Cytological Effects of Serum Isolated from Polytraumatized Patients on Human Bone Marrow-Derived Mesenchymal Stem Cells.

Due to their immunomodulatory and regenerative capacity, human bone marrow-derived mesenchymal stem cells (hBMSCs) are promising in the treatment of patients suffering from polytrauma. However, few studies look at the effects of sera from polytraumatized patients on hBMSCs. The aim of this study was to explore changes in hBMSC properties in response to serum from polytrauma patients taken at different time points after the trauma incident. For this, sera from 84 patients with polytrauma (collected between 2010 and 2020 in our department) were used. In order to test the differential influence on hBMSC, sera from the 1st (D1), 5th (D5), and 10th day (D10) after polytrauma were pooled, respectively. As a control, sera from three healthy donors (HS), matched with respect to age and gender to the polytrauma group, were collected. Furthermore, hBMSCs from four healthy donors were used in the experiments. The pooled sera of HS, D1, D5, and D10 were analyzed by multicytokine array for pro-/anti-inflammatory cytokines. Furthermore, the influence of the different sera on hBMSCs with respect to cell proliferation, colony forming unit-fibroblast (CFU-F) assay, cell viability, cytotoxicity, cell migration, and osteogenic and chondrogenic differentiation was analyzed. The results showed that D5 serum significantly reduced hBMSC cell proliferation capacity compared with HS and increased the proportion of dead cells compared with D1. However, the frequency of CFU-F was not reduced in polytrauma groups compared with HS, as well as the other parameters. The serological effect of polytrauma on hBMSCs was related to the time after trauma. It is disadvantageous to use BMSCs in polytraumatized patients at least until the fifth day after polytrauma as obvious cytological changes could be found at that time point. However, it is promising to use hBMSCs to treat polytrauma after five days, combined with the concept of "Damage Control Orthopedics" (DCO).

[Strategies of closed reduction in treatment of femoral neck fracture using cannulated screw fixation].

OBJECTIVE: To study intraoperative reduction strategy in treatment of femoral neck fracture using cannulated screw fixation and the relationship between excellent and good rate of reduction and postoperative effectiveness. METHODS: A retrospective analysis was made on the clinical data of 174 cases of femoral neck fracture treated between August 2005 and March 2015. There were 78 males and 96 females with an average age of 53.8 years (range, 23-75 years). The injury causes were falling in 85 cases, traffic accident in 61 cases, and falling from height in 28 cases. According to Garden typing, there were 35 cases of type I, 56 cases of type Ⅱ, 47 cases of type Ⅲ, and 36 cases of type Ⅳ. The time from injury to operation was 1-7 days (mean, 2.74 days). Based on reduction strategy, closed 3 hollow compression screws were used; evaluating standards for fracture reduction effect were also established. Harris score was used for effectiveness evaluation. RESULTS: All the cases received follow-up of 12-42 months (mean, 36.5 months). Bone healing was obtained in 152 cases at 6-12 months (mean, 9 months). Non-union and internal fixation failure occurred in 9 and 3 patients respectively, who underwent hemiarthroplasty; femoral head necrosis occurred in 6 patients after removing internal fixator at 15-26 months (mean, 18.5 months) after operation, who underwent total hip arthroplasty; 4 patients with non-union received vascular pedicle iliac flap transplantation. No other serious complications were observed. At last follow-up, the excellent and good rate of reduction was 94.29% for Garden type I, 91.07% for type Ⅱ, 87.23% for type Ⅲ, and 75.00% for type Ⅳ, with a total excellent and good rate of 87.36%; the excellent and good rate of Harris score was 97.14% for Garden type I, 78.57% for type Ⅱ, 68.09% for type Ⅲ, and 50.00% for type Ⅳ, with a total excellent and good rate of 73.56%. CONCLUSIONS: To obtain high Harris score in fixation of femoral neck fractures by using hollow screws, surgeons not only need reasonable technology, but also follow correct and good reduction strategy and assessment,fracture complexity is inversely proportional to excellent and good rate of reduction. Higher excellent and good reduction rate of complexity fracture should be obtained as much as possible in order to achieve good prognosis.