Transplantation of a Scaffold-Free Cartilage Tissue Analogue for the Treatment of Physeal Cartilage Injury of the Proximal Tibia in Rabbits

PURPOSE: The purpose of this study was to investigate the effects of transplantation of an in vitro-generated, scaffold-free, tissue-engineered cartilage tissue analogue (CTA) using a suspension chondrocyte culture in a rabbit growth-arrest model. MATERIALS AND METHODS: We harvested cartilage cells from the articular cartilage of the joints of white rabbits and made a CTA using a suspension culture of 2x107 cells/mL. An animal growth plate defect model was made on the medial side of the proximal tibial growth plate of both tibias of 6-week-old New Zealand white rabbits (n=10). The allogenic CTA was then transplanted onto the right proximal tibial defect. As a control, no implantation was performed on the left-side defect. Plain radiographs and the medial proximal tibial angle were obtained at 1-week intervals for evaluation of bone bridge formation and the degree of angular deformity until postoperative week 6. We performed a histological evaluation using hematoxylin-eosin and Alcian blue staining at postoperative weeks 4 and 6. RESULTS: Radiologic study revealed a median medial proximal tibial angle of 59.0degrees in the control group and 80.0degrees in the CTA group at 6 weeks. In the control group, statistically significant angular deformities were seen 3 weeks after transplantation (p<0.05). On histological examination, the transplanted CTA was maintained in the CTA group at 4 and 6 weeks postoperative. Bone bridge formation was observed in the control group. CONCLUSION: In this study, CTA transplantation minimized deformity in the rabbit growth plate injury model, probably via the attenuation of bone bridge formation.

Result of Transplantation of Chondrocytes and Periosteum-Derived Cells for Long-Bone Growth Plate Injuries of the Rabbits / 대한정형외과연구학회지

PURPOSE: To study the effectiveness of chondrocyte and periosteum-derived cell transplantation in preventing bar formation in growth plate injuries. MATERIALS AND METHODS: Thirty immature rabbits were grouped according to site of growth plate damaged (distal femur or proximal tibia on the medial side) and type of cell and material inserted (chondrocytes plus agar, periosteum-derived cells plus agar, periosteum-derived cells plus Gelfoam, agar alone, or Gelfoam alone). Radiograms were taken for 16 weeks to measure the changes in varus angle of the distal femur and proximal tibia. Transformation of inserted cells was observed histologically. RESULTS: Rabbits inserted with agar alone showed more severe genu varum compared to those inserted with chondrocytes plus agar. Rabbits inserted with periosteum-derived cells plus agar or Gelfoam showed similar deformities compared to those inserted with agar or Gelfoam alone. Some inserted periosteum-derived cells began transformation into chondrocytes. All rabbits showed gradual bar formation and ultimate fusion of the growth plate. CONCLUSION: Cell-based therapy of growth plate injury still has obstacles to overcome. Further study will be required on how to maintain the inserted chondrocytes, or chondrocytes differentiated from the inserted periosteum-derived cells, and to prevent them from changing into osteoid formation cells.

A Clinical Study of the Children's Ankle Fractures with Growth Plate Injury / 대한정형외과학회잡지

The fractures of the ankle in children are differ from those of adults in terms of the fracture pattern and the possibilities of influence to growth. The injuries of the ankle in children occur mostly at the bony structure rather than ligamentous structure, and some injuries of the growth plate may result in the arrest of entire growth plate or parts of growth plate and these may lead to leg length discrepancy or deformity. Many authors agree that the prognosis of injuries of the growth plate is dependent on the fracture type, the age of the patient at the onset of injuries, the degree of displacement of the fracture fragments, whether the injuries open or closed, and the efficacy of reduction. But the authors can not postulate one uniformed method of classification and treatment of the children's ankle fracture because of the variability of injuries. We have reviewed 35 cases of children's ankle fracture treated at our clinics from Dec. 1979 to Feb. 1984. The results obtained are as follows: l. Over half of the patients were between the ages of 13 and 16 years (54.3%). 2. The incidence of each type as Salter-Harris classification was that of type II(48.6%), type I(20.0%),type III(14.3%),type IV (8.6%). 3. The traffic accidents were the main causes of injury (68.5%). 4. The type I fractures occured mostly under 10 years of age and the type II fractures in adolescents. 5. All the type I fractures were treated conservatively without any complication, and the type II fractures were treated conservatively in 13 cases (76.5%) and operatively in 4 cases (23.5%) with variable results. 6. Overall incidence of complication was 20.0%, consisted with two cases of conservatively treated but not accurately reduced type II fractures, a conservatively treated type III fracture, a triplane fracture, and the others.

AN EXPERIMENTAL PATHOLOGICAL STUDY OF CHRONIC COLLISION INJURY OF THE DISTAL RADIAL EPIPHYSIS / 中国运动医学杂志

A special collision unit was used in the experiment by which the distal ends of the fore legs of young rabbits were struck repeatedly on the right aspect. In another group of young rabbits, deep branches of the artery of the right fore legs were ligated and severed. X-Ray examination was made before the two groups of rabbits were killed.Roentgenogram demonstrated: Growth plate of the right fore leg showed wave-like growth, thickened or thinned in the collision group; no difference showed between 2 fore legs in vessel group.Histological demonstrations1. Collision group: 1) Chondrocytcs of articular surface decreased, degenerated and disappeared. 2) Trabecula of the cpiphysis and metaphysis atrophied; osteoblasts and ostcocytcs decreased and degenerated. 3) Growth plate thickened, some arranged wave-like; chondrocytes increased and degenerated. 4) Fibrous tissues and cartilage increased in the mctaphysis. 5) Perichondral ring thickened.2. Vessel group: Similar to the collision group except fibrous and cartilage proliferation in the epiphysis and no arrangement disorder in the growth plate.