[General principles of infection treatment in joint replacements].Acta Chir Orthop Traumatol Cech 2005; 72(3):183-90AC
The treatment of infection in joint replacements, which is a complex issue, is justly considered to be one of the most expensive orthopedic procedures. The choice of treatment is determined by a number of criteria that are based on exact patients' history and their clinical, imaging and laboratory data. The management of infection reflects the development in the field of arthroplasty. In the past, the therapy was rather simple, involving removal of the implant, eradication of the infection and simple anatomical intervention in order to make the extremity useful for the patient, often at the cost of many concessions. At present, with rapid advancements of alloplasty, patients' requirements for joint motion are increasing and the ultimate goal is a new and fully functioning joint prosthesis. This treatment is based on early diagnosis as well as early surgical intervention. Antibiotic therapy alone is indicated only in Coventry's type I infection, when positive results of bacterial cultivation are known only after the surgical procedure. A 6-week antibiotic course is administered according to the sensitivity of the isolated bacterial strain. Although treatment solely with antibiotics is preferred by the patients, its long-term outcomes, with the exception of the indication mentioned above, are completely ineffective. Surgical inspection and lavage without implant removal and a subsequent antibiotic course are indicated in type II infection. The procedure involves thorough debridement and replacement of the articulating component, followed by conventional lavage irrigation. One-stage reimplantation requires implant removal, debridement and insertion of a new implant. This is indicated in patients with type III and type IV alloplasty infection by Gram-positive sensitive bacteria that do not produce a glycocalyx layer and in patients in whom the bone bed is without major defects. The method of choice is an implant fixed with antibiotic- loaded cement.One-stage reimplantation is associated with a shorter absence from work, lower costs and better comfort for the patient. Two-stage reimplantation is generally preferred. It is indicated in type III and type IV alloplasty infections caused by resistant or polymicrobial flora or by glycocalyx-producing bacteria, and in patients with large defects of the bone bed. The first stage includes removal of all prosthetic components, thorough debridement and insertion of a cement, conventional or articulating, spacer. Lavage irrigation follows. Based on clinical and laboratory findings, the second stage procedure is carried out after 6 to 12 weeks and a new, usually cementless implant is inserted and defects are repaired, if present. In the treatment of infected alloplasty, a cement spacer has two roles; it provides stability for the joint region after removal of the replacement and, by releasing antibiotics, it prevents the spacer from colonization by bacteria. The cement spacer can be prepared in several ways. The modification preferred by the authors consists only of antibiotic-loaded bone cement moulded in such a way that it can fulfill its stabilizing function and, in hip joints, partially also its locomotor function. Other options include a commercially-produced cement spacer, which has the shape of a cervicocapital prosthesis and is merely placed in the bone bed, or the PROSTALAC system. A three-stage reimplantation procedure is suitable for treatment of extensive bone defects in which the use of a large amount of morselized homograft can be anticipated. The bone bed created from homografts is allowed to incorporate for about 6 months and, in most cases, a cementless implant is subsequently inserted.