Injury and regeneration of intramuscular connective tissue subjected to various regimes of distraction / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effect on intramuscular connective tissue and passive range of joint motion by the stress produced in limb lengthening.</p><p><b>METHODS</b>An animal model of limb lengthening was established in the tibia of rabbits. Distraction was initiated at a rate of 1 mm/d and 2 mm/d in two steps respectively, and both proceeded until 10% and 20% of the tibia length was achieved. Muscle samples were harvested at the time when distraction ended and at the 4th week of consolidation after the distraction. Scanning electron microscope was applied to observe the morphological changes of the perimysium. The goniometer, which we made for this study, was used to measure the passive range of joint motion.</p><p><b>RESULTS</b>The collagen fibers were partitioned in bundles, crimped and interconnected closely and orderly. In the regime of 1 mm/d distraction with 10% lengthening, no apparent changes of the collagen fiber and passive range of joint motion was demonstrated. When tibia was increased to 20%, the crimped fibers showed a tendency of being straightened while the passive range of joint motion was reduced. The findings remained the same at the 4th week of consolidation. In the regime of 2 mm/d distraction with 10% lengthening, the crimped structure of the collagen fibers in the perimysium disappeared and the fibers were almost straightened. Additionally, the interconnection of the collagen fibers became loosened and interstice was presented among the fibers. At the 4th week of consolidation, the restoration to the original crimped structure was not completed. When the lengthening ratio was increased to 20%, the collagen fibers were straightened completely. This condition remained unchanged throughout all 4 weeks. The passive range of joint motion was reduced dramatically in the regime of 2 mm/d distraction.</p><p><b>CONCLUSION</b>The ultrastructure of perimysium and the passive range of joint motion in the regime of 1mm/d lengthening shows the condition closest to the normal ones. The regime of 2 mm/d lengthening may cause an apparent change in the ultrastructure of perimysium and passive range of joint motion.</p>

A clinical follow-up study on treatment of adolescent idiopathic scoliosis with brace / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate clinical outcomes of bracing and analyze related factors that influence curative effects in adolescents with idiopathic scoliosis, and to investigate indications of bracing.</p><p><b>METHODS</b>Seventy-nine patients with AIS who had no history of prior therapy were treated with a brace. Several parameters were consecutive measured and documented during the period of follow-up including Cobb's angles, curve patterns, menarche status, sitting heights, standing heights, Risser sign, apical vertebral rotation, and so on.</p><p><b>RESULTS</b>The average period of followed-up was 30 months (12 months to 60 months). Twenty-one patients (26.6%) presented curve deterioration, 40 patients have no obvious curve change, 18 patients (22.8%) got a curve improvement. There was significantly lower percentage of curve progression and higher percentage of curve improvement in cases with Cobb's angle less than 35 degrees at the first visit (P < 0.05). The percentage of curve progression was significantly greater in the cases with apical vertebral rotation beyond grade III while the percentage of curve improvement was lower (P < 0.05). Curve patterns, Risser sign and other parameters were found to make their effects on the percentage of curve progression and improvement, which, however, was not statistically significant (P > 0.05).</p><p><b>CONCLUSION</b>Bracing can limit or improve mild and moderate curve of idiopathic scoliosis effectively, especially in cases with initial curve magnitude ranging from 20 degrees to 35 degrees . Risser sign is not a reliable parameter for measuring the outcome of bracing treatment for idiopathic scoliosis. Surgery is advised as soon as possible for the cases with initial Cobb's angles greater than 45 degrees and initial apical vertebral rotation beyond grade III early while bracing did not work.</p>

Compositional variation of fibrous callus and joint cartilage in different internal environments / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the compositional variation of fibrous callus in the fracture site and the joint cavity and joint cartilage after being transplanted in the muscle pouch.</p><p><b>METHODS</b>Thirty 2 month old New Zealand white rabbits (weighing 1-1.5 kg) were randomly divided into two groups: a callus transplantation group (Group A, n=15) and a cartilage transplantation group (Group B, n=15). In Group A, closed radius fracture was made and the autologous fibrous callus was transplanted in the right knee joint cavity at 12 days postoperatively. In Group B, the right knee joint cartilage of the animals was transplanted in the autologous back muscle pouches under anesthesia. Then all the animals were killed by overdose anesthetic 3 weeks after transplantation. And the transplanted fibrous callus, the healed bones in the fracture sites and the transplanted joint cartilage were obtained for assessment of compositional variation.</p><p><b>RESULTS</b>Pure fibrous composition was found in the callus at the fracture sites in Group A at 12 days postoperatively. And for 11 out of the 15 animals, the fibrous callus was transformed into cartilaginous tissues after 3 weeks of transplantation, but the fibrous callus was absent in the other 4 animals. The fibrous calluses at the original site and the fracture locus were differentiated into bony tissues. Bony tissue transformation was found in the transplanted joint cartilages in the muscle pouch of all the animals in Group B.</p><p><b>CONCLUSIONS</b>The fracture sites or joint cavity may facilitate callus differentiation in different ways: the former is helpful for osteogenesis while the latter for the development and maintenance of cartilages, and the muscle pouch is inclined to induce the osteogenic phenotype for cartilages.</p>