Contents
The hip joint is a component of the musculoskeletal system of the human body. The joint is responsible for the activity of the hip (circular rotation / flexion / extension / abduction / adduction) and allows a person to maintain balance. The bone joint is subject to many pathologies – from mechanical damage to cancerous growths or inflammatory processes. Ultrasound is used to prevent or diagnose diseases in a timely manner. What you need to know about the diagnosis, how exactly does it pass and is it necessary to undergo ultrasound as a preventive measure?
The structure of the hip joint
The hip joint is a spherical, multiaxial joint. It is formed by the surface of the acetabulum of the pelvic bone and the surface of the tubular femur, strengthened by several thick and strong ligaments. The joint has 3 axes that are responsible for specific movements – abduction / adduction, pronation / supination, flexion / extension. Due to the spherical surface of the movable joint, circular rotations of the hip are possible.
In most cases, x-rays, computed tomography or magnetic resonance imaging are prescribed to diagnose the pathology of the hip joint. Ultrasound is used if necessary to confirm / refute a preliminary diagnosis or track the condition of soft tissues.
Specificity of the hip joint of newborns
Ultrasound examination of the hip joint is an integral part of newborn screening. This is a mandatory medical event that is carried out for all babies at the age of one or two months. The purpose of ultrasound is to detect or refute hip dysplasia. This is a congenital disease that develops in 2-3% of newborn babies worldwide. There are several varieties of dysplasia – from subluxation to complete dislocation of the hip with various weights. Ultrasound examination helps to identify the nature of the violations and develop an effective course of treatment.
Why ultrasound? First, the procedure is completely safe and comfortable. Ultrasound does not affect the health of the child and does not provoke side effects. During the diagnosis, the baby does not need to be fettered in activity. He can move his limbs freely without feeling discomfort or fear. Secondly, ultrasound allows you to track pathologies in the soft and cartilaginous tissues of a small patient, which is impossible with x-rays.
General characteristics of ultrasound
Ultrasound is based on the interaction of ultrasound and tissues of the human body. How exactly does this happen? Our body is a heterogeneous structure, which consists of liquids, air, tissues of various densities. Each of these structures is a kind of barrier to sound waves, which has acoustic resistance. As soon as the wave approaches the barrier, one part of it passes through it, and the second part is reflected. How the wave behaves depends on the acoustic resistance, and hence on the density/elasticity of the medium (barrier). People have learned to fix the degree of reflection and absorption of sound waves and transform them into a three-dimensional image of the internal space of our body.
What is ultrasound? These are sound waves whose frequency exceeds 20 hertz. For comparison, the human ear is able to detect sound vibrations with a frequency of 000 to 16 hertz. Ultrasound is outside the zone of acoustic perception of human hearing, but with its help dolphins, whales, bats and other representatives of the animal world communicate freely. High-frequency sound vibrations easily propagate in the soft tissues of our body, do not break them, do not trigger pathogenic processes and do not affect the state of health in any way. Mankind has learned to use this property and has created an ultrasound machine.
The apparatus for ultrasound performs a whole set of tasks – it creates ultrasound, captures its propagation, reflection and absorption by specific parts of the body. The computer processes the received information and transforms it into a three-dimensional image. Scanning and data processing takes place at lightning speed, so the finished image is displayed on the screen in real time. Ultrasound comes from a transducer that the ultrasound specialist runs over the patient’s skin.
The human epithelium reflects 99% of sound vibrations, which makes research impossible. But the situation is fixable with the help of liquid gel. It acts as a transitional medium that allows ultrasound to freely reach the interior space. Additionally, the gel minimizes allergic reactions, improves the signal (due to viscosity) and allows the sensor to move freely on any surface.
The sensor transmits the received information to the reconstruction system. Using special algorithms, it is turned into a black and white image, which consists of 64 different shades. The color varies depending on the intensity of the sound wave and the degree to which it is reflected from the internal environment of the body. The most intense waves are shown in white, while the weakest ones are displayed in black.
To assess the functionality of the vessels, duplex scanning of veins and arteries is used – an examination technique that allows you to determine the state of arterial and venous blood flow, to identify various, even minor circulatory disorders in the early stages.
What pathologies of the joints can be detected by ultrasound?
Ultrasound diagnostics will help diagnose:
- arthrosis (chronic pathology of the joints, which is characterized by their deformation and limitations in mobility);
- arthritis (inflammatory process in the joint, can be both the main disease and the manifestation of other disorders in the body);
- bursitis (inflammation of the mucous bag of the joint, most often develops due to mechanical injuries or infections);
- synovitis (an inflammatory process in the shell of the joint, in which an excessive amount of fluid accumulates in its cavity);
- necrosis (death or necrosis of tissues of the human body, may be caused by impaired blood supply, pathogenic bacteria or viruses);
- hip dysplasia (a disease that affects the musculoskeletal system of newborn patients);
- gout (a disease of the joints and tissues, which is caused by a violation of metabolic processes in the body);
- mechanical damage to the joint, sprains, swelling, spasms, injuries of a different nature, ruptures of ligaments and tendons, hematoma of the thigh.
Indications/contraindications for the procedure
There are no contraindications for ultrasound diagnosis of the hip joint. The procedure is absolutely safe and is shown to absolutely all categories of patients – from newborns and nursing mothers to the elderly. Ultrasound diagnostics may be prescribed for pelvic pain, discomfort, or obvious disorders of the musculoskeletal system. If you cannot lean on your leg or feel pain when walking, be sure to consult a doctor. A change in the color of the skin over the joint or indurations, regardless of size, also serve as a reason to visit a specialist. He will conduct a general examination, determine the localization / possible causes of unpleasant symptoms and prescribe the necessary therapeutic course.
Indications / contraindications for a particular diagnostic method is always determined by the doctor. Even preventive examinations must be agreed with the doctor and undergo a preliminary consultation. Do not self-medicate and strictly follow the doctor’s instructions.
How is the research going?
Ultrasound examination does not include preparatory procedures. The patient makes an appointment, transfers medical documentation and follows the simple instructions of the ultrasound doctor. The medical documentation includes a referral for an ultrasound scan, a study area, a preliminary diagnosis, and specific recommendations from the attending physician. Immediately before the diagnosis, the doctor will ask the patient to take off their clothes and apply a liquid gel to the hip joint area.
The specialist must record the sensor readings in four planes – in front, behind, from the inside and outside of the thigh. Initially, the patient lies on his back with straightened legs. During the procedure, he can change the location, alternately raise the leg, bend it, perform translational or circular rotations at the request of the uzist. During the diagnosis, the patient does not experience pain. Discomfort can only be created by a cold gel and constant requests from a specialist to roll over or perform a certain action.
The doctor moves the sensor over the area of the hip joint, evaluates the picture in real time, which is displayed on the screen and collects all the necessary information. Once the process is completed, the doctor prints the images, makes a preliminary diagnosis and redirects the patient to the attending physician (orthopedist). With the help of ultrasound, it will be possible to assess the state of cartilage structures, the specifics of the cavity, the characteristics and amount of intra-articular fluid. Additionally, the doctor pays attention to the tendons, muscles, possible neoplasms.
A detailed interpretation of the results of ultrasound, the preparation of a therapeutic or preventive course is carried out by an orthopedist. The scope of duties of the doctor of ultrasound diagnostics includes only diagnostics and a preliminary assessment of the patient’s health status.