ABSTRACT
Objective The dynamic detection of endotoxin is of great significance for the early diagnosis and treatment of prosthesis loosening after joint replacement. This study aimed to explore and analyze the clinical significance and efficacy of endotoxin detection in prosthetic joint loosening after joint replacement.Methods Fifty-eight patients who underwent arthroplasty in the department of orthopedics in Nanjing General Hospital from January 2015 to June 2016 were selected for prospective study. The patients were divided into the infection loosening group (patients with infectious loosening after arthroplasty, n=15), the aseptic loosening group (patients with aseptic loosening of after arthroplasty, n=23) and the control group (patients were normal after arthroplasty, n=20) according to the postoperative complications. Endotoxin was detected with MB-80 microbial dynamic rapid detection system. We compared the endotoxin level and the ROC curve was made to acquire the sensitivity and specificity under the different cut-off values. Eventually find the best diagnostic threshold.Results The levels of endotoxin in the infection loosening group and the aseptic loosening group \[(0.56±0.11, 0.49±0.08) ng/mL\] were significantly higher than that in the control group \[(0.24±0.06) ng/mL\]. The difference was statistically significant (P0.05). ROC curve analysis showed that when the serum endotoxin concentration was 0.36 ng/mL, the Youden index was the highest, which could be the best cut-off value for diagnosis. It had the best accuracy to judge the prosthesis loosening with a sensitivity of 66.7% and specificity of 88.2%.Conclusion The endotoxin can be a good indicator for early diagnosis of prosthesis looseness. It is helpful to the diagnosis of the prosthesis loosening after arthroplasty.
ABSTRACT
ObjectiveTo establish a method of rapid detection of bacteria endotoxin based on interdigital gold electrode and surface acoustic wave (SAW).MethodsWith the carriers of 3-APTES and glutaral pentanedial,Polymyxin B (PMB) was immobilized on interdigital gold electrode,and then reacted with the bacteria endotoxin' s biological active material (lipopolysacchride,LPS) selectively.Double differential circuit based on SAW was employed to complete the detection.Two output oscillation signals were differentiated through mixer and the endotoxin content was described by frequency shift.ResultsThe experimental results indicated that there was a liner relationship between the frequency shift and endotoxin content within the content range of 75-130 EU/ml.ConclusionComparing with traditional method,the detection time is shortened to 10 minutes,the sensitivity is 13.8 KHz/(EU·mL-1),and repeatability is above 90％.