Objective To investigate the changes of lumbar bone histomorphometry after exposure to low frequency pulsed electromagnetic fields (PEMFs), and to further understand the effect of PEMFs on osteoporosis (OP) in ovariectomizedOP rats. Methods Sixty-six 3-month-old Sprague Dawley rats were randomly divided into 4 groups: group A(n=12), groupB (n=12), group C (n=12), and group D (n=30). In group A, the ovaries were not resected as sham-ovariectomy; in groupsB, C, and D, the ovaries were resected. At 12 weeks after ovariectomy, the rats were exposed to PEMFs at 8 Hz, 3.8 mT, and 40 minutes/ day for 30 days in group B; the rats were administered with premarin [0.065 mg/(kg·d) by gavage for 30 days] in group C; in group D, the rats were housed as ovariectomy control. The hair and activity of rats were observed; the levels of serum estradiol were determined. At 30 days after intervention, all rats were sacrificed to harvest the L4 vertebrae for bone histomorphometry. Results General observation showed hair loss and decreased activity in group D, and no abnormal appearances in groups A, B, and C. The level of serum estradiol in group A was significantly higher than that in group D [(54.93 ± 23.52) pg/mL vs. (31.99 ± 23.45) pg/mL] (t=2.345, P=0.029). Histological observation showed thinness of sclerotin, bigger medullary cavity, and sparse and thinner bone trabecula in group D; uniform bone trabecula with no breakage in groups A, B, and C at 30 days after intervention. The ratio of trabecular bone area in group B was significantly higher than that in group D (P lt; 0.05); it was higher than that in groups A and C, showing no significant difference (P gt; 0.05). The trabecular thickness in group B was significantly higher than that in group D (P lt; 0.05), but it was lower than that in groups A and C, showing no significant difference (P gt; 0.05). The trabecular number in group B was significantly lower than that in group D (P lt; 0.05), but it was higher than that in groups A and C, showing no significant difference (P gt; 0.05). The trabecular separation in group B was higher than that in group D and lower than that in groups A and C, showing no significant difference (P gt; 0.05). Conclusion PEMFs at 8 Hz and 3.8 mT can significantly improve the character of bone microstructure in ovariectomized OP rats, increase the ratio of bone trabecular area and trabecular thickness, and decrease the trabecular number.
Objective To study the effect of Shengguzaizaosan on experimental fracture healing. Methods Thirty six-month-old Chinchilla rabbits were made the models with 3 mm bone defect in the middle of two-side radius and were divided randomly into 3 groups: Shengguzaizaosan group(group A, n=10), Xianlinggubao group(groupB, n=10) and control group(group C, n=10). Five rabbits were sacrificed 14 days and31 days after operation respectively. The double marks with tetracyslin hydrochloride were given on the 4th day and the 5th day for the first mark and on the 11th day and the 12th day for the second mark in the rabbits sacrificed 14 days later,and on the 20th day and the 21st day for the first mark and on the 28th day andthe 29th day for the second mark in the rabbits sacrificed 31 days later. The samples were taken to make the bone histomorphometry study. Results When compared group A with group C, there were significant differences(P＜0.01) in osteoid area density, osteoid mean width, active osteoblastic surface, mineralization surface and dynamic parameters after 14 days,and in mean width of mineralization callus, active osteoblastic surface and mean depth of lacunae after31 days. There was a approximate effect between group B and group C. when compared group B with group A, there were significant differences(P＜0.05) in osteoclastic index,mineralization surface,bone formation rate after 14 days, and in osteoid surface,mean depth of lacunae and bone formation rate after 31 days. Conclusion Shengguzaizaosan can increase osteoid,accelerate mineralization rate and bone formation rate, and reduce mineralization lag time at early period of fracture. It can increase mineralization calluswidth and resorption of osteoclast at later period of fracture. To some extent, shengguzaizaosan can accelerate the experimental fracture healing.
Objective To measure the position of patellar high point and the shape of the osteotomy surface, and to analyze their relationship, distribution, and gender differences. Methods A total of 127 patients who needed anterior cruciate ligament reconstruction or meniscus repair due to trauma between September 2020 and September 2021 were selected as the research subjects. There were 71 males and 56 females, with an average age of 30.5 years (range, 19-43 years). There were significant differences in height and body weight between male and female patients (P<0.05), but no significant difference in age and body mass index (P>0.05). The three-dimensional model of the patella was reconstructed in Mimics software based on the CT images of the knee joint, and then imported into Geomagic Studio software for virtual osteotomy of the patella. The horizontal axis and vertical axis of the osteotomy surface represented the total width (W) and total height (H) of the osteotomy surface, respectively. Then the osteotomy surface was divided into four quadrants with the two axes: inner proximal, inner distal, outer proximal, and outer distal, and the inner width (W1), proximal height (H1), outer width (W2), and distal height (H2) were measured. The midpoint of the patellar ridge was selected as the patellar high point, and the point projected onto the osteotomy surface was defined as the optimal point for patellar prosthesis positioning (OPPP). The distances of OPPP on the horizontal axis (L1) and vertical axis (L2) relative to the center of the osteotomy surface were measured and L1/W1 and L2/H1 were also calculated; the quadrant distribution of OPPP was recorded. The patients were grouped according to gender, and the morphological parameters of the osteotomy surface (W, W1, W2, H, H1, H2) and the parameters related to the position of the OPPP (L1, L2, L1/W1, L2/H1) were analyzed between groups. Results The width and height of each osteotomy surface of the patella in males were significantly larger than those in females (P<0.05). As for the relationship between OPPP and osteotomy surface, the L1 of both male and female patients was 1-7 mm, and there was no significant difference in the distribution between the two groups (χ2=8.068, P=0.149); L1/W1 in both male and female patients was mainly 1/10-3/10. The L2 of male patients was 0-5 mm, and that of female patients was –1-4 mm; the difference in distribution between the two groups was significant (χ2=15.500, P=0.006); L2/H1 in both male and female patients was mainly 0-1/5. The OPPP of male patients was mainly distributed in the inner proximal (98.59%) and outer proximal (1.41%) quadrants, while the female patients were distributed in the inner proximal (91.07%), inner distal (7.14%), and outer proximal (1.79%) quadrants. There was significant difference in the OPPP quadrant distribution between the two groups (χ2=5.186, P=0.036). Conclusion The OPPP points are widely distributed but mainly concentrated on around 1/5 of the medial patella surface and around 1/10 of the superior patella surface. A small portion of females’ OPPP were inferior while all males’ OPPP were superior to the center of the patella.