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PubMed2004

Effects of acute 5-fluorouracil chemotherapy and insulin-like growth factor-I pretreatment on growth plate cartilage and metaphyseal bone in rats.

With the intensified use of chemotherapy and improved survival rates for childhood malignancies, it has become increasingly apparent that some children or adult survivors show poor bone growth and develop osteoporosis. As a step to investigate underlying mechanisms, this project examined short-term effects in rats of chemotherapy agent 5-fluorouracil (5-FU) on cell proliferation, apoptosis, and bone formation at tibial growth plate cartilage and its adjacent bone-forming region metaphysis. In addition, since insulin-like growth factor (IGF-I) is important for bone growth, we examined whether IGF-I pretreatment would potentially protect growth plate cartilage and bone cells from chemotherapy damage. Two days after a single high dose of 5-FU injection, proliferation of growth plate chondrocytes and metaphyseal osteoblasts/preosteoblasts was dramatically suppressed, and apoptosis was induced among osteoblasts and preosteoblasts. As a result, there was a reduction in the chondrocyte number and zonal height at the proliferative zone and a decline in the number of osteoblasts and preosteoblasts on the metaphyseal trabecular bone surface. At day 2, no obvious deleterious effects were observed on the height of the growth plate hypertrophic zone and the bone volume fraction of the metaphyseal primary spongiosa trabeculae. At day 10, while cell proliferation and growth plate structure returned to normal, there were slight decreases in trabecular bone volume, body length increase, and tibial length. While pretreatment with 1-week IGF-I systemic infusion did not attenuate the suppressive effect of 5-FU on proliferation in both growth plate and metaphysis, it significantly diminished apoptotic induction in metaphysis. These results indicate that growth plate cartilage chondrocytes and metaphyseal bone cells are sensitive to chemotherapy drug 5-FU and that IGF-I pretreatment has some anti-apoptotic protective effects on metaphyseal bone osteoblasts and preosteoblasts.

Animals↗
PubMed1998

Potent effect of zinc acexamate on bone components in the femoral-metaphyseal tissues of elderly female rats.

1. The effect of zinc compounds on bone components in the femoral-metaphyseal tissues from elderly female rats (50 weeks old) was investigated in vitro. Bone tissues were cultured for 24 hr in Dulbecco's modified Eagle medium containing either vehicle or zinc compounds (10[-7] to 10[-5] M). 2. Zinc content, alkaline phosphatase activity, deoxyribonucleic acid (DNA) and calcium contents in the metaphyseal tissues were significantly increased by the presence of zinc sulfate (10[-6] and 10[-5] M), beta-alanyl-L-histidinato zinc (AHZ; 10[-6] and 10[-5] M) and zinc acexamate (10[-7] to 10[-5] M). At 10[-5] M, the effect of zinc acexamate on the increase of bone components was more potent than that of zinc sulfate or AHZ. 3. The effect of zinc acexamate (10[-5] M) on the increase of alkaline phosphatase activity in the metaphyseal tissues was remarkable as compared with that of insulin (10[-8] M), estrogen (10[-9] M), insulin-like growth factor-I (10[-8] M), transforming growth factor-beta (10[-10] M), sodium fluoride (10[-3] M), dexamethasone (10[-7] M) and vitamin K2 (menaquinone-4; 10[-5] M) with an effective concentration. 4. The stimulatory effect of zinc acexamate (10[-5] M) on alkaline phosphatase activity and calcium content in the metaphyseal tissues was completely blocked by the presence of dipicolinate (10[-3] M), a chelator of zinc ion, and of cycloheximide (10[-6] M), an inhibitor of protein synthesis. 5. The present study demonstrates that zinc acexamate has a potent anabolic effect on bone components in the femoral-metaphyseal tissues from female elderly rats in vitro. The effect of zinc acexamate may be based in part on protein synthesis related to zinc ion in bone cells.

Alkaline Phosphatase↗
PubMed1998

Anabolic effect of genistein and genistin on bone metabolism in the femoral-metaphyseal tissues of elderly rats: the genistein effect is enhanced by zinc.

The effect of genistein and genistin on bone components in the femoral-metaphyseal tissues obtained from elderly female rats was investigated in vitro. The metaphyseal tissues were cultured for 24 h in a medium containing either vehicle, genistein (10(-8)-10(-5) M) or genistin (10(-7)-10(-5) M). The presence of genistein or genistin caused a significant increase in alkaline phosphatase activity, deoxyribonucleic acid (DNA) and calcium contents in the metaphyseal tissues. The effect of genistein was greater than that of genistin. The bone components increased by genistein (10(-5) M) or genistin (10(-5) M) were completely blocked by the presence of cycloheximide (10(-6) M). The presence of zinc sulfate (10(-5) M) caused a significant increase in the genistein (10(-5) M)-elevated alkaline phosphatase activity, DNA and calcium contents. The enhancement with zinc was not seen by genistin (10(-5) M). The stimulatory effect of zinc on the genistein-induced increase in bone components of the metaphyseal tissues was completely blocked by the presence of cycloheximide (10(-6) M). The present results suggest that genistein and genistin have an anabolic effect on bone metabolism in the femoral-metaphyseal tissues of elderly rats, and that the genistein effect is enhanced by zinc, an essential trace element.

Aging↗
PubMedDate not supplied

[Revision total hip arthroplasty: how do metaphyseal onset, diaphyseal fill and a three-point-stem-fixation influence the postoperative subsidence of a revision straight-stem?].

AIM: It was the purpose of this study to determine the postoperative subsidence of a cementless hip revision stem in regard to the degree of metaphyseal onset, diaphyseal fit and a three-point contact of the stem in the femur. METHODS: Data of 50 revision total hip replacements using a cementless revision straight stem (PFM-R) could be investigated. The degree of subsidence was measured on pelvic X-rays 6 and 12 months postoperatively. The degree of metaphyseal onset, diaphyseal fit and a three-point contact of the stem in the femur was determined on the immediate postoperative X-rays. RESULTS: The amount of subsidence was strongly related to the degree of metaphyseal onset. With minor onset (up to 25 % of the possible) stems subsided 9.4 (6 months), respectively, 13.2 millimeters (12 months) in average within the investigation periods. If there was a large degree of metaphyseal onset (more than 75 % of the possible) the average subsidence was only 1.6 (6 months) or 0.9 millimeters, respectively (12 months). Neither the amount of diaphyseal fit nor the presence of three-point contact of the stem in the femur influenced the subsidence significantly. Conclusion The amount of the postoperative subsidence of stems in cementless revision total hip arthroplasty is predominantly influenced by the degree of the metaphyseal onset of the prosthesis.

Adult↗
PubMedDate not supplied

Tibia valga after proximal metaphyseal fractures in childhood: a normal biologic response.

Seventeen children with 19 proximal tibial metaphyseal fractures were followed-up between 2 and 7 years after injury. Detailed measurements of the metaphyseal/diaphyseal/metaphyseal distances medially and laterally on the injured and noninjured sides demonstrated overgrowth. In four patients, the medial distance of the injured tibia was longer than the lateral distance, which was the same distance as the uninjured tibia. In 11 patients, there was an overgrowth of both the medial and lateral sides of the injured tibia, compared to the unijured tibia, and in each instance, the medial distance of the injured tibia was always longer than the lateral. In a patient with bilateral metaphyseal fractures, the medial length exceeded the lateral length in both tibias. In the child with metaphyseal and diaphyseal fractures, the medial side of the tibia with the metaphyseal fracture was the longest of the four measurements. In five of six patients with Harris lines, there was distal as well as proximal tibial metaphyseal overgrowth, but the distal line was always parallel to the physis and did not contribute to the valgus angulation. Thus there was not only a generalized increased growth proximally and distally, but there also was an eccentric proximal medial overgrowth in every patient.

Adolescent↗
PubMed1991

Metaphyseal acroscyphodysplasia.

Based on two independent personal cases and a pair of sibs from the literature, we delineate a new category of bone dysplasia with cup-shaped large metaphyses, for which the name metaphyseal acroscyphodysplasia is suggested. The main clinical features are severe growth retardation, micromelia predominating in the lower limbs, knee flexion, and severe brachydactyly. The radiological aspect of the knees is very specific: the lower femoral and upper tibial epiphyses embed themselves in their metaphyses, which are severely cup-shaped. Premature central epiphyso-metaphyseal fusion and gross deformation, or even coalescence, of the femoral condyles may occur. The femoral diaphyses are very short and broad, and there is progressive coxa valga. Bowed and/or short stubby tibiae with cone-shaped metaphyses, and varus deformity of the tibio-astragalian joint are other features. Slight deformations of the long bones occur in the upper limb. Severe brachydactyly, brachymesophalangy, phalangeal and metacarpal cone-shaped epiphyses and irregular, bent and shortened diaphyses are the main signs of hand involvement. Psychomotor retardation is present in 3/4. Autosomal recessive inheritance is likely.

Bone and Bones↗
PubMed2002

Posterior distal femoral and proximal tibial metaphyseal stripes at MR imaging in children and young adults.

PURPOSE: To determine the frequency and distribution of the hyperintense stripe seen along the posterior surface of distal femoral and proximal tibial metaphyses at magnetic resonance (MR) imaging. MATERIALS AND METHODS: One hundred forty-two MR imaging studies obtained in 139 children and young adults were reviewed. The authors recorded the presence and distribution of posterior distal femoral and proximal tibial metaphyseal stripes. Presence of stripe was correlated with patient age and sex and with patency of the adjacent physis. Fifty-nine studies of adults were reviewed similarly. Two-way analysis of variance was performed to compare mean patient age for sex among four different categories that were based on stripe presence and physeal patency. Orthogonal contrasts were used to determine whether a linear trend across the categories existed. In one cadaveric femur, imaging and histologic analysis were performed. RESULTS: A metaphyseal stripe was seen in all patients with a completely or partially open physis (110 femora, 102 tibiae) and in 56 femora and 60 tibiae in the patients with fused physes. Thirty-five femora and 35 tibiae showed no stripe; all patients were skeletally mature. Correlations between metaphyseal stripe visualization and physeal patency were significant (P <.001). Differences in mean patient age among the four categories were significant for both (femoral and tibial) locations (P <.001), and a linear trend with age (P <.001) was demonstrated. This linear trend was also observed in both sexes (P <.001). Histologic analysis revealed highly vascular loose fibrous tissue. CONCLUSION: A posterior metaphyseal stripe is seen at MR imaging of the skeletally immature knee and likely reflects normal bone growth.

Adolescent↗
PubMed1993

Indirect trauma to the growth plate: results of MR imaging after epiphyseal and metaphyseal injury in rabbits.

Abnormalities of the growth plate secondary to epiphyseal and metaphyseal injury were studied with magnetic resonance (MR) imaging, radiography, and histologic examination in 20 rabbits. Epiphyseal injury resulted in either the formation of a bony bridge across the growth plate or focal curving of the growth plate caused by a decrease in longitudinal growth. Metaphyseal injury resulted in interference with endochondral ossification, thickening of the growth plate, and extension of cartilage into the metaphysis. Serial MR images obtained during the first 6 weeks after injury showed persistence of abnormalities of the growth cartilage after epiphyseal injury, but resolution of abnormalities after metaphyseal injury. Abnormalities of the cartilage were best seen on T2-weighted images. Gadolinium enhancement showed reconstitution of metaphyseal vascularity after metaphyseal injury but did not enable detection of transphyseal vascularity after epiphyseal injury until a bony bridge formed.

Animals↗
PubMed2005

Standardized bending and breaking test for the normal and osteoporotic metaphyseal tibias of the rat: effect of estradiol, testosterone, and raloxifene.

UNLABELLED: The fracture of bone plays a key role in osteoporosis. BMD measurement, however, is only an indirect parameter of this phenomenon. We therefore developed a highly sensitive three-point bending test for the metaphyseal tibias in rats to evaluate stiffness and strength. This was validated in a right-left comparison and a bioassay with soy-free food, estradiol, raloxifene, and testosterone in orchidectomized rats. INTRODUCTION: Osteoporosis becomes manifest predominantly in the metaphyseal rat tibia. The anti-osteoporotic character of substances should, therefore, be tested (mechanically) in this bone area. MATERIALS AND METHODS: We evaluated a new three-point bending test for the metaphyseal tibia in rats in a right-left trial. In an animal experiment, we studied the change of bone quality under estradiol (E)-, raloxifene (R)-, and testosterone (T)-supplemented food and compared it with trabecular BMD (qCT). RESULTS: In the right-left comparison, the mean difference between the metaphyseal loads of both tibias in 37 rats was 8.43% for the maximum load (Fmax) and 6.46% for the failure load (fL). These results show the high reproducibility of the test, because they are close to the usual intraindividual difference of the two extremities. In a second experiment, four groups of 11 3-month-old male orchidectomized rats were fed with soy-free food only (C) or with the additives E, T, or R for 12 weeks. E and R were similar for Fmax and fL. There were significant differences in the stiffness (E = 406.92 N/mm versus R = 332.08 N/mm), the yield load (yL; E = 99.17 N versus R = 83.33 N), and the ratio between yL and Fmax (E = 86.33% versus R = 76.37%). T was similar to the controls concerning F(max), fL, and stiffness. There were significant differences in yL (T = 49.00N versus C = 39.5N) and the ratio between yL and Fmax (T = 64.28% versus C = 51.28%). CONCLUSIONS: Estradiol is superior to raloxifene concerning stiffness and yield load, and both are superior to testosterone. We conclude that the described three-point bending test for the metaphyseal tibia is a highly sensitive method to study hormones and substances with regard to their osteoprotective character. The precision and the low SD of the presented results are superior to the data from qCT and the calculated index of stiffness (SSI).

Androgens↗
PubMed1998

A regional approach to the classic metaphyseal lesion in abused infants: the distal femur.

OBJECTIVE: The purpose of this study was to analyze the spectrum of morphologic alterations of the classic metaphyseal lesion involving the distal femur of abused infants and to identify features that aid in radiologic diagnosis and assessment of healing. MATERIALS AND METHODS: Thirty-one infants who died with evidence of inflicted skeletal injury were studied with high-detail skeletal surveys, resected specimen radiography, and histologic analysis. We recorded the number of fractures, the portions of the distal femoral metaphyses involved, and the age of the lesions. RESULTS: Fifteen classic metaphyseal lesions of the distal femur were seen in 11 infants. The lesions were bilateral in four infants and unilateral in seven. Nine healing and three acute classic metaphyseal lesions were found. In the remaining three lesions, the age of the lesions was indeterminate. Fractures always involved the posteromedial aspect of the femur; anterior and lateral extension occurred in more diffuse lesions. Fractures tended to be less conspicuous when they were acute and were more easily recognized with healing, especially with specimen radiography. Histologically, the fracture line consistently undercut the medial subperiosteal bone collar. Extension of hypertrophic chondrocytes from the growth plate into the region of fracture was found in all nine healing lesions. CONCLUSION: The classic metaphyseal lesion of the distal femur has distinctive radiologic and histopathologic characteristics that relate to the anatomy of the region. Because the distal femur is a common site for this strong indicator of infant abuse, the region should be carefully evaluated with well-collimated, high-detail skeletal radiographs in all cases of suspected infant abuse.

Case-Control Studies↗
PubMed1999

[Treatment of distal metaphyseal fractures of the tibia with the interlocking flexible osteosynthesis system].

PURPOSE: Accurate anatomic identification of distal metaphyseal fractures of the tibia is necessary when comparing the fixation ability of internal fixation devices. First, we have set the dimensions of the metaphyseal area. The purpose of this study was to evaluate the Interlocking Flexible Osteosynthesis system in properly selected distal metaphyseal fractures, not to be confused with distal shaft fractures. PATIENTS: This study involves 28 fractures, including 10 diaphyseal-metaphyseal fractures, and 18 pure metaphyseal fractures, 9 of which were distal fractures involving the inferior half of the metaphysis. Five of them were segmental fractures. RESULTS: There were 5 severe complications: early loosening (1), nonunions (2), severe malalignments in 2. These resulted from a combination of insufficient distance between the tips of pins, with severe demineralization of bone tissue. The authors have emphasized the technical means available to avoid this. Twenty-five fractures united at a mean of 13.5 +/- 5 weeks (all types). CONCLUSION: Such a fixation is reliable as long as certain technical rules are respected, which requires a great deal of experience with the method.

Adult↗
PubMed2001

[Metaphyseal and diaphyseal modular femoral stems implanted without cement].

PURPOSE OF THE STUDY: We assessed outcome after total hip arthroplasty (THA) using a dual metaphyseal-diaphyseal modular femoral stem with hydroxyapatite coating on the metaphyseal portion only. Implanted without cement, this stem was adaptable to all the anatomic morphotypes defined by the Noble canal flare index. MATERIAL AND METHODS: THA was performed in 116 patients (124 hips), mainly for degenerative joint disease (80% for dysplasia). Mean age was 61.2 years. Follow-up was 6.9 years (72-108 months). RESULTS: There were no preoperative complications excepting 3 cases of neck fissuration without clinical consequence. There was no trochanteric fracture. We had two early and one late dislocations. The Postel Merle d'Aubigné score improved from 8.09 to 17.27. Clinical outcome was not influenced by patient age, weight or morphotype. Radiologically, signs of bone ingrowth were found in more than 80% of the cases. Lucent lines were seen in only 3 cases. There was a single case of migration. No revision was needed among the cases with ossifications (23%, 22% Brooker I) and no femur revisions were required. There was no mechanical problem involving the metaphyseal-epiphysial junction. DISCUSSION: The dual metaphyseal-diaphyseal modular stem was found to be a safe and effective implant adaptable to all anatomic variations of the femur and providing good primary stability. In our series, 58% of the femurs were "standard" but for one-third of the femurs, the modular stem enabled implantation without cement, particularly in young adults with a dysplasic or funnel-shaped femur. CONCLUSION: The dual metaphyseal-diaphyseal modular stem was found to be most useful for optimizing total hip arthroplasty without cement.

Activities of Daily Living↗
PubMedDate not supplied

Metaphyseal and spondylometaphyseal chondrodysplasias.

Diseases characterized by defective metaphyseal ossification, (metaphyseal chondrodysplasias) and defective spinal and metaphyseal ossification (spondylometaphyseal chondrodysplasias) constitute an important group of congenital intrinsic diseases of bones in which orthopedic treatment is of utmost interest. The most common types of metaphyseal chondrodysplasias (Jansen, Schmid, McKusick, and Metaphyseal Chondrodysplasia with Pancreatic Insufficiency and Neutropenia) and spondylometaphyseal chondrodysplasias (Kozlowski) have characteristic well-defined diagnostic features. The importance of proper diagnosis for practical reasons--appropriate medical and psychological treatment, professional training and genetic counseling--cannot be overemphasized. Elucidation of the pathogenesis in this group of diseases is bound to emerge from future histochemical and biochemical research.

Adolescent↗
PubMed2003

A case with Pyle type metaphyseal dysplasia: clinical, radiological and histological evaluation.

Pyle type metaphyseal dysplasia is a rare autosomal recessive disease that is primarily affect metaphyses. Here we present a case with Pyle type metaphyseal dysplasia. The characteristic features of the case were metapyhseal broadening with undertubulation and Erlenmeyer flask sign at distal femoral and proximal tibial metaphyses. There were also platyspondyly with biconcave lens appearance of the vertebral bodies, congenital hip dislocation and normal cranium. Bone histopathology showed decreased number of osteoclasts. To the best of our knowledge, this is the first reported case of Pyle type metaphyseal dysplasia from Turkey.

Abnormalities, Multiple↗
PubMedDate not supplied

"Metaphyseal" cysts in Legg-Calve-Perthes' disease.

Radiographic changes in the femoral metaphysis in Legg-Calve-Perthes' (LCP) remain poorly understood. Our hypothesis was that these "cysts" are not truly metaphyseal but are metaphyseal changes radiographically projected onto the metaphysis. Surface epiphyseal changes were made on a normal hip and a hip with LCP. These "lesions" appeared metaphyseal on radiograph, and in the specimen with LCP, projected deep within the metaphysis due to flattening and three-dimensional distortion. "Metaphyseal" cysts in LCP may be epiphyseal changes superimposed on the metaphysis. This would explain the correlation between the presence of a "metaphyseal" lucency and final result, since it is simply another indicator of the extent of epiphyseal involvement.

Bone Diseases↗
PubMed1990

Biomechanical factors in the metaphyseal- and diaphyseal-lengthening osteotomy. An experimental and theoretic analysis in the ovine tibia.

A post hoc comparison of the mechanical factors that affected the outcome of experimental metaphyseal- and diaphyseal-lengthening osteotomies in sheep tibiae was performed. The resulting motions between bone segments at the metaphyseal and diaphyseal levels were estimated using measured fixator stiffnesses, postural muscle activity, ground reaction forces, and calculated internal and external loads. Relative displacements of bone segments of up to 2.8 degrees were estimated in postural activities; displacements were up to 4.9 times larger at the metaphyseal than at the diaphyseal osteotomy level. The results suggest that due to these increased motions, mechanically inferior conditions for healing at the metaphyseal-lengthening osteotomy level may counteract any supposedly superior biologic healing potential that the metaphyseal region of the bone may have compared with the diaphyseal region. These results correlate well with the clinical findings of the earlier animal study.

Animals↗
PubMed1989

[Radius-femoral dysplasia. A new form of hereditary metaphyseal dysplasia].

Höhle and Braun described a new form of hereditary metaphyseal dysplasia. It is characterized by changes in distal metaphyses of femoral bones which are formed as Erlenmeyer flasks, further by club-shaped dysplasias of the metaphyses of the other long bones, absence of skeletal hyperostosis and by characteristic varus-deformations of radial bones. An extensive family history research showed that the oldest carriers of these anomalies came from a small town in northern Bohemia. Completely identical case reports were published describing the carriers of metaphyseal dysplasia characters whose origin was also traced to the same region. The authors aim at drawing attention to this new disease, finding more carriers of metaphyseal dysplasia characters and at giving an impulse to an extensive research into this extremely systemic rare bone disease.

Adult↗
PubMed1996

[Pragmatism versus metaphysics: a controversy about brain death].

The concept of brain death is still controversial. The Chilean case, as a result of a future transplantation law, seem to demonstrate this issue. The aim of this work is to contribute to the debate. A recent international polemic between metaphysic and pragmatic authors is approached, to establish bases to reject or accept the issue, after giving a brief history of the concept, from its medical origin to its transcendence to other areas as the law. The metaphysical rejection and the socio-cultural frame of the medical attitude that accepts brain death, are commented. It is concluded that the best defense of metaphysical point of view is the right to exclusion of minorities. Finally, brain death is criticized from a socio-cultural point of view of medical acts as a post-metaphysical concept of "useful death" and because of its relationship with "health production".

Brain Death↗