Management of
Infections
About Total Hip
Arthroplasty
Frank Ebert, M.D.
Union Memorial Hospital
Baltimore, MD
Infections About THA
Range:
1.1% - 12.4% - 60’s
Rate 2000 – 0.5%
Rate Primary OA – 0.06%
Complications in Arthroplasty
Infection – Risk Factors
 Skin ulcerations / necrosis
 Rheumatoid Arthritis
 Previous hip/knee operation
 Recurrent UTI
 Oral corticosteroids
Complications in Arthroplasty
Infection – Risk Factors
 Chronic renal insufficiency
 Diabetes
 Neoplasm requiring chemo
 Tooth extraction
Complications in Arthroplasty
Infection – Clinical CourseAcute/Chronic
Pain #1
 Swelling
 Fever
 Wound breakdown drainage
Windsor et al
JBJS; 1990
Infections About THA
Early < 3 months
Lab Value

WBCs
Mayo Series
Mean 7,500

Differential
67 PMN’s

Sed rate
71 mm/hr

Arthrocentesis
Infections About THA
Late > 3 months-Chronic






Pain
swelling
Debride
Active drainage
Sed rate 63 mm/hr
WBC - 8300
96%
77%
27%
27%
Windsor et al
JBJS; 1990
Infections About THA
Late > 3 months-Acute-Late
Hematogenous
Recent Hx-surgery/dental/distal
infection



Classic Symptoms of Sepsis
Fever, Pain,ElevatedWBC
Complications in Arthroplasty
Infection – Surgical Techniques
 Avoid skin bridges-7 cm rule
 Avoid creation of skin flaps
 Hemostasis
 Prolonged operating time
Complications in Arthroplasty
Infection – Work-Up – Requires a
Combination of Studies
 Wound History
 Physical Exam
 Serial Radiographs
 Lab/sed rate/CRP/WBC
 Bone scan / Indium scan
Complications In Arthroplasty
Indium Scan
- Superseded Tech and Gallium
- More Specific and More Sensitive
- Specificity and Sensitivity > 85%
Complications in Arthroplasty
Infection – Work-Up
Arthrocentesis
– direct smear
– gram strain
– aerobic
– anaerobic
– acid fast
– fungi
Complications in Arthroplasty
Infection




Arthrocentesis
Cell count
Diff > 25,000 pmn
Protein – high
Glucose – low
Complications in Arthroplasty
Infection

Host Response
Glycocalyx
Gristina
JBJS; 1983
Prosthetic Joint Infection
Biofilm
Biofilm on implants
and devitalized tissue
causes chronic
disease
Understanding
biofilm enlightens one
to logical treatment
Biofilm
Characteristics
 All bacteria make biofilm
 Foreign and devitalized tissue can
succumb to biofilm formation if
exposed to bacteria
Costerton Science 284:1318. 99
Biofilm
Characteristics
 15% cells, 85% matrix
 Matrix – polysaccharide
 Biofilms have structure
 Cells live in a microecology and
communicate!
Costerton Science 284:1318. 99
Biofilm
Significance in PJI
 In biofilm state, bacteria become 1000x
to 1500x more resistant to antibioctics
 In biofilm state, bacteria express up to
65 new genes which change cell wall
and/or membrane structure
Costerton Science 284:1318. 99
Biofilm State
Significance in PJI and Osteomyelitis
 Resistant to antibiotics
 Biofilm permeable to antibiotics all
the way to base within 90 secs
 Resistant to WBC’s and
Phagocytosis
 Resistant to Antibiotics
Costerton Science 284:1318. 99
Biofilm
Significance in PJI
 Biofilm can colonize, grow and
cover a surface within 4-8 days!
 Prolonged wound drainage should
not be allowed
Costergan. W. MSIS 2000
Treatment Prosthetic Joint
Infection
Chronic Infections
 To effectively treat a chronic infection,
you must be able to planktonize cells
 At present time, effective treatment
means prosthetic removal and
debridement of surrounding devitalized
bone and tissue
Micro Organisms
Complications in Arthroplasty
Infection THA
Organism
Staphylococcus
S. aureus, penicillin sensitive
S. aureus, penicillin resistant
S. epidermis
Gram negative
Pseudomonas
Escherichia coli
Anærobic
Other
Percent
64
14
28
22
12
7
5
6
17
Prosthetic Joint Infection
Classification-Treatment Purposes
 Early Post-Op (<4 weeks)
 Late Hematogenous
 Chronic
Tsukayama et al: JBJS 78A, 96
Prosthetic Joint Infection
Treatment
Early Post-Op Infection < 4weeks
 I&D with retention of components
 Change modular parts
 Resection of components if I&D
fails
Prosthetic Joint Infection
Treatment
Hematogenous Infection
 I&D with retention of components
 Change modular parts
 2 stage reimplantation if I&D fails
Complications in Arthroplasty
Treatment Options-Chronic

Debridement with antibiotic
suppression therapy
— Strep/staphepi -- best
— Avoid repeated attempts
— Frozen tissue section
— Suction drains
Complications in Arthroplasty
Treatment Options-Chronic
 Antibiotic suppression-Acute/Chronic
— Indicated in med compromised
— Organism - gram+ strep staphepi
Complications in Arthroplasty
Two-Stage ReimplantationChronic/Failed Acute Treatment

Most successful treatment

Procedure of choice

Remember Biofilm
Complications in Arthroplasty
Two-Stage Reimplantation
Stage I
–
Complete
debridement
Stage II
–
6 wks IV antibiotics
Stage III
–
Reimplant
Complications in Arthroplasty
Two-Stage Reimplantation Procedure

Remove components, cement,
I&D

Fabricate and place spacer

6 weeks of antibiotics

Reimplantation
Complications in Arthroplasty
Two-Stage Reimplantation
Stage I

remove prosthesis / cement

thorough debridement
Complications in Arthroplasty
Two-Stage Reimplantation
Stage I


create antibiotic spacer
impregnated with antibiotics
wound closure
Complications in Arthroplasty
Two-Stage Reimplantation

Spacer Antibiotic Regimen
Tobramycin
2.4 gm/3.6 gm per
40 gms of PMMA
Vancomycin
> 0.5 gm to 1 gm per
40 gms of PMMA
Infections About THA
Antibiotic Impregnated Spacer

Cidal levels of antibiotic

Spacer to preserve tissue tension

Facilitates reimplant and wound
exposure
Complications in Arthroplasty
Two-Stage Reimplantation
Stage II

Reimplantation after antibiotic
regimen
Stage III – Reimplantation
 Serial aspirations
 Pre-op planning
Bone scan /Indium Scan

ESR/CRP/WBC
Complications in Arthroplasty
Intra-operative Frozen Section


< 5 PMN’s per HPF – no
infection
> 10 PMN’s per HPF – infection
Mirra; JBJS
Complications in Arthroplasty
Resection Arthroplasty

Removal all components

Remove all cement

Effective in medically
compromised patient
Infections About THA
Algorithm
THA
Clinical Sepsis
Acute/Hematogenous
< 4 wks
Debridement
Antibiotics (6 wks)
(GRAM +
Organism)
> 4 wks
2-Stage
Replant
Infections About THA
Algorithm
Debridement
Antibiotics
Success
No
Success
2-stage Replant
2-stage Replant
Success
No
Success
Resection
Arthroplasty
Thank You
Frank R. Ebert, MD
Infections About THA
Stage II – Antibiotic Treatment

Hickman catheter / Pick Line

MIC 1:8 / 6 wks
Complications in Arthroplasty
Treatment Options
 Debridement with antibiotic
suppression therapy
— Limited success
— < 3 weeks
Schoifet
JBJS; 1990
Complications in Arthroplasty
Treatment Options
 Antibiotic suppression
 Aggressive wound debridement
Complications in Arthroplasty
Treatment Options
 Resection arthroplasty
 2 Stage re-implant
 Arthrodesis

Amputation
Complications in Arthroplasty
Treatment Options
Hip (% success)
Knee (% success)
------
18
Complications in Arthroplasty
Debridement with Antibiotic
Suppression
Hip (% success)
25 to 35
Knee (% success)
25 to 35
Complications in Arthroplasty
Results — Gm positive
Windsor et al
92 % JBJS 1990
Insall et al
97% JBJS 1983
Complications in Arthroplasty
Arthrodesis Indications

Extensor mechanism disruption

Resistant bacteria

Inadequate bonestock

Inadequate soft tissues

Young patient
Arthrodesis
Advantages
 Definitive treatment
 Little chance of recurrence
Arthrodesis
Disadvantages
 Difficulty with transfers / small
spaces
 Increase energy requirements