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PubMed1993

Differential effects of glucocorticoids on cortical appendicular and cortical vertebral bone mineral content.

The susceptibility to glucocorticoid-induced bone loss may vary in different parts of the skeleton. We studied 62 patients with rheumatoid arthritis, 26 of whom were on low-dose glucocorticoid treatment. Bone mineral content (BMC) in the forearm was measured by single photon absorptiometry at a cortical, diaphyseal, and at a mixed cortical and trabecular, metaphyseal site. Lumbar BMC was measured by dual energy computed tomography in a trabecular and a cortical region of interest. The presence of vertebral deformities was evaluated on lateral spine radiographs. After correction for possibly confounding variables, prednisone therapy significantly influenced BMC at both the trabecular (-22.0%, 95% confidence interval -36.0% to -8.1%) and cortical (-24.8%, 95% confidence interval -39.3% to -10.3%) lumbar site. A significant effect was also seen at the metaphyseal (-15.7%, 95% confidence interval -27.1% to -4.2%), but not the diaphyseal (-3.9%, 95% confidence interval -14.1% to 6.4%) site in the forearm. Correlations between peripheral and vertebral BMC were moderate at best. The diaphyseal to metaphyseal BMC ratio did not identify patients with vertebral osteoporosis. It is concluded that the anterior cortical rim of the vertebral body is more susceptible to the effects of glucocorticoids than the cortical bone in the forearm, and that measurements of trabecular and anterior cortical vertebral BMC are essential in the management of patients with possible glucocorticoid-associated osteoporosis.

Absorptiometry, Photon↗
PubMed1989

Histopathological features of unilateral stapling in animal experiments.

Blount stapling of the proximal medial tibial growth was performed in 10-week-old domestic pigs. A total of 37 animals for up to 17 weeks were followed up. The histological evaluation showed a different reaction of the growth plate in the medial (stapled), central and lateral area. Up to 6 days after stapling the morphological features were characterized by deviations of the cell column from the axial alignment. Herniations of mature chondrocytes as well as isles of epiphyseal cartilage splintered into the adjacent metaphyseal cancellous bone were seen. From the 10th to the 11th postoperative day on there was a decline in the number of distal hypertrophic and degenerating cartilage cells due to impaired proliferation. Cell atrophy due to disturbed maturation or cell degeneration was evident. Local clusters of chondrocytes with loss of columnar arrangement indicated impaired chondrogenesis. Twenty-eight days after the operation coarser structures and changed alignment of cancellous bone characterized the morphological picture. The postoperative follow-up showed epiphyseal plates bounded by mature bone blocks or even a distinct sheet of horizontally oriented bone plates on the metaphyseal side. Many metaphyseal findings, such as augmented hypertrophic cells in the early postoperative period, or platelike limitations of the epiphyseal plate complete the morphological picture.

Animals↗
PubMed1991

Skeletal manifestations of primary oxalosis.

We describe the clinical, radiographic and histological features of skeletal involvement in four patients with end-stage renal failure due to primary oxalosis. The clinical features were unrelenting bone pain, and in two patients multiple fractures. Radiographic features were, in chronological order: (1) radiodense metaphyses and other red marrow bone; (2) cortical defects in metaphyses; (3) spontaneous fracture-separations of epiphyses of long limb bones which healed poorly. The fractures occurred through crystal deposits, and fracture displacement was associated with extrusion of crystalline material from bone. On histological examination crystals were found to replace metaphyseal bone. Pericrystalline giant cell granulomata replaced bone marrow. Erosion surfaces near granulomas were increased. Subperiosteal and intra-osseous tophi of calcium oxalate were seen. Calcium oxalate appears to precipitate with greater facility than does physiological mineral. Bone showed the features of mixed uraemic osteodystrophy in all four patients. We conclude that: (1) the fractures occurred through heavy crystal deposits; (2) ununited fractures and intra-osseous and subperiosteal tophi contributed to the pain; (3) spontaneous fractures are of poor prognostic significance. We recommend that unstable fractures be internally fixed.

Adolescent↗
PubMed1978

Changes in organic matrix of bone and of bone and blood ATP in rats fed rachitogenic diets.

Vitamin D deficient and phosphate deficient states were produced in young rats by the use of synthetic diets. Whole blood ATP, serum calcium and phosphorus and the ash, phospholipid, hexosamine and hydroxyproline contents of metaphyseal bones of control and rachitic rats were measured after 4 weeks on the diets. There was a decrease in whole blood ATP and serum phosphorus of the rachitic rats, and in the contents of ash, phospholipid and hexosamine of the rachitic metaphyses, while the hydroxyproline contents of the rachitic bones were higher than those of the controls. Subcutaneous injection of ATP or inorganic phosphate in rats, fed a low phosphate diet deficient in vitamin D, caused an increase in serum phosphorus and blood ATP levels and in metaphyseal ash contents. It is suggested that some of the metabolic disturbances in rickets are due to alteration in ATP production.

Adenosine Triphosphate↗
PubMed1992

Skeletal growth in cartilage-hair hypoplasia. A radiological study of 82 patients.

Cartilage-hair hypoplasia is a metaphyseal chondrodysplasia with short-limbed short stature. In childhood radiographs the metaphyseal regions of the tubular bones are widened, scalloped and irregularly sclerotic. We have analyzed radiological characteristics and skeletal growth in 149 radiographic surveys of 82 Finnish patients. All extremity long bones were affected and short for age. The growth failure was progressive. In the adults the median relative lengths were for the humerus -6.3 SD, radius -8.6 SD, ulna -6.7 SD, femur -9.7 SD, tibia -8.7 SD, and fibula -6.8 SD. the severity of the metaphyseal changes correlated with the degree of the growth failure. The skeletal age was markedly retarded in 14% of the patients. Caudal widening of the interpediculate distance in the lumbar spine was observed in 90% of the patients, but it tended to be less than normal. The sagittal diameter of the spinal canal was normal in the cervical region but decreased in the lumbar region. Mild scoliosis was observed in one-fourth of the patients, and its incidence increased with age. Lumbar lordosis was moderately increased. Thoracic deformity was observed in 82% of the patients. The relative interorbital distance was increased with the median of +2.2 SD in the adults.

Adult↗
PubMed1984

Mineral loss in cortical and trabecular bone during high-dose prednisone treatment.

To evaluate the effect of prednisone and triple treatment (sodium fluoride, calcium, and vitamin D) on trabecular and cortical bone serial bone mineral content (BMC) measurements were made at a metaphyseal (BMCD) and diaphyseal (BMCP) site on the forearm on 31 consecutive and previously bone-healthy patients scheduled for at least 24 weeks high-dose prednisone treatment. The patients were randomized into two further treatment groups: group I (n = 16) received prednisone plus triple treatment and group II (n = 15) received only prednisone. The two groups were similar with regard to age, sex, prednisone dose, and initial BMC. During 24 weeks treatment, BMCD (partially representing trabecular bone) and BMCP (mainly representing cortical bone) fell significantly and similarly, demonstrating that there is no preventive effect on bone mineral loss on the triple regimen. The BMC fall after 12 weeks was significantly more pronounced for metaphyseal (partially trabecular) than for diaphyseal (cortical) bone, whereas the values did not differ significantly after 24 weeks; this indicates a greater sensitivity to the hormone treatment of trabecular bone. In the entire group, the fall in BMC correlated positively with individual prednisone dose, significant at the diaphyseal site (r = 0.39, P less than 0.05), but not at the metaphyseal site (r = 0.31, P = 0.08). It is concluded that corticosteroid-induced osteopenia is a diffuse bone disease which affects trabecular as well as cortical bone, suggesting that BMC measured on the forearm reflects changes in bone mineral at other locations.

Adult↗
PubMed1987

Effects of neonatal estrogenization on rat bone development: a histomorphometric study.

The effects of a single dose of 500 micrograms of estradiol benzoate, administered on the first day of life, on rat bone development have been histomorphometrically studied at 15 days of age. Estrogenized animals presented decreased total tibial length (16.55 +/- 0.50 vs. 17.84 +/- 0.73 mm, P less than 0.05) and increased thickness of the cartilage growth plate (528.92 +/- 13.30 vs. 382.77 +/- 37.85 micron, P less than 0.01). This increase was mostly due to the presence of a wider (P less than 0.01) layer of hypertrophic cartilage in the estrogenized rats than in control ones. It might be related to the decreased number of chondroclasts (0.20 +/- 0.01 vs. 0.36 +/- 0.06 mm-1, P less than 0.05) found in the resorption zone. Two metaphyseal zones have been considered. In the upper metaphyseal zone there was an increase in the surface density of the cartilaginous trabeculae (49.20 +/- 1.80 vs. 40.72 +/- 1.95 mm2/mm3, P less than 0.05), without changes in the volume density. It was related to the presence of thinner and more irregular trabeculae in the estrogenized animals. In the lower metaphyseal zone both the volume (0.19 +/- 0.01 vs. 0.14 +/- 0.01 mm3/mm3, P less than 0.01) and surface (34.83 +/- 3.01 vs. 26.52 +/- 2.46 mm2/mm3, P less than 0.05) densities of the osseous trabecular tissue were increased in estrogenized rats. No significant differences were found either in the number of osteocytes per area unit of osseous tissue or in the number of osteoclasts per unit length of trabecular osseous tissue.

Animals↗
PubMed1979

Morphometric analysis of skeletal response to vitamin D in uremic rats fed a low calcium diet.

The response of tibial metaphyses to pharmacologic levels of vitamin D in uremic rats fed a low calcium diet was evaluated morphometrically. Uremic (5/6 nephrectomized) rats given vitamin D had increased percent metaphyseal hard tissue, trabecular surface perimeter and percent trabecular osteoid surface and reduced numbers of osteoblasts and osteoclasts per millimeter of trabecular perimeter compared to either uremic rats given placebo or sham-operated rats given vitamin D. It was concluded that the resistance of metaphyseal trabeculae in uremic rats to vitamin D was due in part to the increase in osteoid-covered surfaces which inhibited osteoclasis and subsequent remodeling. The pathogenesis of worsening osteomalacia as a consequence of vitamin D administration to uremic rats on a low calcium diet remains unclear.

Animals↗
PubMed2000

Alternation in bone components with increasing age of newborn rats: role of zinc in bone growth.

The effect of zinc on bone growth in newborn rats supplied with lactation by maternal rats was investigated. Newborn rats were killed between 1 and 35 days after birth. Increasing age caused a significant increase in zinc content, calcium content, and alkaline phosphatase activity in the femoral-diaphyseal and metaphyseal tissues, while the bone deoxyribonucleic acid (DNA) content was significantly decreased because of elevation of mineral content. Oral administration of zinc sulfate (2.0mg/100g body weight; four times at 24-h intervals) to maternal rats from 1 day after birth induced a significant increase in zinc, alkaline phosphatase activity, DNA, and calcium content in the femoral-diaphyseal and metaphyseal tissues of newborn rats compared with those 7 or 14 days old. The results indicate that the increase in bone components results from lactation with zinc-containing milk of maternal rats. The femoral-metaphyseal tissues of newborn rats obtained at 7 days after birth were cultured for 24h in a medium containing either vehicle or zinc sulfate (10(-6) to 10(-4) M) in vitro. Bone alkaline phosphatase activity and calcium and DNA content were significantly increased by zinc addition. These increases were completely prevented by the presence of dipicolinate (10(-3) M), a chelator of zinc ion, or cycloheximide (10(-6) M), an inhibitor of protein synthesis. The present study suggests that zinc plays a role in the development of bone growth in newborn rats.

Aging↗
PubMed1998

[Screw osteosynthesis in dislocated fractures of the radial condyle of the humerus in the growth period. A prospective long-term study].

UNLABELLED: Pseudoarthrosis and cubitus valgus as main complications following displaced fractures of the radial condyle in children can be prevented by open reduction and fixation by K wires. However, delayed union and stimulation of the radial physis with condylar overgrowth and varisation of the elbow as well as fishtail deformities of the distal end of the humerus are reported nevertheless. To prevent those growth disturbances all primary and secondary (4-day X-ray control) displaced fractures of the radial condyle, i.e. those with a central gap of more than 2 mm, were prospectively treated by open reduction and osteosynthesis with a metaphyseal lag screw beginning 1974. Sixty-six patients (41 boys, 25 girls) with an average follow-up of 10 years (2-22 years) sustained 28 primary and 6 secondary displaced fractures. In 5 cases a K wire fixation was performed in view of the smallness of the fragment. Two children with conservative treatment following overlooked displaced fractures showed condylar overgrowth and varisation of the elbow. Screw osteosynthesis led to symmetric elbow angles and function in all cases, whereas fishtail deformities could be observed in 8 of 27 children, probably as a consequence of the remaining central fracture instability. CONCLUSION: Open reduction and osteosynthesis with a metaphyseal lag screw prevents condylar overgrowth in displaced fractures of the radial condyle by guaranteeing fracture healing in anatomic position within 3-4 weeks. However, fishtail deformity can not be prevented by metaphyseal compression only.

Adolescent↗
PubMed2002

The blood supply of the growth plate and the epiphysis: a comparative scanning electron microscopy and histological experimental study in growing sheep.

The blood supply of the growth plate has been described in the late 50s and early 60s, and there was controversial discussion about the existence of transphyseal vessels. The vascular supply of growth plate and epiphysis of the proximal tibia was reinvestigated using a modern technique, the Mercox-perfusion method, in six sheep aged 6-24 weeks. A comparison was made among pure perfusion specimens, the corrosion casts, and histological sections. The metaphyseal, epiphyseal, and perichondral blood supply systems were confirmed. However, there was evidence of regular transphyseal anastomoses between the metaphyseal and epiphyseal system. Based on the histological arrangement of the blood vessels, the arterial blood flow would appear to be from the metaphysis to the epiphysis. The existence of transphyseal arterial vessels originating metaphyseally and seen both in cast preparations and histological sections was added to the present description of the blood supply of the growth plate. Age-related differences in the vascularization of the growth plate were not found in this study.

Animals↗
PubMed2000

Spinal involvement in Pyle's disease.

BACKGROUND: Pyle's disease is a rare skeletal dysplasia involving the metaphyses of long bones. To date, spinal involvement has been only rarely described in the literature. OBJECTIVE: To show that spinal changes, which are an expression of the same growth defect of the long bones, are an important and constant sign of the disease in the families studied. MATERIALS AND METHOD: The radiographic skeletal changes in five patients have been observed. RESULTS: The pathognomonic metaphyseal widening of tubular bones (known as the 'Erlenmeyer flask sign') was associated with the spinal changes in all cases. Radiographic findings in the spine varied from moderate platyspondyly to the bodies having the appearance of a biconcave lens. This may be attributed to two main causes: (1) a defect in the modelling process of the vertebrae (comparable to that observed in the metaphyses) and (2) chronic pathological fractures secondary to osteoporosis (a typical feature of Pyle's disease). CONCLUSIONS: The finding of platyspondyly of varying severity widens the spectrum of radiographic findings in this disease and can assist in diagnosis.

Adolescent↗
PubMed2004

Erdheim-Chester disease in a child with MR imaging showing regression of marrow changes.

OBJECTIVE: Erdheim-Chester disease is a disseminated xanthogranulomatous infiltrative disease of unknown origin that generally presents in adulthood. A review of the English-language literature demonstrated that pediatric cases were extremely rare, and to our knowledge, only two cases, a 7- and 14-year-old, have been published. DESIGN AND PATIENT: We report a case of Erdheim-Chester disease in a 10-year-old girl evaluated with MR imaging. Radiographs revealed typical bilateral, symmetric osteosclerosis of the metaphyseal regions of long bones of the upper and lower extremities. RESULTS: A histologic examination demonstrated foamy histiocytes in bone marrow smears. Bilateral symmetric low signal intensities of both proximal tibiae and distal femurs were demonstrated on T1-weighted MR images. After oral steroid therapy for 8 months, follow-up MR imaging showed remarkable restoration of normal high signal intensity in both the tibial and femoral metaphyses. CONCLUSION: To our knowledge, this may be the first case of Erdheim-Chester disease that showed normal restoration of the abnormal signal intensities in the metaphyses of long bones after steroid therapy.

Bone Marrow↗
PubMed2006

Achondroplasia and enchondromatosis: report of three boys.

We report on three boys suffering from achondroplasia concurrent with enchondromatosis-like metaphyseal changes. Two boys who were examined by molecular analysis harbored a mutation of FGFR3, which occurs in most achondroplastic individuals. Given the prevalence of achondroplasia and enchondromatosis, the metaphyseal changes in these patients are less likely to represent the coincidence of both disorders, but rather to result from a rare consequence of the FGFR3 mutation. Impaired FGFs/FGFR3 signaling pathway in achondroplasia inhibits chondrocytic proliferation, which accounts for most characteristics of achondroplasia. On the other hand, it causes conflicting biological consequences that can suppress or stimulate chondrocytic maturation. In a small subset of achondroplastic individuals, the suppression of chondrocytic maturation may outweigh the stimulation, which leads to cartilaginous overgrowth into the metaphysis, eventually causing the metaphyseal dysplasia found in the present patients.

Achondroplasia↗
PubMed2000

The effects of cementless femoral stem shape and proximal surface texture on 'fit-and-fill' characteristics and on bone remodeling.

We measured the post-operative radiological "fit and fill" of two different femoral stem designs, one with a straight proximally porous-coated (Bi-Metric, n=50) and the other with a proximally anatomic, hydroxyapatite-coated and distally over-reamed stem (ABG, n=26). A comparison was then made between the clinical and radiological 5-year follow-up data of these two series and also of the bone remodeling changes around the stems. The observed differences in "fit and fill" parameters in the metaphyseal region were minute. However, in the diaphyseal bone the straight stem had substantially more cortical contact. The clinical results were excellent for both groups. Subsidence (>2 mm) was more frequent with the anatomical ABG stems, although the ABG stems had better bone ingrowth in the lower metaphyseal area. The present results indicate that the anatomical design may improve the fit and fill of a femoral stem in the metaphysis. On the other hand, a looser fill of the diaphyseal bone made the stems of this type more susceptible to subsidence. The straight stem with tight diaphyseal fit showed excellent stability, but the good bone ingrowth and remodeling around the distal part of the stem indicates stress transfer through this region and increased stress shielding of the proximal metaphyseal femur.

Adult↗
PubMed1993

Effect of flexible drive diameter and reamer design on the increase of pressure in the medullary cavity during reaming.

Reaming the medullary cavity before insertion of an intramedullary nail, results in an increase in both temperature and pressure. This may lead to aseptic necrosis of the cortex and to fat embolism, whereby the increased pressure in the medullary cavity plays a significant role. This paper aims to determine whether a reduction of the drive diameter combined with a different reamer design reduces the amount of intramedullary pressure. The pressure levels were measured in plexiglass tubes filled with a mixture of vaseline and paraffin. The viscoelastic properties of this mixture at 20 degrees C were equivalent to those of bovine medullary fat at 36 degrees C. In comparison with the conventional reamer system (9.0 mm drive + 9.5 mm AO reamer), the 7.0 mm drive+AO reamer and the 7.0 mm drive+hollow reamer, the pressure values were reduced as follows: 1. 9.0 mm drive + 9.5 mm hollow reamer: diaphyseally by 19%, metaphyseally by 21% 2. 7.0 mm drive + 9.5 mm AO reamer: diaphyseally by 48%, metaphyseally by 49% 3. 7.0 mm drive + 9.5 mm hollow reamer: diaphyseally by 61%, metaphyseally by 66%. If the gap between the flexible shaft and the wall of the plexiglass tube became large enough, only small pressure values were recorded for all three types of reamer. In summary, it can be stated that the reduction of the drive diameter causes a sustained reduction in the intramedullary pressure, but that the newly developed hollow reamer only leads to a further reduction in pressure in combination with a thin flexible drive.

Equipment Design↗
PubMed1982

Skeletal abnormalities in rats induced by simulated weightlessness.

A hypokinetic model has been developed which attempts to simulate the weightlessness experienced during space flight. Male rats (approximately 130 g) were suspended from the model with a head-down tilt for a two-week period. Total mechanical unloading of the hind limbs and partial unloading of the fore limbs occurred. In comparison to pair-fed control rats, the skeletal alterations in the proximal tibial and humeral metaphyses of suspended rats were determined to be a diminished rate of longitudinal bone growth, a reduced mass of mineralized tissue, and an accumulation of marrow fat. Also, suspended rats exhibited decreased numbers of osteoblasts and increased numbers of osteoclasts immediately adjacent to the growth plate-metaphyseal junction at both skeletal sites. Although the reduction in mineralized tissue and the fat accumulation were more marked in the tibia, the skeletal changes in the proximal tibial and humeral metaphyses were generally comparable. The observed abnormalities may be due to mechanical unloading and/or a hypersecretion of corticosteroids.

Adipose Tissue↗
PubMed1994

Absorbable membranes for bone repair: an experimental study on rabbits.

To study the use of absorbable self-reinforced polyglycolide (SR-PGA) membranes for bone repair, distal femoral metaphyseal osteotomies were created in 10 rabbits and diaphyseal osteotomies in five. Osteotomies were fixed with intramedullary PLLA rods and PGA membranes were applied over the osteotomy. They were followed up for 6, 12 and 24 weeks. Radiography, histology, microradiography and oxytetracycline fluorescence labelling studies were used to evaluate the outcome. Healing occurred without complications in the metaphyseal series while failure was recorded in the diaphyseal series. In metaphyseal osteotomies, new bone formation was seen medially (on the side of PGA membrane), more proximal and medial to the membrane than at the inlet of osteotomy.

Animals↗