Method of ultrasound of the ankle
Last reviewed: 23.04.2024
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When performing an ultrasound of the ankle, one should follow a certain sequence of actions and strive to obtain standard positions. According to the anatomical regions, four standard accesses are used to examine all joint elements: anterior, medial, lateral and posterior.
Front access.
This access provides visualization of the tendons of the anterior tibial muscle, the long extensor of the thumb and the tendon of the long extensor of the fingers, as well as the synovial sheaths of the tendons of the anterior group. The patient is lying on the back, the limb is bent, the sensor is installed in the lower third of the shin.
The study begins with an evaluation of the tendon condition of the anterior tibial muscle and the long extensor of the big toe. Following proximally upward, the structure of the muscle tissue is studied, longitudinal and transverse sections of these calf muscles are obtained.
Following further, distally, an image of the tendon of the long extensor of the fingers is obtained, which is fan-shaped divided into four parts and attached to the tendon stretch at the rear of the II-V fingers.
Medial access.
This access provides visualization of the tendons of the posterior tibial muscle, the long flexor of the fingers and the tendon of the long flexor of the thumb, as well as the synovial sheath of the medial group tendons, the deltoid ligament and the posterior tibial nerve.
The patient is lying on the back, the limb is straight. The sensor is placed on the medial surface of the joint, just behind the medial malleolus. First in the transverse position, for orientation, and then in the longitudinal. All the tendons described lie side by side in the same plane. The diameter of the tendon of the long flexor of the fingers is two-thirds less than the diameter of the tendon of the posterior tibial muscle, which lies anteriorly. During the scan, the tendon structure, thickness, contours, hyaline cartilage state, and the presence of effusion in the joint cavity are evaluated. The tendons of the posterior tibialis muscle, the long flexor of the fingers, the long flexor of the thumb and the tibial nerve, located between the last two tendons, are covered from above with a broad ligament - the flexor tendon retina. The posterior tibial nerve is impaired in the tarsal tunnel on the medial surface of the ankle. The sensor is then positioned above the medial malleolus to assess the medial group of ankle ligaments. To improve the visualization of the ligament, the shin is rotated outwards. Above the medial malleolus, the fibers of the tibial-navicular part of the deltoid ligament are visible, which is attached to the rear surface of the scaphoid bone.
Lateral access.
This access provides visualization of the tendon of the long fibular muscle, the tendons of the short fibular muscle and their synovial vagina, anterior talon-fibular ligament, heel-fibula ligament, anterior Tibial-peroneal ligament and lateral joint.
The patient is in a supine position, the limb is straightened, rotated to the inside. The sensor is mounted on the lateral surface of the joint, behind the lateral ankle. The tendons of the long and short fibular muscle are clearly visualized. The tendon of the short fibular muscle is located anterior to the other. Normally, a small amount of liquid, up to 3 mm in thickness, may be present in the vagina of the tendons. When the sensor is rotated downward, the fibers of the heel-peroneal ligament are determined, which starts from the outer surface of the lateral ankle and is directed down to the lateral surface of the calcaneus. When the lower edge of the sensor is rotated, the fibers of the anterior talon-peroneal ligament are determined. To visualize the anterior Tibial-peroneal ligament, the sensor is mounted on the lateral surface of the joint in a transverse position - between the distal sections of the tibia and fibula.
Rear access.
With this access, the fibers of the Achilles tendon, the posterior cirrus sac, the cortical layer of the calcaneus and the condition of the plantar aponeurosis are visualized. The patient is in the supine position, with a free foot hanging down. The sensor is located longitudinally the long axis of the Achilles tendon fibers. Scanning starts from the site of the soleus and calf muscles in the tendon and gradually moves to the attachment point of the tendon on the calcaneus. At this point, usually a visualization of the backbone bursa, whose diameter should not exceed 2.5 mm. The Achilles tendon does not have a synovial membrane, and ultrasound scanning along its edges shows hyperechoic lines - the paratenon. It is necessary to obtain both longitudinal and transverse sections.
The average anterolateral diameter of the tendon with transverse scanning is 5-6 mm. It is important to remember that when the Achilles tendon ruptures, it is necessary to perform a functional test, which consists in assessing the condition of the rupture site during flexion and extension of the foot. If in both these positions the divergence of the broken fibers (diastase) takes place, then surgical treatment is necessary, if not, then conservative.
According to the indications, a study of the plantar foot area is carried out. The structure and the attachment area of the plantar tendon are evaluated. The sensor is installed in the area of the calcaneal tuber and is scanned longitudinally of the tendon fibers. Obtain longitudinal and transverse sections of the tendon.
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