X-rays of the knee joint – what shows the picture?
Despite modern technology, an x-ray is not inferior to its position in the diagnosis of diseases. Method is widely used in all fields of medicine, including orthopedics and traumatology.
Today we will discuss the application of this method in the diagnosis of diseases of the knee joint. Find out, in some cases, doing x-rays of the knee joint and that shows the. Who should not use snapshots, and how many times they can do. Will sort out all these issues.
The picture shows a healthy joint in a straight line projection are visible to the articular ends of the femur and the tibia. On the surface no splinters or cracks. Bone density is also the same. The surface of the ends of the bones meet each other. The joint space is symmetrical on both sides and the same width, has no growths or inclusions.
That may show the radiograph?
On sighting the picture the joint space so wide, as if nothing between the bones. This is because x-rays pass through the cartilage that covers the articular surfaces of the knee joint.
Therefore, the cartilage is not visible, but it changes determine be zamechatelnym plates of the joint.
Radiography of the knee joint reveals pathological changes of the joint:
- Shows the defeat of the articular cartilage by the thickening or thinning of the articular zamechatelnyh records. In the case of arthritis or arthrosis of the joint.
- Detects traumatic injuries of the joints in the form of dislocation, fracture or deformation. In the case of injury x-rays do also for treatment monitoring.
- Pictures are made in the case of congenital changes in the joints.
- X-ray reveals a tumor.
The do in 1 or 2 planes. If you suspect a fracture, do lateral x-rays or prescribe x-ray in the maximum bent position of the knee joint. Although there are more accurate diagnostic methods, but most of the abnormalities seen on conventional x-ray.
Indications for knee radiographs
In the study of diseases or injuries of the joints without x-ray is not enough. This method is used in primary diagnostics and monitoring of dynamic changes in treatment outcome.
X-rays of the knee joint should be done in such cases:
- it redness and swelling with fever;
- deformation of the joint;
- the displacement of the bones;
- to determine the cause of pain in the joint.
X-ray reveals changes in the bones, and detects fluid in the joint. The sooner pathology of the joint, the more opportunities to get rid of the disease.
Contraindications for x-rays and radiation exposure
Although radiation exposure when the picture is minimal, the procedure is contraindicated in certain conditions or diseases
- the metallic denture and bolts in the knee;
- severe obesity distorts the image;
- the serious condition of the patient.
Women are recommended to refrain from conception for 1 month after the x-ray. Men need to use protection for 3 months. If the readings often have to do an x-ray to minimize exposure, you can use green tea, natural juice with pulp and milk.
Radiation exposure from the picture of the knee of 0, 001 millisieverts (mSv). This dose corresponds to a daily dose of radiation received by a person in ordinary life when using a mobile phone and other technologies.
But x-rays possess cumulative properties, so the danger is the total annual radiation exposure, which must not exceed 5 mSv.
Each written report of the doctor there is a mark on the received radiation load, which depends on the apparatus. Smarter than the machine, the less exposure.
Radiological signs in case of changes in the joints
In the first stage examinations of the knee need to do x-rays. Pictures are made in direct and lateral projections, depending on the objectives of the study.
- When deforming osteoarthritis in the picture the joint space is narrowed. A seal of the articular surface and calcification of ligaments. The joint is deformed, visible osteophytes and sklerozirovanie cartilage.
- At fracture are visible bone injuries, different in shape and size.
- Inflammatory diseases are determined by the reduction in the width of the joint space. The adjacent thinned and irregular bony plates visible osteophytes (bone spurs).
- Congenital diseases in the picture appear unbalanced structure.
- If the tumor rentgenpozitivee irregular shape formation, leaving bones around which the visible areas of tissue destruction.
- The dislocation on the x-ray is manifested by displacement of the bone surfaces. In this pathology often damaged patella.
- In the initial stages of arthrosis of the picture shows a reduction in the distance between the bones of the knee joint. In established osteoarthritis the joint space narrowed significantly and unevenly. In addition, pronounced subchondral sclerosis.
Most pictures are made with arthrosis of the knee joint. Qualitatively radiograph shows bone changes, but to determine the pathology of the cartilage and soft tissue ultrasound is applied. The same method should preferably be used in children.
How do x-rays of the knee joint?
Special training for the snapshot is not required. You do not need to observe any diet. During the session, the radiologist requests to take the desired position of the feet. At the time of the snapshot at the request of the doctor need to stop breathing for a few seconds and do not move, otherwise the picture will be blurry.
The picture quality is also reflected correct posture of the patient.
Before the session the patient is placed in the position lying on the back. The direct projection to make in diseases. After the injury required x-rays in lateral projection or sighting. The quality of the image depends largely on the skill of the radiologist.
On plain x-ray is almost not visible cartilage and ligaments. Therefore, use of contrast radiography. For this joint, contrast medium injected air. After filling of the cavity increases its size, and become visible to the ligaments and cartilage. Contrast study is carried out in such cases:
- suspected pathology of the joint shell;
- for detecting chronic injury of the ligaments of the joint;
- the suspected tumor;
- identifying intra-articular pathology (foreign body).
Thanks contrast radiography reveals damage to the menisci. The procedure is not considered easy. After it can develop an allergic reaction. In addition, some patients can experience a crunch in the knee.
Alternative to radiography
A modification of the conventional image is a digital x-ray. It is conducted on the same or improved apparatus, but the image is transferred to the display. The picture quality can be improved and transfer a local network doctor. The digital method allows to quickly obtain an image, which is important in traumatology.
Normal shot reveals the pathology of the bones, but lesions of the cartilage and soft tissues inaccessible to this method. Modern technologies allow a more accurate diagnosis. There is a method of computed tomography (CT). It allows you to take pictures in several planes. In addition, the information is transferred to disks or can be transmitted over the local network and the Internet. Computed tomography has a great radial load, but she is the guidance for the operating surgeon.
Currently, accurate and safe way research is magnetic resonance imaging (MRI). Using MRI to get images of bones, cartilage and soft tissue. The image is transferred to media with the ability to transmit over the Internet.
In the end, the themes recall that x-ray remains accessible and informative method of research. It is indicated for the primary diagnosis of disease and after injury. Digital radiography is much faster and easier getting the picture, besides the improved quality of x-ray and reduced radiation exposure. Frequent pictures, you can use MRI.