Objective To investigate whether the abnormal stress could cause the ultrastructural change of the rats′condylar cartilage in vivo .Methods Fifty‐four SD male rats were randomly divided into condylar neck osteotomy operation(OO)group ,con‐dylar neck fracture operation(FO) group ,and control group ,with 12 rats in each group .Then the OO group rats ,FO group rats and control group rats were executed and sampled at 1st week ,3rd week and 5th week separately to observe the structure of condyle with light microscope(LM ) ,scanning electron microscope (SEM ) and transmission electron microscope (TEM ) .Results LM showed that the general condylar thickness of OO group and FO group were thinner than that of control group at 3rd and 5th week . SEM showed that the collagen and fibre were exposed in the OO group and FO group at 3rd week and 5th week ,the fibre was bro‐ken in the OO group at 5th week .TEM showed that the hypertrophic cell in OO group was more mature than those of FO group and control group at 3rd week .The arrange of fibre was disorder in OO group at 1st week ,the fibre was more disorder and there was even leak in OO group at 5th week .Conclusion The abnormal stress in vivo could result in the ultrastructural change of the rats′condyle ,and this change relates with the stess change degree and affects the growth and development of condyle .

Objective To investigate the effect of vascular endothelial growth factor (VEGF) on the leukocyle function in a rat denervated infect flap model and to investigate the action mechanison of VEGF in the flap anti-infection .Methods An island pedicle flap measured 2 cm × 2 cm was raised on the right abdomen of sixty wister rats ,which were divided into three groups .All flaps re-ceived intradermal inoculation of 107 Staphylococcus aureus ,and the animals were observed for 96 h .The indexes of the leukocyte count ,leukocyte vitality ,hemiluminescence of neutrophils ,tissue bacterial count ,naked eyes observation of falptissue and the light microscope observation were detected .Results The leukocyte count in the exudation at postoperative 96 h had no statistical differ-ences among 3 groups(P>0 .05);while in the indexes detection of the leukocyte vitality ,chemiluminescence of neutrophils ,tissue bacterial count ,etc .,the comparison between the chronic denervated group and the control group showed very significantly differ-ences(P<0 .01);the differences between the VEGF treatment group and the chronic denervated group was very significant (P<0 .01) .The falp pathological change in the control group and the VEGF treatment groups was slight .Conclusion The soft issue af-ter losing the innervation decreases the leukocyte function .VEGF might improve the flap micro circulation and play an important role in improving the leukocyte function .

Objective To explore the effect of primary exchange reamed nailing (ERN) and augmentation compression plating (ACP) combined with autogenous bone grafting (ABG) on health-related quality of life in patients with dystrophic or atrophic nonunion of femoral shaft after intramedullary nailing. Methods The study used a prospective study method. Sixty- two patients with femoral shaft nonunion after intramedullary nailing from August 2010 to October 2016 were selected, and the patients were divided into ERN group (group A, 32 cases) and ACP group (group B, 30 cases) by random digits table method. In group A, isthmus nonunion was in 18 cases (56.2％), and non-isthmus nonunion in 14 cases (43.8％); in group B, isthmus nonunion was in 16 cases (53.3％), and non-isthmus nonunion in 14 cases (46.7％ ). The health- related quality of life was compared between 2 groups, including physical component summary (PCS) and mental component summary (MCS) in the- 12- item short form health survey (SF- 12), brief pain inventory- severity (BPI- S) and brief pain inventory- interference (BPI- I). Results Fifty-four patients were followed-up for more than 1 year, and the mean follow-up time was 18.3 (13 to 37) months. All patients successfully achieved bone union, and the mean time was 5.8 (4 to 8) months. Significant improvements in terms of SF-12 PCS and SF-12 MCS score were noted after operation for patients with isthmus nonunion in both groups (t=3.148, 2.156, 2.456 and 2.559; P < 0.05), but there were no significant differences before and after operation in group A with non-isthmus nonunion (P >0.05). At the last follow-up, SF-12 PCS and SF-12 MCS in group B were significantly improved compared with those in group A: (45.2 ± 5.8) scores vs. (33.6 ± 4.7) scores and (48.8 ± 6.5) scores vs. (39.4 ± 5.6) scores, and there were statistical difference (P<0.05); SF-12 BPI-S and BPI-I showed obvious relief: (4.6 ± 2.1) scores vs. (6.2 ± 2.5) scores and (5.2 ± 1.9) scores vs. (6.8 ± 2.7) scores, and there were statistical differences (P<0.05); however there were no statistical difference in SF-12 PCS, SF-12 MCS, BPI-S and BPI- I between 2 groups (P>0.05). Conclusions Compared with ERN combined with ABG, ACP combined with ABG can significantly improve the quality of life in patients with dystrophic or atrophic nonunion of femoral shaft after intramedullary nailing. It has greater advantage on the improvement of health-related quality of life, especially for patients with non-isthmus nonunion.