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Tendons
When imaged in a longitudinal view (long axis), the tendon appears as a ribbon-like hyperechoic structure. The tendon has an internal fibrillar echotexture that can be appreciated as a series of thin hyperechoic fibrillar bands, light undulations, which tend to grow apart from each other when the tendon relaxes and moves in closure. This fibrillar echotexture is caused by specular reflections within the tendon, defined by the existing acoustic interface between the septa of the endotenon.
Ligaments
When the US beam is not orthogonal to the course of the tendon fibers, both a decrease in reflected and an increase in the diffracted echoes occur, resulting in a significant or partial reduction of tendon echo texture.
Peripheral nerves
The number of fascicles in a nerve can vary depending on the appearance of nerve branching. Systematic scanning in short-axis planes is preferred for tracing nerves throughout the limbs. With this technique, called the “lifting technique,” the examiner can explore long segments of the nerve throughout the limbs and extremities in seconds.
Cartilage and bone
Muscles
With the advent of high resolution transducers and specific image processing software, evaluation of the inner structure of tendons has been made easier. Both margins are best visualized when the direction of the US beam is perpendicular to the cartilage surface. The value of the angle varies depending on the function of the muscle and, within the same muscle, on the functional state (contraction/relaxation).
Long Head of Biceps Brachii Tendon (LHBBT)
Subscapularis Tendon
Supraspinatus Tendon and Subacromial-Subdeltoid
Coracoacromial Ligament
Infraspinatus and Teres Minor Tendons
Acromion-Clavicular Joint
The medial edge of the probe is located on the coracoid (C), and the lateral edge is rotated to the acromion (A). It originates from the infraspinatus fossa and runs upward and laterally, inserting on the posteroinferior surface of the greater humeral tubercle. Push the probe medially to the posterior side of the joint and extrarotate the patient's arm (in the same position as for subscapularis tendon assessment) (Figure 2.23).
Anterior Compartment
Distal Tendon of Biceps Brachii
Anterior Joint Recess
Median Nerve
Radial and Posterior Interosseous Nerves
Lateral Compartment
Common Extensor Tendon
Humeral-Radial Joint
Medial Compartment
Common Flexor Tendon
3.16) during longitudinal scanning, the proximal edge of the probe should be placed on the medial epicondyle (epitrochlea) (Fig. 3.17a, b).
Medial Collateral Ligament
Posterior Compartment
Triceps Brachii Muscle and Tendon
Olecranon Fossa and Posterior Olecranon Recess 41
Deeper than the triceps brachii tendon, the olecranon fossa and the posterior olecranon recess can be seen. The ulnar nerve is located within the cubital tunnel, between the medial epicondyle and the olecranon (Fig. 3.25) and cubital tunnel (Fig. 3.26). Ulnar nerve stability can be assessed by forced hyperflexion of the forearm onto the arm (Fig. 3.27).
The ulnar nerve enters the axillary cavity from the secondary trunk of the brachial plexus. It is directed to the front or part of the arm, passing along the humeral artery and the median nerve. It then pierces the medial intermuscular septum and reaches the posterior compartment of the arm.
In the elbow it runs medially to the triceps brachii to the epicondyle-olecranon tunnel. White arrowheads, ulnar nerve; 1, humeral head of the flexor carpi ulnaris muscle; 2, ulnar head of the flexor carpi ulnaris muscle; void arrowhead, Osborne retinaculum; U, ulna; H, humerus. The patient should sit in front of the examiner, with the upper limb resting on the table.
Palmar Side
Carpal Tunnel and Median nerve
The palm should be placed on the table in a neutral position (Figure 4.9), except for the evaluation of compartments I and VI (see below). It arises from the ulna, the interosseous membrane and the dorsal side of the radius. Its distal tendon crosses the second part of the extensor tendon and inserts into the proximal phalanx of the thumb.
The muscle is very small and immediately becomes a tendon that runs on the lateral aspect of the radius along with the extensor carpi radialis longus tendon. Its distal tendon enters the fourth extensor compartment and then joins the extensor digitorum tendon of the second ray over the corresponding metacarpophalangeal joint. The extensor digiti minimi is a superficial muscle located in the back of the forearm, medial to the extensor digitorum muscle.
It arises together with the extensor digitorum from the posterior aspect of the lateral epicondyle and the antebrachial fascia. It enters the fifth extensor compartment and then joins the extensor digitorum tendon of the fifth ray through the corresponding metacarpophalangeal joint. It arises from the posterior aspect of the lateral epicondyle, the radial collateral ligament, the annular ligament, and the antebrachial fascia.
The examination can be started from the back or palm side of the hand.
Ventral Side
- Palmar Aponeurosis
- Flexor Digitorum Tendons
- Metacarpophalangeal and Interphalangeal Joints . 68
- Extensor Digitorum Tendons
Changing the relationship between the superficial and deep flexor tendons (Fig. In contrast, the superficial tendons go to the middle of the proximal phalanges, where they divide into two branches that surround the deep tendons and insert into the head of the middle phalanges.
Note that the flexor digitorum superficialis tendon of the little finger can often be absent. FDS, flexor digitorum superficialis tendon; FDP, flexor digitorum profundus tendon; M, metacarpal bone; L, psoas muscle; white arrows, common digital nerve; open arrows, common digital arteries (Doppler signal in red); *, interosseous muscles. The back area can be assessed with the hand lying on the table, palm down (Figure 5.8).
Anterior Hip
Sartorius and Tensor Fasciae Latae
Rectus Femoris
Iliopsoas
Femoral Neurovascular Bundle
Hip Joint
Medial Hip
Adductor Tendons and Muscles
Lateral Hip
Gluteus Tendons and Muscles
Posterior Hip
Ischiocrural Tendons (Hamstrings)
Sciatic Nerve
Anterior Compartment
Quadriceps Tendon
Suprapatellar and Paracondylar Recesses
Femoral Trochlea
Patellar Retinacula
Patellar Tendon or Ligament
Medial Compartment
Medial Collateral Ligament
Goose’s Foot Tendons
Lateral Compartment
Iliotibial Tract
The iliotibial tract can be viewed by performing a longitudinal coronal oblique scan on the lateral distal aspect of the knee and can be followed to the tibial insertion on Gerdy's tubercle (Figures 7.20a, b). Rotating the probe 90° allows evaluation of the iliotibial tract on the short axis (Figures 7.21a, b). It extends into the anterior lateral thigh and inserts distally onto Gerdy's tubercle with a tendon common to the iliotibial tract.
Lateral Collateral Ligament
Posterior Compartment
Medial Tendons
Semimembranosus Bursa
The anatomical diagram of the distal myotendinous junction of the biceps femoris is shown in the figure. By moving the transducer to the posterolateral side of the knee, the biceps femoris can be visualized. The long head common to the semitendinosus muscle arises from the superior tubercle of the sciatic tuberosity.
Evaluation should begin with horizontal axial scans of the proximal to lateral malleolus. Peroneus brevistendon arises from the peroneus brevis muscle, located in the lateral compartment of the leg. To evaluate the posterior bundle, the distal end of the probe should be moved posteriorly (Fig. 8.16a, b).
Anterior tibio-talar ligament: deep to the tibio-navicular ligament, inserts on the medial aspect of the talus. The probe should be placed in an axial plane on the anterior side of the ankle. Its tendon enters the extensor retinaculum of the ankle and inserts on the fifth metatarsal bone.
The examination can be started from the dorsal or from the plantar side of the foot.
Popliteal Neurovascular Bundle
Posterolateral Corner and Biceps Femoris Tendon 111
The tendon should be assessed on both the longitudinal and axial scans and followed distally to its insertion on the peroneal head (Fig. 7.31a-c). The biceps femorismus muscle is located in the posterolateral compartment of the thigh and consists of two heads. The short head arises from the middle third of the lateral lip of the linea aspera and from the lateral intermuscular septum.
The two heads merge into a common belly that inserts on the fibular head, while a few fibers also insert on the tibial lateral condyle. The standard US protocol involves the evaluation of four compartments of the ankle: lateral, medial, posterior, and anterior.
Lateral Compartment
Anterior Talo-Fibular Ligament
Anterior Tibio-Fibular Ligament
Calcaneo-Fibular Ligament
Peroneal Tendons
Medial Compartment
Deltoid Ligament
The anterior tibiotalar ligament can be assessed with the ankle in a neutral position (Figures 8.14a, b). This area should be carefully assessed, including with longitudinal scans, due to the complexity of the enthesis that could develop. This is a very thin accessory tendon that in full-thickness tears can be confused with residual fibers of the Achilles tendon.
The tendons should be followed distally to their insertion on the first cuneiform or fingers (Figures 8.25a, b). The deep peroneal nerve is one of the terminal branches of the common peroneal nerve. At the level of the fibular neck, it pierces the anterior intermuscular septum, which reaches the front of the leg.
Here, it runs parallel to the anterior tibial artery, between the extensor hallucis longus tendons and the anterior tibialis tendons. Distally, it passes behind the extensor hallucis longus tendon and enters the anterior retinaculum between the extensor hallucis longus and extensor digitorum longus, ending in the subcutaneous tissue, innervating the skin of the first and second fingers. The anterior tibio-talar notch appears as a hyperechoic triangular area when not distended by fluid.
This can be done by pressure on the skin on the dorsum of the foot or by lateral compression of the entire forefoot (Mulder's maneuver).
Tarsal Tunnel
Posterior Compartment
Achilles Tendon
Posterior Tibio-Talar Recess
Anterior Compartment
Anterior Tendons and Deep Peroneal Nerve
The tibialis anterior tendon, the extensor hallucis longus tendon and the extensor digitorum longus tendon can be seen. In 5% of cases, an accessory tendon (peroneus tertius) can be seen lateral to the extensor digitorum longus tendon. The deep peroneal neurovascular bundle can be seen deep between the extensor hallucis longus and the extensor digitorum longus tendons (Fig. 8.25c).
The empty arrowhead indicates the extensor hallucis longus tendon; white arrowhead indicates the deep peroneal nerve.
Anterior Tibio-Talar Recess
Hindfoot
Plantar Aponeurosis
Forefoot
Plantar Side
Dorsal Side
