Recon Flashcards
what complication Is increased with quad sparing TKA
quad tendon laceration
tx of open wound over TKA patella tendon
rotational gastroc flap
which pcl fibers are usually tight for balancing
anterolateral bundle of PCL
anteromedial vs posteromedial OA
PM OA is seen with ACL incompetent knees
AAOS CPG grade for pharm/scd for vte propjhylaxis
MODERATE
fatigue wear shows as what on tibia poly
pitting and delamination
adhesive and abrasive wear on tibia poly is seen on
tibia BACKside
what image is needed before UKA
valgus stress to evaluate for correction AND lateral joint space
UKA vs TKA survivorship
lower for UKA at 10 years
what is consequence of patella baja in TKA
anterior knee pain
what does high Co ion ratio to Cr mean
trunionsis (vs MoM has EQUAL rise in ions)
what is head liner swap for ATLR
ceramic head with Ti sleeve
after femoral nerve block for TKA make sure to use
Knee immobilizer
osteotomy for early OA
if valus -distal femur; if varus - prox tibia
requirements for distal femoral osteotomy for valgus
12-15valgus and at least 15-90 motion
tibia periprosthetic frx classification
type 1 - plateau; type 2 next to stem, type 3 is distal to stem - A is well fixed, B -loose. Type 4 is tubercle, C is intra-op
complication of navigation TKA
femoral shaft fracture from array pins
what is protocol for tib tubercle osteotomy for TKA
WBAT and ROM as tolerated
risk factor for failure of cementless femoral stem
osteoporosis
main risk of radiation to cementless surgery
poor ingrowth
tx of nondisplaced GT fracture
PWB 4-6 weeks
osteonecrosis of femoral head -ok to resurface?
only if < 40% involved; avoid for large femoral head lesions
tx of charcot knee in poor candidate
amputation; even knee fusion is not best option
what size micron for histiocytic response in osteolysis
SUBMICRON .1-1micron
when was tranistion to high cross link Poly
2001-2002
which conditions do you avoid pharamcologic dvt ppx
Acute liver disease and hemophiia
excess femoral flexion in PS knee leads too
cam-post impingment and wear of the post
most important factor for stress sheilding
poor bone quality
major and minor criteria for PJI
major - draining sinus, 2 positive cultures same org; minor - high SYNOVIAL WBC, high PMN percentage; high ESR/CRP; high WBC on HPF frozen, SINGLE positive culture
MSIS infection if how many criteria are met
1 major or 3/5 minor
what is considered acute time frame for TKA, THA
6 weeks for PJI; use CRP cut off of 100 or Synovial WBC > 10k; ESR does not have a number
what is at risk with antermedial hip approach
obturator artery
nitrogen containing bisphos
alendranate - farnesyl transferase
early failure of cementeless TKA look for
aspetic loosening
patellar fracture with TKA and extensor lag
do NOT ORIF patella - revise it all
early acetab loosening seen with which liner
OFFSET liner; NOT constrained
tx of uncontained prox tibia defects
tantalum cones
innervation of sup and inf gluteal nerves
inf gluteal coveres Glut MAX; sup glut covers medius and minimus
cell count in setting of metallosis
needs a manual count - automated can be high bc particles seen as cells
which paprosky is most common in revision THA
IIIA - exntesnive proximal and diaphyseal bone loss BUT with > 4cm diaphysis left
acute tka pji cuttoff
30000 for acute (6 weeks)
timing of etanercept
stop 1 week before and resume 2 weeks after
best recommendatio for knee OA
tramadol
does popliteus affect static knee balance
NO
alpha defensin is test from what fluid
SYNOVIAL -not a serum test
paprosky acetab classification
I - minimal bone loss; II is 2cm or less, III is more than 3cm bone loss/hip migration
patients in 80s have lower femoral fracture risk with
cemented stem
how much acetab can be uncovered in THA
30-40% before worrying about aseptic loosening
how much deformity can you correct in TKA via bone cuts
10-20 coronal, up to 20 sagittal
tha revision with discontinuitiy tx with
CAGE or triflange - no allograft
risk factors for patella clunk
valgus; PS knees; smaller patellar component; large increased posterior condyle offset (Smaller femurs; fixed flexion femurs or thick Poly can also contribute)
line for acetab quadrants
ASIS to ischial tuberosit is first line then 90 deg perpendicular
what is modified Kerboul method
combined coronal and mid sag angle < 190 no collapse; moderate risk in 190-240; and > 240 collapse
acetab frx with THA cup. - what next
orif and revise cup
what is tx of intraop MCL injury
repair and BRACE - do NOT switch to PS
post capsule repair for dislocations
failure of repair leads to increased disocation rate up to 6.4%
what positivity rate of bone scan after TKA
20% at 1 y; 12% at 2y - thus lots of false positives
what is benefit of spinal anesthesia for EBL
lower EBL with hypotensive spinal anesthesia
tx of local injection induced asystole
20% fat emulsion
when to use jumbo cup in revision hip
if > 50% bone left and no major bone loss; other wise use augments; if discontinuity then go to cup cage or triflange
tx of late instability from abductor damage
revision to constrained liner
tx of scarred patella in revision setting
lateral release; can also consider Tib tubercle osteotomy?
zirconia head in tha means
monoclinc phase transformation - look for osteolysis
all poly tibia rate of loosening
same as regular tibia
absolute indication for patellar resurfacing
RhA
metal on metal revision
must revise acetab component, cannot just put a new poly liner in
does head size affect THA wear rate
NO 22-46mm has no diff in wear rate
best predictor of pain from fem head AVN
bone marrow edema
what is benzoyl peroxide
initiator in polymer powder (polymethylmethacrylate)
approach with highes HO
extended illioFEMORAL
what is Q ankle
ASIS to patella to TT
center of knee rotation in flexion
shifts posterior on the LATERAL side with flexion
bone scan to identify aseptic loosening
good after 2-3 years look for WHERE the activitiy is - even with long stem can be metaphyseal problem
most common causes of charnley reviion
acetab, both component, deep infection, femoral
reasons to do tib tubercle osteotomy in revision tka
patella baja
what causes debris to spread into increased joint space
inflamation leads to increased hydrostatic pressure which pushses debris
what are the ways to get pincer FAI
overcoerage OR retroversion
what is PJI risk and RHA
higher risk; and RhA has higher risk of LATE pji
before total joint in RhA what else is needed
c=spine flex/ex views
what is double density on MRI for femoral head osteoN
revasc and new bone formation
what position is THA cup in anky spondy patietns
more horizontal and less anteverted to avoid ANTERIOR hip dislocation
moA of TXA
TXA binds to lysine binding site on plasminogen and renders it inactive
what TKA design to be used in Rheumatoids
any design is acceptable
key demogrpahic difference between Acetab dysplasia vs DDH
DDH is more common in Females; left Hip; Breech; bilateral, more likely to have first order family members with DDH
do you need bone scan for stem loosening
NO if clinical and XR lines up - go ahead and revise
what is insertion of glut med and glut minimus
G. medius is superoposterior and lateral facet with bald spot between medius and minimus
how much subsidenc is allowed in femur
up to 1cm before you must revise
medial opening vs lateral closing HTO
less pain, more ROM, more satisfaction, better union with LATERAL CLOSING
does cup position affect offset
NO - hip center medial/lateral DOES NOT affect of femur
moving cup medial does what
decreases joint reactive forces and abductor forces
LMWH vs warfarin
LMWH is a/w more bleeding at surgery site with equal rates of PE prevention and LOWER rate of asymptomatic DVT
evidence on steroid injection for knee OA
INCONCLUSIVE
ceramic head hitting metal is what type of wear
adhesive
adhesive wear is when
two diff metals where one adheres on to the other
Vit k dependent clotting factor
2,7,9 10
when to use constrained liner
ONLY if components are in solid position; if not then those MUST be revised first
avg ROM gained with MUA
37deg; no diff at 6 vs 12 weeks
PAO for middle age
good option for early OA in patients with preserved joint space
what lab values are higher risk for wound complications
Zinc< 95; Albumin< 3.5; WBC < 1500
TKA after Tib Plateau outcomes
similar satisfaction and PR-outcomes but higher complication
order of complication frequency after TKA
infection, aseptic loosening, instablity, poly wear; arthrofibrosis and malalignment
one complication after THA conversion from IMN
higher dislocation
nv injury with knee dislocaiton
ultra low and high velocity have same rate (40%) but low velocity is lower around 5-10%
what are risk factors for peroneal nn injury in TKA
flexionand valgus; OR if previous HTO - choose this one
what timeframe for surgical site infection if implants
365days
decreased abduction of acetabular cup leads to
NO difference in wear rate or dislocation rate, may reduce ROM
mrsa nasal colonization risk factors
black, male, — females and older age are reduce risk
when does VTE happen post-op total joint
1week to 6 weeks post-op
PCL retaining TKA principles
choose same size femur to match AP size; take least amount of tibia to keep joint line; tension and balance via soft tissue not bone; avoid distal femur cuts
highest risk factor for dislocation after surgery
previous hip surgery
before selecting hip scope look for
dysplasia on Xray including cross over sign
osteyltic defect management
other than liner exchange - need to debride and possible bone graft defects IF components are stable
m/c complication after revision for MoM hip
instablity due to abductor damage - in which case may need to consider constrianed liner
rate of intra-op tibia fracture with long stem revision TKA
3-5%; most are treated non-op
tissue finding in MoM tissue reaction
lymphocytes AND plasma cells
high cell count, normal ESR/CRP, no eccentric wear
think trunionsis causing metal reaction and pseudotumor - needs head/liner exchange
risk factors for failure of MoM
female; young age ; small components and DDH as diagnosis for OA
cuting post obique ligament helps balance knee how
extension tightness
obese tja vs non-obese
similar change in clinical function and satisfaction; but obese is overall lower clinical scores compared to controls
before confirming dysplasia check for
proper AP; up to 9 deg of inclination can result in cross over sign, post wall signs, or ischial spine signs
patellar clunk syndrome prevention and tx
prevention involves taking synovial fold above patella; using a CR knee. Tx is arthroscopic resection; does not recur
after THA foot turns out
stem is RETROverted
CPG for normal risk pts after TJA dvt prophylaxis
MODERAT strenght recommendation
standard THA neck angle
131 degrees
bisphos fractures
treat right away - no other work up needed
tx of fixed varus deformity during tka
start with medial soft tissue release - including MCL
half life of apixaban
12 hours
what other artery supplies femoral head
inf gluteal artery supply retinacular vessles
what is main nerve at risk at level of anterior Ankle
medial branch SPN - NOT the DPN
CPM and Drain for TKA what are CPG
STRONGLY AGAINST
CPG for periarticular injection
strong evidence FOR
gait mechanics direct anteior vs posterior
same at 3 months
why does screw home mechanism occur in tibia
external rotation bc medial tib plateuea is LONGER
what is wear rate of NON cross link UHMWPE
0.1-0.2; >0.1 is a/w loosening
factors that reduce mechanical properties of X-link HMWPE
thickness < 6mm; malalignment, patients< 50; men; higher activity
MoM vs Poly wear - what cells invovled
MoM -lymphocytes, poly - macrophage
when to stop DMARDS before REVISION for PJI
4-6 weeks
