RESUMO
This retrospective study assessed the radiographic results of 16 patients with avascular necrosis following treatment for developmental dislocation of the hip (DDH) who were subsequently treated between 1991 and 2005 by rotation acetabular osteotomy (RAO) combined with femoral intertrochanteric osteotomy (FIO). Initial treatment was by Pavlik harness, cast fixation, or overhead traction. The parameters that showed consistent improvement were the index of centralization, the index of acetabular coverage, adequate reduction of the greater trochanter, and abductor sufficiency. The combined procedure appears to be effective in cases in which preoperative planning shows a reasonable expectation of congruency and osteoarthritis is limited to the early stages.
Assuntos
Acetábulo/cirurgia , Fêmur/cirurgia , Luxação Congênita de Quadril/cirurgia , Osteonecrose/cirurgia , Osteotomia/métodos , Adolescente , Adulto , Fenômenos Biomecânicos , Feminino , Luxação Congênita de Quadril/diagnóstico por imagem , Humanos , Masculino , Osteonecrose/diagnóstico por imagem , Radiografia , RotaçãoRESUMO
The localization and expression of neurotrophins and their receptors during distraction osteogenesis was investigated in 72 male rat femurs (11 weeks old) to further clarify the concurrence of cellular and molecular events of new bone formation. After osteotomy, a 7-day lag phase was followed by distraction at the rate of 0.25 mm/12 h for 21 days (distraction phase), and a 7-day consolidation phase. The localization of neurotrophins (NGF, BDNF and NT-3) and their receptors tropomyosinrelated kinases (TRKA, TRKB and TRKC) by immunostaining showed positive staining in bone forming cells in each stage, although the presence and staining intensity varied by cell type and phase. The expressions of NGF, BDNF and NT-3 by real-time polymerase chain reaction (real-time PCR) showed that the peak of the mRNA expression of NGF occurred 10 days after distraction. NT-3 increased during bone extension, but decreased when distraction stopped. In contrast, BDNF continued to increase gradually throughout the distraction and consolidation phases. These findings suggest that neurotrophins and their receptors may play different roles in endochondral and intramembranous ossification in distraction osteogenesis. The tension stress caused by distraction may stimulate the expression of neurotrophins and their receptors, and promote osteogenesis.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator de Crescimento Neural/metabolismo , Neurotrofina 3/metabolismo , Osteogênese por Distração , Receptor trkA/metabolismo , Receptor trkB/metabolismo , Receptor trkC/metabolismo , Animais , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Regulação da Expressão Gênica , Masculino , Fator de Crescimento Neural/genética , Neurotrofina 3/genética , RNA Mensageiro/metabolismo , Ratos , Receptor trkA/genética , Receptor trkB/genética , Receptor trkC/genéticaRESUMO
To investigate the localization and expression of connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24/CCN family member 2 (CTGF/Hcs24/CCN2) during distraction osteogenesis in the rat femur, we studied a total of 54 male rats (11 weeks old). We performed osteotomy in the midshaft of the right femur. After 7 days (lag phase), distraction was started, at the rate of 0.25 mm/12 h for 21 days (distraction phase) by using a small external fixator, and this was followed by a 7-day consolidation phase. Localization and expression of CTGF/Hcs24 during distraction osteogenesis in the femur were examined by immunostaining, in situ hybridization, and reverse transcriptase polymerase chain reaction (RT-PCR). Immunostaining showed the localization of CTGF/Hcs24 in various cells located in the bone-forming area around the osteotomy site. During the distraction phase, in situ hybridization showed that CTGF/Hcs24 mRNA was expressed not only in hypertrophic chondrocytes and osteoblasts but also in fibroblast-like cells and mesenchymal cells at sites of end-ochondral ossification, and not only in osteoblasts but also in pre-osteoblasts and fibroblast-like cells at sites of intramembranous ossification. RT-PCR showed higher level expression of CTGF/Hcs24 mRNA in the distracted group than in the nondistracted group. These results revealed an elevated pattern of CTGF/Hcs24 mRNA expression during distraction osteogenesis, and suggest that CTGF/Hcs24 may play some roles in the endochondral and intramembranous ossification processes that occur during distraction osteogenesis.
