give details and recent status of prosthetic joint infection, diagnosis , investigation markers ,and management

1. PROSTHETIC JOINT
INFECTION (DIAGNOSIS AND
MANAGEMENT)
DR CHANDRA
JUNIOR RESISDENT DEPARTMENT OF
ORTHOPEDICS JIPMER,PUDDUCHERRY

2. OBJECTIVES
 What is prosthetic joint infection(PJI)?
 Burden of disease
 How is PJI different from other infections(eg.. FR,ODRI ,OIRI )
 Diagnosis
 Treatment
 Recent advances
 Prevention

3. WHAT IS PROSTHETIC JOINT INFECTION(PJI)?
• Periprosthetic joint infection (PJI) is a unique clinical entity, markedly different from
infections involving native bones or joints.
• Prosthetic joint infection (PJI), also referred to as periprosthetic infection, is
infection involving the joint prosthesis and adjacent tissue
• PJI is characterized by a complex interplay between microbes, predominantly bacteria but
occasionally fungi, and the host immune response.
• Only a minimal microbial burden is required to initiate a PJI.

4. • etiologic organisms can adhere to the surfaces of arthroplasty components
and form biofilms.
• Biofilms notoriously exhibit a marked resistance to a wide array of
antimicrobial agents and are adept at avoiding innate immune defenses.
• It may occur in the period after the joint replacement or many years late

5. • There is no uniformly accepted definition for PJI.
• several groups, including the Infectious Diseases Society of America (IDSA) and the
Musculoskeletal Infection Society (MSIS), have published proposed or accepted
definitions for the diagnosis of PJI .
• Although the definitions vary, a recent study showed a high concordance between
the IDSA and MSIS definitions of PJI .
• Additionally, the European Bone and Joint Infection Society (EBJIS), the American
MSIS, and a number of other organizations from around the world recently held an
international consensus meeting in an attempt to refine an international consensus
definition of PJI .

6. MSIS : Definitive evidence of PJI is a sinus tract in communication with the
prosthesis or an identical pathogen found in two separate periprosthetic tissue or
fluid samples. The presence of four (or more) of six minor criteria can also fulfill a
diagnosis of PJI.
IDSA : The presence of the sinus tract and two or more sterile site cultures with
identical microorganisms to be definitive evidence of PJI.
International Consensus Meeting definition of PJI 2018 brought out
Diagnosis criteria to overcome short coming of these definitions.

7. BURDEN OF DISEASE
• Prosthetic joint infection is a difficult complications affecting replacement surgery
.
• It is painful ,disabling ,often requiring removal of prosthesis .
• After the introduction of modern hip arthroplasty ,septic complication threatened
the continued viability of procedure .
• Charnley reported in 6.8% of 1st 683 procedure.
• Experience of Wilson et.al in united states was even more ominous with 11% of
100 arthroplasties becoming infected.
• About 1.4-2.5% of all joint replacements worldwide are complicated by PJIs.

8. • Currently approximately 1-2% of hip arthroplasty,2-3% of TKR
and 4-5 % after revision THR and 5-6% after revision TKR
• Infection after Total ankle replacement appears to be relatively infrequent
Rate of superficial infection ranges 0-15% ( average 8%)
Rate of deeo infection 0-5%( average 1%)
• Infection rate after shoulder replacement is low (less than 1%)
• Infection rate after elbow arthroplasty is 7-8%.

9. Advancesinunderstandingof patientselection,
operatingroomenvironment, surgicaltechniqueand
useof prophylacticantibioticshavedramatically
reducedtheriskofthisdevastingcomplication

10. HOW IS PJI DIFFERENT FROM OTHER INFECTIONS(EG.. FR,ODRI
,OIRI )
Common orthopedics Infections and abbreviations :
• SSI : surgical site infections
• FRI : fracture-related infections
• BAI : biomaterial associated infections (or)
IAI : implant-associated infections
also known
ODRI : orthopedic device related infection
OIRI : orthopedic implant related infection
• PJI : periprosthetic joint infections

11. • Although the rate of PJI is low compare to other orthopedic infections , it has
dramatic effects on the patients’ health.
• Its involved articular surfaces /joints those are inevitable for locomotion
• Diagnosis and treatment of PJI challenging
• It is difficult to eradicate resulting in a severe complication with a significant patient
and socioeconomic burden.
• Very close and regular clinical follow ups are crucial to detect and management .

12. • Most other bone related infection implant removal and adequate antibiotic
therapy may complete the treatment
• But prosthesis removal and antibiotic therapy is not a solution for PJI ,Need
reintervention .
• Biofilm formation more common in PJI compare to other bone related infection.
• Biofilm formation on prosthetic surface make eradication of infection more
difficult compared to other infections.

13. BIOFILM
• The most important factor influencing periprosthetic infection treatment
• All bacteria make biofilm.
• Biofilm consists of approximately 15% cells and 85% polysaccharide matrix
and
forms on ( All foreign materials ,Devitalized tissues ,Soft tissue and bone)
• Biofilm, once established, matures into sophisticated microenvironment.
Biofilms typically mature over 4 weeks
• Bacteria communicate via signaling molecules and nanowires
* Nanowires are very small cell to-cell connections that allow bacteria in a biofilm to
communicate with one another

14. CLINICAL IMPORTANCE OF BIOFILM STATE
• Bacteria become 1000 to 10,000 times more resistant to antibiotics
• Essentially, bacteria within a biofilm state cannot be killed with standard dosing regimens of
antibiotics
• In vivo, biofilm can colonize, grow, and cover a surface within 4–8 days
• Effective treatment for established biofilm infection requires:
Removal of implants and foreign bodies
Removal of all devitalized bone and soft tissue
Inadequate debridement of biofilm material is the reason for treatment failure and infection
recurrence
This includes retained cement and metal left in the medullary canals adjacent to the affected
prosthetic joint

16. DIAGNOSIS

17. CLINICAL HISTORY AND EXAMINATION
History :
• The clinical manifestations of PJI vary depending upon the virulence of the organism, the mode of initiation of infection, the host immune
response, the soft tissue structure surrounding the joint, and the joint involved.
• Commonly reported signs or symptoms of PJI include pain(70-90%), joint swelling or effusion, erythema or warmth around the joint, fever,
drainage, or the presence of a sinus tract (72%)communicating with the arthroplasty
Physical examination :
• sinus tract to the joint is a definite infection
• warmth, redness, or swelling
• low grade fever
• Motion limited by pain and swelling

18. IMAGING
Radiographs :
Imaging may support the diagnosis of PJI in certain circumstances but rarely has a definitive role in PJI diagnosis.
Plain radiographs are typically obtained in patients undergoing evaluation for possible PJI.
They may help identify noninfectious causes for the presenting symptoms, including periprosthetic fracture, fracture
of the arthroplasty material, or dislocation
.Detection of periprosthetic lucency, loosening of the prosthesis components, effusion, adjacent soft tissue gas or
fluid collection, or periosteal new bone formation may suggest infection but is neither sensitive nor specific

19. CT scan
Computed tomography (CT) and magnetic resonance imaging have the advantages of high spatial resolution and allow
evaluation of signs of infection in the periprosthetic tissues.
no difference in the evaluation of the bony structures compared to the use of plain radiographs.
Furthermore, the use of these techniques is limited by imaging artifacts due to the presence of the metal prosthesis
MRI
magnetic resonance imaging can be performed only with certain metals, such as titanium or tantalum

20. Bone scan
Tc-99m (technetium) detects inflammation and In-111 (indium) detects leukocytes
triple scan can differentiate infection from fracture or bone remodeling
indications
if infection is suspected, but cannot be confirmed by aspiration or blood work up
99% sensitivity and 30% to 40% specificity
Positron emission tomography (PET)
may help to identify areas of high metabolic activity using fluorinated glucose
98% sensitivity and 98% specificity

21. LABORATORY
• WBC(not specific or sensitive)
• CRP( > 3omm/h ),ESR ( 10mg/l) D-dimer (> 850)
• Joint aspiration :
> One of 3 is elevated with suspicion of infection
whenever there is a strong suspicion in order to confirm the diagnosis even of negative blood markers )
Should not undertaken until at least 2weeks after discontinuation of antibiotic
(cell count and differential, crystals , gram stain , cultures and specificity )
synovial WBC >10,000 cells/ccl in the first 6 weeks after TKA suggestive of infection
WBC >3,000 cells/cc and PMN >80% for hips
WBC >1166 cells /cc and PMN >64% for hip antibiotic spacers

22. Synovial fluid leukocyte esterase: ( 81% sensitivity and 77% specicity)
Leukocyte esterase is an enzyme present in neutrophils.
A colorimetric strip measuring leukocyte esterase is widely available as a point-of-care test to determine pyuria for the diagnosis of urinary tract infection.
This test strip has recently been proposed as a point-of-care test for synovial fluid from either preoperative or operative aspirates.
Gram stain (specificity > sensitivity)
positive test would be indicative of infection,
however a negative test does not rule out infection
repeat aspiration(indicated in cases of inconclusive aspirate and peripheral lab data )
waiting two weeks for a repeat aspiration off antibiotics

23. • Preoperative periprosthetic tissue biopsy: sensitivity 73% andspecificity 95%
Testing of periprosthetic tissue is one of the most valuable components in the routine microbiological diagnosis of PJI.
Samples of periprosthetic tissue are most often obtained at the time of revision surgery but preoperative arthroscopic tissue biopsy may alternatively or
additionally be performed
cultures obtained by using swabs :
• Cultures obtained by using swabs have a limited role in the microbiological detection of PJI.
• While the presence of a sinus tract is considered definitive evidence of PJI swab culture of the drainage from the sinus tract is neither sensitive nor
specific for the microbiological detection of PJI

24. CRITERIA INTERNATIONAL CONSENSUS MEETING (ICM) ON
MUSCULOSKELETAL INFECTION :98% SENSITIVITY AND 99.5% SPECIFICITY
• .

25. CLASSIFIACTION
ACUTE INFECTION CHRONIC INFECTION
<3WEEKS
Considered a non-biofilm state
Implants are salvageable
Treatment is surgical
=> 3WEEKS
Biofilm state
Implants are not salvageable
Treatment is surgical and implants are removed

26. TSUKAYAMA CLASSIFICATION
1) early postoperative infection : onset within 1st month of surgery
2) Late chronic infection : onset more than 1month of surgery ,insidious onset of
symptoms
3) Acute hematogenous infection : onset more than 1month of surgery , acute
onset of symptoms in previously well function prosthesis , distant source of
infection
4) Positive intraoperative cultures : positive culture obtained at the time of revision
for supposedly aseptic conditions.

27. TRAMPUZ AND ZIMMERLI CLASSIFICATION
Early infection : <3 month
Delayed infection : 3-24 month
Late infection : > 24 month

28. TREATMENT
• ACUTE INFECTION : Debridement, Antibiotics and Implant Retention (DAIR)
31 to 82% of success rate
Radical debridement surgery is performed, including synovectomy and lavage
Modular bearings are exchanged
All prosthetic spaces must be accessed and flushed/debrided of bacterial load
Intravenous antibiotic therapy used for 4–6 weeks
Arthroscopic lavage of an acutely infected joint replacement is not acceptable treatment.
The success rate with the DAIR procedure for S. aureus appears to be lower than that for other organisms
If infection recurs, treated as a chronic infection.
A second debridement surgery attempt should not be made

29. CHRONIC INFECTION
a)Implant removal :
Includes all implant cement (PMMA), nonabsorbable suture material, screws, cables, and metallic
fragments
b) Radical debridement, including synovectomy, removal of necrotic bone and all devitalized soft
tissue, and copious lavage
c)Stabilization of joint with methylmethacrylate spacer loaded with high-dose antibiotics
d) Intravenous antibiotic therapy for 4–6 weeks
e) Second-stage reconstruction

31. WOUND COVERAGE
MEDIAL GASTROCNEMIUS ROTATIONAL FLAP :
The workhorse for deficiencies about the knee
Blood supply—medial sural artery
Used to cover medial and anterior deficiencies
Good excursion
LATERAL GASTROCNEMIUS ROTATIONAL FLAP:
Blood supply—lateral sural artery
Used to cover lateral soft tissue deficiencies
Little excursion
Risk—peroneal nerve palsy from traction of the flap as it is pulled anteriorly to lateral side of knee

32. RECENT ADVANCES

33. ONE-STAGE REPLACEMENT ARTHROPLASTY
• Indications
used more commonly in Europe for infected THA
no sinus tract, healthy patient and soft tissue, no prolonged antibiotic use, no bone graft
low-virulence organism with good antibiotic sensitivity
Technique(use antibiotic-impregnated cement)
Advantages
• lower cost and convenience with single procedure
• earlier mobility
Disadvantages
• higher risk of continued infection from residual microorganisms
• Outcomes : variable success of 75-100%

34. TWO-STAGE ARTHROPLASTY EXCHANGE
• Success rate 87 to 100%
• Two-stage arthroplasty exchange, also referred to as a staged exchange, is considered to be the most definitive
strategy in terms of infection eradication and preservation of joint function.
• This strategy involves at least two surgeries. In the first surgery, cultures are obtained, all infected tissue is debrided,
and the components and PMMA are removed.
• An antimicrobial-impregnated PMMA spacer is typically implanted into the joint space prior to closure to deliver local
antimicrobial therapy and maintain limb length.
• Pathogen-directed antimicrobial therapy is usually given intravenously for 4 to 6 weeks following the first stage. This
is then followed by at least a 2- to 6-week antibiotic-free time period.

35. ANTIMICROBIAL-LOADED PMMA SPACERS
Antimicrobial-loaded PMMA spacers serve two functions in a two-stage arthroplasty exchange.
First, both articulating and static spacers provide mechanical support during the time in which the arthroplasty is
removed. This preserves proper joint position, prevents muscle contractures, and enhances patient comfort between
the first and second stages.
The second function of antimicrobial-loaded PMMA spacers is to provide local
antimicrobial therapy to augment systemic therapy during the time between the first and
second stages.
Types
 static spacer used if joint stability is compromised by soft tissue and/or bone loss
 Articulated spacer preferred if joint stability preserved. ( Because of better preservation of joint function)

37. • ANTIBIOTIC LOADED ACRYLIC CEMENT (ALAC) :
Construct consists primarily of methylmethacrylate cement loaded with high dose
antibiotics
• PROSTHESIS WITH ALAC (PROST ALAC) :
Construct that contains temporary metal and plastic prosthesis along with ALAC
• Both constructs are acceptable for treatment.
There is no proven superiority of ALAC over PROST ALAC.
PROST ALAC spacers tend to function better and are generally more stable

38. o. Reimplantation of joint arthroplasty:
Requires revision/salvage system to accommodate bone and soft tissue loss from
infection debridement surgery
o.Bony arthrodesis :
Used when there is significant loss of functional tissues
Bone stock must be adequate for fusion.

39. o. Prosthetic end fusion device :
Bone defects are spanned by modular rods connected at the knee
Device maintains functional leg length unlike classic bony arthrodesis.
o. Amputation :
Indications:
Neuropathy and chronic pain too debilitating for reimplantation to be considered
Recurrent infection after resection arthroplasty
Patient too medically compromised to be able to combat infection
o. Permanent résection : Patient unfit for surgery

40. INFECTION (PJI) PREVENTION IN TOTAL JOINT
REPLACEMENT
Bacterial inoculation of prosthetic joint occurs usually at time of surgery ( majority of
cases)
• Bioburden ( airborne particles containing bacteria ) : Deposit into the wound or
are transferred from contaminated equipment into the surgical wound.
• All healthcare personnel shed bacteria into the air from degrading skin cells, which are
shed from the body at a rate of 103–104 particles per minute. These particles (called
fomites) contain bacteria that are embedded within human skin (called the bacterial
biome). These ultrasmall particles float into the air and are carried by vortex air currents
and deposited onto the surgical wound or surgical equipment.

41. proven infection prevention :
>Prophylactic antibiotics:
( first or 2nd generation cephalosporins such as cefazolin or cefuroxime , vancomycin for
carriers of resistant s.aureus or high risk of colonization , clindamycin for allergic to
cephalosporin)
>Administered 30 minutes before skin incision
>Continued for 24 hours after surgery
>Vertical laminar air flow in operating room
>Vertical flow systems are superior to horizontal flow systems (because horizontal flow
systems create large vortex currents that circulate unfiltered air into the surgical wound)

42. Antibiotic-impregnated cement ;
No more than 1 g of antibiotic powder per 40 g packet of cement (so as not to
reduce mechanical properties of cement)
Indicated for higher-risk patients
Use may be associated with increased rates of aseptic loosening
(because even 1 g of antibiotic powder may reduce mechanical properties of the
cement enough to cause premature cement fatigue in high-load situations)

43. REFERENCES
• Campbell’s operative orthopedics 14th edition
• Miller’s review of orthopaedics 8th edition
• www.orthobullets.com
• periprosthetic joint infection,(Folusakin Ayoade; Daniel D. Li; Ahmed
Mabrouk; John R. Todd.)

44. THANKS……