^

Health

Roentgen of the knee in two projections

, medical expert
Last reviewed: 19.10.2021
Fact-checked
х

All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.

We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.

If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.

Pain in the knee, impaired mobility of the joint in this area and traumatic injuries are quite frequent reasons for contacting a doctor. Determine by eye, with which unpleasant symptoms are associated, it is not easy even for an experienced doctor. But the diagnosis is not an essay on a free subject, and when it is staged, the surgeon, traumatologist or orthopedist should rely on accurate information that can be obtained by conducting additional diagnostic measures. One such compulsory and inexpensive study is the x-ray of the knee joint.

trusted-source[1], [2], [3], [4], [5], [6], [7], [8], [9]

Indications for the procedure

X-ray examination is a procedure that allows a doctor to see deep structures invisible to the human eye, which can not enlighten soft tissues to view denser formations. In contrast to the fluorogram, which must be taken regularly once a year, the doctor will appoint the X-ray of the knee joint only if certain pathologies affecting the bones, cartilage tissue, knee ligament apparatus are suspected. Usually this happens when you go to the doctor for pain and leg restric- tion, or when you are admitted to the waiting room for trauma.

What violations and pathologies may require X-ray confirmation:

  • Violations of the integrity of the bones of the joint. The best way to see X-ray images is hard tissue - bone, it is clear that such a study makes it possible to accurately diagnose any of their damages: fractures, the presence of cracks and dents resulting from a strong impact. The value of X-ray research in this case consists in the fact that the doctor receives information about the exact location of the lesion, the location of bone fragments, the size of cracks and bone impressions.
  • Dislocation / subluxation of the joint. To judge the nature of the displacement allows an incorrect arrangement of bones relative to each other. In the joint, the bulge of one bone must coincide with the depression in the other. Any discrepancies can speak of the displacement of bones as a result of a stroke or an inadvertent movement.
  • Damage to the ligamentous apparatus (ruptures, distension). Their presence is judged by the distance between the bones, because the ligaments themselves do not reflect X-rays in full, so they are seen badly.
  • Traumatic injuries of the patella (patella) and menisci (internal and external cartilage). Also found by the displacement of the bone or the presence of cracks in it
  • Congenital pathologies of bones and joints (osteodystrophy and osteopathy).

X-ray examination allows you to make an accurate diagnosis when:

  • arthritis and arthrosis (there is a change in the shape of the joint and the size of the joint gap),
  • osteoporosis and osteomyelitis (bone density varies on different sites, unusual stratifications may appear),
  • synovitis (due to the accumulation of liquid to the deer and an increase in the thickness of the synovial capsule, the joint gap increases),
  • osteochondropathy König and Osgood-Schlätter (foci of necroticisation of bones with even uneven edges are detected).

Radiography of the knee joint can reveal such pathologies, which the patient did not even suspect. For example, tumor processes affecting the bones and soft tissues of the joint, the presence of cysts and unusual bone growths (osteophytes), the presence of a foreign body.

Referring to a doctor with complaints of pain in the area and changes in the shape of the knee (regardless of whether the person was injured), knee joint mobility, edema and reddening of soft tissues that indicate an inflammatory process are already good reasons for prescribing an X-ray examination .

 

What does the x-ray of the knee joint show?

 

trusted-source[10], [11], [12], [13]

Preparation

Roentgen of the knee joint is considered a procedure that does not require any preparation. A person can go for a study immediately after consulting a doctor. Radiography of various parts of the lower limb does not require restrictions in nutrition and medication. And even if it is carried out with contrasting. The fact is that the contrast is not entered into the vein, but directly into the joint bag. The only thing that can be needed is an allergy test to identify the sensitivity of the body to contrast.

Before the procedure, it is desirable to expose the area under investigation, the clothing can contain details that distort the radiographic image. If a bandage was previously applied to a patient on the knee area, it is not necessary to remove it, but the devices that fix the leg after the injury in the desired position should be removed as far as possible.

Since the lower part of the body is exposed to irradiation, a special lead apron is placed on the area of the reproductive organs, not allowing X-rays to pass through. However, this is more important for children whose body size is less than that of adults, which means that X-rays can also capture a small part of the child's body.

trusted-source[14], [15], [16], [17]

Technique of the x-ray of the knee joint

Roentgen of the knee joint to the infant (and it may be required in connection with the birth trauma and congenital pathologies) is carried out with the utmost care. In this case, special protective devices cover the entire body of the baby. This is due not only to the fact that for crumbs, irradiation is more dangerous than for an adult. The growth of the baby is still very small, therefore, in the field created by the X-ray radiator, the whole body of the child, and not only the limb being examined, can fall.

There are no special nuances in radiography. The main requirement is to be in the static position indicated by the doctor. Any movement will cause distortions in the pictures, making it difficult to diagnose. Often in such cases, repeated radiography is required, and this is an additional dose of X-ray irradiation.

It is most difficult to keep a stationary position to the child, so the X-ray table is provided with special fixatives. If the cause of anxiety is pain, the patient may be given an injection of anesthetic to conduct a qualitative study.

To accurately diagnose the abnormalities described above, one usually requires not one, but at least 2 pictures in different projections. A direct projection (a picture is made when a person lies on the back) is most indicative in case of suspected fractures of the bones entering the joint. In the standing position, several images can be taken: in the lateral, tangential and over-the-posterior projection. The latter, if necessary, can be done in the supine position on the side.

With tangential projection, pathology of the patella and inflammatory-degenerative joint changes are better. Chromosclerosis is prescribed to detect sprain, necrotic processes in the bone tissue, with suspected osteoarthritis. But with a lateral projection, you can diagnose the accumulation of fluid in the joints.

In some cases, doctors are limited to one projection, but with a controversial diagnosis, it is still more important to consider images taken from different angles. Most often, doctors prescribe the x-ray of the knee joint in two projections.

The efficiency of different structures of the knee joint can be assessed if you take additional pictures of the leg bent at different angles. In this case, the radiography can be carried out both at rest and with a load.

Contraindications to the procedure

Roentgen of the knee joint is a procedure associated with the process of irradiating the patient's limb with harmful ionizing radiation. In this case, if you cover the body with protective clothing, the consequences after the procedure will be minimal.

It is believed that irradiation with X-rays has a negative impact on human health. In this case, we are not talking about symptoms characteristic of the early period after receiving a dose of radiation: redness of the skin (radiation burn), detachment of the epidermis, the appearance of erosion, increased fatigue, etc. But different sources are talking about late complications after the procedure, such as increased risk of cancer, mutational changes, decreased sexual functions, etc.

In fact, such consequences are possible if the radiography is taken daily for a long period without protective measures. But according to the reviews of doctors and patients, they did not encounter anything like this (at least to establish a clear dependence of the symptoms that subsequently appeared and diagnostic measures failed).

The dose of irradiation in modern X-ray machines during the study of the knee joint is approximately equal to the dose of radiation that we receive in one and a half days of life under natural conditions. At the same time, it is ten times smaller than the one that surrounds us in airports and airplanes. Therefore, even repeated pictures are not capable of inflicting great harm to the body, even taking into account the irradiation received while watching TV, working on a computer, etc.

Nevertheless, there are some contraindications to the procedure. It is undesirable to appoint pregnant women and nursing mothers, because radiation can adversely affect the development of the fetus in the womb and penetrate into breast milk, and with it in the body of the newborn. If there is no other alternative, the entire body of the woman, with the exception of the knee, must be protected from penetration of X-rays.

X-rays affect the quality of sperm, so for some time after the procedure you need to abstain from sexual intercourse, the purpose of which is to conceive a child. But the results of x-rays in obese people can turn out to be unreliable because of the high density of adipose tissue, which makes the pictures fuzzy.

It is not advisable to prescribe an X-ray examination to people diagnosed with schizophrenia, as well as to patients who are in very serious condition with signs of hemorrhage.

If the diagnosis is carried out by the child, it is better to choose safer methods if possible. The most popular diagnostic methods are ultrasound, computer and magnetic resonance imaging. The most safe of all is still the MRI, where instead of X-rays, the energy of the magnetic field is used.

All these methods can be prescribed in combination with or in lieu of an X-ray. Choosing what is best: ultrasound, CT or MRI, you need to understand that the difference between studies is not only safe for the body.

If a patient chooses to make an MRI or an X-ray of the knee, one should understand that in case of hard tissue pathologies X-ray examination is preferable, i.e. Conventional x-ray of the joint or computed tomography, which is also based on the penetrating ability of X-rays. In this case, CT is considered more informative for injuries and neoplasms in the knee region.

But the MRI easily helps to diagnose diseases associated with soft tissue structures: muscles, cartilage, ligaments, i.e. Tissues with a high water content, which reacts to the magnetic field.

True, the cost of computer and magnetic resonance tomography is much higher than the simple X-ray, which is considered quite sufficient for the diagnosis of pathologies of the knee joint.

Choosing an ultrasound or an X-ray of the knee joint, again, it must be remembered that the latter, although less safe, is more informative for the diagnosis of bone pathologies. If it is a ligamentous apparatus, pathologies of synovial bags and cartilage, it is better to give preference to ultrasound examination, the cost of which is still lower than that of popular MRI.

trusted-source[18], [19], [20]

Normal performance

It must be said that the information from the X-ray image is intended primarily for specialists and has no value for a person far from anatomy issues. At best, the patient will be able to independently diagnose a bone fracture. In fact, the decryption of information from the picture should be entrusted to the doctor.

X-rays have a good penetrating ability, but tissues of different densities in various ways delay radiation. Dense tissue absorbs more rays, so on the X-ray they are more clearly visible than others. The most permeable are the tissues of the tendons and cartilages. The latter are not visible at all, but their status and characteristics can be judged by the size of the joint gap (the larger the gap between the bones, the thicker the cartilaginous tissue) and the change in the interposition of the end plates.

Upon careful examination of the results of the x-ray of a healthy knee joint, the distal sections of the femoral and tibia, the patella (patellar bone) and a small fibula are clearly seen in the picture. In this case, all bones have approximately the same color, which indicates an equal density of tissues, as well as flat surfaces without any defects (clearly delineated areas of darkening or clarification, incomprehensible layers, changes in the shape of the bone). Dark areas can indicate fractures and cracks, and too light correspond to tumors, cysts, fluid accumulation.

The head of the bones correspond to the indentations, the joint gap has normal dimensions, while its width on both sides of the joint should be the same, and the shape is symmetrical. The norm in the x-ray of the knee joint does not provide for any inclusions in the cavity of the joint gap (outgrowths, incomprehensible particles).

Meniscus of the knee joint on the x-ray is not visible, because it is a cartilaginous tissue. The state of such tissue can be judged only on the width of the joint gap, as well as in the size and shape of a small wedge-shaped shadow, the extended portion of which should be directed downward. If a meniscus injury is suspected, the purpose of the X-ray examination is to exclude or confirm the bone fracture in the area.

Well, with fractures, dislocations (when there is a shift of bones relative to each other), the tumors seem to be clear, but how to determine inflammatory-dystrophic changes in tissues on the x-ray. Let's consider, what signs on a picture help the doctor to put the exact diagnosis:

X-ray signs of arthrosis of the knee joint. In this case, the evaluation of the width of the joint gap, which is viewed in the straight and lateral projections, comes to the fore. With arthrosis, the joint gap narrows along the entire perimeter or on a separate site. The disease is characterized by a thinning of the periosteum, on which the x-ray can reveal tuberosity and tapering, characteristic for growing osteophytes. At later stages of the disease, marginal osseous tissues of the joints can be noted.

X-ray signs of arthritis of the knee joint. In contrast to arthrosis, which is considered an age-related degenerative disease, arthritis can remind itself of itself at a young age. In addition to the inherent arthrosis of the degeneration of joint tissues, this disease is characterized by a local inflammatory process, supported by other disorders in the body.

The initial stages of the disease can not be seen on the x-ray, but later such signs as osteoporosis of the bones (decrease in their density, resulting in the color of the hard tissues will be darker than usual), arthritis and arthritis narrowing the joint gap, the appearance of bone growths on the distal bone. The surface of the joints gradually becomes flatter, the bone and cartilaginous tissues change their structure and characteristics, gradually disrupting the mobility of the joint (in this case, the joint gap can practically not be visible).

X-ray signs of bursitis of the knee joint. The pathology consists in the development of the inflammatory process in the synovial knee bags. X-rays at the same time will show the deep disposition of these structures and areas of calcification, peculiar to the inflammatory process. There is no narrowing of the joint gap.

In fact, radiography is an additional method of diagnosing this disease. Its goal is to exclude inflammatory-degenerative pathologies of joints (arthrosis and arthritis), as well as traumatic injuries that cause pain in the knee.

X-ray signs of synovitis of the knee joint. Synovitis is less well known than others, a pathology characterized by the accumulation of fluid in the joint cavity. In this area, an unusual darkening will be observed in the area of the synovial bag. In chronic course of pathology, thinning of the cartilaginous tissue and complete loss of cartilage are observed, holes are formed on the bones in the joint region through which the exudate flows into the soft tissue cavity. There is no formation of osteophytes.

X-ray signs of Baker's cyst of the knee joint. On the roentgenogram, the cyst looks like a rounded neoplasm of light shade with localization in the popliteal fossa, which can be clearly seen in the lateral projection. Particular attention is paid to the doctors clearly defined boundaries of the defect, characteristic of cystic formations.

Tumors in the picture do not have clear boundaries and a certain shape. X-rays can detect such neoplasms, but can not say anything about their nature.

trusted-source[21], [22], [23], [24], [25], [26], [27]

Care after the procedure

Radiography, despite the danger of X-rays, is a painless procedure. The doctor spends it for barely more than 3-5 minutes, and the results can be obtained almost immediately.

If the radiography is carried out digitally, a person can receive a response immediately on a disk or flash drive, while the information obtained can be viewed on the computer monitor screen. In this case, the clarity and contrast of the digital image is usually higher than that of the X-ray film. On it, with the appropriate resolution, even soft tissue structures are seen.

For the manifestation of a film snapshot with an analogue radiography, it takes time (about 10 minutes), after which the patient receives a photo on his hands. If you need an additional description of the picture, you'll have to wait some more time.

Some sources recommend that after fresh X-rays, you drink more fresh cow's milk, because it helps to remove radiation from the body. It should be said that there is no special need for this, but with all the useful properties of a natural product, why not follow the advice that helps saturate the body with useful substances.

Roentgen of the knee joint is a diagnostic procedure that allows doctors to make an accurate diagnosis for many diseases of the musculoskeletal system. This method is time-tested, affordable and relatively safe, given the low dose of radiation received during a single radiography session. The information received by the X-ray apparatus is considered sufficient for diagnosis of most traumatic and inflammatory-degenerative knee diseases. And only with inflammatory and oncological processes I may need additional diagnostic methods.

trusted-source[28], [29], [30], [31]

Translation Disclaimer: For the convenience of users of the iLive portal this article has been translated into the current language, but has not yet been verified by a native speaker who has the necessary qualifications for this. In this regard, we warn you that the translation of this article may be incorrect, may contain lexical, syntactic and grammatical errors.

You are reporting a typo in the following text:
Simply click the "Send typo report" button to complete the report. You can also include a comment.