Elbow RMSK Flashcards
Prominent recess/FOSA of elbow
coronoid and radial fossa anteriorly and olecranon fossa posteriorly
Where are the fat pads located
in each joint recess. it is intracapsular but extrasynovial
Medial elbow joint stabilizers
UCL- 3 components anterior , posterior and oblique
Which is the most important medial stabilizer
anterior bundle
Lateral elbow stabilizer
LCL complex
what are the components of the lateral elbow stabilizer
radial collateral ligament, annular ligament, small accessory radial collateral ligament and LUCL
Brachialis inserts to
Ulna BRU!!!
Biceps brachii inserts where?
radial tuberosity
what kind of insertion is biceps brachii
dual insertion… short head is more superficial and inserts distally on radial tuberosity
triceps inserts to
olecranon process
which muscles compose the superficial layers of the distal triceps?
lateral and long head
shorter head of triceps and deeper
medial head
Where can you find the anconeus
between olecranon process and lat epicondyle
Medial compartment of elbow
common flexor tendon ( FCR, PL, FCU, FDS) all originating from medial epicondyle
Lateral compartment of elbow structures?
ECRB, ED, EDM, ECU all from lateral epicondycle
Not including ECRL- since it is more proximal
Where is origin of ECRL
proximal to lateral epicondyle
Space between olecranon process of ulna and Medial epicondyle is bridged by what ligament
bridged by the cubital tunnel retinaculum ( osborne ligament)
True cubital tunnel
between two heads of flexor carpi ulnaris and deep to arcuate ligament
WHere does median nerve course through sa elbow
between ulnar and radial headfs of pronator teres
Radial nerve course from humerus .. which muscles does it pass
posterior aspect of humeral shaft then distally and laterally beneath the brachioradialis.. deep branch courses under supinator and superficial branch beneath BR into forearm
Commonly missed in elbow scan
anterior joint recess. ulnar collateral ligament, LCL complex, radial head and annula recess, capitellum, posterior joint recess, olecranon bursa
vascular Landmark of biceps brachii tendon
lateral to brachial artery
Two different superficial nerves of anterior elbow and landmarks
lateral antebrachial cutaneous nerve- lateral and superficial ..( continuation of musculocutaneous nerve) to BT, radial nerve- superficiial and deep
Lacertus fibrosus location
superficial to biceps tendon
Views for distsal biceps tendon
usual anterior aproach.. lateral to brachial artery
Other views for distal biceps tendon
Medial approach v1 ( move medial until brachial artery seen then angle lateral toward center of elbow. + heel toe maneuver + slight flexion )
Another medial approach v2
SAX then LAX once footprint is seen
3rd method for distal biceps
Pronator window approach- elbow flexed… transducer over medial epicondcle and elbow flexed… viewing at coronal plane , move towards wrist and slightly anterior to visualize radial tuberosity
structures to evaluate on posterior elbow
joint recess, triceps, soft tissues over olecranon, trochlea, capitellum, olecranon fossa, cartilage
superficial layer of triceps brachii posteriorly comprised of which heads
long and lateral heads
deeper layer of triceps represent
medial head of triceps
lateral structures ( tendon, ligament, bony landmarks)
common extensor tendon, LCL complex, raidal head, annula recess, capitellum, radial collateral ligament
foorptint origin of common extensor tendon
proximal 46% of bone surface.. a bony ridge may be seen at the ending.
structure to remember near the radiocapitellar joint
meniscus like synovial fold called the POSTEROLATERAL PLICA
differentiate the radial collateral and the lateral ulnar collateral ligament
RCL adjacent to CET… LUCL.. oblique and inserts to crista supinator of ulna
Which recess in elbow most sensitive for joint fluid accumulation
posterior olecranon recess
Complex fluid in elbow appearance
hypoechoic to hyperechoic
heterogeneous fluid indicates?
hemorrhage or infection
findings that suggest complex fluid
compressibility, redistribution or motion of contents, lack of internal flow on color doppler
findings suggestive of synovial hypertrophy
non compressibility
flow on color doppler
What causes synovial hypertrophy
infection, RA, inflammatory arthritis, intra-articular osteoid osteoma
synovial pathology with calcified hyperechoic foci
pigmented villonodular synovitis… if synovial chondromatosis there will be hyperechoic foci
Common sites for intra-articular bodies
olecranon, coronoid, annula recess
synovial fold syndrome
adjacent to radial head it is heterogeneous thickener or elongated
Evaluate for articular hyaline cartilage where
over capitellum and look for osteochondral abnormaloty
olecranon bursa location
superficial to olecranon process of ulna, must FLOAT
findings suggestive of gout
hyperechoic synovial hypertrophy with internal hyperechoic foci
findings suggestive of a full thickness tear
anechoic or hypoechoic tendon fiber disruption, tendon retraction with refraction shadowing
distal biceps tendon tear of only one head will be classified as
partial thickness tear
dynamic evaluation of full tear
proximal segment will show little or no movement with pronation to neutral
dynamic evaluation of partial tear
somve movement is seen equal to amount of rotation
appearance of DOMS
focal or diffuse hyperechoic area of the involved muscle with possible enlargement ( triceps, biceps, brachiorad)
partial thickness tear triceps 4 considerations
Observe superficial layer of tendon,
Usually combined lateral and long head attachments,
May have fractured displaced osteophyte 2-4cm retraaction of avlused bone
Lateral epicondylitis most common tendon
most common carpi radialis brevis ( most anterior and most common)
findings of lat epic
tendinosis >4.2mm if common extensor tendon with possible hyperechoic calcification and adjacent bone irregularity
Poor prognosis for lat epicondylitis
size of intasubstance common extensor tendon tear and radial collateral ligament inclusion- poor outcome
what stabilizes the medial elbow joint?
Ulnar collateral ligament ( APO) anterior posterior and oblique
Insertion of the anterior bundle
sublime tubercle
full thickness tear appears
complete fiber discontinuity, variable anechoic, hypo echoic isoechoic fluid and hemorrhage.. difficult to distinguish from partial
dynamic evaluation of elbow for ulnar collateral ligament tear criteria for joint gapping and requirements for surgery?
during valgus stress joint gapping >1mm difference- UCL tear req. surgery… if 2.5mm full thickness tear
Are all calcifications pathologic in UCL?
can be asymptomatic with baseball players
Lateral elbow stabilizers and ligaments?
radial collateral ligament , annular ligament, LUCL.
Criteria for cubital tunnel syndrome
> 9mm2 or ratio of >2.8
Where does the ulnar nerve dislocate
medially and anteriorly over the medial epicondyle and reloates with extension
snapping triceps syndrome
includes medial head of triceps and also ulnar nerve.. so 2 snaps.
anconeus epitrochlearis muscle incidence? and possible pathology
normal variant in 23% can cause ulnar nerve compression.. diagnosed in extension
Median entrapment sites
distal humerus- ligament of Struthers (supracondylar process). antecubital region- pronator syndrome, distally AIN from fibrous bannds of anomalous muscles
Radial nerve pathologies
spiral groove syndrome - wrist drop and sensory but spared triceps function
Humeral shaft injury
can injure radial nerve from enlargement to transection
Spiral groove compression
Saturday night palsy
Radial tunnel syndrome location and distribution and manifestation?
between two heads of supinator..
Proximal lateral forearm pain in present without motor abnormalities
Posterior interosseous nerve syndrome clinical manifestation
painless lack of finger and thumb extension without wrist drop. imaging is enlargement of radial nerve deep branch just proximal to entrance between two heads of supinator
causes of PIN syndrome
Arcade of Froshe,
fibrouse bands,
leash of henry.
The deep branch of radial nerve normally flattens as it enters supinator meaning
not nerve compression
Peripheral nerve sheath tumors echo characteristics?
schwanoma and neurifibroma appear as defined hypoechoic mass with low-level internal echoes. may havei ncreased through transmission
Inflammatory epitrochlear lymph node
enlarged, oval shape, normal echogenic hilum and hilar vascular pattern..
Malignant epitrochlear lymph node
round with absence of echogenic hilum, thickening of hypoechoic cortex and peripheral or mixed vascularity
Lateral flexion approach- can view full thickness tear of BT
elbow 90 degress, transducer is placed transverse to radius and at the beginning of radial head.. go distally till you see the supinator at level of radial tuberosity
Dorsal flexed pronation view good for what ?
can see distal biceps and good position for injection
Medial flexion view can view what structure?
can see BT more proximally can see bicipitoradial bursa if enlarged
