More Ortho 1/5/17 Flashcards
define acetabulum
confluence of ilium ischium pubis forming socket over femoral head
growth plate for the acetabulum
triradiate cartilage (confluence of ilium ischium pubis, at medial acetabulum)
also appositional growth at edges, increasing acetabular depth
if DDH goes untreated
chronic disloc sublux
shallow acetabulum
rsk oa as adult
innominate bones….
ilium ischium pubis
big hole made by the ischium and pubis
obturator forman
ligamentum teres
from acetabular fovea to femoral head fovea
contains artery of ligamentum teres (a branch of obturator artery)
delivers 10-20% blod flow to femoral head
hip analogue to knee meniscus
labrum
ligamentem teres aka
round ligament
largest sesamoid bone
patella
sesamoid bone = embedded in tendon
what kind of bone is the pisiform
sesamoid
(in tendon of flexor carpi ulnaris)
carpal
define moment
force applied for torque
moment = force * distance from fixed axis
function of sesamoid bone
inc distance from fixed a is for multiplication of force aka greater moment
moment = f x d from fixed axis
eg patella multiplies force exerted by quads
this bone is an embryologic metacarpal
trapezium
because thumb metacarpal acts more like proximal phalanx
describe a hole in bone
size
location
matrix (what fills hole)
margins
tf
periosteum is soft tissue
t
per delahay
how does cartilage appear on xr
speckled calcification
age of osteosarcoma
teens
also second spike in elderly from malignant transformation of paget’s disease
most common malignancies that go to bone
BLT and a Kosher Pickle
breast lung thyroid kidney prostate (then melanoma)
malignancies that rarely go to bone
ones that kill you quickly
-glioblastoma, pancreaqs, hepatocellular (liver), ovarian
hole in bone in pt over age 50 think…
metastatic until proven otherwise
prostate ca mets to bone osteoblastic or lytic?
osteoblastic
define “acral”
distal
distal to elbow, knees
nose, ears
acral bone met think…
Lung
or leukemia
(acral = distal to elbow, knees… nose, ears)
calcaneal fx is classic for what mechanism of injury
ladder inury
forefoot on ladder, dorsiflexed, heel hits first
calcaneous vs tibia
which is more trabecular/cancellous bone vs cortical
calcaneous trabecular/cancellous
tibia cortical
healing of bone has everything to do with…
blood supply duh
bones most common for non-union post fx
tibia
ulna
mostly cortical bone, little blood supply
(per delahay)
define “leg”
below the knee
“thigh” = above knee,
“lower leg” and “upper leg” are not ortho terms
per delahay
biggest complication of tibial fx
delayed / non-union
mostly cortical bone, little blood supply
tf
“talo-calcaneal joint” is a thing
f
“subtalar joint” is correct term
subtalar joint fx post-traumatic OA functional concern is…
inversion/eversion walking on uneven surfaces (beach)
4 types of (anatomic) cartilage
hyalin
fibro
elastic
physeal
DDH gender preference
female
rare in males
key mgmt step for 6yo w scfe
endocrine referral (eg for hypothyroidism and growth hormone deficiency, which can cause abnormal growth and mineralization of cartilage)
why do kids get greenstick and torus (buckle) fractures
cortex more porous w blood supply,
bone crunches instead of breaking like chalk
what differentiates intertrochanteric from femoral neck fx
intertrochanteric is extra-capsular
femoral neck is intra-capsular so hematoma intracapsular high pressure vascular compromise avn higher risk
tf
risk of death from hip fx = risk of death from breast cancer in 50yo women
t
what kind of elderly pts get total hip arthroplasties vs hemiarthroplasties for hip fx
short life span remaining - hemiarthroplasty ok (doesn’t last as long – wears native acetabulum, but don’t need it to last long
“active elderly” - sporty, active, will not tolerate slower recovery and limited activities of hemi as well, get total and back to stuff faster
vs arthritic elderly, not moving much prior to sx… will tolerate slower recovery better…
soft tissue tears to expect w shoulder dislocation
always come with a labral tear
^4yo likely to have rotator cuff tear as well
reduce a dislocated shoulder
milch - (supine or prone)hand on thoulder with thumb on humeral head, external rotation, abduct, use stabilizing thumb to push humeral head back into place
Hippocratic - supine, put heel in pt’s armpit while pulling arm inferiorly (watch our for axillary nerve inj)
stimson - prone hang weight off arm, leave them there, will spontaneously reduce
stimson - supine, abduct traction while rot int and ext to free, w counter traction provided with folded sheet under arpit pulled to opposite side by assistant
radiographic sign for posterior shoulder dislocation`
light bulb sign
mechanism of posterior shoulder dislocation
eg seizure, lightning strike,
internal rotators are much stronger than external rotators, so in seizure the arm internally rotates (decubitus?) and dislocates
trigger finger define epi associated conditions pres dx tx compx
stenosing tenosynovitis from inflammation of flexor tendon sheath (FDP FDS) (flexor tendon entrapment at level of A1 pulley - over MP joint - most often) w fibrocartilagenous metaplasia of tendon and pulley
diabetics, ring finger most common
DM RA amyloidosis
finger clicking, pain at distal palm (MP joint) near A1 pulley, locking in flexion, ttp over A1 pulley, palpable bump
clinical dx (no imaging required)
nonop splinting, act mod, nsaids… steroid injections..
operative surgical debridement and release of A1 pulley w/wo 1 slip of FDS
compx - radial digital nerve inj
carpal tunnel boundaries
scaphoid tubercle trapezium radially
hook of hamate pisiform ulnarly
proximal carpal row dorsally (floor)
transverse carpal ligament palmarly (roof)
contents of carpal tunnel
nine flexor tendons (FPL most radially, 4 fdp 5 fds)
median nerve
where is carpal tunnel narrowest
at hook of hamate
where to cut carpal tunnel in carpal tunnel release
far ulnar
to avoid cutting recurrent motor branch of median nerve if it is transligamentous (50% extraligamentous, 30% subilgamentous, 20% transligamentous)
carpal tunnel treatment
NSAIDs, night splints, activity modifications
steroid injections
carpal tunnel release
fracture displacement is described with respect to
the distal fragment
what is a spiral fracture
basically a long oblique
what is a segmental fracture
two fractures creating floating segment…?
borders of anterior compartment of leg
tib
sydnesmosis
fib
tib ant fascia
posterior tibial slope
define
function
tibia slopes 10 degrees downward posteriorly, posterior meniscus minimizes to about 3 degrees
to decrease shear force when knee in flexion and generating greater force (vs allowing some increased shear force when standing upright not generating extra force)
complications of high tibial osteotomy
recurrence of deformity loss of posterior slope patella baja compartment syndrome peroneal nerve palsy (more common w Lateral opening wedge osteotomy) malunion or nonunion
causes of patella baja after high tibial osteotomy
rasing of tibiofemoral joint after Opening wedge osteotomy
retropatellar scarring causing tendon contracture
indications for high tibial osteotomy
varus deformity more than valgus deformity
to redistribute weight bearing away from worn side
most common location of knee ocd
posterolateral medial femoral condyle
stap muscles of the neck
aka infrahyoid muscles, 4 pairs
sternothyroid (most medial, deep)
sternohyoid (overlaying sternothyroid and thyrohyoid)
omohyoids (just lateral)
thyrohyoid (superior to sternothyroid, deep to sternohyoid)
vertebral body level of
hyoid
thyroid cartilage
cricothyroid cartilage
C3
C4-C5
C6
why is left side typically preferred for ACDF anterior cervical discectomy and fusion
because course of recurrent laryngeal nerve more consistent
where are scalenes relative to strap muscles
lateral, similar plane
neck muscles superficial to deep
platysma
scm, traps
straps and scalenes deep to scm (and scalenes deep to traps too)
name 3 scalenes
anterior
middle
posterior
blood vessels to patch out for when dissecting the pretrachial fascia with straps retracted medially and scm retracted laterally
sup
mid
inf thyroid arteries
in pretracheal fascia anterior to C3 C5 C6 respectively
ascending location of left recurrent laryngeal nerve
in tracheoesophageal groove near midline (nearer than right recurrent laryngeal)
after curving around aortic arch
after branching from vagus
right recurrent laryngeal nerve curves around…
right subclavian artery
retract structures to perform ACDF anterior cervical discectomy
incise platysma
straps medial, scm lateral
dissect paratracheal fascia, watching out for sup mid and inf thyroid arteries
carotid sheath lateral, trach and esoph medial
elevate longus colli
describe longus colli muscles
crom c vertebral bodies (anteriorly) to other c or upper t vertebra
and c and upper t vertebral bodies to transverse processes
name ligament along posterior side of vertebral bodies, anterior to spinal cord
posterior longitudinal ligament
vertebral foramen vs intervertebral foramen
spinal cord vs roots
origins of superior and inferior thyroid arteries
sups - external corotids
infs - subclavians
how many xr planes to eval displacement
2 duh
tf
knee dislocation xr is a rare thing to see
t
should be
should be reduced immediately, don’t wait for xr
fracture patterns from lowest to highest energy
avulsion spiral transverse oblique comminuted/segmented
segond fx
avulsion fx of lateral tibial plateu (eg lcl) usually associated w ACL tear (w rotation and varus stress usually… not more common acl mechanism of valgus stress…)
define degloving
extensive section of skin torn off (a type of avulsion), severing blood supply
common sites of heterotopic ossification
in muscle “myositis ossificans”
brachialis - distal humerus fx
quadriceps - contusion
hip abductors - surgical dissection
grades of nerve injury
from high recovery rate
to low recovery rate
neuropraxia - physiologic disruption (stretch)
axonotmesis - axonal disruption, epineurium intact
neurotmesis - nerve transected
mechanism of buckle fx
compression
examples of people who get stress fxs
new military recruits
ballet dancers
anorexics
more…
salter-harris classification
of pediatric growth plate fractures
i - thru physis (parallel with)… that’s it… can’t see on acute xr, only mos later when…
II - thru physis out metaphysis (away from joint) * most common
III - thru physis out epiphysis into joint
IV - thru physis, metaphysis
V - thru physis only, like type I, but due to crush injury and causes growth arrest
define ganglion cyst
mucin-filled synovial cyst caused by…
- trauma
- mucoid degeneration
- synovial herniation
filled w fluid from tendon sheath or joint
no true epithelial lining
most common hand mass
ganglion cyst (65% of hand masses)
mucin-filled synovial cyst caused by…
- trauma
- mucoid degeneration
- synovial herniation
common locations of ganglion cysts of hand
and associated conditions
dorsal carpal 70% (scaphoid-lunate articulation)
volar carpal 20% (radiocarpal or scaphotrapezotrapezoidal articulations)… median or ulnar nerve compression, vascular occlusion hand ischemia
dorsal dip (mucous cyst assoc w heberden nodes… dip oa osteophytes
molecules in synovial fluid
include
hyaluronan secreted by synovial membrane cells
lubricin (a proteoglycan) secreted by chondrocytes of articular cartilage
interstitial fluid filtered from blood plasma
contents of carpal tunnel
9 or 10 tendons depending 4 flexor digitorum superficialis 4 flexor digitorum profundus flexor pollicus longus plus minus flexor carpi radialis - technically embedded in flexor retinaculum the roof of carpal tunnel but some consider part of contents
1 nerve, median nerve
visualize axial cut of wrist, contents of radial carpal tunnel around the horn to dorsal radial aspect
median nerve just radial and superficial to flexor digirotums in ct
flexor pollicus longus radial to that
flexor carpi radialis embedded in flexor retinaculim the roof of carpal tunnel
thenar muscle superficial to top tip of trapezium distally or scaphoid just proximal
abductuor pollicus longus tendon radial to trapezium/scaphoid, start snuff box
extensor pollicus brevis tendon just deep to that, basically perfectly lateral
cephalic vein slightly lateral to…
radial artery
extensor policus longus, end snuff box
extensor carpi radialis longus then brevis
directly inferior shoulder dislocation
how common
mechanism
rare
body surfer w hands extended over head crashing into sand
hill-sachs lesion
depression of posterolateral cortex of humeral head, from impaction against anteroinferior lenoid rim w anterior shoulder dislocation
-specific for anterior shoulder disloc so can be used to id past disloc… can be painful w clicking catching or popping
mechanism of knee dislocation
classically high velocity
low velocity becoming concerningly more prevalent with very obese
manage knee dislocation
propofol right away don't take no for an answer reduce it don't even wait for xrays popliteal artery an acute risk, and a hematoma can occlude late
multiple septic joints think…
gonococcal
rheumatic
septic jionts usually occur in isolation
most sensitive test for septic joint
pain w passive motion
what to do w aspirate of swollen painful joint
cell count
cx
crystals
to diff septic arthritis from crystalline…
common bugs in septic arthritis by hematogenous spread
staph a - skin lesions (cuts pimples eczema etc)
pseudomonas - diabetic foot wound… ivdu (but staph a still more common)
e.coli - older woman uti
joints w mataphysis partly in the joint…
4 shoulder hip elbow ankle...
tx infection in ortho
bug
succeptibility
right drug
right route…
crystal molecule in
gout
pseudogout
monosodium urate crystal deposition
CPPD calcium pyrophosphate dihydrate
tf
presence of uric acid crystals excludes septic arthritis
f
gout and septic arthritis commonly associated
define primary gout
idiopathic disorder of nucleic acid metabolism (inc purine breakdown product) leads to hyperuricemia and monosodium urate crystal deposition in joints
define secondary gout
disease w high metabolic turnover (psoriasis hemolytic anemia leukemia chemo)… inc purine breakdown product leads to hyperuricemia and monosodium urate crystal deposition in joints
presentation of gout
male 40-60yo lower limb (podagra - gouty arthritis attack of big toe), tophi in ear eyelid achilles etc
iatrogenic risk factor for gout
chemo
high metabolic turnover (psoriasis hemolytic anemia leukemia chemo)… inc purine breakdown product leads to hyperuricemia and monosodium urate crystal deposition in joints
gout pathophys
dysfunc nucleic acid metab (purine breakdown)… hyperuricemia… monosodium urate crystal deposition… inflammatory response activates proteases prostaglandins leukotriene b4 free ROS
conditions associated w gout
renal stones septic arthritis (presence of urate crystals does not exclude septic arthritis)
gouty arthritis sx… also check for…
kidney stone sx
what does gouty tophus aspirate look like
white toothpasteish
gout xr
pseudogout xr
ap and lateral views
punched out periarticular erosison w sclerotic overhanging borders
soft tissue crystal deposition (tophi)
chondrocalcinosis… calcification of fibrocartilage structures eg knee meniscus
tf
elevated blood uric acid is diagnostic of gout
f
80% of those elevated will never get gout
diagnose gout
aspirate - crystal analysis - thin tapered needle shaped intracellular strongly negatively birefringent crystals
elevated blood urate not diagnostic! 80% of those w elevated urate never get gout…
presentation of pseudogout
acute warm erythematous Monoarticular joint tenderness
knee or wrists usually
mimics gout except older pts (^60yo) affects more proximal joints (knees or wrists) POSitively birefringent crystals
loosely define tfcc
triangular fibrocartilage complex
composed of multiple ligaments and tendons at base of wrist
scoring criteria to predict risk that metastasis will cause pathologic fracture
mirel's criteria site upper vs lower vs peritrochanteric pain mild moderate functional lesion blastic mixed lytic size... 3 sizes...
score 1-3 for each
total ^8 recommend prophylactic fixation
when is total joint arthroplasty indicated
pain… subjective pain level and desire for total joint basically… per churchill
proposed mechanisms of aseptic implant loosening from bone
type 4 (delayed type hsn, cell-mediated cd4+ Th cells present mhc II to macs…) response to metal
innate inflammatory response to polyethylene
lurching vs vaulting gait
lurching shoulders move laterally
vaulting shoulders move up and down
do non-cement implants see aseptic loosing earlier or later than cement implants
non-cement loosen EARLY - once bone bonded/grown into pores etc it it pretty in there…
cement implants loosen later after inflammatory response erodes surrounding bone
xr views of ankle
ap lat mortis
triplane fracture
of peds distal tibia
epiphyseal fx in sagittal plane (seen on ap xr)
physis separated in axial plane
metaphysis fx in coronal plane (seen on lateral xr)
salter-harris type IV thru epiphysis physis diaphysis
from rotational force
usually older children in last 2 years of growth (12-14yo… physis closing cent med lat order), like tillaux fx
tillaux fracture
salter-harris III (physis epiphysis) of distal tibia
caused by avulsion of aitfl anterior inferior tibiofibular ligament… from external rotation force
usually older children in last 2 years of growth (12-14yo, physis closing cent med lat order), like triplane fx
manage femoral fracture
0-6mo - pavlic harness
7mo-5yo - spica.. or… flexinails if body habitus… obese?
5yo-11yo flexinail vs submuscular plate…. vs im nail via lateral troch entry if obese…
to check on exam in femoral shaft fx
fem neck
length rotation alignment
knee exam
lumbosacral motor roots on exam
hip flexors L2 knee extensors L3 ankle dorsiflexors L4L5 big toe extensor S1 ankle plantarflexion anal sphincter S4S5
6 types of spondylolisthesis
dysplastic isthmic degenerative traumatic pathologic iatrogenic
presence of degenerative disk on MRI in asymptomatic pop
34% age 20-39
93% age 60-80
(boden et al…weisel… 1991, 2001)
annulus
vs
nucleus pulposus
of intervertebral disc
types of collagen
annulus - type I collagen
nuc pulp - type II collagen
nerve endings in intervertebral disc?
only in outer annulus… not within disk itself…
