Shoulder RMSK Flashcards
Subscapularis inserts to
Lesser tuberosity
Supraspinatus insertion
Greater tuberosity, superior and middle facet
Supraspinatus footprint
2.25cm A-P - may insert some into lesser tuberosity
Infraspinatus Insertion
Middle Facet of greater tuberosity overlapping posterior of Supraspin
Teres Minor Insertion
INFERIOR FACET of GREATER tuberosity
Intraarticular part of biceps is stabilized by
BICEPS Reflection Pulley
What comprises the biceps reflection pulley?
SGHL and CHL
GH joint and biceps long head tendon sheath
are connected so joint and biceps are connected
Other joint recess of shoulder?
Axillary and subscapularis recess, subcoracoid bursa
Location of subscapularis recess?
medial to the rotator interval and inferior to coracoid process
Location of subcoracoid bursa? and relationship to GH joint
Anterior to subscapularis and not connected to GH-Joint
Frequently missed in shoulder checklist
biceps tendon dislocation, AC dynamic, teres minor, infraspinatus atrophy
Why scan up to pectoralis tendon area
biceps may retract to this area
Shape of lesser tuberosity
pyramid shape
Shoulder in neutral and evaluation of supraspinatus shows what
only the Distal insertion but proximal pathology will be missed
Crass position shows limited view of
Rotator interval
Infraspinatus tendon appearance and location
middle facet striations are present
Articular surface of humerus
usually round and hypoechoic articularly
Subacromial impingement test bunching ( what plane during scan?)
subacromial impingement but may be asymptomatic ( coronal oblique)
subacromial impingement test incomplete glide
adhesive capsulitis
Indirect signs of supraspinatus tear
cortical irregularity, tendon thinning, volume loss, joint effusion, cartilage interface sign
Bony landmark for scapular spine
osseous ridge of posterior scapula demarcating supra infra and teres minor
Shoulder external rotation shows paralabral cyst look alike
actually DILATION of suprascapular vein but collapses on internal rotation
Infraspinatus teres minor ratio
Infraspinatus 2x size of teres minor over scapular body..
Supraspinatus acute tears location?
proximally and may or may not have cortical irregularity
Chronic supraspinatus tears cause and location?
attrition, superimposed injury, occur DISTALLY, usually with cortical irregularity
Locations of supraspinatus tears
Bursal, articular, greater tuberosity surface
If only at greater tuberosity what is it called
intrasubstance or concealed interstitial delamination tear – not visible at arthroscopy or bursocopy
Define a full thickness tear of supraspinatus
articular to bursal extension
Types of full thickness tear
focal/incomplete or if involves entire tendon. complete or full width tear
Large supraspiatus tear appearance?
tendon retraction, volume loss of tendon, loss of normal superior convex shape
Sequelae for full thickness tears located anteriorly
retraction, atrophy, PROPAGATION overtime
Partial thickness tear description
well defined hypoechoic or anechoic abnormality disrupting tendon fibers
appearance of a tendon stump
mixer hyperechoic-hypoechoic appearance.. hypo is fluid hyper is torn tendon
cortical irregularity adjacent to tendon tear caused by what process
chronic attrition
cartilage interface sign
hyperechoic interface between the tendon tear and the hyaline cartilage
what is a rim rent tear?
also called a PASTA lesion. partial articular side supraspin tendon avulsion.. it is a far distal articular side partial thickness tear beside greater tuberosity surface
Bursal surface tear appearance
tendon thinning and volume loss usually present
well defined anechoic cyst in rotator cuff associated with
supraspinatus articular side tear
Chronic tears sequelae
remodeling of greater tuberosity and tapering of distal torn tendon without adjacent fluid but may have synovial hypertrophy
How to determine if supraspinatus tear includes infraspinatus
short axis over greater tuberosity, if it extends to posterior aspect of middle facet! includes infraspin already
Poor outcomes of rotator cuff repair
Fatty infiltration, muscle atrophy
Focal tendinosis apperance
heterogeneous ill defined hypoechoic area
Diffuse tendinosis
entire tendon hypoechoic
Cortical irregularity on posterior humerus at bare area
NORMAL if not extensive
cortical irregularity of lesser tuberosity insertion of subscap
Normal
Simple joint and bursal fluid echogenicity
anechoic
Complex fluid appearance
hyper or even isoechoic to adjacent tissue
SASD bursa fluid parameter
1-2mm anechoic
signs of posterosuperior impingement syndrome
posterosuperior labral tear, cortical irregularity of posterior aspect of greater tuberosity, partial thickness infraspinatus
isolated infraspinatus atrophy can occur from what pathology
from just a supraspin tear in can happen from altered biomechanics
spinoglenoid notch paralabral cyst
isolated to infraspinatus
paralabral cyst from labral tear affecting
supraspscapular notch
fatty degeneration and atrophy appearance on msk
increased echogenicity of muscle and poor differentiation bet. muscle and tendon
fatty degeneration and atrophy appearance on msk best seen where
at myotendinous junction at short axis
bony landmark for infraspin and teres minor for atrophy
posterior scapular cortex
Types of tendon calcification and explain
Degenerative and hydroxyappetite
Stages of calcification
pre-calcific (tendon metaplasia) , calcific (((Formative, resting, resorptive))) , post-calcific (fibrotic scar)
which stage causes pain?
calcific- resorptive
IS there a tear usually in calcific tendinosis?
no tears
Most commonly affected in calcific tendinosis ?
supraspin –> infraspin –> subscap
Different appearances of calcifications
amorphous, globular,
do all calcifications have shadowing?
NO
How to determine amorphous
replaces normal fibrilar tendon and can be seen with angulations
Can calcifications cause impingement?
yes it can cause impingement of acromion
Amorphous without shadow temporal relationship
ACUTE
well defined with shadowing
subacute or chronic
doppler findings indicate
higher chance of resorptive phase
what consists the coracoacromial arch?
acromion, distal clavicule, AC JT, coracoid process, coracoacromial ligament
Other findings of subacromial impingement?
gradual distention of SASD bursa with synovial tissue or abrupt movement of a thickened bursa , superior bulging of coracoacromial ligament seen on SAX of sspn
Late stage of subacromial impingement?
abnormal upward migration of humeral head
Coracoid impingement syndrome?
subscap tendon and SASD between coracoid process and lesser tuberosity impinged, anterior aspect of SASD distention
Adhesive capsulitis PE?
Limited ER during subscap eval & limited supraspin sliding under aromion
Location of sspin tear in younger individuals?
anterior, near Rotator interval
How to ensure full visualization of supraspin in lax and sad
in sax reach rotator interval, in lax visualize biceps tendon near Rotator interval
Rotator Interval and biceps locati
intraarticular part of LHBT
SGHL location?
subscapularis side
SASD distention misinterpretation
check fluid if anechoic or if it has complex fluid ( synovial hypertrophy or isoechoic).. Bursal thickness tears or full thickness tears may display thickened bursa so watch out it may mimic a tendon
Rim rent tear appearance?
well defined hypoechoic or anechoic abnormality at location of articular end adjacent to greater tuberosity
What do you call a tear only with greater tuberosity
intra-substance tear and cannot be seen in arthroscopy
characteristics of a tendon tear
anechoic, well defined, thin, homogenous, bone irregularity
characteristics of tendinosis
hypoechoic, ill defined, heterogeneous, increased thickness and SMOOTH cortex ( only for >40 yrs old )
cortical irregularity important finding in patients over 40
shows adjacent cortical irregularity and supraspinatus abnormality.
What is the bare area
posterior humerus beneath infraspin is devoid of cartilage… can have normal irregularities but if EXCESS consider labral injury and artial thickness infraspin tear.. if both are present ( posterosuperior impingement syndrome)
Synovial hypertrophy findings?
flow on color or power doppler and lack of internal movement
Complex fluid finding
internal movement artifacts, isoechoic, to hyperechoic
2mm in bicipital tendon sheath is equal to
8ml of effusion
differentiate gh joint effusion from biceps tenosynovitis
tendon sheath distention is focal and hyperemia,,, with pain on transducer pressure consider tenosynovitis, fluid that remains focal or loculated at level of bicipital groove with palpation also indicated tenosynovitis
gh joint distention at biceps features
long asymptomatic distention usually from joint recess….(gh joint or subscap)
PPV of biceps effusion and sasd effusion for rotator tears
60% and 95% for sasd bursal fluid
Watchout for refraction shadow of deltoid fascia
may appear as tendinosis
Location of biceps tendon pathology
usually within 3.5cm of origin… proximal to or at the bicipital groove
Indirect signs of biceps instability
chonrdal print sign, showing subchondral bone cortex irregularity adjacent to biceps
relationship between subluxation and dislocation with tears
usually associated with partial tear
Where can we see distention of SASD
laterally - over supraspin, anteriorly- over subscap and biceps, post over infraspin
echogenicity of distended bursa
anechoic/ hypoechoic - simple fluid…. Hyperechoic or hypoechoic - complex fluid or synovial hypertrophy
power doppler on SASD suggests
synovial hypertrophy
Causes of SASD bursal distention
impingement, tear, hemorrhage, AMYLOIDOSIS, infection, RA, calcium hydroxyapatite, synovial proliferative disorders
clues for gas-forming infection
hyperechoic focu with ring -down artifact
apperance of a normal glenoid labrum
hyperechoic, triangular attached to bony glenoid
degenerated labrum appearance
heterogeneous hypoechonecity
Glenoid tear appearance
well defined hypoechoic or anechoic cleft
Accuracy of posterior labrum ultrasound
88 % for abnormal - normal ? 98% differentiating posterior labral tear from normal or degeneration
How to assess superior labrum
LAX supraspin between clavicle and scapular spine,
paralabral cyst
usually from a labral tear
suprascapular nerve entrapment affects which muscle
depends on location… if spinoglenoid area- infraspin only… If suprascapular fossa both IS and SS
greater tuberosity fracture
step off deformity, log segment cortical step off and discontinuity at the margins and point tenderness
Anatomic landmarks for pectoralis major
deltoid, biceps brachii tendon, coracobrachialis, sternal and clavicular head of pec major
Normal AC joint distention
3mm or less
DOA of AC joint is common at what age
40 yrs
axillary lymph node normal
oval, hypoechoic cortical rim, hyperechoic hilum, hilar pattern of vascularity if ever
malignant lymph node
peripheral vascularity… roundness, hilar thinning, absence of hilum, eccentric thickening of cortex
elastofibroma
tumor specific to shoulder, not true tumor,, caused by friction from chest wall and scapula.. Hyperechoic interspersed curvilinear hypoechoic strands, located at scapular tip deep to serratus anterior .
sternalis muscle
normal variant
nodule of xiphoid process
palpable mass
slipping rib syndrome
abnormal mobility of lower anterior rib end
