a cheaper alternative.

After the doctor and patient have decided on the model of the endoprosthesis, the shape and size of the endoprosthesis is selected individually. To do this, the patient is given special X-rays, on the basis of which a computer selection of an endoprosthesis is made based on a data bank with more than 40,000 prostheses.

So, which endoprosthesis is the best?

So, firstly, the best endoprosthesis does not exist.

Secondly , of course, there are many different endoprostheses, and some of them are better, while others... are better in something else. Under one small condition - if we are talking about endoprostheses from well-known world-famous manufacturers.

In general, we can say that there are more expensive models of endoprostheses and cheaper ones. But again, this does not mean that expensive models are better. Of course, when releasing a new model of an endoprosthesis, the manufacturing company is forced to make it more expensive than previous models, because the development of a new implant requires significant money spent on research, modernization of production lines, marketing, etc. New models of endoprostheses take into account the shortcomings of previous generations, and it is likely that modern models will be more durable and reliable.

Thirdly, it is much more important how well the operation is performed, and not how “cool” or “expensive” the endoprosthesis is chosen. Unfortunately, incorrect installation will not save the “best” endoprosthesis, but an “average endoprosthesis” correctly installed during surgery can confidently and without problems last for many decades.

However, a surgeon, especially one who operates a lot, has his own preferences in choosing certain models of hip joint endoprosthesis. Surgeons of leading multidisciplinary hospitals in Kyrgyzstan, such as Bicard, Cardio Asia+, Osh-Cardio, NIIHSTO, OMOKB 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.

Aesculap hip endoprostheses are known for their high quality and affordability. The effectiveness of implants from this manufacturer has been confirmed internationally. The structures are developed using the latest technologies used in surgery.

How does a hip replacement work?

The operation is performed under general anesthesia (anesthesia) or using regional anesthesia methods - conduction or spinal anesthesia. First, an incision is made on the skin about 10-15 cm long, then the muscles and ligaments are separated without the use of a scalpel to provide optimal access to the joint.

After excision of the capsule, the surgeon inspects the joint, finally deciding on the type of implant, removes the destroyed joint or parts thereof, and installs an endoprosthesis. After draining and suturing the wound, a sterile dressing is applied. The operation lasts no more than 1-1.5 hours.

After the operation, the patient is under round-the-clock supervision by medical staff in the intensive care ward. He is prescribed antibacterial therapy to prevent infectious complications, anticoagulants, and painkillers.

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 the company's 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.

What is the essence of the endoprosthetics procedure, why is it prescribed?

Content:

• What is the essence of the endoprosthetics procedure, why is it prescribed?
• Indications and contraindications for surgery
• Types of endoprosthetics: how a surgeon can help a patient
• How does a patient prepare for surgery?
• The day before surgery: what the patient can expect
• Carrying out endoprosthetics: intervention algorithm
• After surgery: patient's condition
• Postoperative period and return to normal life

Various degenerative-dystrophic lesions of the articular apparatus can develop in a person at any stage of his life. Their main danger is that, firstly, they only progress over time, and secondly, if medical assistance is not provided in time, a person may completely lose the ability to move independently and find himself bedridden. Diseases and pathologies of the hip joint can cause disability in the affected person.

Deforming arthrosis is especially common, in which a progressive pathological process gradually changes the shape of the articular elements, deforming them, as a result of which a person loses the mobility of the limb and constantly feels pain.

Conservative treatment in such cases is usually ineffective - it can only slow down the process, and only in the early stages. If the disease is advanced, the attending physician decides to perform endoprosthetics.

What is hip replacement? During the operation, the surgeon physically removes the affected elements of the articular apparatus and replaces them with artificial prostheses. The procedure is carried out to achieve several goals - eliminating pain in the joint, improving its mobility, returning the patient to his usual lifestyle, restoring his ability to walk and move.

Metal ceramics

This is one of the most popular materials that is widely used in dental prosthetics. Permanent crowns and bridge structures are made from it. Features of such prostheses:

• The basis is a metal frame, which gives the crowns strength.
• Ceramic lining makes the prosthesis look natural and eliminates the galvanic effect.
• The cost of metal ceramics is in the average range, so such designs are considered affordable.

Preparing for surgery

Before surgery, a thorough diagnosis is carried out to assess the patient’s health status and identify possible contraindications. In addition to the studies that are prescribed to study the affected joint (radiography, MRI, CT), preoperative preparation includes a number of standard studies and tests:

• general, biochemical blood test;
• general urine analysis;
• blood for HIV, hepatitis, syphilis;
• blood type, Rh factor;
• coagulogram;
• X-ray of the lungs;
• FGDS;
• consultation with a therapist;
• ECG.

Additional consultations with specialists may be required: dentist, otolaryngologist to identify chronic foci of infection, and others.

At least a week before surgery, you need to stop drinking alcohol and drugs that affect blood clotting. If a person takes any medications on an ongoing basis, it is necessary to notify the doctor, as they may need to be discontinued. It is important to avoid possible sources of infection; even a simple ARVI will be a reason to postpone surgery for several days, since a viral infection can lead to complications.

Recommendations before hospitalization

In addition to the necessary examinations, before surgery it is recommended:

• eliminate foci of infection in the oral cavity;
• normalize weight, this is an additional load on the joints;
• become familiar with the rules for performing therapeutic exercises that will be required during the rehabilitation period;
• After replacing the hip and knee joints, you will have to move around on crutches or a walker. It is recommended to learn to walk with their help in advance;
• prepare compression stockings;
• choose comfortable shoes without heels, complex fasteners, laces;
• remove carpets and wires from the floor that can get caught and fall, make room in the room for free movement on crutches;
• prepare a high chair or bed so that you don’t have to bend the joint too much. An additional mattress can be added to increase the height. The free edge of the bed should be on the side of the operated limb;
• place all the objects that the patient often uses in accessible places so that there is no need to reach for them, bend over, or even climb onto a chair;
• attach additional handrails in the bathroom, install a high seat on the toilet;
• To avoid situations of falling in the dark, it is necessary to ensure sufficient lighting of the premises at night.

It is necessary to talk with loved ones about help at least during the first 2-3 weeks after surgery with cooking, cleaning, support when walking, especially if the patient has to go down the stairs.

Anesthesia methods

The anesthesiologist selects the type of anesthesia taking into account concomitant diseases, the method of operation, the general health of the patient, age and other factors. When replacing knee and hip joints, regional anesthesia is predominantly used - spinal and epidural in combination with intravenous sedation to calm the patient.

With both types, the person remains conscious, but does not feel the lower limbs for 4-8 hours. In spinal spinal surgery, the patient is given an injection with an anesthetic into the subarachnoid space of the spine to block the conduction of nerve impulses. With epidural, for the same purpose, the drug is injected into the epidural space of the spinal column.