Bases moleculares de la infección asociada a implantes ortopédicos / The molecular basis of infections associated to orthopedic implants

Infections associated with the use of orthopedic implants are still the major complication associated with these devices and an unsolved challenge. The frequency of infection associated with orthopedic implant is relatively low, estimated to range between 0.5 to 5%. However, it has devastating consequences for the patient and health institutions. The majority of infections is secondary to gram-positive aerobic microorganisms belonging to the genus Staphylococcus. These bacteria establish chronic infections due to its ability of adhesion and biofilm formation. Biofilms are complex communities in a polysaccharide matrix. This structure retains nutrients and protects the bacteria against the immune response and antimicrobial agents. The study of molecular characteristics and biofilm formation regulation is vital for the understanding of judicious clinical management and the development of novel strategies for the prevention of infection.

La infección asociada a la utilización de implantes ortopédicos es la principal complicación asociada a estos dispositivos y es un desafío aún sin resolver. La frecuencia de infección asociada a implante ortopédico es relativamente baja, estimada en un rango de 0,5 a 5%. Sin embargo, sus consecuencias son devastadoras para el paciente y las instituciones de salud. La mayoría de las infecciones son causadas por microorganismos aerobios grampositivos pertenecientes al género Staphylococcus. Estas bacterias establecen infecciones crónicas gracias a su capacidad de adhesión y formación de biopelículas, complejas comunidades en una matriz de polisacáridos. La biopelícula retiene nutrientes y protege a las bacterias contra la respuesta inmune y agentes antimicrobianos. El estudio de las características moleculares y la regulación de la formación de biopelículas es vital para el entendimiento del manejo clínico juicioso y el desarrollo de estrategias novedosas para la prevención de infección.

Role of debridement and retention of prosthesis in treating infection after total knee replacement / 中国矫形外科杂志

[Objective]To review our experience in treatine infection after total knee arthroplasty with debridement and component retention to determine To the feasibility,indication,factors related to success and failure,and the main points of technique.[Method]Since 1990 to 2004,9 patients were treated with debridement and component retention at our department.[Result]Four of 9 patients successfully retained their component at most recent follow-up,without ongoing infection(mean 18 months,range 10～25 months).We have not draw the statistically significant factors that related to successful and failure,but the factors such as acute infection,surfacing replacement,immediate debrided after onset of symptoms,and the bacteria sensitive to antibiotic were relate to success.[Conclusion]Debridement and component retention can be used in acute postoperative infection and later acute hematogenous infection after total knee replacement,but timing and indication must be chosen strictly.