Ultrasound of knee joints with osteoarthritis

As is known, radiography in most cases allows you to determine the damage to the knee joint with the involvement of bone elements in the pathological process. Often these changes are irreversible, the treatment of such patients is difficult.

Advantages of ultrasound of the knee joint are accessibility, economy, absence of radiation load on the patient, the possibility of visualization of soft tissue components of the joint, which allows revealing early signs of lesions, which are practically not determined by radiography.

Developed by L. Rubaltelly (1993) ultrasound technique allows to determine the main signs of pathology of the knee joint - traumatic injuries, degenerative-dystrophic and inflammatory processes, etc.

Ultrasound is usually started from the suprapatellar area. Here, the tendon of the quadriceps femoris muscle, the contours of the upper patella pole, the suprapatellar sac (upper curvature), which is especially useful for diagnosing the degenerative-dystrophic and inflammatory lesions, is well visualized for longitudinal and transverse scans. Normally, the synovial membrane is not visualized. With deforming osteoarthritis with synovitis, there is an increase in the bag, rectification of the folds, and the presence of excess fluid.

Further investigation when bending the knee joint and moving the transducer to the transverse position allows visualization of the PFD joint, in particular hyaline cartilage and the presence or absence of excess fluid over it. Transformation of the sensor to the area below the patella gives the opportunity to determine the superficially located patellar ligament, its structure, the podnadkolennikovoe fat body, the podnadkolennikovu synovial fold, the deeper of which is the anterior cruciate ligament. The transverse position of the sensor makes it possible to visualize the articular cartilage of the lateral and medial condyles, the changes in the shape of the articular surfaces of the femur (flattening, etc.). The installation of the sensor on the inner and outer lateral surfaces of the knee allows visualization of the inner and outer collateral ligaments, the marginal bony extensions of the femoral and tibia, and the presence or absence of effusion, respectively.

With ultrasound of the popliteal fossa, it is possible to visualize the pathological formations of this region (Baker's cyst), articular cartilages of the lateral and medial condyles, the posterior parts of the medial and lateral condyles, the posterior horns of the lateral and medial meniscus, the posterior cruciate ligament.

In one of the studies 62 patients with gonarthrosis were examined , and a comparative evaluation of ultrasound and thermography was made. Ultrasound of the musculoskeletal system was carried out on the SONOLINE Omnia (Siemens) with a linear sensor 7.5L70 (frequency 7.5 MHz) in the ortho mode in standard positions. The condition of the articular surfaces of the bone was evaluated (including the condition of the cortical layer, including the subchondral bone), articular fissures, periarticular soft tissues, the presence of effusion and its features, changes in the ligamentous tendon apparatus, and some other parameters.

According to ultrasound, in patients with osteoarthritis of the knee joints, narrowing of the joint gap was observed due to a decrease in the height of the articular cartilage (transverse position of the sensor), bone growths (osteophytes) and / or defects of the articular surfaces of the bones, changes in the synovial membrane and the presence of effusion in the joints, changes paraarticular soft tissue (all positions). Changes in the surface of the cortical layer of articular surfaces (unevenness, formation of surface defects) were recorded already at the initial stages of the disease (I radiological stage according to Kellgren) and reached the maximum extent in the III and IV stages.

Exudation in the joint was noted in 28 (45.16%) patients with gonarthrosis, mainly in the II and III stages of the disease, it was mainly localized in the upper turn (in 32.3% of patients), in the lateral part of the joint space (in 17.7 %), less often - in the medial part of the joint space (9.7%) and in the back turn (3.2%)

The effusion had a homogeneous anechoic echostructure provided that the duration of clinical symptoms of osteoarthritis was up to 1 month, and in patients with clinical signs of persistent inflammation in the joint, it was inhomogeneous, with inclusions of various sizes and echomolarities. The thickness of the synovial membrane was increased in 24 (38.7%) of the examined, and its uneven thickening was recorded in 14 of them. It should be noted that the average duration of the disease in these patients was greater than in the group of patients with gonarthrosis as a whole (6.7 + 2.4 years), and in patients with uneven thickening of the synovial membrane it was even greater (7.1 + 1,9 years). Thus, the synovitis features reflected the duration of gonarthrosis and the severity of the process at the time of the examination.

Evaluation of the hyaline cartilage of the joint (podadnikennikovy access, transverse position of the sensor) was carried out according to the following criteria: thickness, uniformity of thickness, structure, surface, changes in the surface of the subchondral bone (the presence of cysts, erosions, other defects). The height of the cartilage was more reduced on the medial condyle in accordance with the greater mechanical stress on this area.

Attention is drawn to the results obtained when comparing remote thermography data and ultrasound.

A strong or very strong direct correlation was found between the temperature gradient in the medial and lateral regions of the knee joints, on the one hand, and the effusion in the joint and the thickening of the synovial membrane, according to the data of the ultrasound, on the other. A weaker relationship is found between the presence of bone growths in the medial region of the knee joints (ultrasound data) and the temperature gradient in all the joint sites examined.

Consequently, ultrasound and thermography are complementary methods in the diagnosis of osteoarthritis of the knee joints, which is especially true of the activity of the process and the severity of degenerative joint changes.