BACKGROUND:To decrease operation amount of finite element analysis and increase its clinical practice,previous studies explored the material properties and 10 kinds of material attributes were assigned,which met the requirements of finite element analysis.Moreover,it can be used to calculate bone density.OBJECTIVE:To explore a method for measurement of bone density based on three-dimensional reconstruction and finite element analysis.METHODS:A total of 11 specimens of femoral superior segment were selected.The mass of control group was firstly measured.The experimental groups were treated with thin-slice high resolution CT scan and three-dimensional reconstruction in Mimics 10.0,volume meshing in Ansys,assigned with 10,100 and 400 kinds of material attributes Mimics,exported to Ansys to calculat the volumes of the block elements of every types of material attributes.The mass and the density of the specimens was harvested according to the empirical formula concerning the gray value and the bone density.All results were treated with one-way ANOVA.RESULTS AND CONCLUSION:One-way ANOVA showed that there were no significant differences between control group and experimental groups assigned with 10,100 and 400 kinds of material attributes (P＞0.28),and there were no significantly among the experimental groups (P＞0.8).Results show that the method was able to measure the mass and the density of bone quantitatively,as well as the proportion between compact bone and cancellous bone;to assign 10 kinds of material attributes to three-dimensional model of femur could match the needs for measurements.The results can be used as an initial preparation for the unification of bone density and finite element analysis for osteoporosis.

Objective:To explore the clinical effects of fiberoptic bronchoscopy airway lavage (FBAL) in the treatment of extremely severe burn patients with severe inhalation injury.Methods:From January 2015 to January 2019, 47 extremely severe burn patients with severe inhalation injury who were hospitalized in Tongren Hospital of Wuhan University & Wuhan Third Hospital, meeting the inclusion criteria, were recruited in this retrospective cohort study. According to whether or not they were treated with FBAL, the patients were divided into fiberoptic bronchoscopy group (23 cases, 19 males and 4 females) and routine group (24 cases, 20 males and 4 females), with the age of (44±11) and (49±9) years, and the admission time of 4 (3, 4) h and 4 (3, 5) h respectively. The patients in routine group were given routine comprehensive treatment, and the patients in fiberoptic bronchoscopy group were treated with FBAL on the basis of routine comprehensive treatment. The pH value, arterial partial pressure of oxygen (PaO 2), arterial partial pressure of carbon dioxide (PaCO 2), arterial oxygen saturation (SaO 2), oxygenation index, white blood cell count (WBC), neutrophils, blood lactic acid, and procalcitonin (PCT) at admission and on post injury day (PID) 3, 5, 7, and 10, the time of mechanical ventilation, the day of intensive care unit (ICU) stay, the incidence of complications and death within PID 28 were compared between the two study groups. The occurrences of bronchospasm and asphyxia of patients in fiberoptic bronchoscopy group were monitored. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, Bonferroni correction, chi-square test, and Fisher′s exact probability test. Results:(1) At admission, the values of pH, PaO 2, PaCO 2, SaO 2, and oxygenation index of patients in the two groups were similar ( Z=-0.118, -0.320, -0.362, -2.416, -0.234, P>0.05). On PID 3, 5, 7, and 10, the values of pH, PaO 2, SaO 2, and oxygenation index of patients in fiberoptic bronchoscopy group were significantly higher than those of routine group ( Z3 d=-4.711, -4.161, -5.525, -2.661; Z5 d=-3.489, -4.678, -5.875, -3.599; Z7 d=-5.104, -4.619, -5.876, -4.844; Z10 d=-4.026, -5.698, -5.877, -4.716; P<0.05 or P<0.01). The PaCO 2 values of patients in fiberoptic bronchoscopy group were significantly lower than those of routine group ( Z=-2.895, -3.162, -3.407, -2.831, P<0.05 or P<0.01). (2) At admission and on PID 3, 5, and 7, the values of WBC, blood lactic acid, and PCT of patients in the two groups were similar ( Z=-0.830, -0.915, -0.458, -0.648, -1.714, -1.479; -0.330, -0.128, -1.766, -0.494, -1.396, -1.522, P>0.05). On PID 10, the values of WBC, blood lactic acid, and PCT of patients in fiberoptic bronchoscopy group were significantly lower than those of routine group ( Z=-3.502, -2.630, -2.662, P<0.05 or P<0.01). At admission, the value of neutrophils of patients in fiberoptic bronchoscopy group was 0.887 (0.862, 0.912), which was similar to 0.887 (0.856, 0.897) in routine group ( Z=-0.404, P>0.05). On PID 3, 5, 7, and 10, the values of neutrophils of patients in fiberoptic bronchoscopy group were respectively 0.848 (0.802, 0.867), 0.831 (0.815, 0.849), 0.798 (0.771, 0.849), 0.796 (0.751, 0.869), which were significantly lower than those of routine group [0.882 (0.820, 0.906), 0.871 (0.835, 0.903), 0.845 (0.819, 0.905), 0.881 (0.819, 0.916), Z=-2.756, -2.810, -2.618, -3.033, P<0.05]. (3) The time of mechanical ventilation and the days of ICU stay of patients were shorter in fiberoptic bronchoscopy group than those in routine group ( Z=-2.199, t=2.368, P<0.05). Within PID 28, the number of patients with complications was significantly less in fiberoptic bronchoscopy group than in routine group ( χ2=5.436, P<0.05), while the incidence of death within PID 28 in fiberoptic bronchoscopy group was similar to that of routine group ( P>0.05). The airway lavage procedures of patients in fiberoptic bronchoscopy group went well with no bronchospasm or asphyxia occurred. Conclusions:FBAL is effective in treating extremely severe burn patients combined with severe inhalation injury. It can improve the oxygenation status of the lung, reduce the systemic inflammatory reaction of patients, shorten the time of mechanical ventilation and ICU stay, and reduce the incidence of complications.

Objective:To investigate the clinical effects of expanded flaps in reconstructing scar contracture deformities in the face and neck after extensive burns.Methods:A retrospective observational study was conducted. From May 2016 to September 2022, 17 patients with scar contracture deformities in the face and neck after extensive burns were admitted to Tongren Hospital of Wuhan University & Wuhan Third Hospital, including 13 males and 4 females, aged 23 to 55 years, with 3 patients having degree Ⅱ cervical contracture, 14 patients having degree Ⅲ cervical contracture, and 12 patients having facial scar contracture deformity. In the first stage, 34 rectangular skin and soft tissue expanders (hereinafter referred to as expanders) with rated capacity of 100-600 mL were inserted into the face, chest, shoulder, and abdomen, and then the normal saline was injected for expansion. In the second stage, the scar tissue was removed and the contracture was released to correct the deformity. Two expanded facial flaps were transplanted in local fashion, 17 expanded flaps were transplanted in pedicled fashion, and 15 expanded flaps were freely transplanted to repair the secondary wounds after release, with artery pressurization was performed in 7 flaps. Indocyanine green fluorescence imaging was used to evaluate the arterial blood perfusion and venous return of the flaps during transplantation. The incision area of 32 flaps except 2 facial flaps was 10 cm×8 cm-36 cm×16 cm. The wounds of 31 flap donor sites were closed by direct suture, and the wound of 1 flap donor site was repaired by autologous split-thickness scalp transplantation. The skin condition of inserted place, expansion time, and total amount of normal saline injection of expanders, complications of skin and soft tissue expansion surgery, and survival of flap after the second stage surgery were observed and recorded. The long-term face and neck reconstruction effect and recovery of flap donor area were followed up. At the last follow-up, the 5-level Likert scale was used to evaluate the efficacy satisfaction of patients.Results:Of the 34 expander inserted places in 17 patients, 22 places were superficial scar skin after deep partial-thickness burns, 8 places were superficial scar skin after multiple skin donations, and 4 places were normal skin. After 4 to 15 months of expansion, the total normal saline injection volume was 238 to 2 000 mL, with no complications occurred. After the second stage surgery, the distal part of 2 pedicled flaps was partially necrotic, and the necrotic wounds were healed after flap dressing and free transplantation of contralateral expanded triangular flaps, respectively; the other flaps survived completely. During 6 to 18 months of follow-up, except for 2 expanded paraumbilical flaps and 1 expanded groin flap, which were bloated and improved by flap thinning, the appearance and texture of the other flaps were good, and all the flap donor sites recovered well. At the last follow-up, the face and neck scar contracture deformities were significantly improved in all patients, and the satisfaction of curative effect of patient was very satisfactory in 8 patients and relatively satisfactory in 9 patients.Conclusions:The expanded flaps of chest, abdomen, and other parts, combined with local advance, pedicled, and free transplantation, can effectively reconstruct scar contracture deformities in the face and neck after extensive burns, restore the function of operative area and improve the appearance simultaneously, with high degree of patient satisfaction, which is worthy of promotion in clinic.