Musculoskeletal ultrasound—correct interpretation of common terms!

Author: Guo Ruijun, Chief Physician, Beijing Chaoyang Hospital, Capital Medical University

Reviewer: Li Jun, Chief Physician, Peking University First Hospital

In clinical practice, musculoskeletal ultrasound examination is recommended as the first choice for swelling and pain in muscles, tendons, and joints.

When it comes to the report form of musculoskeletal ultrasound examination, many of the terms on it will confuse people. Today we will talk about the specific meanings of these terms.

The normal feathery structure of the local muscles disappears and the echo decreases:

It refers to a type of injury tear, which can be understood as elongation tear, where the muscle fibers are stretched but not broken. This is the easiest diagnosis for clinical doctors, called soft tissue contusion.

Figure 1 Original copyright image, no permission to reprint

Generally speaking, soft tissue contusion is a minor injury because the muscles and tendons are not broken and do not require special treatment. If the patient has pain and ecchymosis or purpura appears after the injury, symptomatic treatment is sufficient and the patient will recover in about one or two weeks.

Muscle enlargement with irregular anechoic areas:

Generally speaking, this type of ultrasound description mostly indicates a type of injury, or it is heavier than soft tissue contusion, but lighter than complete tear, which is called incomplete tear. It means that after the muscle is injured, some muscle fibers are broken, so the whole muscle will increase. At the same time, due to the damage to small blood vessels, there will be bleeding in the muscle and gap, and no echo or effusion can be seen at the bleeding site.

In the case of incomplete tear, if the tear is large and the patient is an athlete, treatment may be needed, and blood or fluid may need to be drawn out under emergency ultrasound. But for ordinary people, special treatment is generally not needed and they can slowly recover on their own.

The muscle fiber is broken, and the broken ends can be seen drifting sign:

This is a more serious injury or a complete muscle tear.

When the muscle is broken, the continuity of the muscle fibers is lost, the broken ends are severely damaged, there is a lot of bleeding, and there is a lot of fluid around, so the broken ends seem to be floating or swimming in the water, so it is called the drift sign.

Generally speaking, the sooner the treatment of complete muscle rupture is performed, the better. It requires surgical intervention or minimally invasive treatment under ultrasound guidance. After the bleeding is drawn out, there is now a technology called PRP injection (injection of concentrated platelet plasma).

After the muscle is completely torn, take about 10 ml or 20 ml of your own blood. Centrifuge at high speed, which should be above 2000 rpm. After centrifugation, take out the concentrated platelet plasma, which contains many growth factors. Then, under ultrasound guidance, inject this concentrated platelet plasma into the torn part to promote healing.

Discontinuity of the tendon, with fluid accumulation around it:

We mentioned earlier that after a muscle is torn or severed, there is fluid around it. In fact, the same is true for tendons. Tendon rupture may also cause bleeding and fluid may be seen around it. This is a typical ultrasound description of a complete tendon rupture.

Generally speaking, surgical intervention is required after a tendon ruptures. For example, if the thumb flexor tendon is broken, the thumb will not be able to move normally. The function of the thumb accounts for more than 50% of the entire hand function. If it is not treated actively, daily tasks such as holding a pen and cooking cannot be completed smoothly, so surgical intervention is necessary at this time.

The tendon is thickened, echogenic, and the tendon sheath is thickened with a small amount of fluid surrounding it:

In modern society, mobile phones and computers are used very frequently. Many people use their mobile phones or mouse almost every day, repeating the same action over and over again. In fact, the tendons are the most seriously damaged.

This description is the most common type of modern disease, called tendinitis and tenosynovitis. What does it mean? The tendon is swollen because of repeated friction, which causes the tendon to become inflamed, and the surrounding tendon sheath will also become inflamed. We call this tendinitis and tenosynovitis.

Figure 2 Original copyright image, no permission to reprint

The patient will experience pain and discomfort, and the finger may feel like it is stuck, resulting in a snapping finger, also known as trigger finger.

If it is a typical tendinitis or tenosynovitis, it is recommended to release or inject under ultrasound guidance. If the pain is severe, a small amount of hormone can be given. Of course, this treatment must be completed under ultrasound guidance, that is, it needs to be injected into the lesion under ultrasound monitoring.

In fact, PRP can also be injected at this time. Because PRP is one's own blood and is a green treatment, it is recommended.

If you have snapping fingers, you used to have to undergo surgery, cut the skin and subcutaneous fat, cut the pulley, and then remove the stitches two weeks later. But now with minimally invasive technology and musculoskeletal ultrasound, you can use a needle knife to pick and cut the thickened pulley under ultrasound guidance. This surgery is very minimally invasive, the wound is the size of a pinhole, and you can just put on a Band-Aid after the surgery. The next day, the patient can go to work and live as usual, so minimally invasive surgery is an epoch-making revolution.