To determine the characteristics of magnetic resonance (MR) signals of normal growing cartilage and identify the difference in transverse relaxation times between physeal and epiphyseal cartilage in vivo. 24 distal femora of 12 two-week-old piglets were imaged on a 1.5 Tesla GE MR scanner. Comparison was made between signal intensity on MR images and the structure shown in corresponding histologic sections. T2 values were measured in eight piglets by means of multiecho spin-echo sequences. Our results showed that MR imaging delineated five regions between the secondary ossification center and the metaphysis, which histologically correspond to the zone of provisional calcification of the secondary ossification center, physis of the secondary ossification center, epiphyseal cartilage, physis and zone of provisional calcification. The T2 value in the physeal cartilage was much larger than that in the epiphyseal cartilage (P<0.05). It is concluded that MRI findings could differentiate the different regions of growing cartilage. T2 is longer in physeal than in epiphyseal cartilage, perhaps reflecting differences in water binding by proteoglycans.
Animals, Newborn ; Femur/anatomy & histology ; Femur/growth & development ; Femur/metabolism ; Growth Plate/*anatomy & histology ; Growth Plate/*growth & development ; Growth Plate/metabolism ; *Magnetic Resonance Imaging ; Osteogenesis/physiology ; Swine

The goals of treatment of the slipped capital femoral eiphysis(SCFE) are to stabilize the slipped epiphysis, prevent further slipping and induce early closure of the epiphyseal plate. Mutiple pinning was used for the treatment but in recent years, percutaneous in-situ fixation technique with 1 or 2 cannulated screws is preferred due to the advantages of low rate of complication such as pin penetration. We report the results of experimental study and the functional results after percutaneous pinning. The purpose of the experimental study was the investigation for changes of the screw length and the site of screw entry point according to the degree of slipping by bony model. The entry point of the screw was changed toward anterior and proximal portion of femoral neck and the length of inserting screw was changed to be shorter according to the degree of slip. We have treated 10 patients(13 hips) with slipped capital femoral epiphysis(SCFE) at our department since Jan. 1989. Among them, 6 patients(7 hips) could be followed for more than 2 years. There were 5 boys and 1 girl. One case was affected on the both hip. The average age at operation was 11.8 year old. All cases were obese. Degree of slipping was showed 6 cases in mild and 1 case in moderate. The slipping of acute onset was 3 cases, acute-on chronic 3 cases and chronic 1 case. In radiographic results, 6 cases were showing in Grade 0, 1 case was in Grade II. In functional results, 3 cases were excellent, 3 cases in good and 1 case in poor. One poor functional result was a case complicated by chondrolysis.
Epiphyses ; Female ; Femur ; Femur Neck ; Growth Plate ; Hip ; Humans ; Slipped Capital Femoral Epiphyses

To understand the expression of hoth TGF-beta l and II ligands and the receptors, artificial fracture was made on rat femur. Fracture callus and epiphyseul plate were stained immunohistochemically on 3rd. 7th, 14th, 21st, 42nd and 56th day after trauma. Polyclonal antibody was used to stain TGF-beta I and II ligands and receptors. At epiphyseal plate, both ligand and receptor were expressed from each cell in proliferating and maturing zone. But there was no difference between type I and II except expression time. TGF-beta II ligand and receptor were expressed earlier: they were expressed mostly by the cells at the zone of proliferating cartilage but TGF-beta1 ligand and receptor were expressed mostly hy the cells at zone of maturing cartilage. At fracture site, TGF-beta expression was observed from 3rd day after trauma and it reached its maximum intensity at 2 weeks. It decreased thereafter and disappeared at 6 weeks after trauma. In enchondral ossification area, TGF-beta expressing cells were scattered throughout the enchondral mass. In intramembranous ossification area, the ligands and receptors were expressed from the osteohlasts just heneath the periosteum. ln summary, TGF-beta ligands and receptors were expressed at epiphyseal plate and fracture callus. There was no difference between TGF-beta 1 and 2 expres.ion except the appearance time at epiphyseal plate. We could not draw any conclusion about ligand and rcceptor mechanism with this immunohistochemical staining.
Animals ; Bony Callus* ; Cartilage ; Femur ; Growth Plate* ; Ligands* ; Periosteum ; Rats ; Receptors, Artificial ; Transforming Growth Factor beta ; Transforming Growth Factor beta1

It has been known that osseous stability of the hip is dependent upon the inclination, anteversion and depth of acetabulum and also upon neck-shaft angle and anteversion of femur. Acetabulum enlarges from two different growth centers; one from the concave articular surface cartilage and the other from the triradiate cartilage. The former contributes primarily to the thickness of acetabular wall, where as, the latter to the central enlargement of the acetabular socket. Additionally the shape of acetabulum can be changed by deformity of the femoral head and neck, which can be explained by Wolff's and Hueter-Volkmann's laws. Yet there are still many factors to be clarified by clinical researchers in the future Authors in this experiment tried to clarify the role of triradiate cartilage and greater trochanteric growth plate upon the development of acetabulum. The material used for this study consiated of 30 rabbits of both sexes, aged 8 weeks. Animals were divided into 3 groups, and each group consisted of 10 rabbits In group I. hip was not injured and used as a Control: in group II, right greater trochanter with its growth plate was destructed completely; in group III, triradiate cartilage of right side was destructed. Subsequent to injury of Y cartilage ot greater trochanter with its growth plate, radiographs of the pelvis including hips were obtained weekly on each rabbit over 6 weeks period. and to evaluate the effect of injury upon the hip development acetatular angle, C-E angle, and acetabular depth and width were measured. The following results were obtained; 1. The shape of acetabulum of rabbits have showe remarable developmental changes until the 10 weeks of age after birth, but the changes became less remarkable by age of the 14 weeks. Thereafter it remained unchanged. 2. In group II, at the age of 14 weeks, compared with the values of the normal hip, the acetabular angle showed an increase of 1.9 degrees, and the center dege angle and acetabular depth showed a decrease of 3.21 degrees and 0.43mm respectirely. 3. In group III, at the age of 14 weeks, compared with the values of the normal hip, the acetabular angle increased by 18.9 degress while the center-edge angle decreased by 22.8 degrees. The acetabular depth showed a decrease of 1.81mm and the acetabular width showed an increase of 0.73mm. These observations suggest that the development of acetabulum depends largely upon the growth of triradiate cartilage, and also is affected secondarily by valgalization of femoral neck which is resulted by destruction of greater trochanteric growth cartilage.
Acetabulum ; Animals ; Cartilage ; Congenital Abnormalities ; Femur Neck ; Femur ; Growth Plate ; Head ; Hip ; Jurisprudence ; Neck ; Parturition ; Pelvis ; Rabbits

The purpose of this study is to define the appearance of normal epiphyseal and metaphyseal marrow and normal changes of marrow due to fatty conversion on Gadolinium (Gd)-enhanced MR Imaging. Unenhanced and enhanced T1-weighted MR imaging were performed in proximal and distal femoral ends of 8 healthy piglets at the ages of 2, 4, 6 and 8 weeks, respectively. The changes with age in signal intensity and enhancement ratio of the epiphyseal and metaphyseal marrow with age were examined. The correlation of MRI characteristics with histological findings was studied. Our study showed that marrow of the metaphysis and of periphery of the 2nd ossification center were well vascularized hematopoietic marrow and had great enhancements. The enhancement ratio of metaphysis was greater than that of epiphyseal marrow and both enhancement ratios degraded gradually with age. The central regions of the epiphyseal ossification center and of the diaphysis were of fatty marrow and had little enhancement. It is concluded that on Gd-enhanced MR imaging the hematopoietic marrow of metaphysis and of periphery of the 2nd ossification center had greater enhancement than that of fatty marrow of central region of the 2nd ossification center. All of their enhancements decreased gradually with age.
Epiphyses/*anatomy & histology ; Femur/anatomy & histology ; Femur/*growth & development ; Gadolinium/*diagnostic use ; Growth Plate/*anatomy & histology ; Growth Plate/blood supply ; Growth Plate/growth & development ; Image Enhancement ; Magnetic Resonance Imaging ; Swine ; Swine, Miniature

BACKGROUND: Abnormalities of calcium homeostasis and bone remodelling were known in acromegaly, but controversy concerning the influence of chronically elevated serum growth hormone (GH)/insulin like growth factor-I (IGF-I) concentrations on bone metabolism has been existed. In this study, we assess the effect of chronically elevated serum GH/IGF-I levels on bone metabolism and bone mineral density (BMD) in patients with acromegaly and compare the markers of bone metabolism and BMD of active acromegaly according to gonadal function. METHODS: We measured biochemical markers of bone turnover and BMD in 50 acromegalic patients (41 active disease, 9 inactive disease) and 41 control subjects. RESULTS: Active acromegalic patients had significantly higher serum oteocalcin levels (13.8+/-7.7 versus 6.8+/-4.7, 6.0+/--3.4 ng/mL, p<0.05) and urinary type I cross-linked N-telopeptide (101.7+/-64.2 versus 49.3+/-33.3, 56.1+/-39.4 nM BCM/mM Cr, p<0.05) compared with inactive acromegaly and control subjects. Serum IGF-I levels correlated positively with serum osteocalcin levels(r=0.69, p<0.05) and urinary type I cross-linked N-telopeptide (r=0.44, p<0.05). In the female patients with active acromegaly, BMD (T-score) was elevated in the femoral neck(1.00+/-0.14 versus 0.89+/-0.12,p<0.05) and trochanter (0.88+/-0.15 versus 0.77+/-0.11, p<0.05), whereas BMD of lumbar spine(1.13+/- 0.17 versus 1.17+/-0.17, p>0.05) and femoral Ward's triangle (0.78+/-0.16 versus 0.77+0.13, p>0.05) were not different from those of control subjects. In the patients with active acromegaly, serum osteocalcin levels (16.4+/-8.8 versus 14.9+/-10.1 ng/mL, p>0.05) as well as urinary type I cross-linked N-telopeptide (104.8+/-68.1 versus 122.0+/-80.3 nM BCM/mM Cr, p>0.05) were not different according to gonadal function. Also, femoral and spinal BMD were not different according to the gonadal function. CONCLUSION: GH/IGF-I excess increase bone turnover and might achieve a positive bone balance at each remodelling cycle. Markers of bone turnover and BMD of skeletal bone were not influenced by gonadal function in the patients with active acromegaly.
Acromegaly* ; Biomarkers ; Bone Density* ; Calcium ; Female ; Femur ; Gonads ; Growth Hormone ; Homeostasis ; Humans ; Insulin-Like Growth Factor I ; Metabolism ; Osteocalcin

Transforming growth factor-beta1(TGF-beta1) has been suggested to be a useful growth facto. that could maintain the phenotypic characteristics of cultured chondrocytes. We performed this study to investigate the dose-dependent effects of TGF-beta1 on cell proliferation and matrix synthesis in relation to the degree of chondrocyte dedifferentiation in monolayer culture. Chondrocytes were isolated from the articular cartilage of distal femur of neonatal Sprague-Dawley rats and were cultured in monolayer. When the cell population reached 70-80% of confluence, the cells were subcultured successively for 6 weeks for the following studies. Every weak, the dose dependent effects of rhTGF-beta1 (0ng/ml ,1ng/ml, 5ng/ml, 10ng/ml, 20ng/m1) on DNA synthesis, proteoglycan synthesis and collagen synthesis were evaluated by 3H-thymidine incorporation, 35S-sulfate incorporation and 3H-proline incorporation respectively. The DNA synthesis decreased with time of culture. The DNA synthesis was significantly decreased by the addition of rhTGF-beta1 at all concentrations. The dose-dependent inhibitory action was most prominent at initial 3 weeks. Proteoglycan synthesis was in the highest level at the second week and markedly decreased after 2 weeks. At 2 weeks, TGF-beta1 treatment increased the proteoglycan synthesis at all concentrations and this stimulatory effect was prominent at the concentrations of 5ng/ml and 10ng/ml. There was no significant difference in the level of collagen synthesis during the whole experimental period. TGF- beta1 treatment increased collagen synthesis at all concentrations and this stimulatory effect was prominent at the concentrations at 5ng/ml and 10ng/ml. The results of this study suggest that if the cultured chondrocytes treated by TGF-beta 1 are used for transplantation, the time for TGF-beta1 treatment and transplantation to be recommended is before 3 weeks and the beneficial concentration of TGF-beta1 is 5ng/ml to 10 ng/ml for the maintenance of the phenotypic properties.
Cartilage, Articular ; Cell Proliferation* ; Chondrocytes* ; Collagen ; DNA ; Femur ; Proteoglycans ; Rats, Sprague-Dawley ; Transforming Growth Factor beta ; Transforming Growth Factor beta1

OBJECTIVE: This study was designed to evaluate the effect of growth hormone on bone mineral density of corticosteoid-induced osteoporosis in male rat. METHOD: Twenty Sprague-Dwaley male rats was studied, divided into four group, each group has 5 rats. The group 1 was treated with saline. The group 2 was treated with corticosteroid (Methylprednisolone 10 mg/kg). The group 3 was treated with corticosteroid and growth hormone (recombinant human growth hormone 0.5 IU/kg). The group 4 was treated with growth hormone after corticosteroid treatment. The treatment duration was 6 weeks for each group. After six weeks of hormone administration, the animals were sacrificed, the bilateral femur were removed and tested for bone mineral density using dual energy X-ray absorptiometry and examined histomorphometrically. RESULTS: Administration of growth hormone after corticosteroid therapy, the growth hormone could reverse the decrease in body weight and bone mineral density induced by corticosteroid therapy (p<0.05). CONCLUSION: When growth hormone is administrated after corticosteroid therapy, the growth hormone can protect the osteoporosis in male rats induced by a high dose of corticosteroid.
Absorptiometry, Photon ; Animals ; Body Weight ; Bone Density* ; Femur ; Growth Hormone* ; Human Growth Hormone ; Humans ; Male ; Osteoporosis* ; Rats*

PURPOSE: The aim of this study was to determine the effect of alcohol on the expression of VEGF-A, PEDF, and VEGFR-2 in human osteoblasts. MATERIALS AND METHODS: Human osteoblasts primarily derived from the intertrochanteric region of the femur with osteonecrosis and fracture (control) were cultured with alcohol (0, 20, 100, 150 mM). The level of cell proliferation and the expression levels of VEGF-A mRNA, PEDF mRNA, and VEGFR-2 mRNA was evaluated according to the alcohol concentrations and the culture periods. RESULTS: Osteoblasts with the added alcohol showed an early increase in cell population, and a subsequent decrease or steady level thereafter compared with those without alcohol (p<0.05). The osteoblasts in the osteonecrosis group showed an increase in VEGF-A mRNA and PEDF mRNA expression at high alcohol concentrations (100, 150 mM), resulting in an decreased VEGF-A/PEDF ratio, while those in the control group showed an increase in VEGF-A mRNA expression and a decrease in PEDF mRNA expression, resulting in an increase in the VEGF-A/PEDF ratio (p<0.05). CONCLUSION: Alcohol stops the proliferation of osteoblasts and can cause an imbalance between VEGF-A and PEDF, thereby inhibiting the neovascularization of osteonecrosis.
Cell Proliferation ; Femur ; Head* ; Humans ; Necrosis* ; Osteoblasts* ; Osteonecrosis ; RNA, Messenger ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factor Receptor-2*

PURPOSE: To evaluate the MR findings of a development of bony bridge within tunnels drilled across growth plates after injury in immature rabbits, and to correlate the MR and pathological findings. MATERIALS AND METHODS: In 19 young rabbits, a growth-plate injury model was constructed in the distal femur by longitudinal drilling with a 5-mm drill. Coronal scans with T1-weighted, T2-weighted fast spin-echo, gradient echo, and gadolinium enhanced T1-weighted sequences were obtained immediately, and at 1, 2, 3, and 4 weeks, and 3, 6 months, postoperatively. Each group underwent pathologic examination, and the signal intensity, shape, and enhancement pattern of the drill holes were assessed. All results were correlated with pathologic findings. RESULTS: During the early period, the signal intensity of the defect site varied due to hemorrhage and inflammatory reaction in the lesion, becoming isointense to that of metaphyseal marrow on all sequences during the late period (3 and 6 months). Pathologically, it corresponded to replacement of the osseous bridge with fatty marrow. The new bone formation shown by pathologic examination to be present in the periphery of the defect during the first week corresponded to the vertical dark rim seen on MR images. It appeared during that week and became more distinct, thickening gradually until the fourth week. Enhancement was absent or faint on follow-up immediately after surgery, inhomogenous and seen in half the rabbits at week 1, and maximal and homogenous at weeks 2 and 3. In had decreased by week 4, and was absent at months 3 and 6. These findings corresponded to the changes in transphyseal vascularity across the drill hole revealed by pathologic examination. CONCLUSION: The contrast enhancement demonstrated by defective growth plate may indicate the development of vascularity throughout the plate, a phenomenon which precedes the formation of a bony bridge after trauma.
Bone Marrow ; Femur ; Follow-Up Studies ; Gadolinium ; Growth Plate* ; Hemorrhage ; Magnetic Resonance Imaging* ; Osteogenesis ; Rabbits