MSK

Rim of living bone that surrounds the sequestrum is an involucrum

1) osteomyelitis
2) LCH ("button" sequestrum)
3) osteoid osteoma
4) lymphoma
5) fibrosarcoma

Infectious periosteal rxn affects the metaphysis.

1) infantile cortical hyperostosis.
2) coarse, irregular, asymmetric periosteal reaction
and soft tissue swelling

1) physiologic (1-6 months, no metaphyseal involvement)
2) trauma
3) infection
4) PG therapy
5) Caffey disease (infantile cortical hyperostosis)

1) renal osteodystrophy
2) osteopetrosis
3) Paget disease

*Don't forget about mets!

1) ank spondylosis
2) IBD
3) RA
4) hyperparathyroidism

1) reactive arthritis
2) psoriatic arthritis
3) OA
4) septic arthritis

1) RA
2) CPPD
3) gout
4) CVD
5) hemochromatosis

1) OA
2) erosive OA
3) psoriatic arthritis
4) reactive arthritis
5) RA

joint preservation

1) reactive arthritis
2) psoriatic arthritis

CPPD

calcium pyrophosphate dehydrate

CPPD beaklike osteophytes often spare the 4th and 5th MCP joints

1) CPPD arthropathy
2) hyperparathyroidism (usually primary)
3) hemochromatosis
4) Wilson disease

1) LCH
2) leukemia/lymphoma
3) infection
4) mets

preservation of disk space

cleidocranial dysostosis

hypothyroidism

1) Down's syndrome
2) OI
3) Rickets
4) Cleidocranial dysostosis
5) hypothyroidism

Triangular configuration of the distal radius and ulna articulation with wedging of the proximal carpal bones between the distal radius and ulna

1) idiopathic
2) Turner syndrome
3) skeletal dysplasia
4) trauma
5) infection

1) metaphyseal spurs (Perlkan spur)
2) osteopenic epiphysis with dense peripheral calcs (Wimberger ring)
3) lucent metaphyseal bands adjacent to a thickened zone of provisional calc (zone of Frankel)

bilateral upper medial tibial destruction

Rickets

1) Leukemia
2) Rickets
3) Infection
4) neuroblastoma mets
5) Scurvy
6) Syphilis

1) enchondroma
2) chondrosarcoma
3) bone infarct
4) chronic osteomyelitis

1) hyperparathyroidism
2) scleroderma
3) trauma (burn, frostbite)
4) psoriasis
5) Hajdu-Cheney syndrome

Giant cell tumor of the tendon sheath

1) joint effusion
2) subchondral cysts
3) erosions
4) preservation of the joint

1) hemarthrosis
2) chronic juvenile arthritis or hemophilia
3) PVNS
4) septic arthritis
5) crystalline arthropathy

1) knee
2) facet joints in the spine
3) hands/wrists
4) odontoid process

1) synovial osteochondromatosis
2) pigmented villonodular synovitis
3) RA (rice bodies)

1) fibrous dysplasia
2) enchondroma
3) bone cyst
4) LCH
5) Ewing sarcoma
6) mets

1) ABC
2) osteoblastoma
3) infection
4) mets
5) LCH

midcarpal dislocation (ligamentous injury at the lunotriquetral jt)

1) hemorrhage
2) fibrous tissue
3) cystic components

MO should demonstrate a zone of mature ossification peripherally.

The opposite is true for sarcomas.

1) hemangioma
2) scleroderma
3) myositis ossificans
4) gout
5) soft tissue sarcomas
6) tumoral calcinosis

1) osteopoililosis
2) melorrheostosis
3) osteopathia striata (Voorhoeve syndrome)

1) abnormal marrow signal with ill-defined margins
2) extension of abnormal marrow signal into the pedicles
3) associated soft tissue lesion
4) marked abnormal enhancement

1) chondroblastoma
2) GCT
3) LCH

*Adults, think also infection, mets, chondrosarcoma

Parosteal:
-arise from outer layer of periosteum
-low grade tumor
-cauliflower-like with lucent cleavage plane between lesion and cortex

Periosteal:
-arise from inner layer of periosteum
-intermediate grade
- saucerized cortex with cortical thickening and periosteal reaction adjacent to chondroblastic soft tissue mass

1) posterior shoulder dislocation
2) linear impaction fx of the anterior humeral head

ulnar fx with prox radial dislocation

radial shaft fx with distal radioulnar dislocation

radial head fx and distal radioulnar dislocation

distal radius fx with:
1) dorsal angulation
2) ventral angulation

IA distal radius fx/dislocation

Fx/dislocation at base of 1st MC

comminuted Bennett fx

ulnar collateral ligament injury at the 1st MCP

IA fx of radial styloid (can have dorsal displacement).

Comes from car drivers getting kick-back when they started the engine using a lever

iliac wing fx

SI jt or sacral fx with both ipsilateral pubic rami fx

Fx of all four pubic rami (both obturator rings)

Fx at the lateral tibial condyle.

Associated with ACL injuries

IA, comminuted distal tibia fx

SH-3 fx of the lateral distal tibia

Tillaux fx with extension into the tibial metaphysis (SH-4 fx)

avulsion of the medial margin distal fibula

fx of fibula above tibiofibular ligament

tarsometatarsal fx/dislocation

1) usually on same plane as the AC joint
2) the biceps anchor is in view

anterolateral branch of the anterior circumflex artery and vein

1) space between the supraspinatus and subscapularis tendons
2) biceps tendon, coracohumeral ligament, SGHL

1) coracoacromial ligament anteriorly
2) HH posteriorly
3) acromion superiorly

Part 2:
1) subacromial/subdeltoid bursa
2) supraspinatus
3) LH of biceps tendon

Impingement occurs when there is a decreased size of the coracoacromial arch.

1) acromial shape/orientation
2) os acromiale
3) AC deg changes
4) post-traumatic etiology
5) shoulder instability
6) muscle overdevelopment
7) thick coracoacromial ligament

1) magic angle occurs at specific location (1 cm from SS insertion onto HH)
2) no irregularity to tendon with magic angle
3) signal abnormality disappears on T2W imaging with magic angle

partial thickness tear of the insertional fibers onto the greater tuberosity

can miss a rim rent tear of the SS tendon because it approximates the bicipital groove

transverse humeral ligament

impingement of the IS/SS tendons between HH and posterosuperior labrum

Common in pitchers

subscapularis tendon

adhesive capsulitis

the glenohumeral ligaments

(Note: the IGHL arises from both the anterior and posterior inferior labrum.)

inferior glenohumeral ligament

coracoid process.

SGHL is at the level of the coracoid, while the MGHL is at the inferior tip of the coracoid.

where the anterosuperior labrum is not attached to the glenoid

Anterosuperior labrum congenitally absent with a thick MGHL

Humeral avulsion of the glenohumeral ligament, particularly the anatomic neck of the humerus avulsing with the IGHL

mineralization of the posterior band of the IGHL from chronic traction (usually from pitching).

May be associated with a posterior labral tear.

Tear of the anteroinferior labrum with torn periosteoum. May have an associated fracture (bony Bankart).

Stands for Anterior labroligamentous periosteal sleeve avulsion.

Variation of the Bankart lesion with injury to the anteroinferior labrum, but the periosteum remains intact.

Stands for Glenolabral articular disruption.

Tear of the anteroinferior labrum with a glenoid chondral defect.

glenoid dysplasia.

Associated with an increased incidence of posterior labral tears or detachments.

Tear of the superior labrum, oriented in an anterior and posterior direction, occurring at the attachment site of the LH of the biceps tendon.

Part 2:
1) fraying of the free edge of the superior labrum
2) detachment of the superior labrum from the glenoid. Note that detachment indicates extension to the biceps anchor.
3) bucket-handle tear of the superior labrum.
4) bucket-handle tear extending into the LH of the biceps tendon

Note: A "bucket-handle" tear of the labrum is a full thickness tear, separating the labrum into medial and lateral components.

Just remember the important features of SLAP lesions:
1) labrum: detached or torn? If torn, partial thickness or bucket handle?
2) biceps anchor: torn? Not torn?

acute brachial neuritis, usually affecting the suprascapular, axillary, subscapularis, and long thoracic nerves

1) dorsal
2) middle

1) DISI (dorsal intercalated segmental instability)
2) SLAC (scapholunate advanced collapse)

1) VISI
2) TFC tear

1) scapholunate ligament
2) lunotriquetral ligament

acute brachial neuritis, usually affecting the suprascapular, axillary, subscapularis, and long thoracic nerves

1) dorsal
2) middle

1) DISI (dorsal intercalated segmental instability)
2) SLAC (scapholunate advanced collapse)

1) VISI
2) TFC tear

1) scapholunate ligament
2) lunotriquetral ligament

1) radioscaphocapitate
2) radiolunotriquetral

Part 2: radioscaphoid, radiolunate, and radiotriquetral

1) TFC
2) radioulnar ligaments (dorsal and volar)
3) extensor carpi ulnaris tendon sheath
4) ulnar collateral ligament
5) meniscus homologue

1) medial aspect of the ulnar styloid
2) lateral radial cartilage (emphasize "cartilage" and not "bone." Do not confuse high signal of cartilage with a tear.)

The RU ligaments attach directly to bone, while the TFC attaches to the cartilage (of the radius).

The UCL is found deep to the adductor aponeurosis

Tear and retraction of the UCL, which is displaced superficial to the adductor aponeurosis (switch places)

The Stener lesion.

The yoyo is the retracted UCL. The string is the adductor aponeurosis.

1) abductor pollicus longus, extensor pollicus brevis
2) extensor carpi radialis longus and brevis
3) extensor pollicus longus
4) extensor indicis and extensor digitorum
5) extensor digiti minimi
6) extensor carpi ulnaris

Between the 2nd and 3rd extensor component on the dorsal aspect of the radius

First

1) focal or segmental swelling of the median nerve
2) flattening or angulation of the median nerve at the distal carpal tunnel (level of the hook of the hamate)
3) bowing of the flexor retinaculum (increased bowing ratio)
4) increased T2 signal of the median nerve

median nerve

1) ulnar nerve, artery, and vein
2) flexor retinaculum, hypothenar musculature, pisiform, and hook of the hamate

bony proturberance on the dorsal aspect of the wrist, located at the base of the 2nd and 3rd metacarpals

1) proximal pole of the scaphoid
2) lunate

low T1 and T2

Remember, think PVNS.

1) ganglion cyst
2) Giant cell tumor of tendon sheath

1) high T2, low T1
2) intense enhancement
3) bony erosion
4) usually located on the dorsal aspect of the fingertip, beneath the nail

pisotriquetral synovial cyst

Plantaris tendon.

Don't confuse this for an Achilles tear!

1) Achilles tendon
2) extensor tendons of the hands

Triad of retro-Achilles bursitis, retro-calcaneal bursitis, and thickening of the Achilles tendon distally

AKA "pump bumps"

posterior tibial tendon

Tears can lead to flat foot. Tears are associated with sinus tarsi syndrome and abnormalities of the spring ligament. Tears are more common with accessory navicular bones.

navicular bone.

It also inserts onto all the cuneiforms and the 1st through 4th metatarsals, but can't really see this with MR.

flexor hallicus longus

flexor hallicus longus

1) identify a tear of the retinaculum
2) the tendons are located lateral to the distal fibula, instead of posterior to it

1) tibiotalar ligament
2) tibiocalcaneal ligament
3) talonavicular ligament
4) spring ligament (most medial)

posterior tibiofibular ligament

calcaneofibular ligament

Think: C is for calcaneofibular and coronal.

1) PTT
2) post tibial artery/vein
3) post tibial nerve
4) FHL tendon
5) flex digitorum tendon

chronic plantar digital nerve entrapment, leading to perineural fibrosis.

Usually found in and plantar to the metatarsal heads.

turf toe

(hyperdorsiflexion at the 1st MTP joint

1) high T2 signal surrounding the fragment
2) absent or displaced fragment
3) crack in the overlying cartilage
4) large subchondral cysts deep to the fragment

talus and calcaneus

1) lipoma
2) UBC
3) ABC
4) giant cell tumor
5) chondroblastoma

synovial sarcoma

1) enchondroma
2) giant cell tumor
3) chondroblastoma
4) mets
5) myeloma
6) chondrosarcoma

iliopsoas

amyloid arthropathy

Divided into intra-capsular and extra-capsular.

Intra-capsular:
1) subcapital
2) transcervical
3) basicervical

Inter-trochanteric are extra-capsular

1) proximal radioulnar jt
2) radiocapitellar jt
3) ulna (olecrenon) with the trochlea of the humerus

capitellum

Osteochondrosis of the capitellum, which occurs in throwers as a result of trauma.

Other info:
-5-10 yr olds
-No loose body formation (seen in an osteochondral lesion)
-diffuse low T1 and high T2 signal of the capitellum.

1) radial collateral ligament proper
2) lateral ulnar collateral ligament (most important)
3) annular ligament
4) accessory collateral ligament

Part 2: lateral epicondyle, deep to the common extensor tendon

1) anterior bundle (most important)
2) posterior bundle
3) transverse bundle

The anterior bundle originates at the medial epicondyle and inserts onto the medial coronoid process of the ulna.

1) radial tuberosity
2) brachialis muscle/tendon
3) bicipital aponeurosis
4) no

anconeus muscle is lateral, and arises from the lateral epicondyle, inserting onto the olecrenon

extensor carpi radialis brevis

1) anterior, posterior, medial, lateral

2) answers:
a) biceps -- anterior
b) triceps -- posterior
c) supinator -- lateral
d) anconeus -- posterior (and lateral)
e) brachialis -- anterior
f) pronator teres -- medial
g) common extensor -- lateral
h) common flexor -- medial
i) brachioradialis -- lateral

anterior interosseous nerve syndrome

Roof -- flexor carpi ulnaris aponeurosis
Floor -- ulnar collateral ligament and capsule

Ulnar nerve

thin aponeurotic band extending from the medial head of the triceps to the medial intermuscular septum.

Cause for ulnar neuropathy

1) 2

2) bucket handle tear, radial tear, medially flipped flap tear, and meniscal cyst

3) discoid meniscus

arthrofibrosis in Hoffa's fat pad after ACL reconstruction

Gerdy's tubercle of the tibia

1) LCL
2) arcuate ligament
3) popliteofibular ligament
4) popliteus tendon

Part 2: disruption of the joint capsule at the lateral joint line on axial imaging.

1) medial
2) suprapatellar
3) infrapatellar

1) non-weight bearing surface (lateral aspect) of the medial femoral condyle

2) spontaneous osteonecrosis of the knee, now known as insufficiency fx of knee, which occurs on medial side (wt bearing surface)

polio

dermatomyositis

macrodystrophia lipomatosa

1) sickle cell
2) osteopetrosis
3) Paget's
4) hypervitaminosis D