MSK Crack the Core Flashcards
Healing time for bones (general)
6-8 weeks
Slowest and fastest bones to heal?
slowest: tibia (3 months)
fastest: phalanges (3 weeks)
which band of scapholunate ligament is most important for carpal stability
dorsal
which band of lunotriquetal ligament is most important for carpal stability?
volar
from least to most severe, what are the types of carpal dislocations?
1) Scapholunate dissociation
2) perilunate dislocation
3) midcarpal dislocation
4) lunate dislocation
Space of poirier
ligament free area in the wrist; between the greater and lesser arc
DISI
dorsal intercalated segmental instability; occurs after radial sided injury and the lunate tends to rock dorsally; more common than VISI
VISI
volar intercalated segmental instability; occurs from ulnar sided injury (lunotriquetral side); disruption of T-L ligment –> lunate gets ripped volar with the scaphoid
what tendon’s causes dorsolateral dislocation in a Bennett Fracture?
abductor pollicis longus (APL)
What is a Stener lesion?
when the adductor pollicis tendon gets caught in torn edges of the ulnar collateral ligament in the setting of an avulsion fracture of the UCL at the base of the proximal 1st phalanx (Gamekeeper’s or skier’s thumb)
Colles Fracture
fracture of distal radius with dorsal angulation; ulnar styloid commonly associated; old ladies
Smith Fracture
fracture of distal radius with volar angulation; ulnar styloid commonly associated; younger patient
Barton Fracture
radial rim fracture; volar or dorsal but volar is more common; radial-carpal dislocation is hallmark; typically surgical
What tendon is associated with the TFCC?
extensor carpi ulnaris (compartment 6)
Monteggia fracture
proximal ulnar fx with anterior radial head dislocation
galeazzi fracture
radial shaft fx with dislocation of ulnar at the DRUJ
Essex-Lopresti
radial head fracture and anterior dislocation with anterior dislocation of the distal radial ulnar joint (DRUJ); unstable; with rupture of interosseous membrane
most common causes of cubital tunnel syndrom
1) repetitive valgus stress
2) accessory anconeus epitrochlearis (on medial side)
what is Osborne’s ligament
aka epicondylo-olecranon ligament; the site where the ulnar nerve passes beneath the cubital tunnel retinaculum
tillaux fracture
salter harris 3 fracture of distal tibial epiphysis in the anterolateral aspect; occurs in adolescents because the distal tibial growth plate closes from medial to lateral
High risk stress fractures
lateral femoral neck; anterior tibial; 5th metatarsal; transverse patellar; navicular; sesamoids of great toe
talus
Low risk stress fractures
medial femoral neck; posteromedial tibia; 2nd and 3rd metatarsals; calcaneus; longitudinal patellar
Kohler’s disease
osteonecrosis of navicular; more common in boys; tx is not surgical
Freiberg’s disease
AVN of head of 2nd metatarsal - more common in girls
Sever’s disease
osteonecrosis of the calcaneal apophysis
Panner’s disease
osteonecrosis of the capitellum; kids 5-10; no loose bodies
Scheuermann’s disease
osteonecrosis of the thoracic spine, resulting in kyphosis (3 adjacent levels with wedging + thoracic kyphosis of > 40 degrees)
dequervain’s tenosynovitis
inflammation of the 1st extensor compartment - extensor pollicis brevis and abductor pollicis longus
intersection syndrome
occurs where 1st extensor compartment crosses over the 2nd; affects the extensor carpi radialis longus and previs
Buford complex
absent anterior/superior labrum with thickened middle glenohumeral ligmaent; labral tear mimic
sublabral foramen
unattached portion of labrum from 1 to 3 o’clock; mimics SLAP tear; should not extend below 3 o’clock (horizontal)
What are the types of Bankart lesions?
GLAD, Perthes, ALPSA, cartiagineous, osseous
GLAD
Glenolabral Articular disruption; most mild version; superficial anterior inferior labral tear with associated articular cartilge damage; no instability
Perthes
detachment of anterior inferior labrum (3-6 o’clock) with medially stripped but intact periosteum
ALPSA
Anterior labral periosteal sleeve avulsion; medially displaced labroligamentous complex with absence of the labrum on the glenoid rim; intact periosteum
True bankart
cartilagenous or osseous; periosteum is disrupted
What are the types of reverse bankart lesions?
reverse osseous; POLPSA; bennett lesion, Kim’s lesion
Reverse osseous bankart
fracture of posterior inferior rim of glenoid
POLPSA
posterior labrum and posterior scapular periosteum are stripped from glenoid, resulting in a recess that communicates with the joint space; periosteum remains intact
Bennett lesion:
extra-articular curvilinear calcification associated with posterior labral tears; related to injury of posterior band of the inferior glenohumeral ligament
Kim’s lesion
incompletely avulsed/flattened/mashed posteiror-inferior labrum; glenoid cartilage and posterior labrum relationship is preserved
HAGL
Humeral avulsion glenohumeral ligament; non bankart lesion; avulsion of inferior glenohumerla ligament, often results from anterior shoudler dislocation; J sign - normal U shaped inferior glenohumeral recess is retracted away from the humerus and looks like a J
What muscle is atrophied in quadrilateral space syndrome?
teres minor (From compression of axillary nerve)
Parsonage Turner syndrome
idiopathic involvement of brachial plexus; pathology in 2 or more nerve distributions
Master Knot of Henry
where the flexor digitorum longus and flexor hallucis longus cross at the medial ankle
Most common location for Morton’s neuroma
between 3rd and 4th metatarsal heads
features of TB in the spine
- spares disc space
- multi level skip involvement
- large paraspinal abscess
- calcified psoas abscess
- gibbus deformity - destructive kyphosis
mimic for TB in the spine
Brucellosis
what are rice bodies
sloughed, infarcted synovium; seen in end stage RA and TB infection
Tuberculosis dactylitis
kids > adults
- involves short tubular bones of hands and feet
- diaphyseal expansile lesion with soft tissue swelling
Factors favoring low grade chondrosarcoma over enchondroma
- pain
- cortical destruction
- scalloping of > 2/3 of cortex
> 5 cm in size - changing matrix
what is X-18 translocation associated with?
synovial sarcoma
Mazabraud syndrome
- polyostotic fibrous dysplasia
- multiple softi tissue myxomas (T2 bright, T1 darker than muscle)
Don’t touch bone lesions
- myositis ossificans
- cortical desmoid
- synovial herniation pit
- avulsion injury
3 classic appearances of EG in a kid
1) vertebra plana
2) lucent skull lesion with beveld edge
3) Floating tooth - lytic lesion in alveolar ridge of mandible
Jaffe Campanacci syndrome
- multiple NOFs
- cafe au lait spots
- cardiac malforamtions
- hypogonadism
- mental retardation
POEMS
- myeloma with slcerotic mets; rare
- plasma cell proliferation, neuropathy, and organomegaly
Trevor’s disease
multiple osteochondromas developing in the epiphyses
- aka dysplasia epiphysealis hemimelica
differential for tibial bowing
- NF-1: anterior; hypoplastic fibula with pseudoarthrosis
- Physiologic: lateral; 18 months - 2 years
- Rickets: lateral
- Hypophosphatasi: lateral; rickets in a new born
- blount’s disase - tibia vara in a fat black kid; associated with early walking
- Osteogenesis imperfcta
- dwarfism
Felty syndrome
RA for > 10 years
splenomegaly
neutropenia
CPPD locations
- TFCC
- peri-odontoid tissue and intervertebral discs
- shoulder
- elbow
- patellofemoral joint
- radiocarpal joint
Milwaukee Shoulder
- apocalyptic destruction of shoulder due to hydroxyapatite
- occurs in old women with history of trauma to the joint
- similar to neuropathic destruction
SLE arthritis
- reducible ulnar subluxations at the MCPs on Norgaard view; reduce on AP view
- NO articular erosions
- SLE also predisposes to patellar dislocations
Jaccoud’s arthropathy
similar to SLE in the hand
- ulnar deviation of 2nd - 5th fingers at MCP
- non erosive
history of rheumatic fever
red marrow –> yellow marrow conversion order
- extremities –> axial skeleton (hands/feet first)
- epiphyses/apophyses –> diaphysis –> distal metaphysis –> proximal metaphysios
Normal red marrow variants
- proximal femoral metaphysis - teenagers
- distal femoral metaphysis - teenagers + menstruating women
best sequence for determining Active Paget’s vs. malignant transformation
- T1 pre-con
- both will be T2 bright and enhance
Chloroma
granulocytic sarcoma; destructive mass in a bone of a patient with leukemia
Engelmann’s disease
progressive diaphyseal dysplasia (PDD); fusiform bony enlargement with sclerosis of the long bones
Bone findings in thalassemia
- hair on end skulls
- expansion of facial bones
- expanded ribs
- extramedullary hematopoisis
- obliterates sinuses (vs. sickle cell)
