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Adult Reconstruction
intermediate
X-Type

Periprosthetic Joint Infection Diagnosis

Complications

A 68-year-old woman presents 14 months after primary total knee arthroplasty with persistent knee pain and stiffness. She has no fever but reports recent fatigue. Examination shows a warm, swollen knee with limited range of motion. ESR is 45 mm/hr and CRP is 18 mg/L. Knee aspiration yields cloudy fluid with 12,000 WBC/μL with 85% neutrophils. Regarding the diagnosis of periprosthetic joint infection (PJI):

Mark each as TRUE or FALSE

A

The MSIS (Musculoskeletal Infection Society) criteria define PJI as present with one major criterion...

B

Serum inflammatory markers: CRP greater than 10 mg/L and ESR greater than 30 mm/hr are suggestive of...

C

A single positive culture is sufficient to diagnose PJI; CRP and ESR are not useful; synovial WBC le...

D

Alpha-defensin is a synovial fluid biomarker with high sensitivity (97%) and specificity (97%) for P...

E

Culture-negative PJI occurs in 7-42% of cases due to prior antibiotics, biofilm formation, fastidiou...

Answer the questions to see explanations

Click T (True) or F (False) for each option