Ultrasound of elbow injuries and diseases

Epicondylitis. A common disease characterized by pain in the area of the epicondyles of the humerus. It often occurs in people whose profession is associated with monotonous repetitive hand movements, especially pronation and supination (typists, musicians), or with physical stress on the hands in a certain static position of the body (mechanics, dentists), as well as in athletes (tennis players, golfers). In the clinical course, acute and chronic stages are distinguished. In the acute stage, the pain is constant in the area of one of the epicondyles, radiates along the muscles of the forearm, and the function of the elbow joint may be impaired. Pain occurs when squeezing the hand, the inability to hold the arm in an extended position (Thompson symptom), to hold a load on an outstretched arm (fatigue symptom), weakness in the arm appears. In the subacute stage and chronic course, pain occurs under stress, has a dull, aching character. Muscle hypotrophy or atrophy is noticeable.

The most typical pathological condition is lateral epicondylitis or so-called "tennis elbow". Medial epicondylitis is called "golfer's elbow" or "pitcher's elbow". Both of these conditions occur due to traumatic and inflammatory conditions in the fibers of the tendons of the corresponding muscle groups. Medial epicondylitis is associated with changes in the flexor tendons. Lateral epicondylitis is associated with pathology of the tendons of the extensor muscles. With the development of tendinitis, the tendon thickens, its echogenicity decreases. The structure may be heterogeneous with the presence of calcifications and hypoechoic areas reflecting intratendinous micro-tears. The pathological process at the onset of the disease is characterized by aseptic inflammation of the periosteum and tendon-ligament apparatus in the area of the shoulder epicondyles. Degenerative-dystrophic processes develop later. Radiologically, in approximately a third of patients, periosteal growths in the epicondyle area, elbow spurs, rarefaction of the bone structure of the epicondyle, areas of enostosis, etc. are detected.

During ultrasound examination, a typical picture of degenerative changes may be observed at the attachment site of the forearm muscles to the epicondyles of the humerus: hyperechoic fragments or areas of tendon, well demarcated from the surrounding tissues. Intra-articular bodies may also be identified. During treatment, the ultrasound picture may change: hyperechoic areas may change their size and shape.

Ruptures of the distal biceps tendon. They are observed mainly in middle-aged individuals, weightlifters, or athletes working with weights. Among all upper limb injuries, ruptures of the distal biceps tendon account for up to 80% of cases. This type of injury significantly impairs joint function, so fresh ruptures are more common. On examination, the biceps muscle is thickened and deformed compared to the contralateral limb. Flexion at the elbow is difficult due to the muscles of the brachialis, brachioradialis, and pronator teres. Ruptures of the biceps tendon occur at the site of its attachment to the tuberosity of the radius. On palpation, it is possible to feel the torn proximal end of the tendon, displaced upward to the lower third of the shoulder.

In ultrasound examination, tendon damage may occur with fractures of the radius. At the site of the rupture, a hypoechoic area appears above the tuberosity of the radius, discontinuity of the fibrillar structure of the tendon, cubital bursitis, and inflammation of the medial nerve are noted.

Ruptures of the triceps tendon. Ruptures of this type are less common. Clinically, pain is noted along the back of the elbow joint, and palpation reveals a defect in the tendon above the olecranon. When the elbow joint is raised above the head, the patient cannot straighten the arm (complete rupture) or the action is accompanied by significant effort (partial rupture).

Complete ruptures are observed more often than partial ones. In case of partial ruptures, a hypoechoic area - a hematoma - is formed at the rupture site. In case of complete ruptures, a hypoechoic area (hematoma) is formed at the attachment site of the triceps tendon, olecranon bursitis is added, in 75% of cases, avulsion fractures of the olecranon, subluxation of the ulnar nerve and fracture of the head of the radial bone can occur.

Damage to the lateral ligaments. Isolated damage to the lateral ligaments is rare. Most often, it is combined with a rupture of the capsule, fractures of the coronoid process of the ulna, medial epicondyle, and head of the radius. The medial ligament is damaged more often than the lateral one. The mechanism of ligament rupture is indirect - a fall on an arm straightened at the elbow joint.

Ligament ruptures most often occur at the attachment site to the epicondyles of the humerus, sometimes with a bone fragment. A ligament rupture is indicated by abnormal mobility in the elbow joint, swelling and bruising extending to the back of the forearm.

Fractures. Fractures of the elbow joint include fractures of the condyles of the humerus, the olecranon and coronoid processes of the ulna, and the head of the radius. The most common fractures are of the head of the radius, accounting for up to 50% of all elbow injuries. In this case, the distal part of the biceps tendon may be damaged.

In 20% of all elbow joint injuries, fractures of the olecranon occur. With fractures of the olecranon, there are also injuries to the triceps tendon. When swelling of the elbow joint occurs, the ulnar nerve may be pinched.

Effusion in the joint cavity.When examining the coronoid fossa area from the anterior approach, even a small amount of fluid can be detected in the elbow joint. Fluid can also accumulate in the olecranon fossa area, where intra-articular bodies are often detected.

Tendinitis and tenosynovitis. In tendinitis, the tendons of the biceps or triceps muscle thicken, echogenicity in the acute stage decreases, these manifestations are especially noticeable when compared with the contralateral side. Unlike ruptures, the integrity of the tendon is preserved. In chronic tendinitis, hyperechoic inclusions are formed at the site of attachment of the tendon to the bone. The structure of the tendon may be heterogeneous.

Bursitis. Bursitis is most common in the olecranon region. Bursitis may accompany ruptures of the triceps brachii or contribute to their occurrence. Bursitis is characterized by the presence of a hypoechoic cavity above the olecranon. The contents of the bursa may have varying echogenicity from anechoic to isoechoic. Changes in the echogenicity of the contents also occur over time: hyperechoic inclusions may appear. With long-term changes, the walls of the bursa become thick and hyperechoic. In ultrasound angiography modes, vessels in the walls of the bursa and surrounding tissues are visualized. Cubital bursitis is less common. It may accompany ruptures of the distal biceps tendon, and is also observed in tendinosis. Ultrasound examination reveals the brachioradialis bursa in the area of attachment of the biceps brachii tendon to the tuberosity of the radius.

Compression of the ulnar nerve in the cubital tunnel is the most common reason for all ultrasound examinations of the ulnar nerve. Compression of the nerve occurs between the medial edge of the proximal ulna and the fibrous fibers connecting the 2 heads of the flexor carpi ulnaris. The main ultrasound manifestations of cubital tunnel syndrome include: thickening of the nerve proximal to the compression, flattening of the nerve inside the tunnel, decreased mobility of the nerve inside the tunnel. Measurements of the ulnar nerve are performed using transverse scanning.

Calculations are made using the formula for the area of an ellipse: the product of two mutually perpendicular diameters divided by four, multiplied by the number y. Studies have shown that the average area of the ulnar nerve is 7.5 mm2 ^at the level of the epicondyle. The transverse diameter of the ulnar nerve in men is on average 3.1 mm, and in women 2.7 mm. The anteroposterior dimensions are 1.9 mm and 1.8 mm, respectively.

Displacement of the ulnar nerve. Displacements are easily diagnosed by ultrasound examination, when the nerve comes out of the groove when the arm is bent at the elbow joint and returns to its place when it is extended. This pathology is associated with the congenital absence of the limiting bundles of the cubital tunnel. This pathology occurs in 16-20% of cases. It is usually asymptomatic, but can manifest itself in pain, tingling, fatigue or loss of sensitivity. With subluxation, the ulnar nerve is more susceptible to injury.

Ultrasound examination shows that the nerve is enlarged to an average of 7.2 mm x 3.7 mm. Scanning for nerve dislocation should be performed without applying pressure to the area being examined. The examination is performed using a dynamic test with extension and flexion of the arm at the elbow joint. When the nerve exits the groove, displacement is noted. This phenomenon is also observed in injuries to the distal humerus, and triceps anomalies in weightlifters. However, in these cases, displacement of the ulnar nerve is accompanied by displacement of the medial head of the triceps. Bursitis, triceps ruptures, and aneurysms can also lead to displacement of the ulnar nerve.