Bakterielle Kontamination bei Implantation von Knie und Hüftendoprothesen

Summery The deep bacterial infection is one of the most critical complications in the total joint arthroplasty. The intraoperativ contamination of the wound represents the most important mechanism in deep infection development. The staff in the operating room and the patients were identified as the predominate source of bacterial contamination. The bacteria is transferred into the wound either by direct contact or indirectly by carriers like air particles or sterile materials. In this study 22 microbiology hygienic samples have been taken from 60 primary hip- and knee arthroplasty operations to examinate the bacterial colonizing on the patient, surgeon, lamp handles, instrumentationtable, instruments and in the air. Further we studied in which way the length of the operation, the daytime, the number of persons in the operating theater, the interruptions in the airflow, the joint, the operating theater, the surgeons and the theater sisters influenced the bacterial contaminationrate. We analysed the influence of patient dependent variables like prophylactic antibiotics, the state of health, the age and the sex on wound healing. The average airborne contamination during the skin preparation and draping of the patient (25,6 CFU) and during the postoperative period (56,2 CFU) was clearly higher than during the proper operation (16,3 CFU). Bacterial contamination was found on the lighthandles in 5 (9) operations. The instrumentation table has been contarminated in 18 (16) cases. Bacteria was registrated on the subcutaneous needle (3x) the skinblade (2x) and the deep blade (1x), but the suction tip was always sterile. On the patient was found bacteria on the plastic surgical adhesive drape (1x), the suture (1x) and the deep wound (2x). Concerning the surgeons bacterial contamination was documented on the surgeons gown in 3 (8) and on the glove in 7 cases. On the surgical facemasks there was on average 1,75 CFU and on the forehead 844 (800) CFU. The bacterial spectrum of all hygienic samples showed mainly gram positive cocci and other skincommensales. Staphylococcus aureus was found in 23,3% of the surgeons forehead, in 3,3% of the facemasks and one times in the air and on the glove, never on the patient. Compared to operating theatre 9 a significantly higher bacteria concentration was found at the instrumentation table of operating theatre 12 with increasing length of operation. Regarding the gown our analysis showed more bacterial contamination in operations with an interruption in the airflow then in operations without interruption. The lighthandles in hip operations were more contaminated than in knee operations. This was explained by the position of the operation lights behind the surgeons heads during hip operations. Regarding the number of persons, the daytime and the experience of the surgeons no influence on the bacterial colonization was found. In this study correlations between the contamination of different hygienic samples could be recognised, which showed that the human being is surely the source of the bacterial contamination in the operating theater. Sterile materials were probably contaminated by direct contact or by the air. Unfortunately it was not possible in this study to determine the exact source and way of contamination. However we could show that exposed skinregions like the forehead and an unfavourable composition of the ventilation lead to higher contamination rates. The state of health, sex, age or antibiotic prophylaxis did not influence the woundhealing. The woundhealing in total hip replacement operations was more frequently than in total knee replacement operations. This could be explained by longer suture and more subcutaneous tissue. None of the 60 patients developed a deep infection so that a statement of the influence of certain factors on the infectionrate was not possible.