Objective To observe the operative technique and cl inical effects of hidden tension suture after tibiofibular fracture fixation with absorbable thread. Methods From October 2003 to October 2008, 203 patients (220 sides) with tibiofibular fracture underwent hidden tension suture (test group, 102 cases of 112 sides) and the common interrupted suture (control group, 101 cases of 108 sides), including 179 males and 24 females with an median age of 36 years (3-75 years). Fracture was caused by traffic accident in 170 cases, by heavy bruise in 21 cases, and by fall ing from height in 12 cases. Therewere 186 cases of single-side fracture, and 17 cases of double-side fracture. Of them, 127 sides were closed fracture, and 93 sides were open fracture (including 38 sides of type I, 45 sides of type II, and 10 sides of type IIIA according to Gustilo classification for the open fracture). The locations were upper tibia in 55 sides, middle tibia in 126 sides, and lower tibia in 39 sides. The X-ray films showed that there were transverse fractures in 65 sides, obl ique fractures in 53 sides, spiral fractures in 45 sides, and comminuted fractures in 57 sides. No blood vessel injury, osteofascial compartment syndrome and pressure syndrome were observed. The time from injury to operation was 2 hours to 7 days with an average of 2 days. Of 220 sides, 45 sides were fixed by interlocking nails, others by internal steel plate. Results In control group, heal ing by first intention was achieved in 70 cases (69.3%) and heal ing by secondary intention in 31 cases (30.7%); in test group, heal ing by first intention was achieved in 93 cases (91.2%) and heal ing by secondary intention in 9 cases (8.8%); and showing significant difference (P lt; 0.05). All patients were followed up for 6 months to 2 years (average 9 months). No compl ication occurred in test group, and scar was obvious in the control group. Conclusion The hidden tension suture with absorbable thread can be a good alternative for the incision heal ing after tibiofibular fracture fixation. It deals with the problems of the incision tension and difficult-to-suture, and is good for the incision heal ing after operation.
ObjectiveTo explore the effect and mechanism of miR-21 down-regulated which was induced by H2O2 on osteogenic differentiation of MC3T3-E1 cells.MethodsMC3T3-E1 cells were cultured and passaged, and the 7th generation cells were harvested to use in experiment. The MC3T3-E1 cells were treated with different concentrations (0, 40, 80, 160, and 320 μmol/L) of H2O2. The expression of miR-21 was detected by real-time quantitative PCR (RT-PCR) and the cell viability was determined by MTS. Then the appropriate concentration of H2O2 was obtained. To analyze the effect of H2O2 on osteogenic differentiation of MC3T3-E1 cells, the MC3T3-E1 cells were divided into blank control group (group A), H2O2 group (group B), osteogenic induction group (group C), and H2O2+osteogenic induction group (group D). The expression of miR-21 and the osteogenesis related genes expressions of Runx2, osteopontin (OPN), and collagen type Ⅰ alpha 1 (Col1a1) were detected by RT-PCR. The expression of phosphatase and tensin homolog (PTEN) was detected by Western blot. The extracellular calcium deposition was detected by alizarin red staining. To analyze the effect on osteogenic differentiation of MC3T3-E1 cells after the transfection of miR-21 inhibitor and siRNA-PTEN, the MC3T3-E1 cells were divided into H2O2 group (group A1), H2O2+osteogenic induction group (group B1), H2O2+osteogenic induction+miR-21 inhibitor group (group C1), and H2O2+osteogenic induction+miR-21 inhibitor negative control group (group D1); and H2O2 group (group A2), H2O2+osteogenic induction group (group B2), H2O2+osteogenic induction+siRNA-PTEN negative control group (group C2), and H2O2+osteogenic induction+siRNA-PTEN group (group D2). The osteogenesis related genes were detected by RT-PCR and the extracellular calcium deposition was detected by alizarin red staining.ResultsThe results of MTS and RT-PCR showed that the appropriate concentration of H2O2 was 160 μmol/L. The expression of miR-21 was significantly lower in group B than in group A at 1 and 2 weeks (P<0.05). The expression of miR-21 was significantly lower in group D than in group C at 1 and 2 weeks (P<0.05). The expression of PTEN protein was significantly lower in group C than in groups A and D (P<0.05). The mRNA expressions of Runx2, OPN, and Col1a1 were significantly lower in group D than in group C at 1 and 2 weeks (P<0.05). The extracellular calcium deposition in group D was obviously less than that in group C. The expression of PTEN protein was significantly higher in group C1 than in group D1 (P<0.05). The mRNA expressions of Runx2 and OPN were significantly lower in group C1 than in groups B1 and D1 at 1 and 2 weeks (P<0.05). The mRNA expression of Col1a1 was significantly lower in group C1 than in groups B1 and D1 at 2 weeks (P<0.05). The extracellular calcium deposition in group C1 was obviously less than those in groups B1 and D1. The mRNA expressions of OPN and Col1a1 were significantly higher in group D2 than in groups B2 and C2 at 1 week (P<0.05). The extracellular calcium deposition in group D2 was obviously more than those in groups B2 and C2.ConclusionH2O2 inhibits the osteogenic differentiation of MC3T3-E1 cells, which may be induced by down-regulating the expression of miR-21.