[Analysis of pathogen distribution and drug resistance of acute,delayed and chronic periprosthetic joint infection].

Objective: To analyze the pathogen distribution and drug resistance in acute,delayed and chronic periprosthetic joint infection (PJI). Methods: The clinical data of 316 patients with periprosthetic infection after primary hip and knee arthroplasty admitted to the Department of Arthroplasty,the First Affiliated Hospital,Xinjiang Medical University from August 2010 to August 2020 were retrospectively analyzed.There were 146 males and 170 females,aged (62.3±14.2) years (range:22 to 89 years).One hundred and sixty one patients underwent total hip arthroplasty and 155 patients underwent total knee arthroplasty.According to the time of postoperative infection,the patients were divided into acute PJI group (65 cases),delayed PJI group (83 cases) and chronic PJI group (168 cases).The results of pathogen species,composition ratio and drug susceptibility tests were collected,and the independent sample t test,Chi-square test or Fisher's exact probability test were used for comparison. Results: Gram-positive bacteria were the main pathogens of PJI (49.7%,157/316),and the positive rates of culture in patients with acute PJI,delayed PJI and chronic PJI were 33.8% (22/65),55.4% (46/83) and 53.0% (89/168),and the difference was statistically significant(χ²=8.343,P=0.015).The common bacteria were coagulase-negative Staphylococcus (54.8%,86/157) and Staphylococcus aureus (30.6%,48/157),The drug-sensitivity to linezolid,vancomycin and tigacycline was 100%.The gram-negative bacteria were mainly Escherichia coli and Enterobacter cloacae,and the drug resistance rate to carbapenems was low,ranging from 0 to 9.09%.The drug resistance rates of acute PJI patients to rifampicin,ciprofloxacin and erythromycin were significantly higher than those of late onset and chronic PJI patients,the difference was statistically significant(rifampicin:χ²=14.332,P=0.001;ciprofloxacin:χ²=12.086,P=0.002;erythromycin:χ²=9.096,P=0.010);The drug resistance rate of acute PJI patients to levofloxacin,clindamycin and tetracycline was higher than that of chronic PJI patients,and the difference was statistically significant(levofloxacin:χ²=10.500,P=0.002; clindamycin: χ²=7.103,P=0.007; tetracycline: χ²=6.909,P =0.012).The resistance rate of ampicillin/sulbactam in acute PJI (60.0%) was significantly higher than that in chronic PJI (16.7%),and the difference was statistically significant(χ²= 5.853,P=0.040). Conclusion: Gram-positive bacteria are the main pathogens of PJI,and the resistance rate of pathogens of acute PJI is higher than that of late onset and chronic PJI.

Effect of total hip arthroplasty in patients with stiff hip and severe length discrepancy / 中华外科杂志

Objective@#To observe the outcomes of total hip arthroplasty in patients with stiff hip and moderate or severe leg length discrepancy and to explore the strategy for balance recovery.@*Methods@#A retrospective review was conducted on the clinical data of 30 patients who had stiff hip and moderate or severe leg length discrepancy treated with unilateral primary total hip arthroplasty at Department of Joint Surgery, First Affiliated Hospital of Xinjiang Medical University from January 2014 to January 2017.There were 18 male and 12 female patients aging of (43.5±9.7)years (range, 30-68 years). All patients had different degrees of pelvic tilt and scoliosis. In operation, contractured soft tissues were released, periarticular osteophytes were removed thoroughly and the center of ratation was restablished without femoral shortening osteotomy.Patient satisfaction, Harris hip score, perceived leg length discrepancy (LLD), true LLD and functional LLD were collected.Data were analyzed by paired-samples t-test.@*Results@#The mean follow-up duration was (17.6±7.6)months (range, 12-30 months). The Harris hip score was improved from 37.6±5.7 preoperatively to 84.3±5.2 at last follow-up (t=-57.54, P=0.000). The preoperative and last follow-up data of true LLD((3.19±0.82)cm vs.(0.70±0.71)cm), functional LLD((4.36±1.72)cm vs.(0.46±0.53)cm) and perceived LLD((7.74±2.01)cm vs.(0.98±0.79)cm) was significantly difference(t=26.47, t=15.05, t=26.9, P<0.01). Twenty-seven patients were restored to normal level (LLD≤10 mm ) and there was no sciatic nerve injury observed after surgery. 90.0% (27/30) patients were satisfied by the outcome.@*Conclusions@#Total hip arthroplasty have satisfactory effect in correcting leg-length discrepancy of stiff hip patients. Preoperative assessment, individualized surgical methods and soft tissue releasing are important for balance recovery of affected limbs.