Periprosthetic Joint Infection Bubble Study

Inclusion Criteria: * Be at least 18 years of age * Be medically stable * If female of child-bearing potential, must have a negative pregnancy test * Be conscious and able to comply with study procedures * Have read and signed the IRB-approved Informed Consent form for participating in the study * For Cohort 1, be scheduled for one- or two-stage exchange arthroplasty revision surgery for PJI of the knee * For Cohort 2, be scheduled for DAIR revision surgery for PJI of the knee Exclusion Criteria: * Females who are pregnant or nursing * Patients currently on chemotherapy requiring systemic infusion treatment * Patients who are medically unstable, patients who are seriously or terminally ill, and patients whose clinical course is unpredictable * Patients with a history of anaphylactic allergy to perflutren or any other components of Definity * Patients with a history of failed one- or two-stage revision for infection * Patients for which placement of a surgical drain is contraindicated * Patients in protected classes (e.g., prisoners)