Sonication as a method to optimize the microbiological diagnosis of infection in lower limb arthroplasties

• Grant number: 12/51162-8
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2013
• End date: January 31, 2016
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Ana Lucia Lei Munhoz Lima
• Grantee: Ana Lucia Lei Munhoz Lima
• Host Institution: Instituto de Ortopedia e Traumatologia Professor Francisco Elias de Godoy Moreira (IOT). Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

The worldwide incidence of infection in knee and hip arthroplasty is estimated at between 0.3 and 1.9%, reaching in some studies, up to 5% of cases. For endoprosthesis after resection of bone tumors, the incidence is even higher. The relevance of studies on this issue is the growing number of such procedures worldwide and the consequent increase in the number of infected cases. In 2006 around 800 thousand surgeries for knee and hip arthroplasty were carried out in the United States. In a significant percentage of cases is not obtained evidence of the infection causing agent, which compromises the choice of type and duration of antibiotic adjuvant therapy. The cases of negative culture represent 7-35% of cases. Diagnosis of infected arthroplasty is difficult due to the variability of possible symptoms and the lack of specific tests. Among the challenges facing the diagnosis and treatment of infected arthroplasty is the biofilm issue, which is a structured community of bacteria embedded in the polymer matrix produced by the microorganisms adhered to and living on inert surfaces. The biofilm is an important factor of failure in the treatment of infections in arthroplasties when the surgeon's choice is the maintenance of the implant. On the other hand, because of hosting large numbers of bacteria, presumably related to the infectious bacteria, the possibility of breaking biofilm by sonication, may allow easier identification of the organism by culture fluid around the piece I referred to the method. The present study aims to determine the accuracy of sonication technique in microbiological diagnosis of infection in prosthetic implants of lower limb compared to the conventional diagnosis (culture of bone material). This study shows the process of investigation the etiologic agent in revision surgery of infected prosthesis, the issue of false-positive or false-negative, and the technical feasibility of using the sonication method in the etiologic diagnosis of infected arthroplasty. (AU)