Periprosthetic Infection 996.6

synonyms:

Periprosthetic Infection ICD-9

Periprosthetic Infection Etiology / Epidemiology / Natural History

• TKA = 0.71% (SooHoo NF, JBJS 2006;88:480)
• THA = 0.2% (Mahomed NN, JBJS 2003;85A:27).
• Revision THA = 0.95% (Mahomed NN, JBJS 2003;85A:27).
• TSA = <1%
• Most common etiology: S aureus and S epidermidis either by direct contact during arthroplasty or hamatogenous inoculation.
• Increased risk: rheumatoid arthritis, diabetes mellitus, obesity, glucocorticoid use, prolonged surgery, inadequete/poor timing pre-op antibiotics

Periprosthetic Infection Prevention

• Pre-operative antibiotics
• Body exhaust systems
• Laminar flow
• Antibiotic cement
• Prophylaxis for dental/urologic procedures for 2 years following arthroplasty. AAOS Urologic procedures in patients with THA recommendations. AAOS Antibiotic Prophylasis for Dental procedures.

Periprosthetic Infection Clinical Evaluation

• Pain (initially at night/rest), fever, chills, draining sinus tracts. Symptoms may be mild and difficult to differentiate between asceptic loosening, instability, etc.

Periprosthetic Infection Diagnositc Tests

• Xrays: evaluate for periosteal reaction, scattered foci of osteolysis, bone resoprtion, implant wear, progressive radiolucencies, osteopenia, .
• Bone Scan: sensitivity = 33%, specificity = 86%, positive predictive value = 30%, negative predictive value = 88%. (Levitsky KA, J Arthroplasty. 1991;6:237)
• ESR (Westergen erthrocyte sedimentation rate): rises normally after total joint surgery. Returns to normal 6 weeks after surgery. Infection suggested if elevated 3 months after surgery.
• CRP (C-reactive protein): Rises normally after total joint surgery. Returns to normal @3weeks after surgery. Infection suggested if elevated 3 months after surgery.
• Interleukin-6 (IL-6): Rises normally after total joint surgery. Returns to normal within 48 hours after surgery. Elevated (>10 pg/mL [>10 ng/L]) in patients with periprosthetic infection.
• Aspiration of Joint fluid: send for aerobic culture anaerobic culture, sensitivities, Gram stain, acid-fast staining, CBC with differential. Leukocyte count > 1.7x10⁹/L indicates infection.
• Leukocyte esterase reagent strips: Moderate or large WBC on strips indicates infection.  Sensitivity=92.9%, specificity=88.8%.  Blood or debris in synovial fluid renders the strips unreadable in 1/3 of cases.  (Parvizi, J, AAHKS annual meeting 2011).

Periprosthetic Infection Classification / Treatment

• Acute (within 4 weeks of arthroplasty, symptoms for < 2weeks): immediate arthrotomy with irrigation and debridement and exchange of polyethylene components and retention of solidly fixed implants followed by 4-6 weeks of IV antibiotics determined by cultures & sensitivities
• Late / Hematogenous: Two stage implant exchange. Stage 1: irrigation & debridement with removal of all components and antibiotic cement spacer placement followed by 4-6 weeks of IV antibiotics determined by cultures & sensitivities. Stage 2: reimplantation.
• Medically unstable: chronic suppressive PO antibiotics.
• Life-threatening sepsis / multiple revisions with severe bone loss and infection: amputation.
• High functional demand patient, young age, loss of extensor mechanism, concomitant soft-tissue reconstruction, immunocompromised patient, resistant organism: arthrodesis.
• Plyarticula rheumatoid arthritis with low function demand: resection arthroplasty.

Periprosthetic Infection Differential Diagnosis

• Loosening
• Osteolysis
• Poly wear

Periprosthetic Infection Complications

• Sepsis
• Functional limitations

Periprosthetic Infection Follow-up Care

Periprosthetic Infection Review References

Leone JM, JBJS 2005;87A:2335