| Background: Bracing and surgical treatment has been proven effective in treating adolescent idiopathic scoliosis. At the point of physiology, bracing has extremely lower side effects than surgical treatment. But, the therapeutic efficacy of bracing was lower than surgical treatment in many cases, and there are some cases that are not indicated to bracing. Surgical treatment has been succeded in correcting,but when patients have gotten beautiful shapes, they have been deprived of partial functions and had rigid spines without choices.During the growth of spine, multiple organic centers are formed. These centers are possible to control the growth of spine,and maybe that we could affect the growth of certain organic centers to modulate spinal growth.Then spinal deformity had has been corrected and partial functions been reserved. And we have found in our investigation that it may be available to control or correct spinal deformity through spinal growth control.Objective: In this study, we explored the effect of Nickel-Titanium (NT) memory alloy staples in controlling the growth of the thoracic vertebrates in goats by measuring Cobb angle for the development and clinical application of native medical equipments. Design shape memory alloy (SMA) staples by the characters of Nitinol alloys, observe the process of controlled spine after implanting staples and histomorphological changes of cartilaginous growth in anterior and posterior column in the fixed segments of spine.Methods: The experiment was performed at the Experiment Center for animals and the Laboratory of Orthopaedics of General Hospital of Chinese PLA from March 2007 to 2008. 1.Six fresh specimens of the vertebrae in goats were used to detect. According to these measurements, 4 and 7mm arms of SMA staples were designed. 2. Nineteen infant female goats were selected and randomly divided into long staple group (n =7), short staple group (n =7) and blank control group (n =5). Long staple (7 mm) and short staple (4 mm) were implanted into long and short staple groups by anterior approach. The control group was not given any intervention. X-ray examination was performed pre- and post-operatively. Cobb angle of lateral radiograph was measured by using conimeter.3. SMA staples were implanted in vertebrae in 14 normal goats. Then the goats were observed with X-ray in serial four months. All goats were sacrificed after four months and the histological changes of vertebral bodies in fixed sections were observed.Results: 1. SMA staples were designed into two kinds: short-arm staples and long-arm one: 4mm and 7mm; 2.①One goat in long staple group died of sputum asphyxiation caused by respiratory system infection, one in short staple group died of excessive blood loss, and one in control group died of hypersensitive reaction during immunoprophylaxis. Finally, 6 of long staple group, 6 of short staple group, and 4 of control group were included in final result.②)T4-9 Cobb angle was (8.04±0.69)°in short staple group, and (11.35±4.51)°in long staple group after surgery. There were no significant differences between two groups (P =0.1059).③T4-9 Cobb angle was (0.50 + 7.18)°in two experimental groups before surgery and (10.75±6.72)°after surgery (P < 0.05). T4-9 Cobb angle was (-10.25±1.26)°in control group before surgery and (-10.75±1.50)°after surgery. At the end of experiment, there were significant differences between experimental groups and control group in terms of Cobb angle (P = 0.007). 3. Immun-histologic sections of vertebrae revealed that there are significant differences between all three groups in terms of proliferation activity (P < 0.05).Conclusions: SMA staples have the function of controlling the growth of thoracic vertebrae in goat and kyphosis model could be created successfully by the hemiepiphysiodesis compression. |
PDF Full Text Request