The orthopedic department of the Clinical Center of Friedrichshafen performs all kinds of hip replacement surgeries. Head of the department is an experienced surgeon Prof. E. Winter, whose main focus lies in hip, knee and shoulder replacements. More and more people are beginning to suffer from hip disorders, which result in hip joint pain and serious symptoms and can limit the mobility considerably.
The hip joint represents the connection of the pelvis with the thigh. It allows all movements of the legs against the pelvis or the pelvis against the legs, for example walking and walking. The hip joint allows a large range of motion, which is not fully utilized in most people. The hip joint is the articulated connection between the femoral head - the upper end of the femur (femur) - and the acetabulum of the hip bone. Like the shoulder joint, it is a ball joint that can be moved around three main axes. In principle, the range of motion of shoulder and hip joint are about the same size. However, since we are predominantly walking or walking, these sizes are rarely used. The femoral neck head is held in the socket of the hip bone by various ligaments and a strong joint capsule.
In the hip joint, the movements of the legs relative to the pelvis, without the running, jumping, sitting, the balancing act of ballet dancers, dancing and much more would not be possible.
The three main movements are anteversion, retroversion and abduction:
In addition to these three main movements in the hip joint, an internal and external rotation are added. These movements are best recognized when the foot is stretched inward or outward with the leg extended, or when the knee is flexed, the lower leg flexes inward or outward. In combination of all these types of movement a leg gyration is possible.
A common form of bone fracture in the elderly, whose bones are decalcified by osteoporosis and thus weakened, is the femoral neck fracture: the neck of the femur breaks near the hip joint.
The hip joint can become inflamed (coxitis), distinguishing a bacterial from an abacterial form: the bacterial hip joint inflammation is caused by various bacteria. It may be the result of a hip operation, joint puncture or osteomyelitis. Abacterial coxitis occurs, for example, in the context of rheumatoid arthritis, coxarthrosis (arthrosis of the hip joint), femoral head necrosis or bone tumors.
Coxitis fugax ("hip flu") is also a non-infectious inflammation in the hip joint that can occur in children between four and ten years old, usually after a previous infection of the respiratory or gastrointestinal tract.
Hip dysplasia is a congenital or acquired malformation of the acetabular cup. The femoral head finds no stable hold in the acetabulum and can pop out (hip or hip dislocation).
Conservative treatment may not be sufficient if the osteoarthritis is advanced or if the joint cartilage is severely damaged. Under these circumstances, an artificial joint offers a new mobile life. It is therefore no wonder that people are resorting to surgery and that the number of hip replacement procedures has risen steadily over the last few years. This replacement procedure has become standard in orthopaedic surgery, and is performed almost 200,000 times annually in Germany.
Diseases that can be conquered by the joint replacement are, for example, inflammations of the joint and age-related wear. However, injuries and tumours can also be treated by means of hip replacement surgery. For better understanding of the causes of the disease and choosing a better treatmen option our joint specialists start with diagnosis.
The layer of cartilage isn’t directly visible on an X-ray image. Only a dark gap can be seen between the femoral head and the socket hip. Your doctor can recognize a healthy joint by the joint (articular) gap being smooth and evenly formed. A very narrow or absent joint gap is a sign of the breakdown of cartilage, called osteoarthritis. Osteoarthritis of the hip joint cannot be healed. However, conservative treatment methods can contribute to pain relief and prevent or delay the need for surgery:
The affected individual often adopts a posture which is pain relieving. This can cause the muscles to become shorter and joint capsule may get damaged. The joint may ultimately become stiff. The principle of “as much motion as possible – as little strain as necessary” also applies to the diseased hip joint. Physiotherapy helps to keep you mobile, especially regular exercise in warm water, for example, swimming and aqua gymnastics. The buoyancy of water reduces the body weight acting on the joint and its warmth is soothing and pain relieving.
The aim of medication is to reduce inflammation and alleviate pain. This is often necessary before being able to undergo physiotherapy. Due to their possible side effects, the use of prescription antirheumatic (anti-inflammatory) drugs should be monitored by your doctor.
Besides the treatment of injuries and orthopaedic diseases of all kinds, endoprosthetic hip and knee replacement surgery is one of the main focuses of our clinic in Germany. We perform over 700 hip and knee replacement operations and corrections of these joints annually. In the Clinic for Orthopaedics and Trauma Surgery, we perform the entire spectrum of endoprosthetic (joint replacement) surgery and each of them is preceded by choosing a type of endoprosthesis.
A modern hip endoprosthesis improves your quality of life and gives you more mobility in your free time, during exercise, ordinary daily routines, and in your professional life. The insertion of artificial joints is one of the most successful and most economical treatment methods in the history of modern medicine. As a rule, the surgery enables complete restoration of mobility. Through the use of tried and tested implants combined with minimally invasive surgery techniques, we are able to achieve a very high standard of treatment and patient satisfaction at our clinic in Germany.
The hip endoprosthesis is shaped to resemble the natural hip joint. It replaces parts of the diseased joint: the femoral head and the hip socket. Thanks to intensive research efforts, it has become possible to replace diseased parts of a joint while conserving as much bone as possible. There is a distinction between surface replacement, primary intervention, and revision.
In older patients where the condition of the joint is suitable and in young patients with the right bone quality, the neck of the femur can be retained so that the surgeons have natural bone to work with should the prosthetic hip need to be replaced at a later stage. Whether the condition of your bones meets these requirements or not must be discussed within the framework of a personal consultation and an examination.
In surface replacement, the femoral head is not removed, but rather capped using a metal cap. The cap is fixed by a thin pin a small amount of bone cement. The hip cup is also made of metal. The implant allows a wide range of motion.
The advantages of the Mc Minn joint replacement technique
The surface prosthesis is a more gentle method that avoids trauma of the intact articular tissues. With this technique, first used in Germany in 1997, the surgeon manages to keep the head of the joint and to avoid the extensive removal of the articular surface. This minimally invasive surgery is indicated primarily for young patients. During the research it has been proved that the ion metals (cobalt and chromium) don’t get into the body and can in no way affect the patient's health status.
In primary intervention, the diseased parts of the joint are replaced by an artificial joint that consist of a femoral stem and hip cup. The femoral stem is cemented or pressed into femur, while the hip cup is cemented, screwed or pressed into the pelvis. A ball-shaped head that can move within the hip cup is placed on the femoral stem. It is also possible to use larger ball-shaped heads that offer a larger range of motion and reduce the risk of dislocation (luxation).
The lifetime of a modern hip joint is already more than 10 years. After this time a revision operation may be necessary. Such operations have also become routine. During the revision, the artificial hip joint is either partly or fully replaced by a new artificial hip joint.
The lifetime and functional performance of joint implants depend on a variety of factors: on the one hand the materials of the slide pairings, and on the other hand the lifestyle and general health of the patient (e.g. physical activity, bone characteristics, body weight and the age of the patient, as well as concomitant diseases, such as chronic polyarthritis).
Endoprostheses have to work properly for a long time. High demands are therefore made of the materials used to ensure long-lasting and trouble-free performance of implants. Their structure must keep to a minimum the inevitable wear and tear caused by friction. Moreover, the materials must be corrosio resistant and biocompatible and provide for good adhesion to the surrounding bone by means of growth processes. The majority of modern femoral stems and hip cups are covered with particularly biocompatible titanium or cobalt-chromium alloys. The femoral stems are hot-forged to attain the required strength of the material.
The slide pairings include femoral heads made of ceramic or cobalt-chromium alloys, combined with hip insert made of polyethylene, ceramics or cobalt-chromium alloys (Figs. 1-3).
Besides standard replacement surgery, we also offer modular, sectional and custom-made prosthetics, which, with the aid of X-Ray images and CT datasets, are constructed especially for individual patients. The anchoring of the implants during surgery can be done either according to cemented or cement-free technology, depending on the individual case. If necessary, we perform the procedure with the support of highly modern computer navigation systems. Follow-up treatment after hip or knee replacement surgery is performed by an interdisciplinary team of physicians, nursing staff and physiotherapists, according to a clearly defined treatment plan.
In this hip replacement procedure, the titanium components of the prosthesis are anchored directly onto the bone during surgery. The hip cup is screwed or pressed into the pelvic bone and the femoral stem is pressed into the femur. After preparation with special instruments, the prosthesis is clamped into the bone, where it “heals” into the bone.
The bone-friendly materials of the components have a rough surface that promotes the adhesion to the surrounding bone tissue by osseointegration. Having a good bone quality promotes rapid adhesion. Modern procedures generally ensure that the leg can be exposed to stress, which was not the case many years ago.
If the bone is too weak to provide sufficient stability for a cement-free prosthesis, due to the age of the patient or as a result of specific diseases, the prosthesis will be anchored with so-called bone cement (a synthetic material that has been tried and tested for decades).
The quick-hardening bone cement (shown in blue), fixes the femoral stem and the hip cup to the femur and the pelvis, respectively. In addition, the bone is also stabilised from the inside in order to reduce the risk of a break in the immediate vicinity of the prosthesis. A cemented hip joint can be exposed to a full load soon after this procedure. In so-called hybrid hip replacement surgery, cemented and cement-free prosthetics are combined in order to achieve the ideal treatment for the patient.
This combination unites the advantages of the two procedures. The hip cup is pressed or screwed into pelvis without the use of cement, whereas the femoral stem is cemented into the femur.
In every case, the goal of joint replacement surgery is that after successful rehabilitation, the patient regains his (almost) normal, symptom-free life once again.
This prosthesis consists of two parts: a socket placed in the pelvis at the site of the original acetabulum itself and a prosthetic femoral femoral head inserted into the medullary cavity of the femur after removal of the femoral head and part of the femoral neck. Protruding bony marginal ridges on the hip socket are removed in order to be able to fit the socket in a form-fitting manner to the bearing in the pelvis. For various bone sizes and anatomical variations, various pan and stem models are available.
This creates two boundary layers, once between bone and cement, and between cement and prosthesis. Through a very precise technique when cementing the prosthesis shares cavities in the cement, which could later contribute to a relaxation of the hip prosthesis, avoided as possible. The cement is introduced by appropriate instruments in the still-fluid state in the bone. Immediately thereafter, the implant is inserted in the planned position.
By different design of the prosthetic stems as well as the pan shapes is trying to include the largest possible surface in the anchorage. However, the boundary layer problem in the connection between implant, cement and prosthesis is still not solved satisfactorily today.
The living bone tends to separate from the dead bone cement or implant and to dilute at the site where the bone cement abuts the bone itself. Nevertheless, cementing in correct technique has been proven in many thousands of total hip replacement prostheses. This procedure can not be considered obsolete and still has its meaning and justification. By a rich bond between prosthesis, cement and bone, a kind of individual prosthesis has emerged. Prerequisite, however, is a very precise cementing technique.
Since cemented prostheses can loosen up, it has been partly about 15 years ago to implant the hip prosthesis directly into the bone without interposed bone cement. This requires a specially designed prosthesis whose shaft is designed much like a grater.
In the following, a typical model of the cementless hip prosthesis will be described: The upper end of the shaft implant has a special projection, through which the prosthesis is firmly anchored at the upper thigh end. Depending on the model, the surface structure of these prostheses may be roughened or broken. In this way, the trabeculae can grow close to the prosthesis and thus ensure a close bond between the prosthesis and the femur.
The prosthesis stem is usually provided with a fine-grained titanium alloy or specially coated. Here, too, there are now numerous different prosthesis models and materials, which differ only in smaller details. The loading forces are now transferred directly into the bone, which is adjacent to the prosthesis.
The pans anchoring can be done in a conventional manner in cement technology. However, there is now also the possibility of cementless acetabular implantation in the hip joint chirugie by special screw pans, which also have a fine-grained coating. These pans have an external thread, which is screwed with high force directly into the bone of the old acetabulum. A plastic, ceramic or steel insert (inlay) inside the pan takes up the head of the hip prosthesis. Any existing bone voids are filled if necessary by the patient's own bone from the removed femoral head.
Another technical variant of the cementless implanted acetabulum is the so-called "press-fit" anchoring in the bone. The fine-grained coated cup prosthesis is inserted directly into the milled and cartilaginous acetabulum and immediately finds good support.
The combination of a cemented pan with a cementless stem (or vice versa) may occasionally be required for technical reasons. One speaks then of so-called hybrid prostheses.
In the case of anatomically unfavorable acetabular cups, a so-called cup structure may sometimes be necessary in order to anchor the cup of the prosthesis biomechanically better. Here one uses special support rings or shells, which are fixed with bone screws on the pelvis. Previously, a bone grafting is still necessary to provide the support ring better support and a cheaper embedding in the pelvis. In this support shell, the actual prosthesis pan is then cemented.
These are very important but also quite expensive measures that sometimes also become necessary during the first implantation of a prosthesis. However, these so-called Pfannenaufbauplastiken are mainly performed in prosthetic replacement operations with large bone defects.
In special cases (for example in very elderly patients with fractures of the femoral neck), the installation of the acetabulum is omitted in order to shorten the operating time. In this case, only the prosthesis socket with neck and head is implanted (head prosthesis). The prosthetic head then moves on the cartilage of the normal acetabulum. The so-called duo-head prostheses are based on a similar principle. After a few years, however, this technique can lead to increased cartilage and bone abrasion on the bottom of the pan.
Similar to the cup prostheses, there are numerous models in the shanks. The cemented models usually have a smooth, sometimes even polished surface to avoid cavities between implant and cement. Some stem prostheses have a collar that rests against the remainder of the removed femoral neck. The surface of the cementless related models is always roughened and occasionally provided with special tissue-friendly titanium coatings. Otherwise, the design is usually tailored to the architecture of the bone. The variety of models is immense.
The cementless hip replacements seem to last longer, so these models are being implanted in increasing numbers today. However, a final assessment is not yet possible due to the still insufficient observation time of this method. Nevertheless, the cementless prosthesis seems to be able to sustainably help even younger people with severe hip joint arthrosis when other procedures (conservative treatment, conversion operations) have not led to any significant alleviation of the complaint.
In the case of the premature loosening of a cement-free implanted prosthesis, the technical problems in the replacement operation are usually not as great as with cemented hips. This is a not to be underestimated advantage.
A leg with a cemented prosthesis can be fully loaded quickly. In contrast, patients with cementless new hip joints may only partially bear the operated hip for about two to three months. This is certainly a disadvantage for very elderly patients - this is where the cemented prosthesis is preferred.
In general, it can be said that the cementless and cemented prostheses do not compete. The cementless version is more suitable for younger patients. However, drawing a rigid age limit does not seem to make sense. Whereas hardly any patient under the age of 65 received a hip prosthesis in the past, today people have become much more flexible. The demands of people on their quality of life have also changed sustainably. An individual balance is always important.
The major priority of the German specialists is accurate implantation of an artificial joint. The traditional technique involves the installation of an artificial joint using mechanical tools. However, according to numerous scientific studies, traditional techniques often lead to inaccurate implantation of the prosthesis.
To improve the accuracy, a special computer-navigation is system is applied during the hip replacement, Every step of the operation can be cross-checked. Only if the the computer reports the precise execution of the current surgical procedures, the experts can proceed with the next step. At the end of surgery, the surgeon achieves the exact position of the implant and symmetrical stabilization of ligamentous apparatus. The navigation device also documents the process of surgery.
According to the latest clinical analysis, the introduction of a navigation system can not only reduce the risk of complications, but also helps to improve the functionality of the joint. In addition, there is a low level of blood loss during the computer-assisted hip replacement surgery.
The implantation of a hip prosthesis has become a common operation at orthopedic joint surgery centers. A well-organized team ensures that you receive optimal care and management. The individual steps of the operation follow a well-established procedure.
Surgical replacement of hip can be performed two ways: either traditionally, or with the help of so-called minimal invasion technique. These procedures mainly differ by the size of incisions made.
Your anesthetist will advise you of the possible risks and various methods of anesthesia. Partial anesthesia means that the anesthetist injects a local anesthetic near a large nerve to render the body region involved in the operation numb and insensitive to pain. You will be conscious during the entire operation.
Full anesthesia means that you will be given medication on the day of operation that genty sends you sleep within a few seconds. You will be unconscious and unable to feel any pain. Breathing and circulation will be monitored continuously during the operation. You will receive oxygen through an oxygen mask. The implantation of an artificial hip joint is rarely associated with complications. However, in any operation of this type, there is an inherent risk of bruising, infections, thrombosis or embolism that needs to be noted. Your doctor will advise you of these risks in detail before the operation.
The implantation of the new joint takes, on average, approximately one or two hours. During traditional operation a doctor makes an incision on patient’s hip and removes the muscles attached to the higher part of the thighbone to see the hip joint. Then the ball potion of the joint is extracted by sawing the thighbone (special saws are used to perform this action). An artificial joint is joined to the thighbone with the help of cement or some similar material.
Next step, the exterior of the hipbone is treated: all ruined cartilage is removed, and parts for replacement are attached to the hipbone. To let fluid out, a drain may be put in. After that, the surgeon attaches muscles again and sutures the incision.
During the operation, a patient can experience serious blood loss, which makes a blood transfusion necessary. Prior the procedure, it is recommended to donate your blood.
Although about 80% of hip replacement surgeries are done by the above described way (traditional surgery), but recently, many doctors started practicing an approach that presupposes minimal invasion. In this case, 1-2 incisions up to 5” long are made instead of one long cut. Muscles and soft tissues situated right under the skin do not need to be cut, but can simply be pushed aside. Since the wound smaller, there is less strain for body and the healing process may be accelerated.
Apart from the conventional surgical methods, the minimally invasive techniques preserve the soft tissues particularly well. This way, blood loss is not so severe, pain after surgery is easier to tolerate, scar appearance reduced, and recovery time becomes shorter. But it is crucial to have the operation performed by an experienced surgeon. If a specialist is not skilled enough in this technique, the outcomes from a minimal invasion surgery can be more serious than in cases with usual approach.
The individual steps of the operation are similar whether you receive the cemented or the cement-free hip prosthesis. An incision in the skin is made to gain access to the diseased hip joint capsule, which is then opened in order to expose the hip joint inside. The diseased femoral head is cut off at the femoral neck.
The surfaces of the cartilage of the hip socket, destroyed by the osteoarthritis, are then worked on. The hip socket has to be prepared so that the new, artificial cup fits exactly in place allowing it to be pressed or screwed into place.
The medullar space of the femur is opened. The bone is made to fit the size of the stem of the endoprosthesis using specialized rasps. The stem can then be inserted either with or without the use of bone cement.
A ball-shaped head is then placed on the femoral stem. Finally the surgeon thoroughly checks the new joint for mobility and function, before closing the wound and applying a compression bandage.
In order to minimize the pain you experience, you will receive pain-killing medication. Any exudations from the wound will be removed using drainage tubes to ensure that no major bruises are formed. After one or two days the drainage tubes will be removed and the surgical wound will be checked regularly. The stitches will be taken out after ten to twelve days. If the wound has healed well, you may already start mobilizing, for example, in the rehabilitation pool.
Compression stocking and blood-thinning drugs will be used to protect you from thrombosis. The stockings should be used until the leg can be fully exposed to strain again. Until then, the stockings should only be taken off when you take a bath or shower.
Over the years, an implanted prosthetic hip is exposed to many millions of alternating load movements. This can lead to wearing down of the prosthesis or even to weakening of the anchor-points of the prosthesis, which in turn leads to loosening of the prosthetic hip. In such a case, the prosthetic hip needs replacement. Due to the condition of the soft tissue and the bone, this procedure is often extremely demanding from a technical perspective. This makes it absolutely essential for clinics, such as our clinic in Germany, to offer a broad spectrum of treatment options and special implants, in order to be in a position to solve the individual problems of the various patients. Besides these factors, the experience of the surgeon also has a profound effect on the final result of the hip replacement surgery.
The cost efficiency of the health procedures and health economic aspects are steadily gaining importance in our health system. Despite this, patients should continue to receive high-quality services. The following aspects allow a modern health system to meet these requirements: minimally invasive surgical techniques reduce the length of stay in hospital and rehabilitation time, large ball-shaped heads reduce the dislocation risk; long-lasting high-quality materials improve the lifetime of endoprostheses and thus render revision operations unnecessary in many cases.
The goal at our clinic in Germany is to guarantee the best possible medical treatment for each patient. We would be pleased to discuss questions regarding endoprosthetic hip replacement surgery during our consulting hours. Please call and make an appointment.
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