A Diagnostic Test Accuracy Study Comparing Biopsy to Aspiration in Shoulder and Elbow Arthroplasty Revision Surgery (BASE Study)

Inclusion Criteria: * Aged: 18 years or older. * A participant is willing and able to give informed consent for participation in the study. * Patient undergoing revision shoulder or elbow arthroplasty surgery. * Previous anatomic total shoulder arthroplasty (TSA), shoulder hemiarthroplasty (HA), reverse total shoulder arthroplasty (RTSA), total elbow arthroplasty (TEA), distal humeral hemiarthroplasty (DHH) and radial head arthroplasty (RHA). Exclusion Criteria: * Refusal of consent. * Antibiotic treatment was not stopped 2 weeks before aspiration or biopsy. * Pregnancy. * Part of any other trial with similar interventions unless previously agreed on with investigators.