Many precautions are taken to prevent a PJI after TKA, including appropriate skin preparation, administration of systemic antibiotics, and maintaining a sterile operating room environment. However, some patients are at higher risk of developing infection following the surgery and may develop an infection despite standardized protocols.
Classic history and presentation: The majority of PJIs (60%-70%) occur within 2 years from the primary TKA. Patients may present with pain, stiffness, swelling, and erythema at the site of the prior TKA. Patients may report a recent history of bacteremia, recent procedures (dental work, colonoscopy), or history of intravenous (IV) drug abuse.
Prevalence: Infection occurs in approximately 1%-2% of primary TKAs and 5%-6% of revision TKAs.
Risk factors:
Preoperative –
- Previous infection
- Previous local surgery
- Inflammatory arthropathy (eg, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis)
- Smoking
- Morbid obesity
- Poor dental care, dental infection, and periodontal disease
- Alcohol use disorder
- IV drug abuse
- Immune suppression
- Malnutrition (serum albumin < 3.5)
- Poorly controlled diabetes mellitus (HgA1c > 7)
- Chronic kidney disease
- Chronic liver disease
- HIV infection
- Immunosuppressive drugs
- Antitumor necrosis factor (TNF) agents (eg, infliximab, etanercept, adalimumab, certolizumab, golimumab)
- Antimetabolites (eg, leflunomide)
- Corticosteroids
- Early perioperative infection – Caused by direct inoculation, delayed wound healing, or wound dehiscence. The most common pathogen is S aureus.
- Hematogenous infection – Associated with urinary tract infection, dental work, and other invasive procedures.
Classification is based on timing –
- Acute PJI: Postoperative infection, occurs 2-3 weeks after surgery.
- Delayed-onset PJI: Infection occurs more than 3 months but less than 12-24 months following surgery.
- Late-onset PJI: Infection occurs more than 12-24 months following surgery.