Management Of Septic Arthritis Of The Hip With Associated Avascular Necrosis

Background：Septic arthritis of the hip is rare in patients with femoral head necrosis.Clinical symptoms of these patients usually are hidddend and specificitydiagnostic indicators are scarcity, so surgeons may overlook thesepatients.Once these patients were overlooked by surgeous,and taked totalhip arthroplasty,the probability of periprosthetic infection was increased.To date, there are few reports of disease in abord, but all of this are basedon the analysis of cases reported and lacked systematic analysis. Thisarticle hopes to reveal the characteristics of these diseases through datacollection, and the postoperative follow-up of hospitalized patients.Objective:The present prospective study was performed to evaluate a variety ofinvestigations for the diagnosis of septic arthritis of the hip withassociated avascularnecrosis in order to determine if any combination ofdiagnostic studies could be used to determine which patients are at riskfor a septic arthritis of the hip with associated avascularnecrosis.Analysis of the treatment of septic arthritis of the hip with associatedavascularnecrosis, to evaluate the effect of surgical treatment.Material and Methods:We prospectively analyzed the preoperative and intraoperativeinvestigations used for the diagnosis of septic arthritis of the hip withassociated avascularnecrosis. Clinical data were collected preoperatively.Investigations to determine the presence or absence of infection includeda white blood-cell count, measurement of the erythrocyte sedimentationrate, measurement of the level of C-reactive protein,MRI of hip，preoperative aspiration of the joint,and gram-staining of preoperativeaspiration, examination of intraoperative frozen sections，and culture of intraoperative tissue. A positive result(suggestive of infection) was clearlydefined for eachof the investigations。With SPSS17.0software to analyzethe diagnostic accuracy and evaluate the sensitivity, specificity, positivepredictive value and negative predictive value of a variety ofinvestigations for the diagnosis of septic arthritis of the hip withassociated avascularnecrosis. Compared to risk of septic arthritis of thehip in different risk factors of osteonecrosis of the femoral head. Analysisof nine cases of septic arthritis of the hip with associatedavascularnecrosis patients, evaluation of different surgical approaches fortreatment.Results:Nine patients（6.38percent）weredetermined to be septic arthritis of thehip with associated avascularnecrosis.The prevalence of septic arthritis ofthe hip with associated avascularnecrosis in SLE patients was37.50%,and in alcoholism patients was9.80%(X2=15.00, P <0.005). The WBC,ESR, CPR, hip MRI,ROC curve, AUC values were25.9%,86.5%,84.3%,and97.7%, respectively. ESR, CPR with high specificity.MRI of hip，preoperative aspiration of the joint,and examination of intraoperativefrozen sections have a higher sensitivity and specificity. There was thelow yield rate of smear and culture.MRI showed soft tissue infectionaround hip joint in4hips and bone involvement in3hips.Exploratoryoperration show soft tissue infection in2hips and bone involvement in1hip.7patients were cured.2patients whose MRI show extensiveinfection in hip were reinfection after debridement.Conclusion:（1） Clinical symptoms of patient with septic arthritis of the hip withassociated avascularnecrosis was occulted, so surgeons may overlook thesupervening septic arthritis. (2) SLE patients with femoral head osteonecros have a higher risk ofseptic arthritis of the hip than the other groups. Followed by alcoholismpatients.(3) WBC, ESR and CPR were effective investigations used forexcluding septic arthritis of the hip form patiens with Osteonecrosis ofthe femoral head. MRI of hip，preoperative aspiration of the joint,andexamination of intraoperative frozen sections have important value indiagnosis of septic arthritis of the hip with associated avascularnecrosis.smear and culture positive rate was very low.(4) MRI may be useful for preoperative planning so that all regionsaffected by the infection can be found. Simple debridement was aineffective treatment for patients whose MRI of hip showed extensiveinfection in hip.