استخوان تیبیا

The effects of non-invasive physical agents on wound and bone fracture healing have been considered by investigators of different medical fields. Several studies have been conducted about the effects of magnetic field on bone fracture healing. The purpose of this study was to investigate the effects of pulsed magnetic fields on healing of tibial bone lesion in rabbits. This experimental study was performed in Shahid Beheshti University of medical sciences in 2014. Eight New Zealand male rabbits were divided into control (with bone lesion) and experimental (with bone lesion and under pulsed magnetic field therapy) groups. A 4×10 cm bone lesion with 2 mm depth was made by surgery on both tibias of each rabbit. One month after surgery, the rabbits in the experimental group underwent 75 Hz pulsed magnetic field therapy with 4 mT intensity in lesion site for 30 days and 4 hours a day. Forty, 50 and 60 days after surgery, bone healing was evaluated with digital radiographs and bone density was measured in lesion sites. Data were analyzed using T- test. Mean relative bone density in lesion sites was 138.50, 150.73 and 168.30 for 8 bit grey scale in the experimental group during three consecutive imaging and showed %17.89, %15.46 and %16.59 increase in comparison with the control group. With regards to the results, it seems that pulsed magnetic field therapy improves healing of bone fracture through increasing bone density in fracture site and can be used after orthopedic surgeries.

Adult stature represents fundamental biological characteristics of individuals and populations. Stature estimation from skeletal dimensions is one of the essential parameters in the establishment of an individual identity. In this study، Relative parameters of ulna and tibia bones were measured with radiography and used to establish the mathematical models for stature estimation of Iranian adults (from 20 to 40 years old) in Tehran Province. The radiography of ulna and tibia bones of 49 male and 52 female adult individuals were taken on normal position and the lengths between relative landmarks were measured. The body height of each subject was recorded. Linear regression equations for stature estimation between body height and the lengths of ulna and tibia bones were established. The mean stature of men and women estimated 171 ± 3. 6 and160 ± 3. 6 the mean length of tibia and ulna in menwere 43. 6 ± 0. 4 and 27. 3 ± 0. 6 and in women 40 ± 1. 8 and 25 ± 0. 74 single linear regression equations and 2 multiple regression equations were obtained. These equations could be used to estimate the body height of Tehranian population aged from 20 to 40. The lengths of the ulna and tibia bones measured on the Radiography films could be useful to stature estimation of the personal forensic identification.

Gonadal hormones have effect on the growth through increasing the osteoblastic activity of bone. They have influence on the calcium metabolism and therefore, are influential on the calcium level of serum and the strength of the bones. The purpose of this study is to examine the effects of gonadal hormones deficiency on the percentage of bone calcium of the tibia in rats.

In the present experimental study 50 thirty – day – old Wistar rats comprised the sample. 25 male rats were randomly divided into 2 groups: Experimental group, i.e. orchidectomy ORX, (n=15) and control group, sham- operation, (n=10) and also 25 female rats were divided in the same way into 2 groups: Experimental group, i.e. ovariectomy OVX, (n=15) and control group, sham- operation, (n=10). Samples were sacrificed 6 months after the surgery i.e. orchidectomies, ovariectomies, and sham operations. Percentage of bone calcium was determined by atomic absorption spectrophotometry. Serum testosterone, progesterone and estradiol levels were measured by ELISA.

Serum testosterone level significantly decreased in the ORX group as compared with the male sham- operated group. In this study estradiol level was not changed in OVX group, but despite the significant decrease in progesterone level (p<0.001), no significant differences in all variables were found between the OVX group and female sham- operated group. In the ORX group, body length and weight, were significantly smaller than in the male sham- operated group. No significant difference in bone calcium percentage was found (Student’s t-test) between control and experimental groups.

In conclusion, it seems that the suppression of gonadal hormones secretion in the growth phase cannot decrease calcium percentage of tibia bone in rats.