THIGH:
Anterior compartment :
Table 1: Origin and insertion of the muscles of anterior thigh compartment.
The patient lies supine on the table with the lower limb in a neutral position.
Fig. 1: Lower limb position to evaluate the anterior thigh compartment.
Fig. 2: Anatomical scheme of tensor muscle of fascia lata (TFL) and sartorius muscle (SA).
Palpate the anterior superior iliac spine (ASIS),
which can be considered an important bony landmark,
and place the probe on it in an axial position.
Identify the typical “pseudo-thyroid” aspect with the hyperechoic cortical band between the two proximal insertions of sartorius muscle (medial) and tensor muscle of fascia lata (lateral).
Fig. 3: (a) Probe position to evaluate the proximal insertion of sartorius (SA) and tensor Fasciae Latae (TFL) muscles at ASIS (anterior-superior iliac spine) level. (b) US axial scan : note the typical “pseudo-thyroid” aspect of insertions of tensor muscle of fascia lata (TFL) and sartorius (SA) muscle on ASIS.
Then,
move the transducer caudally to evaluate the muscle belly of tensor fasciae latae and its anatomical relationship with quadriceps muscle.
Fig. 4: (a) Probe position to evaluate tensor of fascia lata (TFL) at proximal third of the thigh on axial plane ; (b) US axial scan at proximal lateral third of thigh illustrates the relationship among the TFL and the vastus lateralis (VL) and rectus femoris (RF) muscles.
Rotate the transducer by 90° to evaluate the TFL muscle on a longitudinal plane.
It continues in fascia lata,
a deep fascia of the thigh.
Fig. 5: (a)Probe position to study TFL on longitudinal scan;(b)Longitudinal US scan : distal insertion of TFL muscle on anterior aspect of fascia lata (FL) that appears as a hyperechoic cordon like band. Vastus lateralis muscle (VL) is deeper than TFL; (c)Extended field of view (EFV) US longitudinal scan of TFL muscle from proximal to distal insertion.
From this position move the probe caudally to reach the distal part of fascia lata that continues in ileotibial tract to the insertion on tibial Gerdy’s tubercle.
Fig. 6: (a) Probe path to evaluate the ileotibial tract on the longitudinal plane;(b) anatomical scheme of ileotibial tract(*);(c) EFV US longitudinal scan of ileotibial tract to the lateral femoral condyle. Ileotibial tract appears like a fibrillar structure located superficially than vastus lateralis (VL) and vasutus intermedius (VI) muscles.
Replace the probe with an axial scan on the anterior superior iliac spine (ASIS) and shift it along the whole sartorius muscle length with a panoramic view.
Longitudinal scans can be performed to evaluate region of interest.
Fig. 7: (a) Anatomical scheme of tensor muscle of fascia lata (TFL) and sartorius muscle (SA).(b) Probe path to explore SA from proximal to distal insertion.(c) Video in axial scan demonstrates SA muscle belly from ASIS to surface of the tibia medial to the tibial tuberosity, just anterior to the gracilis and the semitendinosus tendons (pes anserinus).
Fig. 8: (a) Probe position to evaluate the sartorius muscle (SA) at the proximal third of thigh on the axial plane; (b) US axial scan: in the proximal third of thigh SA is in a superficial position, under the fascia and near the femoral vascular bundle. VL; vastus lateralis muscle; A, adductor lungus muscle.
Complete the examination of anterior compartment of thigh with quadriceps muscle analysis.
Fig. 9: Anatomical scheme of quadriceps muscle group: RF, rectus femoris; VM, vastus medialis; VL, vastus lateralis. The Vastus Intermedius (dotted line) lies deep to the RF.
From ASIS move the transducer caudally to reach the anterior inferior iliac spine (AIIS) where the direct tendon of the rectus femoris can be seen,
deep to the ileopsoas muscle.
Fig. 10: (a) Probe position to visualize RF muscle proximal insertion on anterior-inferior iliac spine (AIIS) on the axial plane. (b) US axial scan at AIIS level shows the proximal insertion of the RF muscle. The tendon has an ovular hyperechoic appearance (arrowhead) just under the psoas muscle (PS). SA, sartorius muscle.
Rotate the transducer by 90° to evaluate the direct tendon on the longitudinal plane.
Deep to the hyperechoic band representing the direct tendon,
note the shadow determined by the change in orientation of the indirect tendon that descends externally and obliquely toward the upper rim of the acetabulum.
Fig. 11: (a) Probe position to evaluate the direct tendon (DT) of the RF muscle on the longitudinal plane. (b) US longitudinal scan of the direct tendon insertion (arrowheads) into the AIIS (anterior-inferior iliac spine). PS, psoas muscle; SA, sartorius.
Fig. 12: US longitudinal scan shows the direct (arrowheads) and indirect (*) tendon of the RF muscle. Identify the hypoechoic appearance of the indirect tendon caused by the change in orientation of its fibres (anisotropy), which runs obliquely and externally compared to the direct tendon.
Place the transducer at middle third of thigh and use extend field of view technique to obtain a panoramic view of quadriceps muscle bellies.
Fig. 13: Anatomical scheme(a) correlated to EFV US axial scan(c) at middle third of the thigh(b) that shows the anatomical relationship among the vastus intermedius (VI), vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF) muscles.
The examination continues with exploration of the muscle belly and its aponeurotic components,
using at first axial scans,
that provide panoramic views.
Place the transducer in an axial position on the myotendinous junction and shift it along the whole muscle length.
Fig. 14: Anatomical schemes correlated to US axial scans at different levels of the RF muscle and its aponeurotic components.
(a,a’) Proximal third of the RF muscle. Visualize the superficial aponeurosis (arrowheads), just under the sartorius (SA) and the central aponeurosis (*).
(b,b’) (c,c’) Proximal and distal middle third of the RF muscle. Note the typical “comma-shaped” appearance of the central aponeurosis (*).
(d,d’) Distal third of the RF muscle. The deep aponeurosis (arrow) is seen as a hyperechoic band between the RF muscle and the VI muscle.
Posterior compartment :
Table 2: Origin and insertion of the muscles of posterior thigh compartment.
The patient lies prone on the table with the lower limb in a neutral position.
Fig. 15: Lower limb position to evaluate the posterior thigh compartment.
Fig. 16: Anatomical scheme of posterior thigh compartment muscles : SM, semimembranosus; ST, semitendinosus; LHB long head of biceps femoris; SHB short head of biceps femoris.
With a longitudinal orientation of the probe,
find the ischiatic tuberosity and visualize the conjoined tendon insertion of the ischiocrural muscles on it.
Then,
rotating the probe by 90°,
perform axial scan.
Fig. 17: (a) Probe position to evaluate the hamstrings’insertion (*) into the ischiatic tuberosity on the longitudinal plane. (b) US longitudinal scan : note the conjoined insertion on ischiatic tuberosity (T) of semimebranosus, semitendinosus and long head of biceps femoris.
Shift the transducer caudally in longitudinal plane to reach the common tendon of semitendinosus and long head of biceps femoris.
Fig. 18: (a) Probe position to evaluate the common tendon (*) of the semitendinosus (ST) and long head of biceps femoris (LHB) muscles on the longitudinal plane. (b) US longitudinal scan of the common tendon with a hyperechoic fibrillar apparence.
Rotate the probe by 90° to evaluate he common tendon on axial scan.
Fig. 19: (a) Probe position to evaluate the common tendon (*) of the semitendinosus (ST) and long head of biceps femoris (LHB) muscles on the axial plane. (b) US axial scan : note the hyperechoic “comma-shaped” appearance of the common tendon.
Place the transducer at proximal,
middle and distal third of thigh and use extend field of view technique to obtain a panoramic view of ischiocrural muscles,
useful to understand the anatomy of posterior compartment.
Fig. 20: Anatomical scheme correlated to EFV US axial scans at different levels of the posterior compartment of thigh muscles. (a,a’) Proximal third. EFV axial scan visualizes the large aponeurosis of semimembransus (SM) which continues in the proximal tendon. Aponeurosis presents a hyperechoic aspect between the semitendinosus (ST) and the aductor magnus (AM) muscles; ST lies just lateral to SM; long head of biceps femoris (LHB) is the most lateral ischiocrural muscles. (b, b’) Middle third. EFV axial scan shows SM with a triangular shape medial to ST. Note the internal septum of ST that appears like a fibrillar hyperechoic band within the muscle belly. LHB has an organized internal structure.(c, c’) Distal third. EFV demonstrates the SM lateral to sartorius muscle (SA), the myotendinous junction of ST with the eccentric distal tendon superficial to SM belly. At this level short head of bicep femoris (SHB) is separated to LHB by a distal aponeurosis which is seen as an hyperechoic band .
Medial compartment :
Table 3: Origin and insertion of the muscles of medial thigh compartment.
The patient lies supine with the thigh abducted and externally rotated and the knee bent (frog leg position).
Fig. 21: Lower limb position (frog leg position) to evaluate the medial thigh compartment.
Fig. 22: Anatomical scheme of medial thigh compartment muscles : PE, pectineus; AB adductor brevis; AL, adductor lungus; AM, adductor magnus; GR, gracilis.
An important body landmark for the study of medial compartment is the anterior surface of the pubis can be seen with a sagittal scan as a hyperechoic cortical band to detect the insertional components of the adductor muscles.
Three muscle layers can be seen: from the most superficial to the deepest,
the adductor longus muscle,
the adductor brevis muscle and the adductor magnus muscle.
Turn the probe over the course of a single muscle belly,
according to the axial and longitudinal planes.
Fig. 23: (a) Probe position to evaluate the proximal insertion of adductor muscles in the anterior surface of the pubis on the sagittal plane. (b) Anatomical scheme of medial thig compartment musclse.PE, pectineus; AB, adductor brevis; AL, adductor longus; AM, adductor magnus; GR, gracilis. (c) US sagittal scan : note the three muscle layers represented from superficial to deepest by AL,AB and AM.
Turn the probe over the course of a single muscle belly,
according to the axial and longitudinal planes.
Fig. 24: (a) Probe path to explore adductor muscles from proximal to distal insertion. (b) Anatomical scheme of medial thigh compartment muscles: PE, pectineus; AB adductor brevis; AL, adductor lungus; AM, adductor magnus; GR, gracilis. (c) video in axial scan demonstrates adductor muscle bellies from anterior surface of pubis to distal insertion.
Place the probe with an axial scan at proximal third of medial thigh compartment an use extend field of view technique to obtain a panoramic view of muscle bellies.
Fig. 25: Anatomical scheme (a) correlated to EFV US axial scan (c) at proximal third of the thigh (b) that shows the anatomical relationship among the ileopsoas (IP), pectineus (PET), adductor longus (AL), adductor brevis (AB), adductor magnus (AM) and gracilis (GR)muscles. At this level the most superficial muscles are AL and GR; AB lies just deeper to AL; AM appears as a large muscle posterior and deeper to AB. Note the superficial femoral neurovascular bundle.
LEG :
Fig. 26: Cross sectional anatomical scheme of leg at middle third level. TA, tibialis anterior; EDL, extensor digitorum longus; EHL, extensor hallucis longus; TP, tibialis posterior; FDL, flexor digitorum longus; FHL, flexor hallucis longus ; SO, soleus; GLH, gastrocnemius lateral head; GMH, gastrocnemius medial head; P, peroneus muscles; F, fibula; T, tibia; thin arrow, posterior neurovascular bundle ; thick arrow, anterior neurovascular bundle.
Anterior compartment :
Table 4: Origin and insertion of the muscles of anterior leg compartment.
Patient seated with the knee flexed and the plantar surface of the foot lies flat on the table.
Fig. 27: a) Leg position to evaluate the anterior leg compartment. (b) Anatomical scheme of anterior leg compartment of extensor muscles : TA, tibialis anterior; EDL, extensor digitorum longus; EHL, extensor hallucis longus. EHL lies in a deeper layer than TA and EDL and its muscle belly arise more distally.
Using EFV technique perform axial scans at different levels to evaluate the extensor leg muscles.
Rotate the probe by 90° to study the internal structure of each muscle belly.
If the extensor muscles are not well separated a muscular contraction can be helpful.
Fig. 28: Anatomical scheme correlated to EFV US axial scans at different levels of the anterior leg compartment. (a,a’) Proximal third. EFV axial scan visualizes the relationship among the peroneus muscles (P) and the extensor muscles. Tibialis anterior (TA) lies just lateral to tibial crest and medial to Extensor digitorum longus (EDL). The interosseus membrane appears as a hyperechoic well definite layer which separate TA from tibialis posterior muscle (TP). T, tibia; F, fibula. (b, b’) Middle third of anterior compartment. EFV axial scan shows TA myotendinous junction with its oval tendon anterior to tibial edge (T). Note the EDL and EHL muscle bellies.(c, c’) Distal third of anterior compartment. EFV US axial scan evaluates the relationship among the peroneus muscles and the extensor muscles at distal third of leg. Peroneus brevis (PB) and Peroneus longus (PL) are not well separated.
Superficial and deep posterior compartment :
Table 5: Origin and insertion of the muscles of superficial posterior leg compartment.
Table 6: Origin and insertion of the muscles of deep posterior leg compartment.
The patient lies prone with the knee extended and the ankle hanging out of the bed.
Fig. 29: Leg position to evaluate the posterior superficial leg compartment.
Fig. 30: Anatomical scheme of posterior leg compartment muscles. (a) Deep posterior leg compartment. PO, popliteus, TP, tibialis posterior; FLD, flexor digitorum longus; FLH, flexor halluces longus. TP is deeper than FLH e FDL.(b,c) Superficial posterior leg compartment : Soleus muscle (SO) lies deep to medial and lateral head of Gastrocnemius (GMH, GLH). SO and GMH e GHL insert on distal aponeurosis (SO aponeurosis *; G aponeurosis **) which continues in Achille’s tendon. Fibres from ** form the superficial layer of Achille’s tendon. Plantaris (PL).
Place the transducer at proximal and middle third of posterior leg and use extend field of view technique to obtain a panoramic view of superficial posterior compartment muscles.
Fig. 31: Anatomical scheme correlated to EFV US axial scans at different levels of the superficial posterior compartment of leg. (a,a’) Proximal third. EFV axial scan visualizes the medial and lateral head of Gastrocnemius which come together in the middle line. Soleus muscle (SO) is deeper than gastrocnemius and is separated from GMH by the distal aponeurosis of G and SO. PO, popliteus muscle. (b, b’) Middle third of superficial posterior compartment. EFV axial scan shows GMH larger than GLH. Distal aponeurosis appears as a hyperechoic band which separates G from SO. At this level note the characteristic internal structure of GLH and GMH consisting of muscular fibres separated by hyperechoic fibroadipose septa.
Rotate the probe by 90° to obtain a longitudinal scan of superficial posterior compartment.
Fig. 32: (a) Probe position to evaluate medial head of gastrocnemius (G) and soleus muscle (SO) on the longitudinal plane. (b) US longitudinal scan : note the distal aponeurosis which appears as a hyperechoic band and separates the two muscles.
Rotate the probe by 90° and shift caudally to reach the myotendinous junction of triceps surae muscle on his axial plane.
The evaluation could be completed with a longitudinal scan.
Fig. 33: (a) Probe position to evaluate Achille’s tendon at level of myotendinous junction with an axial plane.(b) US axial scan : at middle of myotendinous junction, Achilles’s tendon (*) originates from distal aponeurosis of soleus (SO) and it is composed of tendinous fibres of gastrocnemius lateral and medial head. Note the fibrillar echostructure and the crescent shape of Achille’s tendon.
To evaluate the deep posterior compartment,
the patient lies seated on the table with the knee flexed at about 90° and the plantar surface of the foot lies flat on the table (Fig.
27a).
Place the transducer on the axial plane with the medial edge on the distal lateral tibial aspect to evaluate the relationship among the three flexor muscles of deeper posterior compartment.
Fig. 34: (a) Probe position to evaluate the flexor muscles at distal leg level on the axial plane. (b) Anatomical scheme of deep posterior compartment. Po, popliteus; TP, tibialis posterior; FDL, flexor digitorum longus; FHL, flexor halluces longus. (c) US axial scan explains the relationship of flexor muscles. TP is deeper than FD and FHL; FHL is the most lateral.
Lateral compartment :
Table 7: Origin and insertion of the muscles of lateral leg compartment.
Patient seated with the knee flexed and the plantar surface of the foot lies flat on the table.
Place the transducer on fibular head with an axial scan and move it caudally to reach the peroneus muscle bellies until their myotendinous junction.
Continue to evaluate the peroneus tendons moving the probe following a curvilinear line that turns around the lateral malleolus tip.
Fig. 35: Leg position to evaluate the lateral leg compartment.
Fig. 36: Anatomical scheme of lateral leg compartment muscles : peroneus longus (PL) lies superficial to peroneus brevis (PB) and its tendon courses lateral to PB tendon.
Fig. 37: (a) Probe path to explore peroneus muscles and tendons until they turn around the lateral malleolus. (b) Anatomical scheme of peroneus longus (PL) and peroneus brevis (PB) muscles. (c) video in axial scan demonstrates peroneus muscle bellies from the superior tibio-fibular joint. Note the PL myotendineous junction is proximal to PB one. PB tendon has a typical crescent appearance and is located deep to the peroneus longus tendon, which has a typical oval shape.