ObjectiveTo investigate the effectiveness of autologous injectable platelet rich fibrin (i-PRF) combined with bone marrow mesenchymal stem cells (BMSCs) for sciatic nerve injury in rats.MethodsBMSCs were isolated and cultured from tibial bone marrow of Sprague Dawley (SD) neonatal rats aged 10-15 days and passaged to the 4th generation. i-PRF was prepared from posterior orbital venous blood of adult SD rats by improved low-speed centrifugation. Twenty-four adult SD rats were selected and randomly divided into 4 groups with 6 rats in each group after the sciatic nerve Ⅲ degree injury model was established by modified crush injury method. Groups A, B, C, and D were injected with BMSCs suspension+autologous i-PRF, autologous i-PRF, BMSCs suspension, and normal saline, respectively. The Basso-Beattie-Bresnahan (BBB) score was used to evaluate the recovery of neurological function of the affected limb of rats every week from 1 to 8 weeks after operation. At 2 months after operation, the rats were sacrificed and the histological changes of sciatic nerve were observed by HE staining. The microstructural changes of nerve fibers, myelin sheath, and nucleus were observed by transmission electron microscope. The expressions of N-cadherin, Nestin, and glial fibrillary acidic protein (GFAP) were detected by Western blot.ResultsNo immune rejection or death occurred in the rats after operation. There was no significant difference in BBB scores between groups at 1 week after operation (P>0.05); at 2-8 weeks after operation, BBB scores in group A were significantly higher than those in groups B, C, and D, and in groups B, C than in group D (P<0.05), there was no significant difference between groups B and C (P>0.05). HE staining showed that the nerve fibers in group A arranged in order, without defect or demyelination; the nerve fibers in group B were not clear and slightly swollen; some of the nerve fibers in group C were disordered and demyelinated; the nerve fibers in group D were not continuous, obviously demyelinated, and some of the nerve adventitia damaged. Transmission electron microscope showed that the structure of nerve fibers in group A was clear, myelin sheath was complete, and nucleus was dense; group B was slightly less than group A; group C had fuzzy structure, demyelination, and hollowing out; group D had disorder structure, demyelination, and hollowing out, and the middle part of nerve adventitia continuity. Western blot detection results showed that there was no significant difference in the relative expression of Nestin between groups (P>0.05). The relative expression of N-cadherin was significantly lower in groups B, C, and D than in group A, in groups C and D than in group B, and in group D than in group C (P<0.05). The relative expression of GFAP was significantly lower in groups B, C, and D than in group A, in group D than in groups B and C (P<0.05); there was no significant difference between groups B and C (P>0.05).ConclusionAutologous i-PRF combined with BMSCs can effectively treat sciatic nerve tissue injury in rats.
ObjectiveTo investigate the effectiveness of proximal femoral nail anti-rotation (PFNA) and cerclage fixation for complicated femoral subtrochanteric fractures.MethodsA clinical data of 74 patients with complicated femoral subtrochanteric fractures, who were admitted between March 2016 and March 2019 and met the criteria, was retrospectively analyzed. Among them, 39 patients were treated with limited open reduction and PFNA combined with cerclage fixation (observation group) and 35 patients were treated with closed reduction and PFNA fixation (control group). There was no significant difference in gender, age, cause of injury, side and type of fracture, and the time from injury to operation (P>0.05). The ratio of postoperative hemoglobin (1, 3, and 5 days) to the preoperative hemoglobin, the operation time, the first weight-bearing time after operation, and the hospital stay were recorded. X-ray films were taken to observe fracture healing in the two groups and bone resorption around the cerclage in the observation group, and the fracture healing time was recorded. Hip function was evaluated by Harris scoring. ResultsThe operation time of the observation group was significantly longer than that of the control group (P<0.05), but the first weight-bearing time and hospital stay were significantly shorter (P<0.05). All patients were followed up 12 months. There was no significant difference in the ratios of post- to pre-operative hemoglobin (1, 3, and 5 days) between the two groups (P>0.05). X-ray film reexamination showed that the fractures of the two groups healed smoothly, and the fracture healing time of the observation group was significantly shorter than that of the control group (t=−12.989, P=0.000). No bone resorption around the cerclage occurred in the observation group. The Harris scores of the observation group were better than those of the control group at 7 days and 1, 2, and 3 months after operation (P<0.05), and there was no significant difference between the two groups at 6 months after operation (t=1.329, P=0.180).ConclusionCompared with PFNA fixation, PFNA combined with cerclage fixation for the complicated femoral subtrochanteric fractures has a shorter operation time, and can obtain immediate stability after fixation, which can meet the needs of patients for early functional exercise.