BACKGROUND:The age, complication, injury to operation time, and pain level are important factors that affect patients with postoperative mortality, but many scholars disagree. Factors affecting death in elderly patients after femoral head replacement stil need further study. OBJECTIVE:To observe factors related to the survival status of elderly patients within 1 year after receiving femoral head replacement. METHODS:A total of 96 elderly patients receiving femoral head replacement at Department of Orthopedics, the First Affiliated Hospital of Xi’an Jiaotong University from January 2011 to January 2014 were selected. On admission, patients’ age, sex, time from injury to operation, injury to admission time, pain classification, admission hemoglobin, serum albumin content of admission, admission lymphocyte count, and the amount of blood transfusion and preoperative complications were recorded. Fisher test was used to analyze the factors affecting survival status within 1 year after replacement in patients with femoral head replacement using one-way analysis of variance. Multivariate Cox test was utilized to perform multi-factor analysis. RESULTS AND CONCLUSION: The injury to hospital time was > 5 days. Pain classification was grades III and IV. The hemoglobin content was < 120 g/L on admission. The volume of blood transfusion was > 1 000 mL. Serum albumin content was < 35 g/L, which was associated with the increased mortality (P < 0.05). The mortality was significantly higher in patients with more than 86 years old than in patients with 70-85 years old (P < 0.05). The mortality of patients with the time from injury to operation > 7 days was significantly higher than patients with the time from injury to operation < 7 days (P < 0.05). The serum albumin content < 35 g/L and grades III and IV of ASA classification were factors related to patient’s death (P < 0.05). Results confirm that the risk factors for survival status within 1 year of femoral head replacement contain intraoperative volume of blood transfusion, admission to operation time, hemoglobin content, and grading of pain.

BACKGROUND:Recent studies have proved the presence of adjacent vertebral fractures after percutaneous kyphoplasty, suggesting that cement leakage may be an important reason. OBJECTIVE:To investigate the effect of bone cement amount during percutaneous kyphoplasty on adjacent vertebral endplate using finite element analysis. METHODS: Three-dimensional finite element pathological model of Osteoporotic vertebral compression fracture was established using finite element analysis, and 10%, 20% and 30% volume of bone cement were filed, respectively. Then the adjacent vertebral endplate stress under the axial compression, anteflexion and rear protraction were analyzed. RESULTS AND CONCLUSION: Compared with that before operation, the adjacent vertebral endplate stress increased with the increase in filed bone cement volume, suggesting that the increased amount of bone cement wil lead to the increasing of adjacent vertebral re-fractures.