Topic 5 - The hip

Question 1

What are the advantages of ultrasound imaging over other imaging in regards to the hip?

Answer 1

The usual advantages ultrasound has over MRI – cheaper, quicker, dynamic, can pin point tender spots more readily, can trace the sciatic nerve back to the foramen.
The major advantage of ultrasound is its ability to provide real-time assessment of the site of injury. Diagnostic Imaging is expensive, often making ultrasound the first choice when investigating a sports injury because it is cost effective when compared to other imaging modalities.

Question 2

What are the advantages of ultrasound imaging over other imaging in regards to the hip?

Answer 2

Ultrasound is commonly used to describe pathology in the knee associated with acute or overuse injuries, rheumatology and the evaluation of soft tissue masses. MRI and CT are better modalities for imaging the intra-articular structures such as cruciate ligaments, articular cartilage and bone.

Question 3

How can a labral tear at the hip appear on ultrasound?

Answer 3

Sometimes a labral tear can be demonstrated as a hypoechoic cleft in the anterior labrum, but a negative ultrasound does not exclude a labral tear.
A paralabral cyst is suggestive of an anterior labral tear. Joint effusion can be noted, but is not specific

Question 4

What should you look for when examining the iliopsoas tendon?

Answer 4

Look for bursal collections around the tendon and deep to it; compare with contralateral leg
looking for swelling, decreased echotexture, or focal changes such as calcification in the tendon. Enthesopathy of the lesser trochanter is the same as for any bone-tendon interface in the body; look for bone surface pitting, and associated degenerative changes in the tendon attachment.

Question 5

How should you assess the hip in the case of clicking hip?

Answer 5

Hip and knee flexion while scanning over the acetabular-femoral joint can demonstrate if the iliopsoas tendon is able to glide smoothly over the joint. Dynamic scanning with the transducer in transverse to the long axis of the iliopsoas is essential in the patient with a ‘clicking hip’, as this can be related to a shift in position of the iliopsoas.

Question 6

What should you look for when scanning the ASIS and AIIS?

Answer 6

Sartorius and rectus femoris origins at ASIS and AIIS respectively. Tendinopathy can be suspected based on the usual greyscale changes of swelling and hypoechoic texture, calcific tendinitis, focal tenderness, and pain with hip flexion.

Question 7

What should you look for when scanning the inferior pubic bone?

Answer 7

Inferior pubic bone for adductor origins, tendinopathy or tears.
Short and long axis views with leg in external rotation.
Osteitis pubis more commonly involves the adductor origin region, and the pubic symphysis, rather than rectus abdominus insertion.
A curved transducer can improve contact in this region.

Question 8

Where is the iliopsoas muscle?

Answer 8

• The iliopsoas muscle and tendon are just medial to the hip joint, passing inferiorly to attach at the lesser tuberosity.

Question 9

What are the attachments of the vastus muscles?

Answer 9

• Deep muscles are the vastus lateralis, vastus intermedius, and vastus medialis origins at the upper third of the femur. Insert at quad tendon

Question 10

What is the quadriceps origin?

Answer 10

• Overlying muscles are the rectus femoris originating at anterior inferior iliac spine (AIIS), and the sartorius originating at the anterior superior iliac spine (ASIS).

Question 11

What are the attachments of the sartorius?

Answer 11

• The sartorius originates at the ASIS, courses down the thigh medially and inserts onto the tibial tuberosity forming part of the pes anserinus.

Question 12

What are the origins found at the pubic bone?

Answer 12

• Deep muscle origins at the pubic bone are the adductor minimus and magnus.
• Superficial muscle origins at the pubic bone (from medial to lateral) are the gracilis, adductor brevis, adductor longus, and pectineus

Question 13

What are the most commonly injured muscles of the hip?

Answer 13

• the adductor muscles are the most commonly injured, most likely due to rapid and forceful activity with adduction and rotational movement like kicking a soccer ball across the midline
• The most common site of injury is the origin, followed by an intramuscular tear

Question 14

How does a hip joint effusion appear on ultrasound?

Answer 14

• The capsule and iliofemoral ligament will bulge convexly over the neck with an underlying effusion.
• You need to demonstrate a difference of joint distension of greater than or equal to 2 mm between the symptomatic and asymptomatic hips to be considered significant.
• The effusion may be anechoic, hypoechoic, or complex

Question 15

What position is best for assessing hip joint effusions?

Answer 15

• best demonstrated with the hip in extension and slight abduction, with the transducer aligned to the long axis of the femoral neck

Question 16

How does trochanteric bursitis appear on ultrasound?

Answer 16

• This is a well circumscribed fluid collection superficial to the greater trochanter
• It usually collects just posterior to the trochanter between the muscles deep to the iliotibial band

Question 17

What can cause trochanteric busitis?

Answer 17

• caused by trauma, infection, or inflammation due to an abnormal gait.

Question 18

What is weavers bottom?

Answer 18

Ischiogluteal bursitis
• often overlooked cause of buttock pain and/or mass.
• a bursal collection overlying the ischial tuberosity and collecting between the hamstring origin and the overlying gluteal muscles

Question 19

What may weavers bottom result in?

Answer 19

• It may cause compression on the sciatic nerve and therefore the ultrasound diagnosis of this bursitis is useful to differentiate it from spinal disease.

Question 20

What might cause a femoral artery aneurysm?

Answer 20

• Femoral artery pseudoaneurysms may arise post catheterisation procedures, from penetrating or surgical trauma, or from self-administration of intramuscular injections in the thigh.

Question 21

How does a femoral artery aneurysm present clinically?

Answer 21

• Classically, pseudoaneurysm presents as a tender pulsatile mass

Question 22

How does a femoral artery aneurysm present on ulrasound?

Answer 22

• Ultrasound can show the size and site of the aneurysm, the patency of the lumen, the feeding vessel, the size of the lumen, and the extent of mural thickness.

Question 23

What is snapping hip?

Answer 23

• Audible snapping sound of variable intensity produced during motion of the hip or during walking

Question 24

What are some causes of snapping hip?

Answer 24

• Intraarticular snapping hip has been attributed to synovial osteochondromatosis, loose bodies, acetabular labral tears, osteochondral fractures, and transient subluxation of the femoral head
• most common extraarticular causes are the iliotibial band or gluteus maximus snapping over the greater trochanter and the iliopsoas tendon snapping over the iliopectineal eminence

Question 25

How does snapping hip appear on ultrasound?

Answer 25

• Snapping hip is characterized on sonography by a sudden abnormal displacement of the snapping structure

Question 26

What is the most common spot for myositis ossificans to form?

Answer 26

The quadriceps

Question 27

What are the hamstring muscles?

Answer 27

• biceps femoris, semimembranosus, and semitendinosus

Question 28

What is the most common injury of the hamstrongs?

Answer 28

• often subjected to elongation type injuries due to straight leg kicking of a ball, or hyperextension at the knee.

Question 29

What can result in chronic hamstring pain?

Answer 29

Often elite sprinters and footballers will present with a chronic generalised pain in the hamstring region, without any recent trauma.

Question 30

What is hamstring syndrome?

Answer 30

it is thought that microtrauma to the hamstring origin that results in repetitive haemorrhage and repair can lead to fibrosis at the hamstring origin, and pull at or tether the sciatic nerve as it passes just lateral to the ischial tuberosity

Question 31

What is the most common hamstring injury?

Answer 31

• The most common site of injury is the biceps femoris muscle at the central intramuscular tendon followed by the myofascial junction.
Ultrasound can easily identify myofascial and distal musculotendinous tears due to their superficial nature but is not as sensitive as MRI in detecting tears along the central intramuscular tendon of the biceps femoris

Question 32

What is the most common hamstring injury?

Answer 32

• The most common site of injury is the biceps femoris muscle at the central intramuscular tendon followed by the myofascial junction.
Ultrasound can easily identify myofascial and distal musculotendinous tears due to their superficial nature but is not as sensitive as MRI in detecting tears along the central intramuscular tendon of the biceps femoris

Question 33

What is the course of the sciatic nerve?

Answer 33

• Exits the pelvis greater sciatic foramen
• emerges inferiorly to the piriformis (or through)
• descends in an inferolateral direction.
• enters the posterior thigh by passing deep to the long head of the biceps femoris.
• When the sciatic nerve reaches the apex of the popliteal fossa, it terminates by bifurcating into the tibial and common fibular nerves

Question 34

What are the two most common injuries to the sciatic nerve?

Answer 34

• The two most common injuries are acute and chronic tearing.
• An example is an acute tear, complete avulsion of the biceps femoris origin with resultant hematoma that displaces the sciatic nerve posterolaterally. This can occur with any muscle tear and resultant hematoma in the area.
• A chronic tear or hamstring syndrome
• it is thought that microtrauma to the hamstring origin that results in repetitive haemorrhage and repair can lead to fibrosis at the hamstring origin, and pull at or tether the sciatic nerve as it passes just lateral to the ischial tuberosity.

Question 35

What is piriformis syndrome?

Answer 35

• Controversial
• Thought to occur when the nerve divides early and a branch passes through the piriformis muscle
• Any problems with the muscle (spasm, tear, hypertrophy) will then have a nutcracker effect on the nerve
• This can also happen when the whole nerve, undivided, goes through the piriformis

Question 36

What are the major hip joint movements?

Answer 36

• Flexion and extension
• Abduction and adduction
• Medial and lateral rotation (Internal and external).

Question 37

What are the major hip flexors?

Answer 37

(Iliacus + Psoas major = Iliopsoas)

• Iliacus
• Psoas Major

Question 38

What are the internal rotators of the hip?

Answer 38

Pectineus, adductor longus, adductor brevis adductor magnus. These muscles have minor contribution to hip flexion, their primary roles are internal rotation and adduction.

Question 39

What are the different causes of snapping hip?

Answer 39

1 - Tightness of the iliotibial band. Hip flexion or rotation causes the IT band to pass over the greater trochanter.
2 - the iliopsoas tendon overlies various pelvic bony prominences (eg iliopectineal eminence). If it catches any of these during movement, snapping can occur. It also courses over the anterior femoral head, so this has been cited to be a possible snapping location too.
3 - a labral tear. Typically more painful than just the audible snapping, so generally more debilitating for the patient