Week 1 MSK

Question 1

What is reactive Tendinopathy

Answer 1

The tendon is swollen, with fusiform shape, intact collagen fascicles, diffuse hypoechogenicity between intact collagen structures.

Question 2

What is tendon dysrepair

Answer 2

The tendon is swollen, with fusiform shape, intact collagen fascicles, diffuse hypoechogenicity between intact collagen structures.

Question 3

What is degenerative Tendinopathy

Answer 3

extensive vascular changes, disorganised matrix, hypoechoic regions, loss of reflections from collagen fascicles, larger vessels

Question 4

What 3 categories are involved in the continuum of tendnopathy

Answer 4

1. Reactive Tendinopathy
2. Tendon dysrepair
3. Degenerative Tendinopathy

Question 5

Discuss tendinosis and tendinitis

Answer 5

Tendinosis and tendinitis are related but distinct conditions that affect tendons.

Tendinosis: chronic condition characterized by degeneration and breakdown of the collagen fibers in a tendon. overuse or repetitive stress

Question 6

Equipment and image optimisation techniques for MSK

Answer 6

High frequency transducer (7-15MHz)
Linear array, length varied 25mm -75mm
Extended FOV
Doppler for haemodynamics
Cineloop
Stand-off

Question 7

Detail the 4 layers skeletal muscle

Answer 7

1. Endomysium: extensive network capillaries and nerves that surround fibres
2. Perimysium: fibres grouped into bundles composed of connective tissue, blood vessels, nerves, adipose tissue
3. Epimysium: bundles form the muscles that are then surrounded by epimysium
4. Fascia layer: separates the muscle / muscle groups and is a collagenous sheathe that envelopes the MTJ which is then surrounded by subcutaneous tissue

Question 8

What is a retinaculum

Answer 8

Fibrous sheath that covers tendon for stability and keeps tendons close to bone eg in wrist

Question 9

What is peritoneum

Answer 9

A layer of connective tissue that wraps around the tendon

Question 10

Discuss a peripheral nerve

Answer 10

Between muscles and tendons
Never axons are composed of motor, sensory and autonomic neurons
Axons wrapped in myelin -produced by a Schwann cells
Axons form nerve fascicles which are embedded in fibrous connective tissue matrix called endoneurium, perineurium and epineurium
Typical appearance - honeycomb round/e;;i-solid, similar echo to tendons but slight less
Hypo- neural fascicles
Hyper - endo/perineurium
Iso to fat - epinurieum

Question 11

Describe peripheral nerve ndoneurium, perineurium and epineurium

Answer 11

Endo - attached membranous layer Schwann cells and forms neural tube
Peri - between bundles nerve fascicles
Epi - covering entire nerve complex

Question 12

List some MSK artifacts / pitfalls

Answer 12

Shadowing - posterior highly reflective and most of the incident beam is reflected eg bone air calcification foreign body

Enhancement - sound returning amplified, false impression of increased echogenicity eg cyst bladder fluid filler

Comet tail - cover elation eg glass metallic, sound beam repeat reflect

Refraction - bending of beam when travelling eg lesion depicted wrong location, real structure false location eg edge shadowing

Speed - machine assume all speed constant incorrect depth

Question 13

What is anistropy

Answer 13

Anistropy is when a muscle, ligament, tendon or nerve appears falsely hypoechoic due to the obliquely beam and therefore mimic patholguy
To avoid, try to ensure object is perpendicular to beam, heel toe, stand off

Question 14

List some features of a healing muscle tear vs abnormal healing

Answer 14

Normal:
- decease in size and echogenicity of haematoma
- increase in echogenicity of tear margins
- increase margin thickness
- return to normal architecture

Abnormal
- hypoechoic scar tissue (nodular/linear)
- intramuscular cyst
- atrophy

Question 15

Describe a muscle tear healing progress over time (ultrasound)

Answer 15

1. Damages of the muscle leads to damage of the fibres, nerves which can lead to a haematoma
2. The fascia can tear and therefore haematoma herniates beyond belly
3. Extensive scar tissue forms around the periphery, gradually this becomes a central scar after about 6 to 12 weeks

Ultrasound
1. This can look like discontinued fibres, hypoechoic fluid filling the gap in the muscle fibres
2. Echogenic debris with the tear becoming more heterogenous (clotted) this occured in 24-4 hours
3. The next 1 to 3 weeks the tear will again appear hypoechoic and the haematomamay liquify. Shaggy edges. Full retraction.