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