"Hip prothesis"

 

WHAT IS A TOTAL PROTHESIS OF HIP?

        The total prothesis of hip is one of the biggest advances in the orthopedic surgery of this century. The pioneers in their design and use was Sir John Charnley, an orthopedic surgeon that, with the collaboration of a team of engineers, it developed the technique and the materials used in the total prothesis of hip.

        This technique supposes the substitution of an articulation artrosica or injured by an articulation artificial denominated prothesis.

WHAT IS AN ARTICULATION?

         It is a structure of the organism where they insert two bones. In the case of the hip they are the bone of the thigh that is denominated femur whose superior end is a sphere, with a cavity located in the pelvis that is denominated cótilo.

         The ends of the bones that form an articulation are recovered by a material flat and brilliant denominated cartilage articular. This material muffles the forces that act on the underlying bone and it allows that the articulation moves easily and without pain. The articulation is surrounded by a capsule recovered in its interior by a fine membrane denominated sinovial.

         The membrane sinovial produces a lubricant one (the liquid sinovial) that helps to diminish the friction and the waste of the articulation. The bones are united by ligaments that maintain the stability of the articulation. Wrapping the articulation finds muscles and tendons that you/they also help to maintain their stability and they allow their movement.

WHY A TOTAL PROTHESIS IS NECESSARY DE HIP?

        The most frequent reason to place a total prothesis of hip is the one of eliminating the pain and the inability that it causes a severe destruction of the articulation. The surfaces of the articulation can be damaged by the artrosis, process in which the waste of the cartilage takes place to articulate.

       The articulation can also be damaged by the arthritis rheumatoidea. In this illness, the membrane sinovial produces some chemical substances that attack the surface to articulate and they destroy the cartilage to articulate.

        Due to the pain and to the rigidity, the patient avoids the use of the articulation. The muscles that surround the articulation weaken and this contributes to hinder the mobility of the hip. When the destruction to articulate is important, a total prothesis of hip can allow the patient carry out its daily activities again.

       The diagnosis of the artrosis or of the arthritis rheumatoidea its  includes to write down the patient's symptoms, to carry out a physical exploration, laboratory tests and x-rays that show the extension of the destruction to articulate. Once fact the diagnosis, it can be considered the possibility to always place a prothesis after the non surgical treatment or other surgical alternatives have failed without being able to eliminate the pain and the inability.

HOW A TOTAL PROTHESIS IS PLACED DE HIP?

       It is a surgical technique. With the low patient the surgeon anesthetizes it substitutes the articulation damaged by some components carried out with artificial materials. The superior end of the femur that is like a sphere, it is substituted by a metallic sphere together to an offspring that is inserted inside the bone.

        A dome of plastic is implanted in the spherical cavity of the pelvis that is damaged. A prothesis can also be implanted in other articulations although those that you more protetizan often is the hip and the knee.

        The materials used in the total prothesis are designed to allow a similar mobility to that of the normal articulation. The artificial components are usually compound for a metallic element that fits exactly in an element of plastic. Diverse metals, stainless steel, or cobalt alloys, chromium and titanium are used.

        The plastic is polyethylene that is extremely durable and resistant to the waste. Usually, cement is used to fix the artificial component to the bone. Not cemented prothesis also exists. This prothesis type is inserted directly in the bone.

WHICH IS THE PERIOD OF RECOVERY AFTER A TOTAL PROTHESIS OF HIP?

         It varies, depending on the patient. In general, he/she is encouraged so that it uses the articulation soon after of the intervention. The patient can be placed of foot and to stroll in a few days.

         A Physical therapistcan instruct him in the use of crutches.

WHICH ARE THE BENEFITS OF A TOTAL PROTHESIS OF HIP?

        The biggest benefit is the disappearance of the pain. Some patients notice some nuisance in the articulation operated after the intervention. These nuisances are due to the surgery and to that the muscles that surround the articulation are weakened by the inactivity.

        These nuisances can be prolonged during some weeks or months. The muscular force usually recovers when the pain disappears. The mobility of the articulation usually improves. The recovery degree depends on the rigid thing that it was the articulation before the intervention.

WHICH ARE THE RISKS OF A TOTAL PROTHESIS OF HIP?

         Risks exist like in any surgical procedure. The patient that is considering the intervention should explain the surgeon any medical problem that can complicate the surgery.

         To determine the surgical risk, with the maximum accuracy and to prevent possible complications, it is practiced an analytic one, a thorax x-ray and an electrocardiogram. These tests are evaluated by a medical internist and an anesthesist that also carry out an interview with the patient. The anesthesist can inform of the risks of the anesthesia.

WHICH ARE THE POSSIBLE COMPLICATIONS?

        The biggest potential complication in a total prothesis of hip is the infection. It can happen exactly in the area of the wound or in depth around the prothesis. It can happen during the hospital stay or once the patient is in her house. The infection of the wound usually talks to antibiotics.

         The deep infections require surgical treatment and retreat of the prothesis. An infection can take place for dissemination of an infection in another localization of the organism. To prevent this type of infections, people carriers of total prothesis should take antibiotics before being subjected to a dental cleaning as well as other surgery types.

         If an infection takes place it should be treated with antibiotics. There are other complications that are directly related with the installation of a prothesis: Loosening: It is the most frequent mechanical problem after the installation of a prothesis.

         It produces pain and, if the loosening is important, it can be necessary to substitute the prothesis for another. New methods to fix the prothesis to the bone can minimize or to eliminate this problem in a future. Luxation: This complication usually takes place soon after of the intervention. In most of cases the surgeon can place the prothesis manually in his place.

         Another intervention is rarely required. After a luxation a rod can be placed, during some weeks, with the purpose of maintaining the stable articulation. Wear away: it usually takes place slowly. It can contribute to the loosening but it is rarely necessary to intervene by itself because of the waste. It plows: The break of the one implants it is very strange. If it happens it is necessary a second intervention. Nervous lesion: The next nerves are rarely injured to the intervened articulation. This happens in the cases in those that the surgeon owes To correct a very deformed articulation to place the prótesis. With the time the nervous function is usually recovered.

IS THE TOTAL PROTHESIS OF HIP DEFINITIVE?

         Most of old people can hope the prothesis should not be redrawn during the rest of its life. It will provide them years without pain, thing that otherwise cannot get. However, the youths, more active, will probably be subjected to a second intervention to change the prothesis .

        The material and the surgical techniques improve quickly thanks to the orthopedic surgeons that work with engineers and other scientists. The future is promising for those that choose to be placed a total prothesis of hip.