After joint replacement. Is it possible to do an MRI with titanium plates, stents or crowns? Is it possible to do an MRI with an endoprosthesis?

Formation hip joint(TS), classified as simple synovial, occurs with the participation of two articulating bones - the ilium and the femur.

Cup-shaped recess on the outside pelvic bone(acetabulum) and the spherical bone of the femoral head together form the hip joint, which is a kind of hinge structure.

The femoral head is connected to femur the neck, which is popularly called the “femoral neck.” The inside of the acetabulum and the femoral head itself are covered with a layer of special articular cartilage (hyaline).

Cartilage is an elastic and, at the same time, durable and smooth layer in the joint. Provides gliding during joint operation, releasing joint fluid, distributing the load during movement and the necessary shock absorption.

Around the head of the joint there is a capsule consisting of very dense and durable fibrous tissue.

The joint is secured using:

1. Bundles. External ones are attached at one end to femur, others - to the pelvic. And the internal ligament of the head of the pelvic bone connects the head itself with the acetabulum of the pelvic bone.
2. Muscle They surround the hip joint - the buttocks at the back and the femurs at the front. The better the muscular framework of the joint is developed, the less traumatic loads on it when running, unsuccessful jumps and moving heavy objects. It is also important that a good volume of strong working muscles delivers a sufficient amount of nutrients to the joint through the blood.

With the help of the hip joint, a person is simultaneously provided with the following functional capabilities:

• body stability (support, balance);
• variety of movements.

Why is the joint affected?

Obvious causes of damage include injury. Examples are femoral neck fracture, hip dislocation or subluxation.

Non-obvious diseases (infectious and non-infectious arthritis, osteoarthritis, inflammatory processes in the joint and periarticular tissues).

Let's look at the main ones:

• inflammation of the pelvic joint - usually caused by arthritis of various etiologies, bursitis, synovitis, etc.;
• pathology of joint deviation – dysplasia;
• necrosis in the head of the vehicle in some areas bone marrow– non-infectious necrosis (avascular).

When and who needs a hip replacement?

The occurrence of pain in the hip joint is a signal that you should contact a professional to determine its causes. To do this on initial stage You should undergo an X-ray examination of the vehicle.

The solution to the problem for a worn out or irreversibly injured joint can be endoprosthetics, which may be indicated in the following cases:

• non-healing fracture of the head of the vehicle;
• fractures of the femoral neck or acetabulum in elderly patients;
• aseptic necrosis;
• tumor-like diseases of the TS;
• deforming arthrosis of the third stage;
• congenital hip dislocation, etc.

What types of operations does medicine offer?

In modern medicine, patients are offered three types of operations based on the type of prosthetics:

1. Replacement of vehicle surfaces - removal of cartilaginous layers from the acetabulum and replacement with a special artificial material and turning the head of the femur and putting a metal cap on it. Thanks to this replacement of articular surfaces, gliding is achieved that is close to natural.
2. Partial prosthetics is the replacement, for example, of the head of the pelvic joint with part of the femoral neck or articular bed.
3. Complete prosthetics – removal of the entire hip joint and replacing it with an endoprosthesis.

Types of endoprostheses

IN modern medicine Every day there are more than six dozen modifications of endoprostheses. They are divided according to the method of fixation and material. Three methods of fixation are offered today:

• cementless – fixation occurs due to the fact that the joint bone grows into the surface of the joint;
• cement – ​​the endoprosthesis is fixed using special bone cement;
• mixed (hybrid) - the cup is attached without bone cement, and the leg is attached with cement.

Modern combinations of materials from which prostheses are made are selected depending on the patient’s disease, age and lifestyle. They may be:

• metal – metal;
• metal - plastic of very high quality;
• ceramics – ceramics;
• ceramics - plastic.

Preparing for surgery

All necessary information to prepare for surgery will be provided to you by your attending physician.

However, there are moments for which the patient will have to prepare in advance (especially those who are lonely).

Since rehabilitation after a joint replacement continues at home, it is worth preparing your home for the postoperative recovery period:

• purchase special equipment in the form of walkers or crutches, a special toilet seat, etc.;
• stop taking certain medications (aspirin-containing, anti-inflammatory);
• if necessary, reduce your weight;
• do physical training;
• visit the dentist;
• give up bad habits(smoking).

Before the operation, the patient is required to complete Required documents(carrying out an operation in cash, under a contract within the framework of medical insurance or according to quotas federal program provision of free high-tech medical care); talk with an anesthesiologist about the most favorable anesthesia option for you; Stop eating at least 12 hours before surgery.

Joint replacement surgery

Modern advances in medicine make it possible to perform both open and minimally invasive surgeries for hip replacement.

Today, minimally invasive surgeries (MI) are the most common due to their minimal impact on the body.

To carry out MO you need:

• high qualifications and professionalism of the surgeon and all medical staff;
• availability of technical capabilities ( endoscopic equipment, high-tech materials).

Depending on the complexity of the operation (partial or complete prosthetics) its time can last from one to three to four hours:

• anesthesia;
• installation of a catheter in urethra(to prevent involuntary urination and control the amount of fluid released by the body);
• an incision on the outer thigh (or two small ones - on the thigh and in the groin area);
• peeling and shifting of tissues around the vehicle;
• installation of a prosthesis;
• restoring tissue integrity and suturing the wound.

The video clearly shows how hip replacement is performed.

Possible complications

Any surgical intervention in the body may have its own Negative consequences. Complications after the procedure most often occur in those undergoing surgery:

• with large joint deformation;
• with obesity or large muscle mass;
• having a number of serious concomitant diseases– diabetes, diseases of the blood, heart and the entire cardiovascular system, etc.

Joint replacement can cause the following complications:

• incorrect position of the endoprosthesis;
• damage nerve fibers, arteries;
• process disruptions postoperative healing wounds;
• the occurrence of infections;
• fracture of the femur, dislocation or “popping out” of the prosthesis;
• thrombotic phenomena in deep veins.

Rehabilitation after surgery

Rehabilitation after endoprosthetics can be long and take up to 6 months.

The patient should monitor the suture, body temperature and his sensations. Pain during this period may pass and return; the patient must be prepared for this and make efforts to full recovery motor functions body.

For the first few days, the patient is prescribed painkillers and anti-inflammatory drugs.

Further rehabilitation after hip replacement consists of prescribing a special light gymnastics and breathing exercises.

To prevent cicatricial tightening of tendons and skin, to strengthen the muscle frame around the prosthesis, the patient is prescribed physiotherapy(physical therapy).

As indicated by reviews from patients who have undergone endoprosthetics, it is worth adhering to the recommendations of specialists as much as possible and then rehabilitation will be quick and almost painless.

How rehabilitation goes after hip surgery is described in detail in the video.

Where can I have surgery in Russia?

The operation of hip replacement is a high-tech process.

In 2015, the inclusion of high-tech medical care(VMP) into the compulsory health insurance system is provided for by the new legislative draft “On compulsory health insurance in the Russian Federation."

Therefore, here we will not clarify who will pay for the operation - the patient or the insurance companies.

The cost of hip replacement consists of the prosthesis and the operation itself. Today, the cost of the operation (total hip replacement) ranges from 210 to 300 thousand rubles (depending on the cost of the prosthesis).

Hip replacement in Russia is done as in federal budgetary institutions healthcare (FC of traumatology, orthopedics and endoprosthetics, regional clinical hospitals, research institutes) and in private clinics of the Russian Federation.

For example:

• OAO "Medicine";
• Family Clinic;
• City Clinical Hospital No. 67 (Moscow);
• KB MSMU im. Sechenov;
• SM-Clinic;
• Central Clinical Hospital of the Russian Academy of Sciences;
• Multidisciplinary medical Center"K+31";
• DKB named after Semashko;
• Central Design Bureau No. 2 of JSC Russian Railways, etc.

Paget's disease is a disease in which there is a pathological growth of skeletal bone tissue and its deformation due to structural damage. This disease occurs as a result of a violation of the regenerative process in the bones; it is chronic. Otherwise, this disease is called “deforming osteodystrophy” or “deforming ostosis.”

Most often the disease affects the bones of the leg and spine, collarbone and skull, hip and humerus. People over 40 years of age and mostly men suffer from this disease, women - 50% less often. The European population is most susceptible to this disease.

Medicine does not know the exact reasons of this disease, however, there is an assumption that the following factors contribute to its occurrence:

• various conditions leading to disturbances in the metabolism of phosphorus and calcium in the body;
• past viral diseases;
• the presence of viruses in the body in the inactive phase;
• hereditary predisposition.

Sometimes the cause of Paget's disease is a combination of all of these causes. If a hereditary predisposition prevails, then it is advisable for family members of the patient to undergo an x-ray examination of the bones and monitor the level of alkaline phosphatase by taking a blood test. A special place in the series viral causes The development of this disease is attributed to the measles virus.

Paget's disease occurs in two forms: monoostotic and polyostotic. The monoosseous form of the disease is characterized by damage to one bone; in the polyostotic form, several bones are affected. The main difference between this type of disease and other bone diseases is that there are no generalized bone lesions - the disease exclusively affects individual parts of the skeleton. It is known that this bone disease causes a continuous process of change in bone tissue without the influence of any load. It is believed that the disease can develop into bone sarcoma.

In its course, the disease goes through three stages:

• initial;
• active;
• inactive.

The initial or osteolytic stage is characterized by a peculiar resorption of certain areas of the bone, as a result of which hollow pits are formed at this place. During the active stage, this process continues and at the same time bone growth occurs - they begin to acquire a cellular structure.

In the third stage - inactive - bone tissue is replaced connective tissue, i.e. osteosclerosis develops. In this case, the surface of the bones becomes rough, due to their thickening, the mass decreases. If you were hit tubular bones, then they bend and bend. When the disease affects the bones of the skull, they thicken up to 5 cm, which in turn entails deformation of the face and head. In case of damage to the bones of the spine spinal column deformed and twisted.

The onset of the disease occurs without any symptoms; this asymptomatic course is quite long. Signs and symptoms of the disease appear gradually.

Its first manifestations can be detected when examining a patient for other pathological conditions, i.e., the disease is learned only when taking a blood test, when a change in the indicator responsible for metabolism in bone tissue - phosphatase - is accidentally detected. In addition, a sign of this disease is bone deformation.

Pain in the area of ​​the affected bone is the main symptom of the disease.

The pain is usually continuous, aching and dull. Its peculiarity is that it does not subside after rest, but rather intensifies at rest. If the disease occurs near a joint, the patient may complain of osteoarthritis. In addition, there is stiffness of movement, and the mobility of joints in the affected bone is limited.

Upon close and detailed examination, swelling can be seen in the lesions, skin covering at this place is changed - there is hyperthermia of a separate area and its redness. If the doctor feels the affected area, thickening of the bone and unevenness of its edges may be noted. With slight pressure on such a bone, it can break.

As a result of the disease, bone fragility and bone fractures are observed, even as a result of minor trauma. When the spine is damaged, the back becomes deformed and stooped. In this case, the legs are bent and abnormal growth of the skull bones is observed. Deformations of the bones of the skull and spine can cause hearing or vision loss. This can occur as a result of compression of the nerve endings by the deformed bones. For the same reason, the patient may complain of constant headaches, numbness of the limbs and a feeling of “goosebumps” on the skin.

Diagnosis of the disease occurs by biochemical analysis blood and x-ray examination of skeletal bones. If the disease is present, the blood test results will show the alkaline phosphatase enzyme in the blood serum to be higher than normal. If such an increase is detected, it is necessary to regularly take blood tests to monitor possible changes.

X-ray examination is very reliable and informative method diagnosis of bone diseases.

If the disease is present, the image will show the following features:

• the skull bones are enlarged;
• loose bone structure;
• increased intracranial pressure;
• increase in the size of the tubular and pelvic bones;
• thickening of the periosteal layer;
• bone decay and deformation;
• fractures.

Diagnosis of Paget's disease can be carried out using methods such as CT scan and MRI. Their use is advisable only in cases where x-ray no pathology was detected. Technetium bone scanning is also used for diagnostic purposes. It allows you to identify foci of bone tissue with pathological changes and carry out dynamic monitoring of the course of the disease under the influence of treatment procedures.

Until the disease has manifested itself in full force and is asymptomatic, no treatment is required. Basically the disease requires symptomatic treatment. If pain occurs, analgesics and non-steroidal anti-inflammatory drugs (Diclofenac, Ibuprofen) are used. In addition, the use of vitamin D and calcium is recommended.

If there is a change in gait caused by deformation of the bones of the lower extremities, the doctor may recommend the use of orthotics. In some cases, this disease requires orthopedic surgery - endoprosthetics or decompression. If the hip joint is significantly deformed, it can be replaced, as this will significantly improve the patient’s quality of life and relieve him of pain. This procedure is called endoprosthetics. Treatment of Paget's disease also includes exercises with physical activity. It is not recommended to carry out long time in bed, since the pain intensifies at rest.

A mandatory element of therapy is the use of special medicines, the main effect of which is aimed at slowing down the process of bone tissue destruction. This medications- bisphosphonates, their use should be long-term. These medications have their side effects and therefore their prescription should be carried out by a doctor.

Conclusion on the topic

So, bone disease affects mainly older people and is associated with a disruption in the process of bone tissue regeneration. People at risk of developing Paget's disease should undergo regular screening. Its main symptoms are pain and bone deformation.

The disease cannot be completely cured, but it is quite possible to slow down its progression by for a long time. The disease stops its progression under the influence of treatment, but existing pathological changes are irreversible. The duration of the course of treatment is approximately six months and is repeated as necessary.

What are “artifacts” on MRI images?

Artifacts (from the Latin artefactum) are errors made by humans during the research process. Artifacts significantly degrade image quality. There is a wide group of physiological (in other words, related to human behavior) artifacts: motor, respiratory, artifacts from swallowing, blinking, random uncontrolled movements (tremor, hypertonicity). All artifacts associated with the human factor can be easily overcome if the person is completely relaxed during the study, breathes smoothly and freely, without deep swallowing movements and frequent blinking. However, in medical practice cases are not uncommon lung use anesthesia

At what age can children have an MRI?

Magnetic resonance imaging has no age restrictions, so it can be performed on children from birth. But due to the fact that during the MRI procedure it is necessary to remain still, the examination of young children is carried out under anesthesia (superficial anesthesia). In our center, examinations are not carried out under anesthesia, so we examine children exclusively from the age of seven.

What are the contraindications to MRI?

All contraindications to MRI can be divided into absolute and relative.
Absolute contraindications to MRI are the following characteristics of the patient: the presence of a pacemaker (heart pacemaker) and other implantable electronic devices, the presence of ferrimagnetic (iron-containing) and electric stapes prostheses (after reconstructive operations on the middle ear), hemostatic clips after operations on cerebral vessels, abdominal cavity or light, metal fragments in the orbital area, large fragments, shot or bullets near the neurovascular bundles and vital important organs, as well as pregnancy up to three months.
Relative contraindications include: claustrophobia (fear of closed spaces), the presence of massive non-ferrimagnetic metal structures and prostheses in the patient’s body, the presence of an IUD (intrauterine device). In addition, all patients with magnetically compatible (non-ferrimagnetic) metal structures can be examined only after a month has passed after the procedure surgical intervention.

Is it necessary to have a doctor's referral to get an MRI?

A doctor's referral is an optional condition for visiting the MRI center. Your concern for your health, consent to the examination, and the absence of contraindications for MRI are important to us.

I get headaches often. What area should an MRI be done?

Any person is familiar headache, but if it is repeated suspiciously often, of course, this cannot be ignored. We recommend that a patient with severe headaches undergo an MRI of the brain and its vessels. In some cases, this may not be enough, because the cause of headaches is not always associated with brain pathology. Headaches may be a consequence cervical osteochondrosis Therefore, our experts additionally advise you to undergo an MRI of the cervical spine and neck vessels.

How long does an MRI test take?

The average duration of one study in our center is from 10 to 20 minutes, however, it all depends on the changes detected: sometimes, to clarify the disease, the radiologist may expand the study protocol and resort to the use of contrast enhancement. In such cases, the research time increases.

MRI (Magnetic Resonance Imaging) is a method of scanning the body using strong radio waves and magnetic fields. MRI with an endoprosthesis is also possible, but some nuances should be kept in mind to obtain a reliable result. Only those implants that meet a number of requirements are used. They must be made of non-magnetic alloys and metals, be inert in a magnetic field and, of course, be certified.

Conducting a survey

Diagnostics is absolutely safe, as it is not associated with harmful ionizing radiation and the introduction of radioactive substances into the body. However, if the patient has an endoprosthesis, it would be advisable to consult with the surgeon who installed the implant. The possibility of carrying out the procedure will be assessed individually based on the shape and size of the implant, the location of its fixation and the material from which it is made. WITH magnetic field All substances interact without exception, but most strongly are ferromagnets (for example, steel). Prostheses containing such a substance can heat up and move under the influence of the strong magnet of the tomograph.

If during MRI the patient experiences discomfort in the area of ​​the endoprosthesis associated with the heating of the implant, he presses a special button and the examination stops.

Indications for use

Magnetic resonance imaging can detect even the slightest changes and pathological processes. Similar X-ray studies do not always give accurate results. Specifically, magnetic resonance imaging of the hip joint shows in detail the structures of each part of this area of ​​the body: soft fabrics, circulatory system, joints and ligaments, bones. This procedure may be prescribed to monitor the condition after surgery or as a preventive measure. However, being guided by your own initiative, you should not conduct an MRI. This is a rather expensive study and can only be prescribed by a doctor, based on the following indications:

An indication for this type of study may be aseptic necrosis of the femoral head.

• osteoarthritis;
• infectious arthritis;
• rheumatism;
• joint dysplasia;
• injuries and dislocations;
• pain in the hip area;
• detection of tumors and metastases.

Is it possible to do an MRI with an endoprosthesis?

All devices and structures for osteosynthesis and endoprosthetics are made of titanium or steel. Such implants are firmly fixed in the bone and do not budge even under the influence of a strong magnet. However, titanium is a more preferable material, since it cannot move or heat up during an MRI. Steel fixed in the bone also does not move, but tends to get very hot.

MRI is prohibited if the patient has vascular clips. Under the influence of a strong magnet, they shift and can “break away” from their place. People who have a pacemaker or middle ear implant should not undergo magnetic resonance imaging. Such a diagnosis can be dangerous for people whose prostheses or their components (pins and plates) are made of steel and have a length of more than 20 cm.

Carrying out an MRI in the part of the body where the implant is installed is impractical. The metal from which the prosthesis is made distorts the images and making a diagnosis will be difficult.

If the patient has an endoprosthesis, the tomograph requires additional adjustment to other parameters.

MRI with hip replacement can be done, but it should be remembered that the metal in the endoprosthesis can affect the quality of the procedure and the reliability of the results. If it is impossible to do without such an examination, doctors use special programs(for example, MARS) and configure the tomograph in a special way. This helps remove distortions that will be present in the images due to the interaction of the magnetic field with the endoprosthesis.

It is a common belief that people with implants should not have an MRI. In fact, this was the case several decades ago, when patients were given prosthetics made of steel, nickel and cobalt. In those years, magnetic resonance imaging could cause serious harm to human health.

TBS implant.

Let's be clear from the beginning that people with implants, pins, screws, retaining plates, breast implants, and dental implants CAN have an MRI.

What implants can be used for MRI?

MRI is allowed for people who have undergone hip or knee replacement. It is important that the endoprosthesis or fixation for osteosynthesis is made of metals or ceramics with low magnetic susceptibility. This avoids displacement or overheating of the structure during the examination.

Endoprosthesis knee joint.

People with hernia mesh, dental, breast and joint replacements are also allowed to have an MRI. All these implants are made from materials that do not interact with the magnetic field. This makes the study safe. However, you should consult a specialist before an MRI. The doctor will evaluate possible risks and recommend the necessary precautions.

Interaction of different metals with a magnetic field

Different metals tend to interact with magnets differently. Some of them are attracted to it, others are repelled, and others do not react at all. All three types of metals are used for the manufacture of endoprostheses.

Table 1. Metal classes.

Class	Representatives	Description
Diamagnets	Copper Zirconium Silver Zinc	They have negative magnetic susceptibility. This means that when interacting with a magnetic field, they repel rather than attract.
Paramagnets	Titanium Tungsten Aluminum Tantalum Chrome Molybdenum	These metals are characterized by the presence of low magnetic susceptibility, independent of the magnetic field strength. Paramagnetic prostheses usually tolerate the MRI procedure well and do not move or heat up.
Ferromagnets	Iron Nickel Cobalt Steel	They have high magnetic susceptibility, depending on the magnetic field strength. Implants containing a large number of these metals may become dislodged or heated during an MRI.

Composition of modern endoprostheses

All plates, pins and endoprostheses, which are used in modern traumatology and orthopedics, consist of a variety of alloys. Note that different implants contain different amounts of paramagnetic and ferromagnetic materials. The properties of each endoprosthesis, pin or plate depend on the composition.

Not all prostheses are 100% metal. Most of them contain ceramics or polyethylene. The latter does not interact with the magnetic field, therefore, it does not in any way affect the MRI results and the course of the procedure. However, ceramics most often contain aluminum oxide, which still has a certain magnetic susceptibility.

Destroyed components of the hip implant.

Possible combinations of materials in endoprostheses:

• ceramics + polyethylene;
• metal + polyethylene;
• metal + ceramics;
• metal + metal.

Fact! Plates and pins for fixation bone fragments are made of metal alloys. The same applies to external fixation devices (Illizarov type) and clips that are placed on vessels.

Composition of artificial joints:

• cobalt;
• chromium;
• molybdenum;
• titanium;
• zirconium;
• tantalum;
• niobium.

Having familiarized yourself with the composition, you can understand how it will behave in a resonant tomograph. The magnetic properties of each endoprosthesis are determined not only by the material from which it is made, but also by its shape and size. Steel pins and plates longer than 20 cm can heat up above the permissible limit.

Fact! Products containing large amounts of nickel and cobalt interact especially actively with a magnetic field. This means that diagnostics with such endoprostheses should be performed with extreme caution.

Manufacturing companies

Over the past 20 years, medicine has mainly used implants made from chromium-cobalt alloys (as we have already found out, these metals actively react to a magnetic field). Many models made from better materials have appeared on the market. They are better tolerated by patients and do not cause allergies or MRI problems.

Table 2.

Company manufacturer	Characteristics and Application	Behavior of implants during MRI diagnostics
Biomet	Produces high-quality implants that take root well and do not cause allergic reactions.	Thanks to small size and low magnetic susceptibility do not interfere with MRI.
Zimmer	It produces products not from titanium, but from tantalum. The implants have a porous coating and fuse perfectly with the bone tissue.	They don't call unforeseen complications during magnetic resonance imaging and do not distort the results of the study.
Johnson&Johnson	The company produces implants using all available standards and technologies.	Do not interact with magnetic field. When available, MRI is absolutely safe.
Smith&Nephew	Manufactures endoprostheses from an alloy containing zirconium and niobium.	Smith&Nephew implants are hypoallergenic and practically do not interact with the magnetic field.
Stryker	World-famous company of beta-titanium endoprostheses and fixators for internal osteosynthesis.	Owners of Stryker implants can undergo MRI without any worries. Additional precautions may only be necessary if you have several large prostheses.
Aesculap	Produces endoprostheses from titanium, zirconium ceramics, chrome-cobalt alloys.	Most implants can easily withstand magnetic resonance imaging.

If you have a prosthesis from one of the companies listed in the table, you can do an MRI without the slightest fear. However, in any case, you should not undergo the study without first consulting a doctor.

Contraindications to the procedure

If prostheses, pins and plates are firmly connected to the bone tissue and cannot move, then implants of other locations can easily move under the influence of a magnet. Therefore, it is STRICTLY PROHIBITED to conduct magnetic resonance imaging if they are present.

Implants that cannot be used for MRI:

• artificial heart valves;
• stents and clips on vessels of any location;
• middle or inner ear implants;
• pacemakers;
• artificial lens;
• Illizarov apparatus;
• insulin pump;
• large metal implants.

How to find out if you can have an MRI

Remember that an MRI can be done with the permission of a specialist. Only he will determine whether you need this research and whether it will harm you. Perhaps the doctor will make a diagnosis without magnetic resonance imaging. Spinal spondylosis and deforming osteoarthritis of stages II-IV can be detected using conventional radiography.

Comparison of visual diagnostic methods. MRI is on the right.

Possible complications and precautions

MRI in the presence of electronic implants can seriously harm a person or even lead to his death. Performing the study on persons with coronary walls and clips on cerebral vessels can provoke massive bleeding, which will lead to death. Endoprostheses made from some alloys may move out of place or heat up during an MRI, causing burns.

MRI installation before the procedure.

People with certain types of implants are strictly prohibited from undergoing magnetic resonance imaging. But for patients with implants made of “dangerous” alloys, you can still try to perform the study. As a precaution, a button is placed in the person's hand. If he feels a strong burning sensation, he presses it and the study is stopped.

Fact! Metal prostheses tend to “fade”, making the image of nearby tissues unclear. Therefore, it is pointless to try to obtain an MRI image of the replaced joint or bone held together by fonts or plates.

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Planning and monitoring the results of hip replacement using computed tomography and magnetic resonance imaging

IN Lately In traumatology and orthopedics, such highly informative information is being increasingly introduced into everyday clinical practice. radiation methods research how computed tomography (CT) and magnetic resonance imaging (MRI). In this work, the effectiveness of using CT and MRI in tanning and monitoring the results of hip replacement was analyzed. IN preoperative period CT was performed in 53 patients and MRI in 37 patients. Of these, in 34 observations, comprehensive examination using both methods.

As a result of the analysis of the data obtained, the following conclusions were made. The use of CT when planning surgical intervention allows for a more accurate assessment bone structure and dimensions of the acetabulum, proximal and distal parts of the femur, identify the location and size of cystic cavities, bone defects and others pathological changes. The use of MRI helps to clarify the diagnosis, as well as visualize soft tissue structures and the location of the main neurovascular formations. It should be noted that in 7 observations, MRI was used to determine early signs aseptic necrosis head of the femur, despite the fact that, according to CT data, no pathological changes were detected.

IN postoperative period To monitor the correct placement of the endoprosthesis components, only CT was performed (in 21 patients after hip replacement). Using a special protocol of sequential axial sections at 5 levels, the location of the components of the hip joint endoprosthesis was clarified. The acetabular component was positioned at an average angle of 42 to 60°, with an anteversion ranging from 8 to 23°. When assessing the location of the femoral component, it was revealed that in most cases the implantation of the endoprosthetic stem was satisfactory. Only in 1 observation was a slight varus deviation from the longitudinal axis of the femur of 3° noted. In addition, in 9 cases, functional CT was performed to clarify the strength of fixation of the femoral component and early diagnosis development of instability. Functional CT was performed using the following technique. After constructing a standard skiagram, a set of sections was made at the level of the femoral component and at the level of the femoral condyles. In this case, the cuts were made in three series: in a neutral position lower limb, with external and internal rotation. Then, the deviation of the axis of the femoral component was measured in comparison with the condyles in all three series of sections.

As a result of the analysis of the data obtained, the following conclusions were made. CT allows you to more accurately assess the size and structure of bone tissue, which undoubtedly helps to plan the operation more correctly. MRI should be performed, if possible, in all patients for an earlier diagnosis of aseptic necrosis, even with a negative tonic reaction, which corresponds to the pathomorphological process of lipoid degeneration. According to a qualitative study of these muscles, a significant difference was also found in the pattern of location, density of foci of muscle dystrophy, their predominant localization, condition of the fascia, epi- and perimysium.

A. N. Bogdanov, S. A. Borisov, P. A. Metlenko
Military Medical Academy named after. S. M. Kirova, St. Petersburg State Healthcare Institution " City Hospital No. 26", St. Petersburg