Prosthetic joint infection

Background

Complicates about 2% of arthroplasty
- 2% of hip and knee arthroplasties
- 1% of shoulder arthroplasties

Bacteria grown on the prosthesis in a biofilm, making it resistant to medical management

Most commonly occur within the 3 months after arthroplasty (early); 70% within the first two years
Should be suspected when there is a sinus tract, persistent wound drainage, acute onset of pain, or chronic pain after a pain-free interval

Routine investigations should include ESR, CRP, plain film x-ray, diagnostic arthrocentesis, and blood cultures (if fever or other systemic symptom)
- If clinically stable, try to obtain arthrocentesis samples before antibiotics
- Other imaging should not be used routinely
Diagnosis is made most definitively by histopathology of periprosthetic tissue biopsy, and supported by positive intraoperative tissue cultures
- Should take 3 to 6 intraoperative samples
- If clinically stable, try to obtain tissue cultures before starting antibiotics
A definitive diagnosis of PJI requires any of the following:
- Sinus tract that communicates with the prosthesis
- Acute inflammation on histopathology of intraoperatic periprosthetic tissue sample
- Periprosthetic purulence without other cause
- Two or more intraoperative cultures with identical organism, though a single positive culture may be sufficient in some cases
A diagnosis of PJI may still be possible if the above criteria are not met but clinical suspicion remains

Ultimately the decision of whether and how to treat surgically rests with the orthopedic surgeon
Options include:
- Debridement and retention
- One-stage replacement
- Two-stage replacement
Antibiotic-impregnated cement is often used for the spacer
- Usually vancomycin 2 to 8 g per 40 g cement, or an aminoglycoside
  - No clear guidelines for dosing
- No clear evidence of effectiveness, but recommended in all revisions for septic arthritis
- Releases over a period of two to three days

Surgical Management	Species	Location	Duration IV	Total Duration	Adjunctive Rifampin	Chronic Suppressive Thearpy
debridement and retention	Staphylococcus species	knee	2-6 weeks	6 months	yes; 4-6 weeks IV if not given	±
		hip		3 months		±
		elbow				±
		shoulder				±
		ankle				±
	species other than staphylococci	—	4-6 weeks			±
resection ± reimplantation	—	—	4-6 weeks
1-stage exchange	Staphylococcus species	—	2-6 weeks	3 months	yes; 4-6 weeks IV if not given	±
1-stage exchange	species other than staphylococci	—	4-6 weeks	3 months		±
amputation with source control	—	—	24-48 hours
amputation without source control	—	—	4-6 weeks

Species	Preferred Antimicrobials	Alternative Antimicrobials
Staphylococcus species (oxacillin-susceptible)	nafcillin or cefazolin or ceftriaxone	vancomycin or daptomycin or linezolid
Staphylococcus species (oxacillin-resistant)	vancomycin	daptomycin
Enterococcus species (penicillin-susceptible)	penicillin G or ampicillin	vancomycin or daptomycin or linezolid
Pseudomonas aeruginosa	cefepime or meropenem	ciprofloxacin or ceftazidime
Enterobacter species	cefepime	ciprofloxacin
Enterobacteriaceae	ampicillin or ceftriaxone or ciprofloxacin
β-hemolytic streptococci	penicillin G or ceftriaxone	vancomycin
Cutibacterium acnes	penicillin G or ceftriaxone	clindamycin or vancomycin

Antimicrobial	Dose
ampicillin	12 g IV q24h continuously or split q4h
cefazolin	1-2 g IV q8h
cefepime	2 g IV q12h
ceftazidime	2 g IV q8h
ceftriaxone	2 g IV q24h
ciprofloxacin	750 mg PO bid
ciprofloxacin	400 mg IV q12h
clindamycin	300-450 mg PO qid
clindamycin	600-900 mg IV q8h
daptomycin	6 mg/kg IV q24h
ertapenem	1 g IV q24h
linezolid	600 mg PO/IV q12h
meropenem	1 g IV q8h
nafcillin	1.5-2 g IV q4-6h
penicillin G	20-24 MU IV q24h continuously or split q4h
vancomycin	15 mg/kg IV q12h

Duration unclear; 3-12 months or lifelong
In people in whom there is recurrence, it tends to recur within 4 months of discontinuing suppressive therapy

Microorganism	Preferred treatment	Alternative treatment
Staphylococcus species (oxacillin-susceptible)	Cephalexin 500 mg PO tid to qid; Cefadroxil 500 mg PO bid	Dicloxacillin 500 mg PO tid to qid; Clindamycin 300 mg PO qid; Amoxicillin-clavulanic acid 500mg PO tid
Staphylococcus species (oxacillin-resistant)	TMP-SMX DS 1 tab PO bid; Doxycycline 100 mg PO bid
β-hemolytic streptococci	Penicillin V 500 mg PO bid to qid; Amoxicillin 500 mg PO tid	Cephalexin 500 mg PO tid to qid
Enterococcus species (penicillin-susceptible)	Penicillin V 500 mg PO bid to qid; Amoxicillin 500 mg PO tid
Pseudomonas aeruginosa	Ciprofloxacin 250-500 mg PO bid
Enterobacteriaceae	TMP-SMX DS 1 tab PO bid	Beta-lactam, if susceptible
Cutibacterium	Penicillin V 500 mg PO bid to qid; Amoxicillin 500 mg PO tid	Cephalexin 500 mg PO tid to qid; Doxycycline 100 mg PO bid

Used in veterinary practice for decades, but only used experimentally in humans
Intraoperatively insert two Hickman catheters into the intraarticular space
- Two catheters used to ensure that at least one will remain viable for the duration
Vancomycin
- May precipitate local inflammatory response necessitating holding it for several days