Anatomical and biomechanical characteristics of sternoclavicular joint / 中国组织工程研究

BACKGROUND: The clinical experience of the treatment of the sternoclavicular joint dislocation and peripheral fracture is relatively lacking, but its incidence is increasing yearly. At present, there are few studies on the anatomy and biomechanics of the sternoclavicular joint in and outside China, and no systematic anatomical measurements of the sternoclavicular joint are reported. OBJECTIVE: To provide a biological reference for the clinical diagnosis and treatment of sternoclavicular joint dislocation or peripheral fractures by studying the anatomy and biomechanics of the sternoclavicular joint. METHODS: (1) A total of 16 specimens (32 sides) of adult antiseptic and moist cadaveric specimens were selected. The complete manubrium, bilateral clavicle and surrounding tissues of sternoclavicular joint were anatomically separated, and repair to bone-ligament-bone specimen models. (2) The areas of manubrium articular surface and the medial clavicular articular surface of all specimens were measured by the ink pattern combined with grid counting method. (3) The morphological features of the anterior and posterior sternoclavicular ligaments of the specimens in this group were observed, and the length, width and thickness were measured and analyzed statistically. (4) The left and right sternoclavicular joints of each specimen were randomly paired into A and B groups. Group A received simply cutting of anterior sternoclavicular ligament. Group B received simply cutting of posterior sternoclavicular ligament. Before and after cuting off the ligament, the anterior and posterior load experiments were performed on the anatomical sites with the same force arm length and perpendicular to the distal clavicle. The angles of joints and load-angle regression line slopes were compared between the two groups in the anterior and posterior directions load. RESULTS AND CONCLUSION: (1) The area of articular surface of manubrium (239.00±28.78 mm2) was smaller than the area of medial articular surface of the clavicle (482.56±44.89 mm2), and the difference was statistically significant (t=-40.105, P < 0.001). (2) The length, width and thickness of the anterior sternoclavicular ligament were (17.56±1.94 mm), (15.54±1.42 mm) and (1.93±0.32 mm), and the length, width and thickness of the posterior sternoclavicular ligament were (17.21±1.86 mm), (15.97±1.17 mm), and (2.07±0.29 mm) respectively;there was no significantly statistical difference in the length, width and thickness between them (P > 0.05). (3) Before cutting the ligaments, when the loads were 2, 4, 6, 8, and 10 N, the angle backwards of joint caused by loads in the forward direction was less than the angle of forwards of joints caused by loads in the backward direction, but only when the loads were 6, 8, and 10 N, the difference between them was statistically significant (P < 0.05). The slope of the regression line of load-angle for the loads in the forward direction was less than the slope of the regression line of load-angle for the loads in the backward direction, with statistical difference (F=31.413, P < 0.001). After the ligaments were cut, when the loads were 2, 4, 6, 8 and 10 N in the forward direction in group A and group B, the backward angulation of joint in group A was less than that in group B (P < 0.05). The slope of the load-angled regression line in group A was less than that in group B (F=52.224, P <0.001). When the loads in the backward direction in group A and group B were 2, 4, 6, 8 and 10 N, the forward angulation of joint in group A was greater than that in group B (P < 0.05), and the slope of the load-angled regression line in group A was greater than that in group B (F=12.503, P=0.008). (4) These results suggest that contact area between the articular surface of the medial clavicle and the articular surface of the manubrium is narrow, which determines the instability of the joint itself. The sternoclavicular ligament is extremely important for maintaining the joint stability. The forward angulation of joint restriction effect of sternoclavicular ligament was weaker than that of the backward angulation, also because of the joint in the anatomical position of the natural forward angulation, so the sternoclavicular joint was prone to anterior dislocation. It is necessary to pay attention to the repair and reconstruction of sternoclavicular ligament when sternoclavicular joint dislocation or peripheral fractures are treated by operations.

The experimental study of genetic engineering human neural stem cells mediated by lentivirus to express multigene / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore the feasibility to construct genetic engineering human neural stem cells (hNSCs) mediated by lentivirus to express multigene in order to provide a graft source for further studies of spinal cord injury (SCI).</p><p><b>METHODS</b>Human neural stem cells from the brain cortex of human abortus were isolated and cultured, then gene was modified by lentivirus to express both green fluorescence protein (GFP) and rat neurotrophin-3 (NT-3); the transgenic expression was detected by the methods of fluorescence microscope, dorsal root ganglion of fetal rats and slot blot.</p><p><b>RESULTS</b>Genetic engineering hNSCs were successfully constructed. All of the genetic engineering hNSCs which expressed bright green fluorescence were observed under the fluorescence microscope. The conditioned medium of transgenic hNSCs could induce neurite flourishing outgrowth from dorsal root ganglion (DRG). The genetic engineering hNSCs expressed high level NT-3 which could be detected by using slot blot.</p><p><b>CONCLUSIONS</b>Genetic engineering hNSCs mediated by lentivirus can be constructed to express multigene successfully.</p>

Genetic engineering neural stem cell modified by lentivirus for repair of spinal cord injury in rats / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the feasibility for therapy of spinal cord injury (SCI) by genetic engineering neural stem cell (NSC) modified by lentiviral vector.</p><p><b>METHODS</b>Following the construction of the genetic engineering NSC modified by lentivirus to secrete both neurotrophic factor-3 (NT-3) and green fluorescence protein (GFP), hemisection of spinal cord at the level of T10 was performed in 56 adult Wistar rats that were randomly divided into 4 groups (n = 14), namely 3 therapeutic groups and 1 control group. The therapeutic groups were dealed with NSC, genetic engineering NSC, and concentrated lentiviral supernatant which carries both GFP and NT-3, respectively. Then used fluorescence microscope to detect the transgenic expression in vitro and in vivo, migration of the grafted cells in vivo, and used the Basso, Beattie, and Bresnahan (BBB) open-field locomotor test to assess the recovery of function.</p><p><b>RESULTS</b>The transplanted cells could survive for long time in vivo and migrate for long distance. The stable transgenic expression could be detected in vivo. The hindlimb function of the injured rats in 3 therapeutic groups, especially those dealed with genetic engineering NSC, improved obviously.</p><p><b>CONCLUSION</b>It is feasible to combine NSC with lentivirus for the repair of SCI. NSC modified by lentivirus to deliver NT-3, acting as a source of neurotrophic factors and function cell in vivo, has the potential to participate in spinal cord repair.</p>