| Part Ⅰ: Etiology for Prosthetic Joint Infection after Total Hip and Knee ArthroplastyObjective: To investage the bacterial species for prosthetic joint infection(PJI) after total hip(THA) and knee arthroplasty(TKA), and reduce the occurrence of resistant bacteria, improve the therapeutic effect of PJI.Methods: We enrolled in 34 patients with PJI after THA and TKA in the Affiliated Hospital of Nantong University between January 2010 and December 2015. Joint fluid,joint capsule and marrow cavity pseudomembranous organizations and acetabulum in pseudomembranous organization were collected as samples. Bacterial culture, isolation,identification were conducted, and drug resistance were measured by disk diffusion method(Kirby-Bauer method).Results: Bacteria culture positive rate was 76.5%(26/34) in these patients. In the 26 patients with bacteria culture positive, 23 patients had a single bacterial infection, the other3 patiets had mixed infections. Bacterial species constituent ratio between THA and TKA showed no significant difference(P> 0.05). Fungal infections occur only in 2 patients in2015. Pathogens constitute difference variation was not statistically significant(P> 0.05)over time. 15 G +bacteria were high resistance with penicillin and erythromycin, but no vancomycin-resistant bacteria, 12 G- were high resistance with penicillin, erythromycin,gentamicin and rifampin, but sensitive to quinolones, and imipenem. In the 15 G +bacteria,methicillin-resistant strains increased year by year. In 2014-2015, it was reached to 100 percent.Conclusions: 1, Prosthetic joint infection after total hip and knee arthroplasty can be infected by G + and G-bacteria, which had a high proportion of resistant strains. 2, G+bacterias have a high sensitivity against vancomycin, and G-bacterias have a high sensitivity against meropenem and imipenem. So, it can be used as first-line agent. 3,Resistant bacterias increased year by year, fungal infection also appears. These should bementioned in prevention and treatment of prosthetic joint infection.Part Ⅱ: Risk Assessment Model for Prosthetic Joint Infection after Total Hip and Knee ArthroplastyObjective: Prosthetic joint infection(PJI) is a rare and serious complication after hip(THA) and knee arthroplasty(TKA). Prevention for PJI after arthroplasty is very important.The purpose of this study is to establish a risk prediction model for PJI after hip and knee arthroplasty, which used for personalized prevention.Methods: A total of 1,536 patients with THA and TKA in the Affiliated Hospital of Nantong University were enrolled in this study between January 2008 and December 2013.We collected the information of postoperative PJI and the possible risk factors for PJI. All the patients were divided into two cohorts. Patients from January 2008 to December 2012 were enrolled in the model training cohort, and patients from January to December 2013 were enrolled in the model validation cohort. In the training cohort, we used multivariate logistics regression model and Nomograph to construct risk prediction model. In the validation cohort, we used goodness of fit test and ROC curves to evaluate the calibration and the discrimination of the model.Results: In the training cohort, the PJI incidence was 2.9%(34/1536), in the validation cohort, the PJI incidence was 2.7%(10/367). PJI incidence between the two cohorts were not statistically significant different(χ2 = 0.343, P = 0.558). No difference of occurrence time was also found between two cohorts(14.2 ± 7 month Vs. 14.1 ± 7 month;t = 0.231, P = 0.592). In the training cohort, univariate and multivariate logistics regression analysis showed age, preoperative corticosteroids application, diabetes, malnutrition,drainage tube implanted in the surgery, postoperative long-term catheterization, and postoperative urinary tract infection were possible risk factors for PJI after THA and TKA(P <0.05). Predicting Nomograph was drawn based on logistics regression model. In the validation cohort, the goodness of fit tests showed Pearson chi-square value was 250.11(P= 0.278), which showed good calibration for predicting of PJI and THA and TKA; the area under the ROC was 0.7551, which indicated a moderate discrimination for prediction PJI.Conclusions: 1, Old age, preoperative glucocorticoid application, diabetes,malnutrition, planted drainage tube in surgery, postoperative long-term catheterization, and urinary tract infections were independence risk factors for prosthetic joint infection after total hip and knee arthroplasty. 2, Based on these risk factors, we constructed a risk prediction model for prosthetic joint infection after total hip and knee arthroplasty. This model has a good calibration power and moderate discrimination power, which may provided a useful tool in clinical practice.Part Ⅲ: Two-stage revision for treatment of prosthetic joint infection following total hip and knee arthroplastyObjective: The PJI number increased year by year. Two-stage revision is a most widely used treatment for PJI. In this study, we analyzed the patients with two-stage revision for PJI, and evaluate the therapy value for total hip and knee arthroplasty.Methods: We enrolled the PJI patients from January 2010 to December 2014 in the Affiliated Hospital of Nantong University. The participants included 18 THA patients and11 TKA patients. All patients received two-stage revision surgery, which included three periods: the first stage surgery, 3-6 month transitional period, and two-stage renovation. All patients underwent outpatient follow-up. Harris score and HSS score were tested for hip and knee function.Results: On admission for first stage surgery, ESR(48.1 ± 15.6 mm/h) and CRP(125.2 ± 31.5) mg/L were significantly increased for 29 patients. The preoperative Harris score(42.5 ± 10.6; 21-55 points) and HSS score(41.6 ± 5.7; 31-52 points) indicated the poor hip and knee function. After first stage surgery, ESR and CRP were decreased, with35.4 ± 9.6 mm/h and 81.6 ± 15.5 mg/L at 6 postoperative weeks. At postoperative 3months, ESR and CRP decreased to normal levels, with 15.8 ± 4.6 mm/h and 44.6 ± 7.3mg/L. Before two-stage revision, the Harris score were 55.6 ± 10.7 points(35-75 points)and the HSS score were 52.6 ± 6.3 points(40-64 points), which showed significant improvement in hip and knee function. The ESR and CRP were also return to normal(15.1± 3.3 mm/h and 41.4 ± 5.6 mg/L). Intraoperative pathology showed polymorphonuclearleukocytes and macrophages in intra-articular tissue were less than five per high power field. After 6 months for two-stage revision, the Harris score(85.6 ± 8.7 points, 69-95points) and the HSS score(86.6 ± 3.5 points, 79-93 points) indicated pefect hip and knee function. No re-infection, periprosthetic fracture and other complications were found.Conclusions: 1, Two-stage revision is effective for treatment of prosthetic joint infection following total hip arthroplasty and total knee arthroplasty. 2, 3-6 months can be the optimal time interval between the first-stage and second-stage operation for prosthetic joint infection. |
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