Hip and knee board review - PowerPoint Presentation

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Hip and knee board review

Richard Crank DO, FAOALakeland Regional Health

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No disclosures

ResourcesMiller reviewAAOS comprehensive review

Orthobullets

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Femoral Acetabular Impingement

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Alpha angle

>42º=FAI

Center edge angle

<25º abnormal

Tonnis

Angle

0-10º normal

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FAI

CamIncidence 50% in athletesPincer

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 acetabulumTX FAI:<35, activity modification, NSAIDs, INJ

NEVER REMOVE the labrum: detach and fix

POOR outcome: older age female, low BMI, full thickness cartilage defect

Slide8

A 26-year-old male reports persistent activity-related right hip pain. His radiograph is shown in Figure A. After failing a trial of conservative treatment, he undergoes hip arthroscopy. What findings would you expect to see during this procedure?

1 Posteriorly oriented acetabulum and anterosuperior labral tearing

2 Non-hemispherical acetabulum and hypertrophic labrum

3 Non-spherical femoral head and anterosuperior chondral-labral separation

4 Tense iliopsoas tendon and anterior labral tearing

5 Anterosuperior articular cartilage flap of femoral head and hemarthrosis

3

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A 25-year-old female presents with complaints of persistent left hip pain. A pelvic radiograph series demonstrates a lateral center edge angle of 16 degrees, a vertical center anterior margin angle of 18 degrees, a

Tonnis

angle of 15 degrees, a neck-shaft angle of 132 degrees, and a femoral alpha angle of 38 degrees. Magnetic resonance arthrogram demonstrates a degenerative superolateral labral tear with no lesions of the articular cartilage. What is the most appropriate surgical intervention for this patient?

1 Surgical hip dislocation with

femoroacetabular

osteoplasty and labral repair

2 Proximal femoral osteotomy

3 Salter innominate osteotomy

4 Bernese periacetabular osteotomy

5 Total hip arthroplasty

4

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DDH

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DDH

Issue of under coverage and labral pathologyAssociated 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

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Risk factors for a motor nerve palsy following primary total hip arthroplasty

include all of the following EXCEPT?

1 Developmental dysplasia of the hip

2 Limb lengthening

3 Posttraumatic arthritis

4 Obesity

5 Posterior approach

4

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The preoperative radiograph of a 45-year-old woman who is considering total hip arthroplasty with her

orthopaedic

surgeon.

What femoral characteristic is a typical concern in this patient?

1 Osteopenia

2 Excessive anteversion

3 Excessive

varus

4 Excessive bowing

5 Stove-pipe femur

2

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Osteonecrosis

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ON

Crescent sign=impending collapseLook at the other hipMRI 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

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MR image of a 38-year-old male with persistent hip pain.

What is this patient's

Kerboul

angle measurement and corresponding risk for progression to future femoral head collapse?

1 126 degrees; severe risk

2 94 degrees; moderate risk

3 32 degrees; moderate risk

4 230 degrees; severe risk

5 220 degrees; moderate risk

5

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TRANSIENT Osteoporosis of the femur

DDX for ON

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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 3

rd

trimester

Males 5-6 decade

TX: NON SURGICAL

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A 58-year-old man has had groin pain for the past 3 months. The patient reports pain with ambulation and at rest. Examination reveals an antalgic gait and range of motion is mildly restricted. He denies any history of trauma, or steroid or alcohol abuse. Radiographs are normal. An MRI scan is shown in Figure 77.

What is the most appropriate management?

1 Protected weight bearing and anti-inflammatory drugs

2 Total hip arthroplasty

3 Intraosseous steroid injection

4 A vascularized fibula graft to the femoral head

5 Core decompression of the femoral head

1

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OA

Arthroplasty: be conservativeSevere intractable pain for more than 3 monthsWt

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

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APPROACHES

DA: learning curveInterval: Sartorius/TFLDanger: 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

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A 61-year-old man with left hip OA presents to clinic for persistent left hip pain despite a trial of conservative therapy. The decision is made to proceed with total hip arthroplasty via a direct anterior approach. Which of the following correctly describes the superficial

internervous

plane of this approach?

1 Rectus femoris (femoral n.) & tensor fascia

lata

(superior gluteal n.)

2 Tensor fascia

lata

(femoral n.) & sartorius (superior gluteal n.)

3 Rectus femoris (femoral n.) & gluteus

medius

(superior gluteal n.)

4 Sartorius (femoral n.) & gluteus

medius

(superior gluteal n.)

5 Sartorius (femoral n.) & tensor fascia

lata

(superior gluteal n.)

5

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Acetabular component

USE UNCEMENTEDFailure is due to poly wear and osteolysis

in CONVENTIONAL poly

POSITION:

40/20

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Safe zone for screws

POST/SUP and POST/INF

KNOW structures in zone of injury

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A 64-year-old male undergoes acetabular revision of his failed total hip arthroplasty using a large uncemented component. Post-operatively he is noted to have a foot drop and radicular pain in the operative extremity. A CT scan of the hip is obtained and reveals screw penetration into the sciatic notch. Where was this screw most likely inserted in the acetabulum?

QID: 3515

1 Anterior superior quadrant

2 Through the medial wall

3 Anterior inferior quadrant

4 Posterior superior quadrant

5 Through the femoral nerve

4

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Femoral Component

Cemented have good outcome and survivorshipAny 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

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Polyethylene

Highly cross linked= decrease wear and lysisVitamin 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

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A 72-year-old female presents with the radiographs in Figure A 16 years following total hip arthroplasty. Which of the following statements is true regarding this pathological process?

1 TNF-alpha is released by macrophages

2 RANKL is released by osteoclasts

3

Osteoprotegrin

(OPG) binds to RANK

4 RANK and RANKL gene transcription is decreased

5 Interleukins (Il-1, IL-6) are released by osteoclasts

1

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Other bearings

Ceramic- decrease wear ?? CostMOM- 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

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An 81-year-old man reports a year of worsening right groin pain and swelling. A current radiograph and recent MRI are shown in Figures A and B, respectively. ESR and CRP are within normal limits. Aspiration yields 8cc of black liquid with an automated cell count of 7,000 WBC. Manual cell count demonstrates 1,500 WBC and 62% neutrophils. Serum cobalt levels are 12ppb and chromium levels at 2ppb. What is the next best step in management?

1 Greater trochanteric bursa injection

2 Revision arthroplasty with exchange of both components to long modular diaphyseal engaging stem and

multihole

acetabular cup

3 Revision arthroplasty with exchange of both components to long modular diaphyseal engaging stem and constrained acetabular component

4 Revision arthroplasty with antibiotic spacer placement and subsequent revision arthroplasty

5 Revision arthroplasty with conversion to ceramic head with titanium sleeve and new polyethylene liner

5

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A patient with a severe nickel allergy and degenerative joint disease of the hip would be best served by which of the following prosthetic options?

1 Cemented titanium stem, ceramic (alumina) head, and press-fit titanium cup

2 Cemented cobalt-chrome stem, ceramic (alumina) head, and press-fit cobalt-chrome cup

3 Press-fit titanium stem, cobalt-chrome head, and press-fit titanium cup

4 Press-fit titanium stem, titanium head, and press-fit titanium cup

5 Press-fit titanium stem, ceramic (alumina) head, and

cementless

titanium cup

5

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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 prophylaxisIf treating HO: excision and single dose radiation

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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)

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Which of the following complications is the primary reason for early reoperation following the procedure shown in Figure A?

1 Edge loading leading to rapid polyethylene wear

2 Fracture of the femoral neck

3 Pseudotumor formation

4 Infection

5 Groin pain from accelerated acetabular erosion

2

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Revision hip

REVISE MALPOSITIONED COMPONENTS ON TESTLook at leg length, impingement, offsetDUAL MOBILITY: it decreases instability for those RESIVED for instability

Problem: intra-prosthetic dislocation

CONSTRAINED liner only if DEFICIENT abductor AND well positioned components

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Paprosky acetabular

I -hemispherical shellIIa

–

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/cageIIIb – BAD; UP UP/in;

DISCONTINUTIY

Cage,

triphlange

, multiple augments

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Figure A depicts the current radiograph of a 66-year-old man with significant right groin pain after undergoing right total hip arthroplasty (THA) 10 years ago. Revision surgery is planned after infection workup is negative. What is the classification of his diagnosis and what would the most appropriate treatment for the acetabulum?

1

Paprosky

I;

cementless

hemispheric cup with screw fixation

2

Paprosky

I; cemented hemispheric cup without screw fixation

3

Paprosky

IIB;

cementless

hemispheric cup with screw fixation

4 Paprosky IIIA; cup/cage construct

5

Paprosky

IIIA;

triflange

reconstruction

3

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An 80-year-old female presents following a fall from standing. She was an active, independent, community ambulator prior to this event. Past surgical history is significant for a left total hip arthroplasty 10 years prior. A left hip XR is obtained and shown in Figure A. A CT is obtained and demonstrates a displaced transverse acetabulum fracture with medial cup migration. There is no evidence of femoral component loosening or fracture. There is no concern for infection and all inflammatory markers are within appropriate limits. Which treatment is most appropriate?

1 Restricted weight bearing

2 Acetabular revision with a custom

triflange

implant

3 Dual approach pelvic ORIF and acetabular revision

4 Acetabular revision with cup-cage construct

5 Acetabular revision with placement of a jumbo cup

4

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Paprosky

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Paprosky femoral

I – regular stemII – 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

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Vancouver classification

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Vancouver classification

A- treat osteolysisB1- well fixed stem, protection/ stabilize

B2,3 – revise

C - ORIF

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An 85-year-old woman sustains a ground level fall. Her THA was done 25 years ago. She was previously ambulatory but with a significant limp. With regard to the femur specifically, what is the Vancouver classification and preferred treatment option?

1 Vancouver C, revision to proximal femoral replacement

2 Vancouver B1, ORIF with impaction grafting

3 Vancouver AG, ORIF

4 Vancouver B3, revision to proximal femoral replacement

5 Vancouver B2, ORIF with femoral strut allograft augmentation

4

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Spinal fusion and hip arthroplasty

Increase risk of dislocationConsider lateral pelvis xray

: sitting, standing, step-up

Counsel patient for risk

Consider safe zone modification

Consider dual mobility

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stiff

mobile

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Knee OA

NSAIDs, Tramadol, 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

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A 65-year-old man presents to your clinic with chronic, progressive knee pain. Figure A is an x-ray of his right knee. He would like to pursue non-surgical treatment options. The AAOS clinical practice guidelines on the treatment of symptomatic knee arthritis support which of the following with "strong evidence"?

1 NSAIDs; tramadol

2 Weight loss; arthroscopic debridement

3 Weight loss; intra-articular steroid injections

4 Valgus-offloading brace; glucosamine chondroitin injections

5 Tramadol; acupuncture

1

Slide51

Which of the following treatment recommendations lacks Level 1 supporting evidence (Grade A Recommendation) according to the

the

American Academy of

Orthopaedic

Surgeons (AAOS) Guidelines for Treatment of Knee Arthritis (OA)?

1 Recommend patients be encouraged to participate in low-impact aerobic fitness exercises

2 Recommend against glucosamine and/or chondroitin sulfate or hydrochloride for patients with symptomatic OA of the knee

3 Recommend for arthroscopic partial meniscectomy as an option in patients with symptomatic OA of the knee who also have primary signs and symptoms of a torn meniscus

4 Recommend for weight loss in patients who are overweight (as defined by a BMI>25)

5 Recommend against performing arthroscopy with debridement or lavage in patients with a primary diagnosis of symptomatic OA of the knee

3

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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

Slide53

Which of the following benefits can be expected from

unicompartmental

knee arthroplasty compared to total knee arthroplasty for medial compartment knee arthritis?

1 Better clinical outcomes at one year follow-up.

2 Greater survivorship rate at 10 year follow-up

3 Faster postoperative rehabilitation

4 Better postoperative knee alignment

5 Reduced risk of secondary surgery within the first year

3

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TKA

Cemented survivorship better than uncementedAll 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

Slide55

Which of the following will decrease the Q-angle when performing a total knee arthroplasty?

1 Medialization of the femoral component

2 Medialization of the tibial component

3 Medialization of the patellar component

4 Internal rotation of the femoral component

5 Internal rotation of the tibial component

3

Slide56

Saggital balance

Slide57

After implanting trials during a primary cruciate retaining total knee arthroplasty, the surgeon decides to recut the proximal tibia with increased slope. What intra-operative examination findings in the operative knee would lead to this decision?

1 Tight in extension, balanced in flexion

2 Loose in extension and flexion

3 Balanced in extension, loose in flexion

4 Balanced in extension, tight in flexion

5 Loose in extension, balanced in flexion

4

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Coronal balancing

OsteophytesVarus deformity: Medial releaseDeep 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

Slide59

A 66-year-old patient is planning to undergo a right total knee arthroplasty. Figure A demonstrates the preoperative radiograph. Placing the components in a kinematic alignment (compared to neutral mechanical alignment) would result in which of the following?

1 Varus or valgus joint line orientation

2 Varus tibial cuts and valgus femoral cuts

3 Lower rates of patient satisfaction

4 Decreased ROM

5 Increased reoperation rate

2

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tka

CAS increased outliersPatient 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

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A 58-year-old woman undergoes a total knee arthroplasty with a posterior stabilized design. Two years later, she returns with recurrent sterile joint effusions, a sensation of instability without giving way and difficulty with ascending and descending stairs. Examination reveals diffuse tenderness around the pes anserinus and peripatellar region, and increased anterior tibial translation most notable at 90° of flexion. Radiographs demonstrate well cemented implants with 5° of posterior tibial slope. Figure A represents a femoral cutting block with lines 1 through 5 corresponding to femoral bone cuts. The most likely cause of her symptoms is over-resection at:

1 Resection line 1

2 Resection line 2

3 Resection line 3

4 Resection line 4

5 Resection line 5

2

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tka

Nerve injury most common with valgus knee and flexion contracturePeroneal 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

Slide63

A 60-year-old woman undergoes a total knee arthroplasty for end-stage osteoarthritis. Preoperative knee range of motion is 5 to 100 degrees. Postoperatively, she experiences reduced range of motion. She is scheduled to undergo manipulation under anesthesia. In which of the following scenarios is this procedure best indicated?

1 Knee range of motion 0 to 60 degrees at 2 months postoperatively

2 Knee range of motion 0 to 60 degrees at 8 months postoperatively

3 Knee range of motion 30 to 120 degrees at 2 months postoperatively

4 Knee range of motion 30 to 120 degrees at 8 months postoperatively

5 Knee range of motion 30 to 120 degrees at 2 weeks postoperatively

1

Slide64

When compared to a median parapatellar approach which of the following approaches may lead to higher rates of component malposition?

1 Quadriceps sparing

2 Lateral parapatellar

3

Midvastus

4 Quadriceps snip

5 V-Y turndown

1

Slide65

A 60-year-old woman presents for follow-up two weeks after right total knee arthroplasty. She complains of significant anterior knee pain after fall from standing onto a flexed knee. On physical exam, her passive range of motion is 0-120 degrees and she is stable to

varus

and valgus stress. She is able to achieve full extension with active range of motion, though she is experiencing severe pain. Lateral radiograph of the knee is provided in Figure A. What is the most appropriate next step?

1 Non-operative management with long leg cast

2 Closed treatment with immediate active range of motion

3 Removal of patellar component with early active range of motion

4 Open reduction and internal fixation of patella with wire or screw fixation

5 Extensor mechanism repair with Achilles allograft and revision of the patella

1

Slide66

Knee revision

BMI >40: decreased survivorship, increased lucent lines, higher failure, wound complication

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

Slide67

A 75-year-old male requires revision total knee arthroplasty, 15 years after the index procedure. The operative report states the surgeon used standard-sized, cemented, posterior cruciate sacrificing components with size 13mm highly crosslinked polyethylene liner. What would be the MOST LIKELY etiology for revision TKA in this patient?

1 Infection

2 Aseptic loosening

3 Instability

4 Periprosthetic fracture

5 Arthrofibrosis

2

Slide68

Knee revision

Periprosthetic fracture:Know the bone quality

Frx

displacement

Implant stable

Fix vs revise

Slide69

An 82-year-old healthy male presents to the ED with right leg pain and inability to bear weight after a fall from standing. He has a history of revision right total knee arthroplasty performed 5 years ago and was doing well until his fall this morning. On exam, he is able to actively extend his knee, though limited by pain, and is neurovascularly intact. Figures A-B are radiographs of his distal femur. What is the most appropriate treatment?

1 Retrograde intramedullary nail

2 Revision total knee arthroplasty with a stemmed femoral component

3 Nonoperative management with application of a long leg cast

4 Open reduction and internal fixation with a lateral plate

5 Antegrade intramedullary nail

4

Slide70

A 67-year-old female presents to the emergency department with the distal femur fracture shown in figure A. She undergoes procedure 1 shown in figures B and C. When compared to procedure 2 shown in figures D and E, which of the following is true regarding procedure 1?

1 Increased rate of secondary surgery and nonunion

2 Increased rate of nonunion and malunion

3 Decreased rate of nonunion and malunion

4 Similar rate of nonunion and decreased rate of malunion

5 Similar rate of nonunion and increased rate of malunion

a

b

c

d

e

4

Slide71

Infection

Major criteriaSinus tract2 positive cultures

Alpha

defensin

High sensitivity/specificity

Adjunct only

UKA numbers

ESR 25

CRP 17

WBC 6500

PMN 72%

Slide72

infection

Risks: malnutrition, smoking, uncontrolled DM, BMI > 40MRSA 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

AspirateWashout deep space: open fasciaDue I&D early: < 3 weeks from surgery or acute

hematogenous

Slide73

infection

1 stage:Must know organismNo 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

Slide74

A 71-year-old woman has a failed revision hip arthroplasty and is undergoing a re-revision hip arthroplasty.

Her last hip surgery was 4 years ago with revision of the acetabular component.

Radiographs show a well-fixed extensively porous-coated femoral component and a failed acetabular component with proximal and medial migration through the floor of the acetabulum.

Preoperative laboratory studies reveal an erythrocyte sedimentation rate (ESR) of 70 mm/h (normal 0-29 mm/h), a C-reactive protein (CRP) of 23.3 (normal 0.2-8.0), and a negative hip aspiration.

At the time of surgery, tissues look inflamed and a frozen section shows 20 WBC per high power field; however, a Gram stain is negative.

What is the most appropriate action at this point?

1 Proceed with the revision as planned

2 Obtain cultures and proceed with revision of the acetabulum only

3 Obtain cultures and proceed with revision of the femur only

4 Obtain cultures, remove the implants, and insert an antibiotic spacer

5 Obtain cultures and close

4

Slide75

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

Slide76

A 68-year-old patient with diabetes progressively worsening left knee pain of 6 months duration. They underwent a left total knee arthroplasty 7 years ago. Figures A-B demonstrate the current radiographs. Aspiration of the left knee demonstrated 11,500 WBCs and 94% neutrophils. Aspiration cultures grew methicillin-resistant Staphylococcus aureus. What would be the best treatment approach for this patient?

1 Knee arthrodesis

2 Long-term antibiotic suppression

3 One-stage revision arthroplasty

4 Two-stage revision arthroplasty

5 Above knee amputation

4

Slide77

A 64-year-old male is evaluated for a painful, swollen right knee 3 weeks after undergoing a right primary total knee arthroplasty (TKA). As part of his workup, a right knee aspiration is performed and the synovial fluid white blood cell count returns at 10,500 cells/microliter. How should this value be interpreted in the context of evaluating for a prosthetic joint infection (PJI)?

1 It is above the cutoff of ~3,000 cells/microliter in the perioperative period; a PJI is likely present

2 It is below the cutoff of ~30,000 cells/microliter in the perioperative period; a PJI is unlikely

3 It is above the cutoff of ~10,000 cells/microliter in the perioperative period; a PJI is likely present

4 It is below the cutoff of ~50,000 cells/microliter in the perioperative period; a PJI is unlikely

5 It is not possible to interpret the synovial WBC count within 6 weeks of a primary TKA

2

Slide78

GOOD LUCK