ABSTRACT
BACKGROUND: Obtaining synovial fluid for diagnostic test of periprosthetic joint infection is invasive and painful to patients. Platelet count is a regular blood test which has been used as a possible predictor of several infectious diseases. Presumably, it could be one of the indicators of periprosthetic joint infection. OBJECTIVE: To identify the accuracies of platelet combined with white blood cell, erythrocyte sedimentation rate or C-reactive protein in the diagnosis of periprosthetic joint infection. METHODS: Patients undergoing revision arthroplasty from March 2013 to December 2018 in the First Affiliated Hospital of Guangzhou University of Chinese Medicine were retrospectively enrolled. A diagnosis of periprosthetic joint infection was confirmed in 77 patients according to the criterions from the Musculoskeletal Infection Society; the remaining 137 patients were confirmed as aseptic cases. White blood cell, erythrocyte sedimentation rate, or C-reactive protein and platelet count were compared between the two groups. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS AND CONCLUSION: The platelet values were significantly increased in periprosthetic joint infection cases. Sensitivity and specificity of the platelet for periprosthetic joint infection were 64.94％ and 86.13％, respectively. Platelet demonstrated a higher accuracy when compared to erythrocyte sedimentation rate and C-reactive protein. In such cases, the platelet shows a certain reference value in confirming the diagnosis of periprosthetic joint infection. Platelet was enough used as adjunct diagnostic tool in patients suspected with periprosthetic joint infection.
ABSTRACT
BACKGROUND:With the increasing of aging, the incidence and mortality of osteoporotic hip fracture wil rise. It is of great significance to study the pathogenesis and preventing method. At present, finite element analysis can be used to judge fracture, only for the distribution trend of fracture failure in the starting point or section view, but it cannot completely reflect actual situation of fracture. OBJECTIVE:To build the fracture model of the femoral neck fracture caused by fal ing-induced external force based on the finite element analysis LS-DYNA software, and to evaluate the effect of rupture. METHODS:CT image data of one case of elderly femoral neck fracture were col ected. Using Mimics software, region growth of the contralateral area, cavity fil ing, editing, rebuilding the contralateral proximal femur model were conducted. Data were imported in Hypermesh and LS-DYNA software for meshing, and defining material properties. The failure parameters and interfacial properties were set. The load and force boundary constraints simulating the fal ing were simulated. The model of femoral neck fracture was calculated. Rupture effect was evaluated. RESULTS AND CONCLUSION:(1) The validity of contralateral proximal femur three-dimensional model was verified. Based on the finite element analysis software LS-DYNA, the femoral neck fracture model matched the actual fracture line to a degree of close to 83%. (2) Above results confirmed that based on the finite element analysis, LS-DYNA software can wel simulate the femoral neck fracture, which provides experimental basis to the exploration of femoral neck fracture classification mechanism caused by different fal ing-induced external forces.