Objective To provide a comprehensive review for development and existing problems of the perforator flaps. Methods The related home and abroad l iterature concerning perforator flaps was extensively reviewed. Results The perforator flaps are defined as the axial flaps nourished solely by small cutaneous perforating vessels (perforating arteriesand veins), which are exclusively composed of skin and subcutaneous fat. The perforator flaps have the advantages as follows: less injury at donor site, less damage to the contour of the donor site, good reconstruction and appearance of the reci pient site flexible design, and short time of postoperative recovery, which have been widely used in reconstructivesurgery. Conclusion The perforator flaps are the new development of the microsurgery, which usher an era of small axial flaps; However, the controversies of the definition, vascular classification, the nomenclature, and the cl inical appl ication of the perforator flaps still exist, which are therefore the hot spot for future study.
The aim of this experimental study focused on the relationship between pull-out strength (POS) and interfragmentary compressive force (IFCF) of AO cancellous lag screw during tightening procedure. The 6.5 mm AO cancellous lag screw and synthetic cancellous bone were used for this research. The test contains rotation tests and the subsequent pull-out tests, to record the IFCF and POS under different tightening angle groups. The results of this study demonstrated the specific relationship between IFCF and POS and showed that they didn’t reach the peak at the very same time. This study revealed the change of mechanical environment surrounding AO lag screw during tightening procedure and found the effective method to determine the optimum terminating time of AO lag screw inserting.
Objective To review the research progress of miRNA regulation in the differentiation of adipose-derived stem cells (ADSCs). Methods The recent literature associated with miRNAs and differentiation of ADSCs was reviewed. The regulatory mechanism was analyzed in detail and summarized. Results The results indicate that the expression of miRNAs changes during differentiation of ADSCs. In addition, miRNAs regulate the differentiation of ADSCs into adipocytes, osteoblasts, chondrocytes, neurons, and hepatocytes by regulating the signaling pathways involved in cell differentiation. Conclusion Through controlling the differentiation of ADSCs by miRNAs, the suitable seed cell for tissue engineering can be established. The review will provide a theoretical basis for molecular targeted therapy and stem cell therapy in clinic.
Objective To compare the biomechanical properties of the anterior transpedicular screw-artificial vertebral body (AVB) and conventional anterior screw plate system (AP) in lower cervical spine by finite element study. Methods CT images (C1-T1) were obtained from a 38-year-old female volunteer. The models of intact C3-7 (intact group), AP fixation (AP group), and AVB fixation (AVB group) were established and analyzed by Mimics 14.0, Geomagic Studio 2013, and ANSYS 14.0 softwares. The axial force of 74 N and moment couple of 1 N·m were loaded on the upper surface and upper facet joint surfaces of C3. Under conditions of flexion, extension, lateral bending, and rotation, the Von Mises stress distribution regularity and maximum equivalent stree of AP and AVB groups were recorded, and the range of motion (ROM) was also analyzed of 3 groups. Results The intact model of lower cervical spine (C3-7) was established, consisting of 286 382 elements and 414 522 nodes, and it was successfully validated with the previously reported cadaveric experimental data of Panjabi and Kallemeyn. The stress concentrated on the connection between plate and screw in AP group, while it distributed evenly in AVB group. Between AP and AVB groups, there was significant difference in maximum equivalent stress values under conditions of 74 N axial force, flexion, extension, and rotation. AVB group had smaller ROM of fixed segments and larger ROM of adjacent segments than AP group. Compared with intact group, whole ROM of the lower cervical spine decreased about 3°, but ROM of C3, 4 and C6, 7 segments increased nearly 5° in both AP and AVB groups. Conclusion As a new reconstruction method of lower cervical spine, AVB fixation provides better stability and lower risk of failure than AP fixation.
Objective To evaluate the effect of polymethylmethacrylate (PMMA) augmentation on cervical stabil ity after anterior cervical interbody fusion (ACIF) before and after fatigue. Methods Twelve porcine cervical spines (C3-7) were subjected to testing angular displacement parameters, including the range of motion (ROM), neutral zone (NZ), and elastic zone (EZ), in nondestructive flexion and extension, right/left lateral bending, and left/right rotation on Motion Analysis motion capture system and MTS-858 servo-hydraul ic testing machine. Intact cervical spines served as control group (group A); oneleveldiscectomy and fusion was performed with anterior plate fixation based on group A as group B; flexion and extension,left/right lateral bending (5 000 cycles) fatigue testing based on group B as group C; the augmentation screw channel was used based on group C as group D; and flexion and extension, left/right lateral bending fatigue testing were performed based on group D as group E. Results The ROM, NZ, and EZ in group A were significantly different from those in other groups (P lt; 0.05) at flexion/extension, left/right bending, and left/right rotation. The ROM, NZ, and EZ in group B were significantly smaller than those in group C (P lt; 0.05) in flexion/extension, left/right bending, and left/right rotation, but there was no significant difference when compared with group D (P gt; 0.05). The ROM and NZ in flexion/extension and the EZ in flexion in group B were significant smaller than those in group E (P lt; 0.05), but there was no significant difference in the other indexes (P gt; 0.05). The ROM, NZ, and EZ in group C in flexion and extension, left/right lateral bending, and left/right rotation were significantly higher than those in groups D and E (P lt; 0.05). The ROM and NZ in flexion and extension and left/right lateral bending, and the ROM in left/right rotation, and the EZ in flexion and extension, right bending, and left/right rotation in group D were significantly smaller than those in group E (P lt; 0.05), but there was no significant difference in the other indexes (P gt; 0.05). Conclusion PMMA augmentation can significantly increase the instant cervical stabil ity and provide a biomechanics basis in cervical anterior plate fixation.
Objective Series of compl icated molecule signal pathway are involved in the bone regeneration. To explore the possibil ity of nuclear factore kappa B (NF-κB) which is taken as the “key activation” during the fracture healing and provide the laboratory evidence for the gene therapy of nonunion or delayed union of fractures. Methods Thirtythree adult male Wistar rats (weighing 180-220 g) were selected and divided randomly into 4 groups: group A (the control group, n=3), the rigth lower segments of radius were injected with normal sal ine 0.3 mL for 7 days, once per day; group B (Bay 11-7082 injection group, n=6), the middle and distal radius were injected with normal sal ine containing 50 μmol/L NF- κB inhibitor Bay 11-7082 0.3 mL for 7 days, once per day; group C (fracture group, n=12), the right middle and distal radius were cut by a sharp scissors to form per fracture model; and group D (Bay 11-7082 treatment group, n=12), based on group C, 0.3 mL of 50 μmol/L Bay 11-7082 were injected into the fracture site for 7 days, once per day. The callus tissues were harvested at 3, 7, 14, and 28 days after fracture for Western blot analysis, alkal ine phosphatase (ALP) activity assessment, prostaglandins E2 (PGE2) production assay, and histological observation. Results The rats of all groups were survivaltill the experiment completion. At 3 and 7 days after injection, there was no significant difference in the ALP activity and PGE2 production between group B and group A (P gt; 0.05); but group C was significantly higher than group A (P lt; 0.01) and group D was significantly lower than group A (P lt; 0.01). The expressions of NF-κB p65, bone morphogenetic protein 7 (BMP-7), and inhibitor of DNA binding 2 (Id2) were observed at fracture sites of 4 groups. There was no significant difference in the expressions of NF-κB p65, BMP-7, and Id2 between group B and group A (P gt; 0.05); the expressions of NF-κB p65 and BMP-7 were significantly higher and the expression of Id2 was significantly lower in group C than group A (P lt; 0.01); and the expressions of NF-κB p65 and BMP-7 were significantly lower and the expression of Id2 was significantly higher in group D than group A (P lt; 0.01). The histological observation showed that a lot of osseous callus formed in group C at 14 and 28 days, but osseous callus just began to form in group D at 28 days. Conclusion NF-κB p65 can facil itate early fracture heal ing of rat radius by elevating the PGE2 production and regulating BMP-7 and Id2 expression.