Prosthesis Infections

WHAT IS PROSTHESIS INFECTION?

Septic arthritis(infection) or ‘prosthesis infection’ may develop on prosthesis joint in early(first 1-3 months) or late(after 3 months) period following the hip and knee prosthesis replacements due to several problems such as primary osteoartritis, postraumatic osteoarthritis, rheumatoid arthritis and avascular necrosis. The pre-existing infection on the prosthesis joint, sepsis, infection on tissue in the neighboring of the joint, surgical treatment history, uncontrollable diabetes mellitus, malnutrition, morbid obesity(BMI over 40 kg/m2), immunosuppression, long period of hospitalisation, chronic liver and kidney disease, over consumption of cigarette and alcohol, presence of immunosuppressing viruses such as Hepatitis C and AIDS, increase the risk of infection. The other important factors are poor personal hygiene, inadequate sterile environment in the operating rooms and poor aseptic practises of the surgical staff. The most prevalent microorganisms are meticilline sensitive or meticilline resistant staphyloccous aureus. The management of the infected prosthesis is more difficult than the primary prosthesis procedure and increases the costs for the patients and physicians. Therefore, the management of prosthesis infection must be performed in ultra sterile physical conditions by the experienced surgeons.

HOW IS THE TREATMENT MANAGED?

The treatment is performed in two seperate steps. Initially, the infected prosthesis on hip or knee is removed using proper methods and with gentle care so as not to cause damage on the bone. Then, the infected tissues are removed until reaching the alive and bleeding bone and soft tissues. The region is irrigated using about 10 liters of physiologic saline. The second step is initiated using new surgical clothes and covering set. A superficial prosthesis called antibiotic added spacer, which will substitute the hip or knee joint, is inserted. Proper antibiotics are added into the spacer, which will enable closer treatment of the infected region with the antibiotics. In addition, intravenous administration of the proper antibiotics against the specific microorganisms which are reproduced in culture samples obtained during the surgery, are maintained for 4-6 weeks. The antibiotic administration is terminated in about above mentioned periods. The second step of the treatment is initiated in about 3 months if the physician is confident that the infection in the region and the blood tests(Leukocyte, CRP and sedimentation counts) are clear. The spacer is removed, the patient is prepared for the surgery after wound cleaning and irrigation. Proper prosthesis is inserted using antibiotic semented tool(for knee prosthesis) after providing proper cuts. Sement free hip prosthesis may be inserted if adequate femoral canal and acetabulum is prepared.The monitoring of patients are maintained using both X-ray imagings and laboratory testings quarterly after the surgeries.