Hip and knee board review
Transcript of Hip and knee board review
Hip and knee board review
Richard Crank DO, FAOA
Lakeland Regional Health
No disclosures
Resources
Miller review
AAOS comprehensive review
Femoral Acetabular Impingement
Alpha angle
>42º=FAI
Center edge angle
<25º abnormal
Tonnis Angle
0-10º normal
FAI
Cam
Incidence 50% in athletes
Pincer
OA occurs by contact of labrum and bone and leads to cartilage delamination
Evaluate FAI- order an xray
Look for coxa profunda-floor is medial to ilioischial line
Protrusio-head is medial to ilioischial line
Cross over sign=retroversion acetabulum
TX FAI:
<35, activity modification, NSAIDs, INJ
NEVER REMOVE the labrum: detach and fix
POOR outcome: older age female, low BMI, full thickness cartilage defect
DDH
DDH
Issue of undercoverage and labral pathology
Associated with early OA
NEVER REMOVE THE Labrum
TX:
<35, No OA, normal round head, restoration of acetabular coverage on maximum abduction xray, preservation of joint space
Bernese Periacetabular osteotomy-Ganz:
Bernese Periacetabular osteotomy-Ganz: improves acetabular coverage
Abducts acetabulum, medialization of hip center, retroversion of the socket, LEAVES INTACT posterior column
IT IS OK for vaginal child birth after
THA:
Prepare for anteverted femur, small acetabulum, acetabular bone defects (ant/sup and sup/lat), posterior trochanter, small femoral canal
PLACE socket in true acetabulum, not high
Correct femoral version
Femoral shortening osteotomy
Corrects version, corrects trochanter position, protects sciatic nerve from lengthening
Ostenecrosis
ON
Crescent sign=impending collapse
Look at the other hip
MRI most sensitive test
Tx depends on age, underlying diagnosis, extent of ON
IF combined alpha angle on coronal and sagittal xray >200 THEN POOR outcome if non-arthroplasty treatment
If collapse >2mm, poor outcome with non-arthroplasty
If acetabulum involved=DUE arthroplasty
PRECOLLAPSE Tx:
Core decompression with/without bone graft
Postcollapse: THA no matter what age
TRANSIENT Osteoporosis of the
femur
DDX for ON
Transient osteoporosis of the femur
Typical question: 37y/o female
with 3 month hx of severe hip pain
Workup:
Oder the MRI, it will differentiate
from ON
Most common
Women 3rd trimester
Males 5-6 decade
TX: NON SURGICAL
OA
Arthroplasty: be conservative
Severe intractable pain for more
than 3 months
Wt loss, activity modification,
NSAIDs,
Steriod injection within 3-6 months
of surgery increases risk for
infection
FUSION of the hip
Incidence is most common for
exam answer
Most appropriate for septic hip
30º flexion, 0-5º ER, 0-10º ABD
APPROACHES
DA: learning curve
Interval: Sartorius/TFL
Danger: LFCN, LF circumflex art
POST:
Interval: glut max/med, TFL
Danger: sciatic nerve
Higher dislocation
REDUCE by: POST CAPSULAR
REPAIR, larger head
Watson-Jones:
Interval: TFL/Glut med
Danger: femoral nerve, Sup glut
nerve, LF circumflex art
Direct lateral:
Interval: glut med/vast lateralis
Danger: sup glut nerve
PROLONGED LIMP
Acetabular component
USE UNCEMENTED
Failure is due to poly wear and
osteolysis in CONVENTIONAL poly
POSITION:
40/20
Safe zone for screws
POST/SUP and POST/INF
KNOW structures in zone of injury
Femoral Component
Cemented have good outcome
and survivorship
Any pre-coated stem worse
survivorship with cement
Uncemented
Tapered or diaphyseal both good
Trunionosis: think about problem
with titanium stem and
cobalt/chrome head
Modular Neck:
Better control version, offset, length
Problems: fracture, fretting,
corrosion
Polyethylene
Highly cross linked= decrease
wear and lysis
Vitamin E might decrease
osteolysis ?? Cost effective
POSITION OF COMPONENTS IS
IMPORTANT
Vertical is bad= higher wear
Re-melting: REMOVES free
radicals; REDUCES mechanical
properties
Annealing: LEAVES free radicals;
MAINTAINS mechanical properties
Other bearings
Ceramic- decrease wear ?? Cost
MOM- higher failure than other bearing option
Larger head with MOM THA=higher failure
Higher revision in older patient
w/u painful MOM hip: NORMAL w/u first (infection, loosening)
Ions: They will give very high numbers in the question
Advanced imaging: U/S, MARS
Pseudotumor: LYMPHOCYTE, PLASMA CELL
OTHER HOT HIP TOPICS Readmission 3.5-5.5% 30 day, 7% day
Risk factors fair game
Length of stay, SNF, gen anesthesia, blood transfusion
Intraoperative fracture: cable and stable; DO NOT change post op rehab protocol
LINER EXCHANGE only for well fixed, well positioned components with a GOOD tract record
Iliopsoas tendonitis:
Cause: large head, cup protrusion
Tx: conservative
Revise mal-positioned components
Tenotomy ONLY if good position components
HO:
NSAIDs are ONLY for prophylaxis
If treating HO: excision and single dose radiation
Hip resurfacing
“Bone Conserving”
More acetabular bone loss, less
femoral bone loss
PROBLEMS:
MOM problems
Femoral neck fracture
High revision in women and
younger patients
INVERSE relationship between
head size and revision
Bigger heads better (NOT TRUE FOR
MOM THA)
Revision hip
REVISE MALPOSITIONED
COMPONENTS ON TEST
Look at leg length, impingement,
offset
DUAL MOBILITY: it decreases
instability for those RESIVED for
instability
Problem: intra-prosthetic
dislocation
CONSTRAINED liner only if
DEFICIENT abductor AND well
positioned components
Paprosky acetabular
I -hemispherical shell
IIa –
column intact: hemispherical shell
>50% uncovered augment to bring
cup down
IIb – sup lysis, up and out; sup/lat
Column intact: metal augment,
jumbo cup, high hip center
placement
IIc – medial defect; tear drop
gone, ischium intact
Hemispherical cup, RARE cage
IIIa – UP UP/ out; >3cm up, ischial
lysis
Augment, cup, cup/cage
IIIb – BAD; UP UP/in;
DISCONTINUTIY
Cage, triphlange, multiple
augments
Paprosky
Paprosky femoral
I – regular stem
II – metaphyseal loss
Fully porous coated or tapered Wagner
IIIa – metadiaphyseal loss
same stem
IIIb - <4cm scratch fit
Wagner, fully porous coated, PFR, Allograft composite
IV – massive loss
Impaction grafting, PFR, allograft
Vancouver classification
Vancouver classification
A- treat osteolysis
B1- well fixed stem, protection/ stabilize
B2,3 – revise
C - ORIF
Knee OA
Wt loss, activity modification, inj
SCOPE is NOT answer for test
Osteotomy
<60, single compartment, good
motion, NO flexion contracture,
NO inflammatory
Closing: need fibular osteotomy,
LOSS post slope
Opening: higher nonunion rate,
slope maintained
UKA
Lower long term survivorship in
most cases compared tka
Lower short term complications
compared to tka
Singe compartment disease only
never inflammatory
Failure: loosening, OA progression,
PF instability
TKA
Cemented survivorship better than
uncemented
All other outcomes same, CR, PS,
patella resurface or not
There is a higher risk of revision with
patellar resurfacing
If you revise for pain to resurface
the patella ONLY 50% get better
Gap balance
Coronal balancing
Osteophytes
Varus deformity: Medial release
Deep MCL
Post medial corner with
semimembranosus
Pes
PCL
Valgus deformity: lateral release
Osteophytes
IT band if tight in extension
Popliteus if tight in flexion
LCL
RELEASE THE CONCAVE side
tka
CAS increased outliers
Patient specific blocks decrease in
outliers
If cut MCL, INCREASE constraint
and repair
Patellar tracking: ER femur, ER
tibia, lateralize femoral
component, medialize patellar
component
Extensor mechanism disruption:
Acute: repair and augment with
hamstring autograft
Chronic: allograft/mesh THEY ALL
DO BAD, infection, lag
Arthrofibrosis: MUA < 12 weeks
Patellar clunk: occurs 45-30º flexion
ARTHROSCOPIC DEBRIDEMENT
tka
Nerve injury most common with
valgus knee and flexion
contracture
Peroneal nerve
Tx: remove dressing and flex knee
Popliteal artery is posterolateral to
PCL
Dx EARLY
Dx late: poor outcome
Patella fracture
Conservative tx do best
UNLESS: implant loose or ext mech
disruption, must fix POOR outcome
Knee revision
BMI >40:
decreased survivorship, increased
lucent lines, higher failure
Decreased functional scores but
have a higher delta
R/O hip cause for painful TKA
Causes: aseptic loosening,
instability, infection
POLY change is NEVER the answer
(unless says “what not to do”)
Stem fixation: hybrid stems must
engage diaphysis otherwise high
failure
Can retain patella if not oxidized,
well positioned, well fixed
Knee revision
Periprosthetic fracture:
Know the bone quality
Frx displacement
Implant stable
Fix vs revise
Infection
Major criteria
Sinus tract
2 positive cultures
Alpha defensin
High sensitivity/specificity
Adjunct only
UKA numbers
ESR 25
CRP 17
WBC 6500
PMN 72%
infection
Risks: malnutrition, smoking,
uncontrolled DM, BMI > 40
MRSA screening decreases
incidence of infection
Antibiotics preop
Ancef or Clinda < 1 hour
Vanc - 2 hours before
ONLY FOR: MRSA carrier, region
with high MRSA, institutionalized,
health care workers
MOM must have manual cell
count because machine will count
particles
Wound drainage for 5-7 days:
Get labs
Aspirate
Washout deep space: open fascia
Due I&D early: < 3 weeks from
surgery or acute hematogenous
infection
1 stage:
Must know organism
No soft tissue deficit; sinus tract
Not a poor host
Not for resistant organism
2 stage: gold standard
Infection
Early: staph
Late: staph epi, strep veridans, P.
Acne
Other points
Tranexemic acid decreases blood
loss: all forms (oral, iv, topical)
VTE prophylaxis
Healthy: ASA
Everyone else with risk factors:
something stronger
SCD for everyone in perioperative
period
GOOD LUCK