extremity MSK part 1

Pennate muscle pattern -

• fan shaped (feather like)

• parallel to bone

muscle patterns -

• Bipennate

• Unipennate

• Multipennate

• Circumpennate

Tendon -

attachment of muscles to bone

Collagenous Fibers -

• rounded - cord like

• flat sheets

• aponeuroses

Tendons are -

avascular

Synovial sheath

Synovial sheath may or may not -

surround tendon

Synovial sheath -

double layer - fluid

The tendons connect -

muscle to bone

tendons can have a synovial sheath in areas of -

friction such as in the wrist

Tendons without synovial sheath include -

• Achilles

• Patellar

• Proximal Gastrocnemius

Paratenon -

outer layer of tendon made up of loose connective tissue

Epitendineum -

dense connective tissue surrounding the tendon

MSK US allows -

dynamic imaging and side-to-side comparisons

a normal tendon is -

uniform in thickness and echogenicity

identify echogenic fascicles that -

represent the collagen fibers to confirm imaging of the tendon

Enthesis is the -

tendon insertion site

fibrocartilage characteristic -

• avascular

• hypoechoic triangular area

fibrocartilage measurement -

1 cm

fibrocartilage may be mistaken for -

pathology

ligaments connect -

bone to bone

ligaments are -

thin and superficial

ligament size -

2-3 mm

Ligament appearance -

• hypoechoic band

• similar in appearance to tendons

ligament sonography -

• standoff pad

• longitudinal imaging

Bursa -

small ‘sacs’ surrounding muscles, tendons, and ligaments

• viscous, synovial fluid

communicating bursa -

interacts with the joint space

Bakers cyst is a -

communicating bursa

non-communicating bursa -

does not interact with the joint space

Prepatellar bursa is a-

non communicating bursa