Rate of capsular contracture among different breast implants in the last two decades: a meta-analysis / 中华医学美学美容杂志

Objective:To study the rate of capsule contracture after operation of the textured surfaces breast implants and the smooth surfaces breast implants, to provide evidence for plastic surgeons to select the type of breast implants during breast augmentation.Methods:This study started from January 2018 to May 2019. Chinese and English databases including Wanfang Science and Technology Periodical Full-text Database, VIP Chinese Science and Technology Periodical Full-text Database (VIP) and CNKI, PubMed, Cochrane Library, Web of Science, Science Drirect Online were searched by computer. Some relevant studies were collected for this meta-analysis.Results:We identified 9 studies including a total of 13165 subjects for the meta-analysis. The OR value of the study was 0.43 (95% CI: 0.35, 0.51), and the incidence rate of capsule contracture in the experimental group was lower than that in the control group. In cumulative meta-analysis and sensitivity test, the conclusion was stable. And there was no publication bias found by Egger regression test. Conclusions:The textured surfaces breast implants are better than the smooth surfaces breast implants in terms of incidence rate of capsule contracture after augmentation mammoplasty.

External use of recombinant human granulocyte-macrophage colony stimulating factor hydrogel to repair thick skin graft donor sites / 中国组织工程研究

BACKGROUND:There are less reports about the external use of recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) hydrogel to repair thick skin graft donor sites. By now, relevant self-control studies have not been retrieved. OBJECTIVE:To observe the effect of rhGM-CSF on the repair of thick skin graft donor sites. METHODS:Sixty patients with burns and scar hyperplasia undergoing autologous thick skin grafting were enroled, 47 males and 13 females, aged 18-65 years. The thigh was selected as donor sites. According to the depth of donor sites, the patients were divided into 0.4 mm and 0.55 mm groups, with 30 cases in each group. Wounds on the symmetric areas with equal area and same depth were selected or wounds with same depth were selected and divided equaly. The wounds were randomly assigned into treatment group and control group. The treatment group was treated with rhGM-CSF hydrogel externaly; the control group was only given vaseline dressing. At postoperative 3, 7, 10, 14 days, the fresh dressing was changed. Then, the wound appearance, healing time, healing rate and adverse effects were observed in the two groups. RESULTS AND CONCLUSION:At 14 days after operation, the wound surface was smoother and the pigmentation was relatively less in the treatment group compared with the control group; the degree of wound pain was less in the treatment group than the control group during dressing change (P < 0.05). At 10 and 14 days after operation, the healing rate and healing time were better in the treatment group than the control group (P < 0.05). No general malaise or hypersensitivity cases were reported, and local issue hyperplasia was also not found. Al the above indicate that the external use of the rhGM-CSF hydrogel can evidently shorten the healing time and improve the healing condition when it is applied in the thick skin graft donor sites.

A theoretical model study of open section effect on the mechanical properties of long bone / 生物医学工程学杂志

The mechanical model of femur mid-diaphysis with a rectangular open section in the exterior cortex was developed and a finite element method was adopted in calculating and analysing the changes of torsional stiffness and the stress distribution when the dimension of the open section altered. It showed that the open section with a length of 1 OD (femur mid-diaphysis diameter) had little influence on the femur torsional stiffness or stress distribution. The torsional stiffness decreased most dramatically as the length increased from 2 to 4 OD. Shear stress peaked at the center of the open section. This conclusion provides an important theoretical ground for the operative methods and the dimension control of an open section in clinical orthopaedics.

Effect of low stress environment on bone density and geome-morphology of rat femur / 生物医学工程学杂志

6-week old rats were subjected to sciatic nerve resection and the right hindlimbs were then under a low stress environment. Bone mineral density (BMD) of different regions and geome-morphological parameters of femurs were measured. The results showed that the increase in the diameter, subperiosteal area and bone mineral density of femurs were suppressed obviously under low stress environment. But the sensitivity of BMD of different regions of the femur to the low stress environment was different. The suppression of the increase in femoral BMD was composed of an early impairment in the gain of BMD at the femoral metaphysis, which is rich in trabecular bone, and a sustained reduction in the gain of BMD at the femoral diaphysis, which is rich in cortical bone. The results of geome-morphology suggested that the early reduction in the increase of BMD at the metaphysis was due to an enhancement of bone resorption, whereas the suppression of gain in cortical bone mass and size is the result of a sustained reduction of periosteal bone formation.

Biomechanical test study of rat femurs growing under different stress environment / 生物医学工程学杂志

By creating two kinds of stress environment in the same animal model, we performed a three-point bending test and a compressing test on the rat femurs growing under different stress conditions to characterize the effect of stress on bone mechanical properties. The right hindlimbs were subjected to sciatic nerve resection to become cripple and were used as unloading group; the left hindlimbs bore excess load and made up the overloading group; the normal rats were used as control group. The animals were encouraged to exercise for half an hour everyday in the morning, noon and evening. The experiment observation finished in four weeks. The biomechanical parameters of femur diaphyses were measured. The experiment results showed that stress environment may change several mechanical parameters of rat femurs. This study indicated that bone tissues can adapt to its stress environment by changing its mechanical properties. The experimental model in this article is practical and reliable.