What does a knee x-ray show? X-ray of the knee joint: what diagnostics shows Normal X-ray of the knee joint
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X-ray of the knee is an instrumental diagnostic method that, along with innovative CT, ultrasound and MRI, doctors use to assess the condition of the joint, identify deviations from the norm and determine what the patient is sick with.
The examination has become especially widespread in emergency situations, for example, domestic and sports injuries, accidents on roads and enterprises, etc.
Modern diagnostic centers use a digital research method, while the analog one is mainly used in public hospitals with outdated equipment. The procedure can be performed in different projections - the attending physician determines how exactly the patient should be examined.
What does it show?
After examining the resulting images, the doctor can:
- make an accurate diagnosis;
- assess the extent of damage and severity of the disease;
- create an individual treatment program;
- identify relapses of cancer.
X-ray can reveal:
- narrowing of joint spaces;
- indentations and effusions;
- cracks and fractures;
- destruction of osteochondral structures due to the development of degenerative processes;
- signs of osteosclerosis and osteophytes;
- tumors of different sizes.
Attention! Despite the information content, the procedure is not a replacement for laboratory tests. X-rays alone cannot make a diagnosis, so you need to undergo all the tests prescribed by your doctor.
Indications and contraindications
The reason for prescribing this examination is severe pain of unknown origin in the knee area and suspicion of joint diseases such as rheumatoid and gonarthritis. Most often, an X-ray of the knee is taken in case of injury to diagnose dislocations, cracks in the bones, fractures, ligament ruptures, etc., and in oncology it is prescribed to determine the stage of the tumor process and prepare for surgery.
Due to the fact that the procedure involves exposure to x-rays, it is not advisable for some groups of patients to undergo x-rays. These include:
- women bearing a child and breastfeeding;
- Small children;
- seriously ill people;
- patients with bleeding and significant wounds.
Important! For those who are significantly overweight, alternative tests are usually prescribed because clear X-rays cannot be obtained.
How do they do it?
In more than half of the cases, patients are prescribed radiography of the knee joint in 2 projections - frontal and lateral. The resulting projection determines how the procedure is performed, or more precisely, what position you should be in during the examination.
A direct projection is obtained by placing the patient lying on his back with his leg extended, and to take a lateral view, he is moved to his side, keeping the leg in the same position. There are other options for conducting the survey:
- with Schuss and Fick positioning (the leg is bent at an angle of 30 and 45 degrees, respectively);
- in a standing position without support on the sore limb, if the joint is damaged;
- with a load - done when the doctor suspects damage to the ligaments or patella;
- in the transcondylar projection (for diagnosing osteoarthritis and aseptic tissue necrosis);
- in axial or right projection.
There is no need to prepare before the X-ray examination, and during the procedure you should maintain the position in which the radiologist positioned you - this will allow you to get an accurate image of the internal structures.
How and who issues the conclusion?
The interpretation and preparation of an expert opinion is carried out by a certified radiologist who assesses the integrity of the bones (tibia and femur), identifies pathological neoplasms and an increase in the Cato index (determines the topography of the patella).
Also, the doctor’s range of tasks includes detecting changes in the size of the joint gap - if the indicator is less than 5 millimeters, then he notes the likelihood of dystrophy and uneven contours.
If you go to a clinic with the latest generation devices, the images will be digital, which means they can always be reprinted if necessary. After receiving the results, the patient will have a second consultation with a specialized specialist.
Differences from MRI
In medical practice, both methods are actively used, but for diagnosing different types of pathologies. X-rays of the knee are most effective in detecting diseases and injuries of dense structures, while magnetic resonance imaging is much better at reflecting inflammatory processes, neoplasms and other abnormalities of soft tissues and cavities.
Among the advantages of X-ray examination, the following should be noted:
- affordable price;
- Possibility of carrying out for people with pacemakers and heart pumps;
- high information content in case of injuries.
Often, MRI and radiography are used as complementary diagnostic tools, allowing one to accurately determine the problem and select the optimal treatment program for the patient.
X-ray is a classic type of diagnosis. This is the first thing a doctor prescribes when a patient seeks help after being injured or in the presence of pain caused by a disease.
Based on the results of the x-ray, you can make a conclusion, prescribe advanced diagnostics, or select effective methods of therapy. Therefore, the patient is often concerned about the question of where one can get high-quality x-ray diagnostics and how much such a procedure costs.
Image acquisition techniques
It is difficult to find a definite answer regarding the price category. First of all, the cost will depend on the choice of the type of x-ray of the knee joint, as well as in how many projections the pictures need to be taken.
Today in clinics you can find X-ray machines based on two methods. Pictures are formed digitally or analoguely. Of course, preference is given to the more technologically advanced digital method, in which the image of the knee joint in several projections is displayed on the monitor. In this case, it is possible to record images in all projections on disk. This is an additional service, which also determines the price. Most clinics are trying to install equipment for digital x-rays, which allows for information diagnostics.
However, in many hospitals, especially in municipal ones, you can find outdated X-ray equipment based on analogue methods. This is not to say that such a diagnosis will not allow one to distinguish a healthy joint from what a diseased knee looks like. Of course, the resulting images in different projections in such situations are blurry and not so clear. But analogue methods are considered safer for health. In addition, equipment that can be used to take analogue images exists in almost all specialized clinics and clinics. And quite often the price for such an x-ray is simply symbolic, or the procedure can be done for free.
For these two methods, the procedure and image processing does not take more than 5 minutes.
Video
Video - X-ray of a child’s knee
Types of X-ray
The price of the examination also depends on the type of x-ray performed, which is selected by the doctor based on the purpose of the examination.
Survey X-ray
This type of examination of the knee joint allows you to visualize individual parts of the joint, depending on the projections in which the images were taken. Thanks to this diagnosis, you can see various changes that have occurred in bone tissue.
A survey x-ray is prescribed after injury, if a fracture, dislocation, or sprain is suspected. Such an x-ray will also help to diagnose dystrophic changes, accompanied by narrowing of the joint space, the presence of irregularities on the bones, osteophytes and other growths.
Pathologies associated with changes in the structure of bone tissue can also be identified.. This is how osteoporosis or osteoarthritis is diagnosed. Displays x-rays and the presence of congenital bone changes in the form of disproportion of bone ends, growths and bulges. X-ray examination is indispensable for diagnosing tumors that appear in both bone and soft tissues.
This examination does not require any special preparation from the patient. Moreover, it can be carried out in emergency cases. Typically, in trauma centers, patients immediately undergo an X-ray in two projections after receiving injuries.
The patient is placed on the table and first a photograph is taken in anterior projections. In case of fractures, such an examination is sufficient, especially if the pathology is associated with damage to the kneecap.
More often you need to take a picture in two or three projections. To do this, the patient is asked to turn the leg, lie on its side, and rotate the limb to examine the inside. X-rays can also be taken in two projections of the body, that is, standing or lying down, with a straight or bent limb.
Sometimes it is problematic for the patient to be in the positions chosen by the doctor, but without additional, at least two photographs, it will not be possible to make a correct diagnosis. Therefore, in case of very severe pain, the patient is recommended to numb the limb or take a tablet of the same effect.
Blurred images are obtained if the radiologist’s recommendations regarding the position of the leg and movements during the procedure are not followed. Obese patients also experience blurry images.
X-ray with contrast
Considering that ordinary x-rays do not show the condition of cartilage and soft tissues, in order to obtain reliable images, certain substances must be injected into the joint.
Typically, contrast liquids and air are injected into the patient's knee immediately before the x-ray. Of course, the price in such cases will include, in addition to the cost of the image itself, the cost of medicine and the service of injecting the knee joint.
The drug is injected into the knee in advance. Before this, the joint is injected with anesthetics. But despite this, the patient may experience some discomfort or pain during the injection of the drug into the knee. After this, you need to move your leg so that the product is evenly distributed inside the joint. In the future, the procedure is carried out according to a proven scheme similar to a survey x-ray.
X-rays allow the doctor to determine changes in the soft tissues that have occurred in the knee joint. But in order to evaluate the real picture, it is often necessary to take pictures in two or even several projections. X-rays with contrast can determine the condition of the menisci, tendons and ligaments.
However, after the administration of a contrast liquid, complications in the form of crunching or allergic reactions are possible. Such consequences can be avoided by following the manipulation technique.
Choosing a Leg Position
The correctness of the diagnosis will depend on the clarity of the images and the display of the necessary parts of the knee joint in different projections. However, such criteria depend not only on the basic features of the X-ray equipment. More often, the information content of the images depends more on the competence of the radiologist. It is the doctor who can determine in which projections the photo of the knee joint needs to be taken.
Usually one image is not enough to make a diagnosis, and an x-ray is required in at least two projections.- In direct projections, fractures can be detected. For this, the patient is placed on a special table.
- Pictures in tangential projections are taken with the patient standing. They show changes associated with pathological processes and damage to the articular surface and patella.
- In lateral projections, when the picture is taken in a standing position, changes in the patellar bursa and effusion on this side are visible.
- With transcondylar projections, gonarthrosis, ligament rupture or tissue necrosis is diagnosed.
Of course, if pictures are taken in two projections, the price of diagnostics increases.
It should be borne in mind that X-rays are often the starting type of diagnosis, giving the doctor a reason to prescribe an ultrasound or MRI. And these diagnostic methods require additional costs. However, without a comprehensive examination, it is impossible to establish the true cause of pain and select effective treatment methods. And when it is necessary to evaluate changes that have occurred in soft tissues and identify the presence of exudate, one x-ray is not enough to make a diagnosis.
Where is X-ray examination performed?
X-ray is a common diagnostic method with a history. In fact, this is the first visualization method which existed even before the advent of ultrasound or magnetic resonance techniques.
Therefore, you can find X-ray equipment even in rural hospitals. X-ray rooms exist in any municipal clinic. Therapeutic, traumatology, surgical and oncology departments and centers are required to be equipped with them.
You can get an X-ray of your knee at any diagnostic or private medical center. When choosing a diagnostic location, the key point is the quality and type of equipment installed in the X-ray room and, of course, the price of the examination.
However, if emergency diagnostics are necessary, which happens after an injury, an x-ray is taken in an emergency room or trauma department. And in this case, the patient does not choose the methods and place of diagnosis. Emergency diagnostics can be carried out free of charge.
Cost of x-ray diagnostics
The price of the examination, as can be seen from the above, depends on many nuances. In some cases, diagnostics are carried out absolutely free of charge or the cost only includes the price of film for the images.
In any case, x-rays are practically the cheapest type of diagnostics. Even in the most elite clinics such an examination does not exceed 3,000 rubles. And this is an order of magnitude lower than, for example, MRI or CT.
The average price is about 2000 rubles. If you need to record pictures to disk, the price increases by 400-500 rubles.
Of course, you can find a clinic where a knee examination will be performed for free. But you will have to stand in line and adjust to the office’s opening hours, and first receive a referral from a doctor.
If you want to take an X-ray using modern high-tech equipment and immediately get a transcript of the images, it is better to contact private clinics.
In any case, if the doctor recommends an X-ray of the knee, you need to find ways to make a high-quality diagnosis, no matter how much it costs. After all, both the diagnosis and the effectiveness of further treatment and the speed of recovery depend on this.
X-ray, due to its simplicity, low cost and tradition, still remains the most common examination method in medicine. The innovation was first used in 1895 by German physicist Wilhelm Conrad Roentgen, who took a photograph of his own brush. We will tell our readers how an x-ray is taken of the knee joint, in which various pathologies very often occur, and we will also talk about whether this is dangerous.
The essence of the knee joint radiography method
The essence of radiography is to obtain a projection of rays passing through tissue on film or photographic paper.
Different tissues transmit X-rays differently:
- hard bone structures create more resistance, braking and scattering the rays;
- soft (cartilage, bags, capsules, blood vessels, muscles, nerves) - less, transmitting the lion's share of radiation through themselves.
This heterogeneity of the structure makes it possible to obtain a contrast X-ray image. It should be immediately noted that an x-ray of an object that is completely homogeneous in its density will essentially show nothing.
Types of radiography
The performance of an X-ray machine (RA) is determined by the voltage, current and exposure time. The lower the power of the device, the longer the image is taken, and the more radiation the patient is exposed to. The first RAs were very inconvenient, since the duration of exposure was very long, and the person actually received decent doses of radiation.
Today, modern PAs with much greater performance are used.
Analogue radiography
Most of the old domestic devices, due to their low cost, still work according to the old analog method, in which the image is developed on film or photographic paper. Disadvantages of analog radiography:
- the picture must be taken while completely still, otherwise it will turn out blurry;
- image blur also occurs due to the reflection of some of the rays from the object, which is why it is necessary to filter the radiation, and this leads to the need to increase the irradiation dose;
- It may be necessary to re-shoot;
- The patient does not receive the result immediately.
Digital photographs
Today, digital radiography is used in most cases around the world:
- the device is equipped with an electronic matrix that allows you to receive an image directly on the monitor;
- no endurance or manifestation required;
- the result is known within five minutes;
- the patient is exposed to a low dose of radiation;
- the result can be saved to digital media (disks, USB drives, etc.).
But digital RAs are more expensive than analog ones, and not all district clinics have them.
Is it dangerous to take an x-ray?
Radiation dose (RD) is measured in millisieverts (mS).
Patients often have a prejudice about the dangers of x-rays. Meanwhile, radiography of the knee joint is associated with a very small DO - only 0.001 MZt. If we compare it with the natural total ion radiation that we receive daily from monitors, microwaves, phones, then it does not exceed it, and with the current technology-filled life it may be even less.
What does a knee x-ray show?
X-rays of the knee joint will show deviations from the norm for the following diseases:
- (osteoarthritis);
- traumatic pathologies (fractures, dislocations and subluxations of the knee, tears of the menisci and ligaments);
- (marble disease);
- aseptic necrosis;
- tuberculosis of the knee;
- CS tumors;
- etc.
X-ray for gonarthrosis
A study of RA makes it possible to determine the degree of deforming arthrosis disease based on the width of the joint space.
- The greater the degree of DZ, the narrower the gap between the articular surfaces (epiphyses of the femur and tibia).
- An x-ray of a healthy knee joint will normally show a gap of uniform thickness and smooth edges.
- An uneven gap with osteophytes along the edges is evidence of arthrosis of the second or third degree.
- Deformation of the gap (narrowing in one place, widening in another), as well as a violation of the alignment of the femur and the joint bone is a sign of impaired stability of the knee, characteristic specifically in gonarthrosis (in coxarthrosis, degeneration ends in ankylosis - a process reverse to joint laxity, that is, fusion contact surfaces).
But an X-ray of the knee joint gives an incomplete picture of arthrosis: what is visible in the image of the knee in its articular cavity is the subchondral bone and spongy bone tissue. Cartilage, synovial fluid, and the joint capsule itself are not visualized on x-rays, so the articular ends of a healthy joint look separate with empty space between them, although in fact it should be narrower due to the cartilaginous layers and filled with fluid located in the joint capsule.
X-ray of the knee joint for osteoporosis
Conventional X-rays detect this disease late, when it manages to reduce bone density by about a third. Osteoporotic bones appear more transparent than normal healthy bones in an x-ray of the knee.
The photo shows an x-ray of a knee with diffuse osteoporosis.
For osteoporosis, special radiography is indicated - densitometry. The absorption-based method measures the density of the bones in a joint by the amount of calcium in them.
There are also ultrasound densitometry, quantitative computed tomography or quantitative magnetic tomography.
Contraindications for knee x-rays
X-ray is contraindicated:
- during pregnancy and lactation;
- severe critical conditions;
- burns and knee wounds;
- if the day before an X-ray of the intestine was taken with a contrast barium suspension;
- in infancy.
Children's age is a relative contraindication. If the threat from the disease exceeds the risk of radiation, the child will be given an x-ray, but with increased precautions: usually the baby’s entire body, except the knee, is covered with protective aprons.
How to take an X-ray of the knee joint
An x-ray is most often taken in two projections: frontal and lateral.
For some pathologies, in addition to the standard 2, other projections can be used.
- Straight projection is used to diagnose a fracture and is performed lying down.
- Lateral projections are made when examining the bursae in the area of the kneecap
- For ruptures of the lateral and cruciate ligaments, aseptic necrosis, osteoarthritis, transcondylar projection .
- Pathologies of the patella and articular joints - tangential P.-
In case of ligament ruptures, a functional photograph is taken focusing on the affected leg. In all projections except direct, x-rays are taken standing.
How to prepare for a knee x-ray
Special preparation for X-ray of the CS (diet, refusal to eat and drink on the eve of the examination, bowel cleansing), as happens with X-ray of the gastrointestinal tract, is not required.
- The patient must remove all metal objects located in the knee area.
- The groin is covered with a protective apron, and the laboratory assistant performs the necessary positioning of the knee.
- If analogue radiography is taken, then it is necessary to observe the requirement of maximum immobility and be prepared for the fact that it may be necessary to take a repeat image.
- With digital x-rays there is no such need: the examination takes place in the same mode as with ultrasound. The result is displayed directly on the monitor and is immediately deciphered by a specialist.
- The result of analog radiography is obtained with a delay: the patient waits for the film to be developed and the doctor to describe the image.
How else can you examine the knee joint?
X-ray is a good, proven diagnostic method, but it is not omnipotent. It is better to perform it for bone pathologies, but for periarthrosis or periarthritis, cartilage pathologies, soft tissue tumors, for example, synovioma, it is definitely better to resort to other examination methods.
Today we will look at the use of this method in diagnosing diseases of the knee joint. Let's find out in what cases an X-ray of the knee joint is taken and what the image shows. Who should take pictures and how many times can they be taken? Let's look into all these issues.
What is normal in the picture?
Photo of the knee joints
A direct view of a healthy joint shows the articular ends of the femur and tibia. There are no splinters or cracks on their surface. Bone density is also the same. The surfaces of the ends of the bones correspond to each other. The joint gap is symmetrical on both sides and the same width, has no growths or inclusions.
What can an x-ray show?
On a targeted image, the joint space is so wide, as if there was nothing between the bones. This occurs because X-rays pass unhindered through the cartilage tissue that covers the articular surfaces of the knee joint.
Therefore, the cartilage itself is not visible, but its changes are determined by the underlying endplates of the joint.
X-ray of the knee joint reveals pathological changes in the joint:
- Indicates damage to the articular cartilage by thickening or thinning of the articular endplates. This happens in the case of arthritis or arthrosis of the joint.
- Detects traumatic joint injuries in the form of dislocation, fracture or deformation. In case of injury, x-rays are also taken to monitor treatment.
- Pictures are taken in case of congenital changes in the joints.
- X-ray reveals tumors.
X-ray of the knee joint in two projections
The picture is taken in 1 or 2 projections. If a fracture is suspected, a lateral X-ray is taken or a targeted X-ray is prescribed in the position of the knee joint being maximally flexed. Although there are more accurate diagnostic methods, most pathologies are visible on a regular x-ray.
Indications for a knee x-ray
When examining diseases or damage to the joints, an X-ray is indispensable. This method is used for initial diagnosis and observation of dynamic changes as a result of treatment.
An X-ray of the knee joint should be done in the following cases:
- its redness and swelling with fever;
- joint deformity;
- bone displacement;
- to find out the cause of joint pain.
An x-ray reveals changes in the bones and also detects fluid in the joint. The earlier joint pathology is detected, the more opportunities there are to get rid of the disease.
Contraindications for radiography and radiation exposure
Like any other type of examination, radiography has its contraindications.
Although the radiation exposure during the image is minimal, the procedure is contraindicated in certain conditions or diseases:
- pregnancy;
- metal prostheses and bolts in the knee;
- severe obesity distorts the image;
- schizophrenia;
- serious condition of the patient.
Women are advised to refrain from conceiving for 1 month after the X-ray examination. Men should use protection for 3 months. If, according to indications, you often have to take x-rays, you can minimize radiation exposure by drinking green tea, natural juices with pulp and milk.
Radiation exposure when photographing the knee joint is 0.001 millisievert (mSv). This dose corresponds to the daily dose of radiation received by a person in normal life when using a mobile phone and other technologies.
But X-rays have cumulative properties, so the danger is posed by the total annual radiation exposure, which should not exceed 5 mSv.
Each written doctor’s report contains a note about the radiation exposure received, which depends on the device. The more technologically advanced the device, the less radiation exposure.
X-ray signs of changes in joints
Stages of arthrosis of the knee joint
At the first stage of examining the knee joint, it is necessary to take an x-ray. Pictures are taken in frontal and lateral projection, depending on the purpose of the study.
- In deforming osteoarthritis, the picture shows a narrowed joint space. There is compaction of the articular surface and calcification of the ligaments. The joint is deformed, osteophytes and sclerotic cartilage tissue are visible.
- When a fracture occurs, bone damage is visible, varying in shape and size.
- Inflammatory diseases are determined by a decrease in the width of the joint space. Osteophytes (bone growths) are visible on the adjacent thinned and uneven bone plates.
- Congenital diseases appear in the image as an asymmetrical structure.
- With a tumor, an x-ray shows an irregularly shaped formation emerging from the bone, around which areas of tissue destruction are visible.
- A dislocation on x-ray is manifested by displacement of bone surfaces. With this pathology, the kneecap is often damaged.
- At the initial stage of arthrosis, the image shows a decrease in the distance between the bones of the knee joint. When gonarthrosis has formed, the joint space is significantly and unevenly narrowed. In addition, subchondral sclerosis is pronounced.
More often, photographs are taken for arthrosis of the knee joint. An x-ray qualitatively shows changes in bones, but ultrasound is used to determine the pathology of cartilage and soft tissues. The same method is preferable to use in children.
How is a knee x-ray done?
X-ray technician at work
No special preparation is required for the photo. You don't need to follow any diet. During the session, the radiologist asks you to take the desired position of your leg. At the time of the picture, at the request of the doctor, you need to stop breathing for a few seconds and not move, otherwise the picture will be blurry.
The quality of the image also reflects the correct posture of the subject.
Before the session, the patient is placed in a supine position. A direct projection photograph is taken in case of illness. After an injury, additional radiography in a lateral projection or targeted is required. The quality of the image largely depends on the qualifications of the radiologist.
Contrast radiography
On a regular x-ray, cartilage and ligaments are practically invisible. Therefore, contrast radiography is used. To do this, a contrast agent and air are injected into the joint. Once the cavity is filled, its size increases and ligaments and cartilage become visible. A contrast study is carried out in the following cases:
- suspected pathology of the articular membrane;
- to identify old ligament and joint injuries;
- suspicion of a tumor;
- detection of intra-articular pathology (foreign body).
Contrast radiography reveals meniscus damage. The procedure is not considered easy. After it, an allergic reaction may develop. In addition, some patients report a crunch in the knee.
A doctor evaluates an x-ray of the knee joint
Alternative to radiography
A modification of a conventional photograph is digital radiography. It is carried out using the same or improved devices, but the image is transferred to the display. In this case, the quality of the image can be improved and transmitted via a local network to the attending physician. The digital method allows you to quickly obtain an image, which is important in traumatology.
A regular X-ray reveals bone pathology, but damage to cartilage and soft tissue is inaccessible to this method. Modern technologies make it possible to make a more accurate diagnosis. There is a method of computed tomography (CT). It allows you to take pictures in several planes. In addition, information is transferred to disks or can be transmitted over a local network and the Internet. Computed tomography carries a large radiation load, but it is a guide for the operating surgeon.
Currently, an accurate and safe method of examination is magnetic resonance imaging (MRI). MRI takes pictures of bones, cartilage and soft tissue. The image is transferred to storage media with the ability to transmit over the Internet.
As a result of the topic, let us remind you that x-rays still remain an accessible and informative research method. It is indicated for the initial diagnosis of diseases and after injury. Digital radiography has greatly simplified and speeded up the acquisition of images, also improved the quality of radiographs, and also reduced radiation exposure. If you need frequent images, you can use MRI.
The knee joint is considered to be one of the most complex joints in the human body in terms of diagnosis and structure. In this part of the body there are not only articular surfaces, but also menisci, which are more often called joint spacers. This area of the knee is quite vulnerable to various environmental influences and mechanical damage.
It is the knee joint that receives the first blow when the body is in unfavorable climatic conditions and experiences nervous strain, stress, and physical overload. Various non-invasive diagnostic methods, including ultrasound, can determine what is happening to the joints. But to study pathologies of various etiologies, x-rays are still most widely used.
What can x-rays reveal?
It is generally accepted that x-rays have a more harmful effect on the body than ultrasound diagnostics. This is true. In some cases, doctors prescribe ultrasound for preventive purposes - to assess the size, shape and functioning of certain organs, to identify the early stages of certain diseases, as well as to obtain a picture of the health of a pregnant woman and the baby growing in her womb.
Radiography cannot be used frequently even to monitor the development of severe pathologies. It is completely contraindicated for pregnant women, as it can cause irreparable harm to the fetus. Medical specialists do not recommend that patients undergo an X-ray of the knee for preventive purposes; only a doctor can give a referral for such a study. This is due to the fact that the joint tissue receives a daily dose of radiation during analysis. It can negatively affect the normal functioning of the limbs.
It is necessary to immediately undergo diagnostics using X-rays if the following appears in the area of the knee joint:
- pain;
- swelling:
- swelling:
- redness;
- elevated temperature,
- joint deformities;
- signs of bone displacement.
X-ray of the knee joint can reveal the presence of fluid in the joint tissues; it also qualitatively diagnoses the condition of the cartilage. You need to know: if nothing is visible in the image between the bones (where the joints should be), this means that the articular tissues are normal and there are no pathological changes or destructive processes dangerous to health; When there is swelling or fluid in the area of the knee joint, it will become visible on an X-ray of the knee joint. But it will not be possible to accurately determine bone density using such diagnostics, however, x-rays will show the shape and structure of the bones and help determine the pathologies progressing in them. X-rays of the knee area can also detect bone tissue disorders.
If bone tissue in a particular area of the body begins to deteriorate and become thinner, x-rays will detect this deviation, therefore this research method is used as one of the effective ways to detect osteoporosis.
What X-ray diagnostics can’t handle
The earlier arthritis is detected, the greater the chance of slowing tissue destruction and increasing pain symptoms affecting the knee joint. The presence of bone spurs is one of the signs of arthritis, which can be detected by X-ray examination. X-rays are also used to determine the presence of joint spaces. Slight displacement of bones directly affects the functioning of joint tissue, ligaments and muscles of the musculoskeletal system. X-rays can detect such deviations in the location of the knee joint.
What do joints look like in a healthy person?
It is generally accepted. that with the help of X-ray examination all bone damage is detected. This statement is wrong. Radiography, indeed, can detect most of the fractures existing in the human body, but among them there are those that its rays cannot detect. In some cases, only an x-ray can detect the indentation of bones.
In medical practice, there are many cases when this type of diagnosis is unable to detect pathologies of the knee joint. We are talking about the study of joint and bone tissues in people suffering from obesity. Excess muscle and fat mass makes X-rays difficult; the images are blurry and do not give medical specialists an objective idea of what processes are occurring in bone, joint, and cartilage tissues. This is why x-rays are not prescribed to obese patients in most cases. X-rays are not performed for patients suffering from any type of schizophrenia. It is also contraindicated for those who have implants in the area under study.
When a patient has, for example, a titanium knee joint, this type of research cannot be used.
How many x-ray diagnostic techniques are there?
Imaging diagnostics is based on the fact that a beam of X-rays passes through the knee joint and a two-dimensional image of the studied area is created on a special film. In this case, the following components of the knee joint are visible in the image:
- parts of bones and joints;
- sections of the femur, fibula and tibia;
- soft tissues;
- knee cap.
In order for radiography to show the most accurate result, a method can be used where the X-ray machine rotates around a stationary patient whose knee joint is being examined. This technique is called computed tomography. It is used most often in cases where an X-ray of the knee joint is clearly not enough to identify the pathology and processes occurring in the area of the body. Doctors receive the most objective data on the condition of the knee joint if the patient is standing during the diagnosis.
The image revealed the appearance of sharp growths on the bones of the joint and deformation of the gap space
The beams remove the knee joint from the side, front and in a bent position. But this method of examining the knee joint is not universal and mandatory for all patients. The position of a person during diagnosis should be determined individually so that the x-ray immediately gives the desired results and the images are of high quality.
Not all joint projections obtained during the study are considered as informative as possible and carry the information necessary for comprehensive treatment. For a better diagnosis, the knee joint is usually filmed in frontal and lateral projections. The first is needed to identify the gap between the surfaces of the articulation, which, if the knee joint is in normal condition, will be transparent. To solve a similar problem, a second lateral projection is needed. If a patient is suspected of having a torn cruciate ligament, an x-ray is taken while the patient is placing weight on the affected area.
For fractures and dangerous joint injuries, radiography is performed when the victim is in a lying position.
Digital or analogue radiography: which is better?
All types of X-ray examinations are divided into:
- analog;
- digital.
Which of them can be used to most effectively examine the knee joint? Each of the listed types of diagnostics has its positive and negative sides. Digital X-rays are more accurate and reliable in the resulting views, but digital X-rays do not provide as clear information about bone structure as analogue ones.
The digital x-ray procedure takes on average 5 minutes. Medical specialists immediately receive an image of the area being examined on a computer monitor. Analog radiography involves a longer process of image processing and less rapid collection of necessary information.
Both analogue and digital radiography still expose the body to a dose of radiation. To minimize the consequences of diagnosis, patients are recommended to consume:
- milk;
- green tea;
- fresh fruit and vegetable juices;
- natural red wine.
Before the x-ray is performed, your diet includes vegetables and fruits rich in vitamin C. You can eat onions or parsley just before the procedure. If your health sharply worsens after an X-ray examination, you should immediately consult a doctor.
Analog X-rays are more dangerous to the body than digital ones.
Currently, there are many examination methods used for various diseases. Radiography plays a vital role in the diagnosis of many diseases of the musculoskeletal system. And when examining a knee it is impossible to do without it. Therefore, it is important to know what can be seen on an x-ray of the knee joint, what it looks like normally on an x-ray, and how the picture changes as pathology develops. We'll talk about this further.
X-ray of the knee joint: indications and contraindications
This study is necessary in case of injury to the knee area, for making a primary diagnosis, and for dynamic monitoring of the restoration of the bone structure after fractures.
Indications for x-ray examination are as follows:
- Presence of deformation in the articular area.
- Limitation of range of motion in the knee joint.
- The presence of swelling, local increase in temperature and redness of the skin in the knee area.
- Pain in the knee joint at rest or with movement.
- Suspicion of displacement of bone structures.
Many people are afraid of X-ray examinations, because they think that the resulting radiation exposure will have a negative effect on the body. However, this is not the case. Radiation exposure during X-rays corresponds to the permissible daily norm, which each person currently receives when using household appliances, smartphones and computers. Negative consequences are only possible with repeated x-rays, since bones are capable of accumulating radiation. It should be noted that after conducting such a study, women should not plan to conceive within a month.
The following points are contraindications to the study in question:
- The presence of metal prostheses in the examined area.
- The patient's condition is serious, requiring resuscitation measures.
- Pregnancy.
- Schizophrenia and exacerbations of other mental disorders.
If there are contraindications, an alternative to X-ray examination is digital radiography. In this case, the images are of better quality, and the patient is less exposed to radiation. You can also conduct magnetic resonance imaging or computed tomography, which are the most effective examination methods.
X-ray of the knee joint in normal conditions and in various diseases
An x-ray is obtained by passing scattered x-rays through various tissues. The greater the density of the fabric, the more rays it will block and the better it will be visible on film. Bone tissue can be clearly distinguished on an x-ray; soft tissues are less visible. Tendons can only be seen if the required x-ray rigidity is provided. Changes in the thickness of cartilage tissue are judged by the distance between bone structures, as well as by the configuration of the endplates.
An interesting fact is that objects located close to the device produce smaller images than objects located further from it. This is due to the scattering of rays.
What the study can show
An X-ray of the knee joint area will help identify the following pathological changes:
- Deformations resulting from trauma (fractures, dislocations).
- Congenital anomalies in the structure of joint structures or bones.
- Presence of arthritis or arthrosis. These diseases can be diagnosed by measuring the thickness of the cartilage and endplate tissues. They will either thicken or thin.
- Neoplasms of bone tissue.
Traumatologists also use X-rays to monitor the progress of regeneration processes when bone or joint structures are damaged.
How to take an x-ray of the knee
Before taking a photo, it is often recommended to expose the knee area. But if there is a bandage, including a plaster cast, it does not need to be removed.
During the examination, the patient is prohibited from moving, as the image will be blurred and dynamic blur will appear. If the image is of poor quality, making a correct diagnosis will not be possible.
X-rays of the knee joint are performed in both two and one projection. It depends on the presumptive diagnosis. In case of a fracture, it is necessary to take x-rays in two projections. In addition, the doctor can conduct targeted radiography with the lower limb bent at the knee.
After receiving the image, the radiologist describes it and makes a conclusion about the suspected diagnosis. Based on the data obtained, the treating specialist prescribes the necessary treatment measures.
What does a normal knee joint look like?
An X-ray of a healthy knee joint reveals the femur, tibia, patella and partly the fibula. They do not have any pathological neoplasms, the articular surfaces are smooth. There should be no cracks or splinters. The components that make up the joint correspond to each other. The joint gap is the same in width on both sides; there are no inclusions or other formations in its lumen.
X-ray for knee diseases
What will the image show for various diseases? The following pathological changes are visible on an x-ray for knee diseases:
![](https://i1.wp.com/tvoysustavchik.ru/wp-content/uploads/2017/12/rentgen-zdorovogo-kolennogo-sustava-koleno-na-snimke-14.jpg)
X-ray for rare knee diseases
X-ray examination will help diagnose not only diseases that occur with high frequency, but rare diseases. These include cysts, foreign bodies that have entered the joint cavity during injury, osteomyelitis, various osteochondropathy, congenital deformities of the knee, and abnormal tuberosities of the tibia.
In these diseases, the x-ray picture has the following features:
- Bone tissue cysts are visualized in the image as rounded clearings.
- With osteomyelitis, osteoporotic areas and bone tissue degeneration are determined. In some cases, it is possible to identify sequesters.
- Foreign bodies can only be detected if they are of high density.
- Koenig's disease, or osteochondropathy of the knee joint, cannot be diagnosed by X-ray examination alone. This is explained by the fact that with osteochodropathy, due to necrosis of one of the bones forming the knee joint, an articular mouse is formed. But the appearance of a joint mouse is also observed in other diseases of the musculoskeletal system, so further examination will be required.
- With Osgood-Schlatter disease, an X-ray image of the tibia has uneven, blurry outlines, and a pathological tuberosity is determined. After some time, bone fragmentation is possible.
- Congenital bone deformities can be suspected if they appear asymmetrical on the right and left in length and thickness.
An X-ray examination is mandatory to diagnose knee arthrosis. To further check the condition of the cartilage tissue and surrounding muscles, an ultrasound is often prescribed.
Conclusion
X-rays are still in demand in diagnosing various diseases of the knee joint. It is the most accessible and quite informative both when making a primary diagnosis and when monitoring the dynamics of a knee injury. An alternative to this study is its digital version, as well as an MRI study.
X-ray of the knee joint is one of the medical diagnostic methods that can show changes that have occurred in the joint space.
But X-ray examination does not replace ultrasound and the use of other tests, through which it is possible to obtain a more complete clinical picture of changes in the patient’s joint.
What does a knee x-ray show?
The procedure for X-ray examination of the knee is carried out from those angles from which pathology is suspected:
- suspecting a fracture in the patient, the doctor helps the patient lie down on the couch to assess the condition of the knee joint in a direct projection;
- possible pathology of the patella and articular surface requires that a photograph of the knee be taken in a tangential projection when the patient is standing;
- in case of osteoarthritis, ligament rupture or aseptic necrosis of the bone, the picture is taken in the transcondylar projection when the patient is standing or lying on his side;
- effusion in the patellar bursa is determined in the lateral projection when the patient stands or lies on his side.
Typically, an X-ray of the knee is taken in two projections: the direct and lateral techniques are used. This can be considered a standard prescription from the attending physician.
Carrying out an X-ray of the knee joint according to a given scheme makes it possible to carefully study the condition of the articulated bones.
In addition, an x-ray allows one to determine the quality of functioning of the patellofemoral joint.
For this purpose, axial photographs are taken, in which the patient's leg should be bent at the knee to the maximum possible position.
This way, the specialist is able to determine the condition of the cartilage of the lateral and medial facets.
X-rays taken with the knee bent at an angle of 45° allow one to correctly assess the mutual contact of the patella and tibia.
X-rays taken at a certain angle (15°, 30°, 45°, 150°) make it possible to assess the performance of all elements of the joint apparatus.
Also, an image of the patient’s sore knee can be taken under physical or stress load, which allows us to form the most accurate picture of the pathology of the bone connection.
The main feature for which X-rays are prescribed, and not an ultrasound examination of the knee, is the ability to easily and accurately assess the condition of the articular apparatus and bone tissue.
But the inability of x-rays to determine the condition of soft tissues and ligaments sometimes requires an additional procedure, for example, an ultrasound.
What can an ultrasound of the knee joint show?
Since bone tissue does not transmit ultrasound waves, a specialist cannot assess the condition of the bones during an ultrasound. But he can clearly see on the screen of the device what is happening in the joint cavity.
That is why an ultrasound may be prescribed after an x-ray if an inflammatory effusion or the presence of a blood clot in the joint is suspected.
In addition to fluid in the joint cavity, ultrasound can determine bone and cartilage parameters to ensure that the structure of the knee joint is normal.
Using ultrasound, a specialist is able to examine the parameters of the external and internal ligaments of the knee, obtain information about the soft connective tissues that are located in the joint cavity and near it, as well as see heterogeneity and thickening of the meniscus, identify hemorrhage and disruption in the ligaments.
Unlike X-rays, ultrasound is prescribed for children of any age in case of injuries, because it is in childhood that a child most often clogs his knees.
If the injury is not examined in time, then even minor damage to the knee joint can develop into a serious disease of the musculoskeletal system.
In newborn children, ultrasound of the extremities shows pathology in the form of ossification or other formations, and allows one to determine the state of development of the joints of the femur and tibia.
Ultrasound can be used for various diseases in young children, since during this period the musculoskeletal system of the body still transmits sound waves.
An ultrasound of the knee joint, like an x-ray procedure, does not require special preparation on the part of the patient.
X-rays are done quickly, the photo flash lasts a fraction of a second, and the ultrasound examination continues for 15 to 20 minutes.
All this time, the doctor moves a special sensor over the surface of the knee and uses a monitor to study the image of the condition of the internal cavity of the joint.
Rotating the sensor in different directions allows you to examine the affected area in the required planes.
The effectiveness and accuracy of the results of an ultrasound procedure can be achieved by performing ultrasound in stages, which makes it possible to cover each area of the knee joint.
This approach allows us to identify even pathologies that are invisible at first glance. In addition, to increase the accuracy of the information received, the uzologist can compare the damaged joint with a healthy one.
How is a knee x-ray performed?
If the knee joint is normal, then in any projection of the x-ray there are no even minimal pathological formations.
A healthy joint has the same joint space on both sides, without formations or growths.
But it is better not to take an X-ray of a healthy knee joint, since the second radiation received by the body is equal to the radiation dose that a person receives during the day.
Despite the significant information content, x-rays have their drawbacks:
- The X-ray procedure is not prescribed for pregnant and lactating women, as well as children under 14 years of age and patients who have previously been exposed to strong radiation exposure;
- If the limb is positioned incorrectly during the examination, the image quality will suffer, making it difficult to diagnose the affected area of the leg;
- The bone structure of the knee does not always change due to a knee injury; as a result, all damage occurs to the ligamentous-meniscus apparatus, which radiography cannot fully reveal.
You can get a referral for an x-ray if the color of the skin on the affected leg has noticeably changed, it has become difficult to move, there is pain in the joint, due to swelling or deformation of the knee.
X-rays are also indicated for patients with various types of injuries and injuries, for example, fractures and dislocations.
X-rays are mandatory for congenital defects of the musculoskeletal system, arthritis and gonarthrosis of the knee joint.
Since no special preparation for the x-ray is required, the patient can immediately go for the procedure, which in total will take a couple of minutes.
First, the patient exposes the limb and is positioned on a special table. During the procedure, at the request of the radiologist, the patient flexes and extends the knee, leaving it in the desired position.
To avoid irradiation of all other parts of the body, the doctor covers them with lead protection during the procedure.
Analyzing the received images, the radiologist draws up a description, enters data on the current state of the bone surfaces into the medical protocol, indicates the parameters of the joint space and the position of the patella, confirms or denies the presence of pathological formations.
With the result obtained from the radiologist, the patient goes to his attending physician, who studies the protocol data and prescribes the optimal method of treating the knee joint.
X-ray of the knee joint is still one of the most popular diagnostic methods and is prescribed for injuries and many diseases of this joint. It allows you to identify traumatic, deformational and destructive changes and can be used both for examining the patient and for assessing the quality of treatment.
What are the indications and contraindications for knee X-rays? How is the procedure performed? What do knee joints look like normally and with diseases? You can get answers to these questions by reading this article.
X-rays of the knee joint do not require any preparatory measures, are performed in just a few minutes and do not cause discomfort. During this study, the doctor can obtain an image of the bones, cartilage layer, joint space, ligaments and periarticular bursa. To take an image, an effective radiation dose of 0.001 mZt is used, which is considered low and is equal to the natural radiation received by a person throughout the day. That is why radiography can be performed not only for diagnosis, but also to evaluate the effectiveness of treatment.
Indications
Knee pain is a direct indication for x-rays.The doctor may prescribe an x-ray of the knee joint if the patient has the following complaints and symptoms:
- , occurring at rest or during movement;
- swelling, redness and local hyperthermia of the skin in the knee area;
- limitation of joint mobility;
- knee deformity;
- the likelihood of displacement of the articular surfaces of the knee.
An X-ray of the knee joint is prescribed if the following diseases are suspected:
- injuries to the structures of the knee joint: bone fractures, sprains or ruptures;
- congenital pathologies;
- joint tumors and metastases.
Contraindications
There are few contraindications for performing an X-ray of the knee joint. Photos are not taken in the following cases:
- pregnancy (without special protection);
- the patient's serious condition requiring resuscitation measures;
- exacerbation of mental illnesses in which the patient’s immobility cannot be ensured.
X-rays of the knee during breastfeeding can be performed only in cases of extreme necessity, when the study cannot be replaced by an ultrasound or CT scan of the joint.
Radiography techniques
Nowadays, analogue or digital x-rays can be used to obtain images of the knee joint. With the analogue method, image processing requires more time and the patient receives more radiation exposure. The digital technique allows you to obtain an image of the joint on the monitor almost immediately, and specialists prefer to use it.
Depending on the clinical case, photographs of the knee joint can be taken in different projections:
- straight – used to identify injuries and deformations, the patient is in a supine position;
- lateral – used to identify effusion, performed in a lateral or standing position;
- transcondylar – used to identify ligament ruptures, aseptic bone necrosis and osteoarthritis, performed in a standing position;
- tangential - used to identify pathologies of the articular surfaces or patella, performed in a standing position.
To evaluate the patellofemoral joint, the image can be taken with the knee flexed to 45 degrees.
How is the procedure performed?
Before the x-ray, the patient bares the knee (if necessary, a bandage or plaster cast is left) and takes the position necessary to take the picture. The doctor warns the patient not to move during the x-ray, as movement will make the image blurry and uninformative. If necessary, to ensure immobility in case of severe pain, an injection of an anesthetic drug is performed before the examination.
After taking the pictures, the radiologist describes them and issues radiographs and a preliminary diagnosis report to the patient. In the future, interpretation of the results should be performed by the attending physician.
What does a healthy knee joint look like?
In the absence of pathologies, the image visualizes the connection of the articular cavity of the femur with the heads of the tibia and fibula. Their articular surfaces are smooth, do not have any pathological inclusions and are separated by a uniform layer of cartilage tissue. The interarticular gap is the same width on both sides, and there are no inclusions or formations in its lumen. The integrity of the joint capsule and ligaments is not compromised.
Image for pathologies of the knee joint
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On x-rays, pathologies of the knee joint look like this:
- arthrosis - the gap between the articular surfaces unevenly narrows and deforms, osteophytes (growths of bone tissue) are visualized at the edges of the joint, bone tissue thickens at the border with the cartilaginous layer, calcified ligaments are more clearly visible in the image;
- arthritis – the joint space widens due to the presence of effusion in the joint cavity;
- fracture - damage of various configurations is found on the bones, cracks are better visualized a few days after the injury;
- dislocation – the image visualizes the displacement of bone structures, in which the shapes of the bone surfaces do not correspond to each other;
- sprain – due to damage to the ligamentous apparatus, there is an increase in the distance between the thigh and lower leg;
- violation of the integrity of the patellar tendon - the patella moves to one side or another;
- long-term degenerative-dystrophic processes - bone tissue grows on the lateral surfaces of the joint, and osteophytes provoke bone deformation;
- osteoporosis - the structure of bone tissue becomes more transparent, and the contours of the bones look more emphasized compared to other tissues;
- tumor processes - formations are visualized on bone tissue or other structures of the joint, they do not have clear contours and destroy surrounding tissues;
- bone tissue cysts – visible on the image as round-shaped clearings;
- foreign bodies – visualized only when they are high in density;
- – manifested by areas of osteoporotic tissue and foci of bone degeneration, sometimes sequestration is visible;
- congenital deformities - abnormal structures look asymmetrical on both sides in thickness and length;
- – the outlines of the tibia are blurred and uneven, there is a pathological tuberosity, and when the process is advanced, bone fragmentation occurs.
Which doctor should I contact?
If it is necessary to take an X-ray of the knee joint, you should take a referral from a surgeon, orthopedist, traumatologist or rheumatologist. Depending on the identified pathology, treatment is carried out by doctors of these specialties. The radiologist describes the images and gives an opinion, but this in itself is not a diagnosis.