ObjectiveTo observe the ability of osteogenesis in vivo using the injected absorbable polyamine acid/calcium sulfate (PAA/CS) composites and assess their ability to repair bone defects. MethodWe selected 48 New Zealand white rabbits, and half of them were male with a weight between 2.0 and 2.5 kg. Bone defect models were made at the rabbit femoral condyle using electric drill, and the rabbits were divided into two groups. One group accepted implantation of the material at the defect, while nothing was done for the control group. After four, eight, twelve and sixteen weeks, the animals were killed. The line X-ray and hard tissue slices histological examination (HE, MASSON staining) were observed to assess the situation of degradation, absorption and bone formation of the material. ResultsFour weeks after operation, bone defect of the experimental group had no obvious callus growth on X-ray imaging. Histology showed that the material began to degrade and new immature trabecular bone grew. The bone defect of the experimental group had a small amount of callus growth on X-ray imaging after eight weeks. And histology showed that the material continued to degrade and new immature trabecular bone grew continually. There was an obvious callus growth after twelve weeks, and the bone defect area had smaller residual low-density shadow on X-ray imaging. Histology showed that most of the materials degraded and parts of woven bone grew into lamellar bone. After sixteen weeks, the composites were absorbed completely, replaced by new bone tissues, and the new bone was gradually changed from woven bone into mature plate of bone. There was no significant change in bone defect in the control group within twelve weeks, and part of bone defect hole became smaller, and partial edge repair could be detected. ConclusionsThe PAA/CS composites can be completely degraded and absorbed, with a certain activity of bone formation, expected to be used as bone repair materials.
Systems-based integrated course is a advanced and mainstream educational mode in western medical education, and also it is a hotspot of current medical education reform in China. In this article, we introduce our practice and the students' feedback of the orthopedic module of 8-year clinical medicine systems-based integrated course. During practice, we follow the integral curriculum design of Sichuan University, establish a team of teachers, integrate the curriculum of relevant disciplines, and improve teaching methods, ameliorate evaluation forms, etc. Through the implementation of this course, we recognize that this new course system aims to cultivate excellent clinical doctors, which focuses on the bilateral permeation and reconstruction among disciplines, especially between basic curriculums and clinical curriculums, changes traditional teaching methods, and strengthens the ability of practice and lifelong learning.
ObjectiveTo explore the value of the long time lower abdominal aorta balloon block technology in the pelvis or sacrum tumor surgery. MethodsFrom January 2005 to June 2013, the sacrum or pelvic tumor patients underwent the long time lower abdominal aorta balloon block technology in the Orthopedics Department of West China Hospital of Sichuan University were enrolled. According to the balloon blocking time, patients were divided into A (<90 mins), B (90 to 180 mins), and C (>180 mins) groups. The intraoperative blood loss, blood transfusion amount, average lengths of hospital stay, postoperative volume of drainage, and postoperative complications were compared among the three groups. ResultsA total of 78 patients were included, of which 21 were in group A, 38 were in group B and 19 were in group C. All patients received en bloc resection, and did not experience intraoperative balloon shift and abdominal aorta flow leakage. Comparing the three groups, there were significant differences in intraoperative blood loss (P=0.026) and average lengths of hospital stay (P=0.021). Further pairwise comparison showed the intraoperative blood loss and average lengths of hospital stay in group C were significantly higher than those in group A and group B. In addition, there were no statistical differences among the three groups in blood transfusion amount, postoperative volume of drainage and postoperative complications. ConclusionIn the pelvis and sacrum tumor surgery, extending the time of abdominal aorta balloon block can reduce bleeding, save blood, increase the safety of surgery without increasing in postoperative complications.