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PubMed1978

[Cranial metaphysial dysplasia (Jackson) (author's transl)].

The typical development of the radiological and clinical features of cranial metaphyseal dysplasia were observed over a period of nine years in one patient. This condition is most commonly confused with metaphyseal dysplasia (Pyle), but differs from the latter in showing pronounced changes in the skull leading to blindness, deafness and facial paralysis as well as club-shaped metaphyses. Cranial metaphyseal dysplasia, particularly in its autosomal recessive form, leads to reduced intelligence and life expectancy of the patients. The diagnosis can usually be made in early childhood.

Abnormalities, Multiple↗
PubMedDate not supplied

[Effect of risk factors and therapy on intermediate-term hip deformity in Perthes disease].

UNLABELLED: The prognostication of risk factors for the outcome of LCPD was examined. The radiographic results of conservative treatment with Thomas splint and operative treatment with intertrochanteric derotational varus osteotomy (DVO) were compared using the Index of Deformity (D). METHOD: Radiographs of 153 patients with unilateral LCPD were evaluated retrospectively 1.5-3 years and 3-7 years after diagnosis using the Index of Deformity and Index of Direction. We investigated the radiographic changes in relation to acetabular or metaphyseal reaction, Waldenström classification or limited range of motion at diagnosis and in dependence of therapy. RESULTS: There was a significant better acetabulum-head-index of deformity after DVO. Children with metaphyseal or acetabular reaction had bigger deformities. Patients with metaphyseal reaction had smaller deformities after DVO compared with conservative treatment. Free range of motion (ROM) was prerequisite for good results after DVO. Waldenström classification at diagnosis did not have any influence on morphologic changes after 3-7 years. CONCLUSION: DVO leads to a better containment than conservative treatment with Thomas splint, metaphyseal reaction should be an indication for operative treatment. Prerequisite for DVO is a free ROM. Because Waldenström class at diagnosis does not influence the outcome, free ROM before starting the treatment is more important than an immediate start of therapy.

Adolescent↗
PubMedDate not supplied

[Morphological, morphometric and stereological aspects of Blount's unilateral stapling of the growth plate in animal experiments].

Medial stapling of the proximal tibial growth plate in ten-week-old pigs effects in the first instance a local reaction of the growth plate being first limited to the region between the staple branches. From the 4th-5th postoperative day on, there is a significant decrease of the growth rate, the surface area of cells in the zone of opening cells, and of the surface density of the adjacent metaphyseal spongiosa. From the 10th-11th day after stapling a significant decrease in the height of the metaphyseal columns and the growth plate occurs in the medial compartment as well as a trabecular broadening of the metaphyseal spongiosa in the stapled area. Subsequently, the surface density of the metaphyseal spongiosa is significantly lower, the volume density significantly higher than the control values. With advancing postoperative interval the stapling effects involve the whole growth plate. However, the central and the lateral compartments show always less distinct findings. Unilateral stapling of the growth plate brings about a significant diminution of the radiologically determined length of the epiphysis, metaphysis and the total tibia as well as an evident broadening of the growth plate.

Animals↗
PubMed1963

Turnover of the organic matrix of cartilage and bone as visualized by autoradiography.

Tibiae and humeri were removed from suckling rats at intervals of time after intraperitoneal injection of C(14)-L-phenylalanine, C(14)-L-leucine, S(35)-sulfate, or Ca(45) Cl(2). Autoradiograms of sections of the bones were prepared. Ca(45) was removed from sections treated with dilute acetic acid; neither the concentration of S(35) nor that of C(14) was thereby markedly decreased. The S(35) was removed from the demineralized sections on incubation in a solution of testicular hyaluronidase; the C(14) was not. These results are interpreted as indicating that most of the S(35) was present in the bones as chondroitin sulfate and that most of the C(14) in the bones was present as protein. In the epiphyses, the C(14) was initially concentrated in the proliferaing and hypertrophic chondrocytes, as was the S(35). Secretion of S(35)- and C(14)-labeled materials into the matrix followed. Thereafter, however, although the S(35)-labeled material (chondroitin sulfate) persisted in the matrix, albeit at a diminished concentration, and was incorporated into metaphyseal bone, the C(14)-labeled material (protein) was almost completely removed from the matrix. When rats were given repeated doses of 17-beta-estradiol benzoate so as to inhibit resorption of their metaphyses, repeated doses of S(35)-sulfate were discerned as strata of S(35) in their metaphyses. This was not the case if the rats received repeated doses of C(14)-L-phenylalanine or C(14)-L-leucine. On the basis of the results in these experiments it is suggested that although a portion of the chondroitin sulfate produced by the chondrocytes of the epiphyseal plate is retained and becomes part of the cores of metaphyseal spicules of bone, the protein of the proteinpolysaccharide is somehow removed before calcification of the cartilage ensues.

Animals↗
PubMedDate not supplied

The geometry of slipped capital femoral epiphysis: implications for movement, impingement, and corrective osteotomy.

Metaphyseal impingement limits motion in high-grade slipped capital femoral epiphysis (SCFE). A three-dimensional volume/surface computer model was used to study the geometry of impingement, which may take the form of impaction, which causes levering or requires compensatory alteration in motion, or inclusion that occurs after remodeling and may lead to acetabular cartilage damage. The majority of deformities seen clinically can be reproduced with posterior epiphyseal displacement in the plane of the physis. By using the 3-D movements of normal walking, this model predicts little anterior metaphyseal impingement in the normal hip. As posterior slip angle increases to 25 degrees , minor impingement can be eliminated with as little as 20 degrees of external rotation. High-grade posterior slips (75 degrees ) require external rotation of 50-60 degrees during walking to minimize impaction. Sitting increases impingement for all slip geometries, requiring proportionately greater external rotation. As remodeling restores a more normal arc of motion, an increasing proportion of the femoral head is composed of the remodeled, included metaphyseal prominence. This study explores the potential role of contact between the acetabulum and the metaphysis in the production of abnormal range of motion after SCFE, and simulation estimates the correction needed by osteotomy to allow normal walking and sitting. The inclusion of significant metaphyseal surfaces in the remodeled hip may be one factor in subsequent degenerative changes associated with SCFE.

Acetabulum↗
PubMedDate not supplied

Sever's injury: a stress fracture of the immature calcaneal metaphysis.

Magnetic resonance imaging (MRI) in children with a presumptive diagnosis of Sever's apophysitis and with continuing pain after conservative treatment demonstrated bone bruising within the trabecular bone of the metaphyseal region adjacent to the calcaneal apophysis. Limited portions of the apophyseal secondary ossification center showed similar increased signal changes. MRI studies following treatment with immobilization showed subsidence or disappearance of the metaphyseal but not any apophyseal signal changes commensurate with improvement in symptoms. Accordingly, the disorder commonly referred to as Sever's ''apophysitis'' may be a metaphyseal trabecular stress fracture, similar to the toddler's calcaneal stress fracture that has minimal or no involvement of the apophyseal ossification center, and thus should not be referred to as an apophysitis. Rather, it appears to be an overuse injury causing microinjury within the developing metaphyseal "equivalent" trabecular bone that has not completely adapted to the changing biologic (biomechanical) requirements of the growing, athletically active child.

Calcaneus↗
PubMed2001

Differential expression of fibroblast growth factor receptors in human digital development suggests common pathogenesis in complex acrosyndactyly and craniosynostosis.

The Apert hand is characterized by metaphyseal fusions of the metacarpals and distal phalanges, symphalangism, and soft-tissue syndactyly. More subtle skeletal anomalies of the limb characterize Pfeiffer and Crouzon syndromes. Different mutations in the fibroblast growth factor receptor 2 (FGFR2) gene cause these syndromes, and offer the opportunity to relate genotype to phenotype. The expression of FGFR1 and of the Bek and KGFR isoforms of FGFR2 has, therefore, been studied in human hand development at 12 weeks by in situ hybridization. FGFRs are differentially expressed in the mesenchyme and skeletal elements during endochondral ossification of the developing human hand. KGFR expression characterizes the metaphyseal periosteum and interphalangeal joints. FGFR1 is preferentially expressed in the diaphyses, whereas FGFR2-Bek expression characterizes metaphyseal and diaphyseal elements, and the interdigital mesenchyme. Apert metaphyseal synostosis and symphalangism reflect KGFR expression, which has independently been quantitatively related ex vivo to the severity of clinical digital presentations in these syndromes. Studies in avian development implicate FGF signaling in preventing interdigital apoptosis and maintaining the interdigital mesenchyme. Herein is proposed that in human FGFR syndromes the balance of signaling by means of KGFR and Bek in digital development determines the clinical severity of soft-tissue and bony syndactyly.

Acanthosis Nigricans↗
PubMedDate not supplied

Determination of safe depth of pin penetration for repair of distal femoral physeal fractures in immature dogs: a comparison of normograde and retrograde pin placement.

OBJECTIVE: The purpose of this study was to determine the depth that implants may be safely placed into the distal femoral epiphysis (DFE) for the repair of distal femoral physeal fractures. STUDY DESIGN: The depth of the DFE was related to the radiographic thickness of the patella in this experimental study. ANIMALS OR SAMPLE POPULATION: Twenty immature canine cadavers. METHODS: Patella thicknesses were measured from lateral radiographs. Actual DFE depths were determined for pins driven in normograde fashion and for pins driven retrograde from the central depression between the metaphyseal pegs and from the cranial pegs. The association of DFE depth and patella thickness was evaluated using linear regression analysis. Using 95% confidence intervals, rules for estimating the safe depth of implant placement into the DFE were determined. RESULTS: DFE depth had significant correlation with patella thickness for pins placed in retrograde fashion from the central depression between the metaphyseal pegs (r2 = .83) and from the cranial pegs (r2 = .82) and for pins placed in normograde fashion (r2 = .65). CONCLUSIONS: Based on 95% confidence intervals, pins placed in retrograde fashion from the central depression between the metaphyseal pegs may be safely driven into the DFE a distance equal to 140% of patella thickness. Pins placed from the cranial metaphyseal pegs may be driven to a depth equal to 80% of patella thickness, and pins placed in normograde fashion may be driven to a depth equal to 30% of patella thickness. CLINICAL RELEVANCE: Measurement of patella thickness assists the surgeon in determining the approximate depth that pins may be driven into the DFE without penetrating the articular surface of the stifle joint.

Animals↗
PubMedDate not supplied

In vitro pullout strength of screws inserted in adult equine third metacarpal bone after overdrilling a 4.5-mm threaded insertion hole.

OBJECTIVE: To determine and compare the in vitro pullout strength of 5.5-mm cortical versus 6.5-mm cancellous bone screws inserted in the diaphysis and metaphysis of adult equine third metacarpal (MCIII) bones, in threaded 4.5-mm cortical bone screw insertion holes that were then overdrilled with a 4.5-mm drill bit to provide information relevant to the selection of a replacement screw if a 4.5-mm cortical screw is stripped. STUDY DESIGN: In vitro pullout tests of 5.5-mm cortical and 6.5-mm cancellous screws in equine MCIII bones. SAMPLE POPULATION: Two independent cadaver studies each consisting of 14 adult equine MCIII bones. METHODS: Two 4.5-mm cortical screws were placed either in the middiaphysis (study 1) or distal metaphysis (study 2) of MCIII bones. The holes were then overdrilled with a 4.5-mm drill bit and had either a 5.5-mm cortical or a 6.5-mm cancellous screw inserted; screw pullout tests were performed at a rate of 0.04 mm/second until screw or bone failure occurred. RESULTS: In diaphyseal bone, the screws failed in all tests. Tensile breaking strength for 5.5-mm cortical screws (997.5 +/- 49.3 kg) and 6.5-mm cancellous screws (931.6 +/- 19.5 kg) was not significantly different. In metaphyseal bone, the bone failed in all tests. The holding power for 6.5-mm cancellous screws (39.1 +/- 4.9 kg/mm) was significantly greater than 5.5-mm cortical screws (23.5 +/- 3.5 kg/mm) in the metaphysis. There was no difference in the tensile breaking strength of screws in the diaphysis between proximal and distal screw holes; however, the holding power was significantly greater in the distal, compared with the proximal, metaphyseal holes. CONCLUSIONS: Although tensile breaking strength was not different between 5.5-mm cortical and 6.5-mm cancellous screws in middiaphyseal cortical bone, holding power of 6.5-mm cancellous screws was greater than 5.5-mm cortical screws in metaphyseal bone of adult horses. CLINICAL RELEVANCE: If a 4.5-mm cortical bone screw strips in MCIII diaphyseal bone of adult horses, either a 5.5-mm cortical or 6.5-mm cancellous screw, however, would have equivalent pullout strengths. A 6.5-mm cancellous screw, however, would provide greater holding power than a 5.5-mm cortical screw in metaphyseal bone.

Animals↗
PubMed1999

Salvage of tibial pilon fractures using fusion of the ankle with a 90 degrees cannulated blade-plate: a preliminary report.

Six patients with ankle joint destruction and delayed metaphyseal union after tibial plafond fracture were surgically treated with tibiotalar arthrodesis and metaphyseal reconstruction, using a fixed-angle cannulated blade-plate. The procedure was performed through a posterior approach in five cases and a lateral approach in one case. The subtalar joint was preserved in all cases. Metaphyseal union and a stable arthrodesis were obtained in all cases without loss of fixation and with no mechanical failure of the blade-plate. Union was obtained in an average of 26 weeks. No secondary procedures were required to obtain union. All six patients were ambulatory at last follow-up. Stable internal fixation for simultaneous tibiotalar fusion and metaphyseal reconstruction can be achieved with a cannulated blade-plate while preserving the subtalar joint in complex plafond fractures.

Adult↗
PubMed1995

Droloxifene, a new estrogen antagonist/agonist, prevents bone loss in ovariectomized rats.

The purpose of this study was to determine the effects of droloxifene (DRO), a new estrogen antagonist/agonist, on bone turnover, bone mass, total serum cholesterol, and uterine weight in rats made estrogen deficient by ovariectomy. Sprague-Dawley female rats were ovariectomized (OVX) or sham operated (sham) at 5 months of age and treated with 17 beta-estradiol (E2) at 30 micrograms/kg, sc, daily or with DRO at 5, 10, or 20 mg/kg.day, orally, for 4 weeks. At the time of death, body weight gain, uterine weight, and total serum cholesterol were measured. Bone area, bone mineral content (BMC), and bone mineral density (BMD) of whole femora, distal femoral metaphyses, femoral shaft, and proximal femora were determined ex vivo using dual energy x-ray absorptiometry. Static and dynamic cancellous bone histomorphometric analysis of proximal tibial metaphyses was performed in double fluorescent labeled, undecalcified, 4- and 10-microns longitudinal sections. Body weight gain in E2-treated OVX rats was significantly reduced compared to that in OVX controls, but was not different from that in sham controls. Body weight gain in DRO-treated OVX rats was decreased significantly compared to that in both sham and OVX controls. In OVX rats, uterine weight was completely preserved by treatment with E2. Uterine weight in DRO-treated OVX rats was slightly, but significantly, increased from the vehicle-treated control value, and was significantly lower than that in sham controls and E2-treated OVX rats. Treatment with sc injection of E2 in OVX rats had no effect on total serum cholesterol, whereas OVX rats orally treated with DRO at 5-20 mg/kg.day decreased total serum cholesterol by 33-46% compared to levels in sham and OVX controls. Compared to sham controls, OVX decreased BMC and BMD of distal femoral metaphyses, increased BMD of the femoral shaft, and had no effect on BMC and BMD of whole femora and proximal femora. Treatment with either E2 or DRO prevented these changes induced by OVX. Proximal tibial metaphyseal trabecular bone volume and trabecular number were increased, and trabecular separation, percent osteoclast perimeter, osteoclast number, percent mineralizing perimeter, mineral apposition rate, bone formation rate, and bone turnover rate were decreased in 5, 10, or 20 mg/kg.day DRO-treated OVX rats compared to OVX controls. These cancellous bone histomorphometric indexes in DRO treated OVX rats did not differ from those in E2-treated OVX rats or sham controls, suggesting that DRO completely prevented the increases in bone turnover and the decrease in bone mass induced by OVX in rats.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Characteristics and bisphosphonate treatment of a patient with juvenile osteoporosis.

We studied a 13 1/2-yr-old boy with severe juvenile osteoporosis and multiple metaphyseal and vertebral fractures. Biochemically, there was evidence of non-PTH mediated excessive bone resorption, low intestinal calcium absorption, and a strikingly negative calcium balance. He was treated with (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate, a bisphosphonate capable of inhibiting bone resorption rapidly, and had dramatic clinical and biochemical improvement. All indices of resorption were normal within a week after initiation of therapy and his 1,25-dihydroxyvitamin D concentration, which was only 9.6 pg/ml before treatment, rose to 62.4 pg/ml. These changes were associated with an increase in calcium absorption and positive calcium balance. Radiological improvement with healing of metaphyseal and one diaphyseal fractures and signs of sclerosis near the growth plates of the affected metaphyses and at the end plates of the vertebrae also occurred. (3-Amino-1-hydroxypropylidene)-1,1-bisphosphonate, therefore, with its rapid suppression of resorption and the accompanying hormonal changes, is a very effective treatment for juvenile osteoporosis. The primary defect of this obscure syndrome seems to be uncontrolled activity of metaphyseal osteoclasts; disturbances of vitamin D metabolism and of intestinal calcium absorption are secondary events.

Adolescent↗
PubMed2004

Oral administration of beta-cryptoxanthin induces anabolic effects on bone components in the femoral tissues of rats in vivo.

The effect of beta-cryptoxanthin on bone components in the femoral tissues of rats was investigated. Beta-cryptoxanthin was isolated from Satsuma mandarin (Citrus unshiu MARC.). Bone tissues were cultured for 48 h in serum-free Dulbecco's modified Eagle's medium containing either vehicle or beta-cryptoxanthin (10(-7) or 10(-6) M). The presence of beta-cryptoxanthin (10(-7) or 10(-6) M) caused a significant increase in calcium content and alkaline phosphatase activity in the femoral-diaphyseal and femoral-metaphyseal tissues. These increases were completely abolished in the presence of cycloheximide (10(-6) M), an inhibitor of protein synthesis. Thus beta-cryptoxanthin had an anabolic effect on bone calcification in vitro. Moreover, beta-cryptoxanthin (10, 25, or 50 microg/100 g body weight) was orally administered once daily for 7 d to young male rats. The administration of beta-cryptoxanthin (10, 25, or 50 microg/100 g body weight) caused a significant increase in calcium content and alkaline phosphatase activity in the femoral-diaphyseal and femoral-metaphyseal tissues. Femoral-diaphyseal and femoral-metaphyseal DNA contents were significantly increased by the dose of 25 or 50 microg/100 g body weight. A significant increase in metaphyseal DNA content was also seen with the dose of 10 microg/100 g body weight of beta-cryptoxanthin. This study demonstrates that beta-cryptoxanthin has an anabolic effect on bone components in rats in vitro and in vivo.

Administration, Oral↗
PubMed2006

Oral administration in combination with zinc enhances beta-cryptoxanthin-induced anabolic effects on bone components in the femoral tissues of rats in vivo.

The effects of combined beta-cryptoxanthin and zinc on bone components in the femoral-diaphyseal (cortical bone) and -metaphyseal (trabecular bone) tissues of rats in vivo were investigated. Rats were orally administered either vehicle, beta-cryptoxanthin (5 or 10 microg/100 g body weight), zinc sulfate (0.1 or 0.5 mg Zn/100 g), or their combination once a day for 7 d. Calcium content, alkaline phosphatase activity, and DNA content in the femoral-diaphyseal tissues was not significantly altered by the administration of beta-cryptoxanthin (5 microg/100 g) or zinc (0.1 or 0.5 mg/100 g). Combined administration of beta-cryptoxanthin (5 microg/100 g) and zinc (0.1 or 0.5 mg/100 g) caused a synergistic increase in calcium content, alkaline phosphatase activity, and DNA content in the diaphyseal tissues. The effect of beta-cryptoxanthin (5 or 10 microg/100 g) in increasing calcium and DNA contents in the metaphyseal tissues was significantly enhanced by the combined administration of zinc (0.1 or 0.5 mg/100 g), but did not have a significant effect on the metaphyseal components. The metaphyseal alkaline phosphatase activity was markedly increased by the combination of beta-cryptoxanthin (5 microg/100 g) and zinc (0.1 or 0.5 mg/100 g). This study demonstrates that the oral administration of the combination of zinc at lower doses synergistically enhances beta-cryptoxanthin-induced anabolic effects on bone components in the femoral tissues of rats in vivo.

Administration, Oral↗
PubMed2000

In vivo demonstration that human parathyroid hormone 1-38 inhibits the expression of osteoprotegerin in bone with the kinetics of an immediate early gene.

Osteoprotegerin (OPG) is a potent inhibitor of osteoclast formation and function. To elucidate how OPG is regulated in bone, we examined (1) the expression and localization of OPG protein in bone tissue, (2) the effect of human parathyroid hormone 1-38 (hPTH 1-38) on OPG messenger RNA (mRNA) levels in rat femur metaphyseal and diaphyseal bone, and (3) the effect of hPTH(1-38) on expression of OPG mRNA in cultured osteoblast-like cells derived from the metaphysis and diaphysis, and in ROS 17/2.8 osteosarcoma cells. Because PTH has been shown to stimulate osteoblast activity via the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signal transduction pathway we also investigated whether PTH action on OPG in vivo is dependent on activation of cAMP/PKA pathway. Immunohistochemistry was used to evaluate OPG protein expression and Northern blot hybridization was used to analyze OPG mRNA expression both in vivo and in vitro. Immunohistochemistry of OPG protein expression in the rat distal femur metaphysis revealed that it was localized predominantly in preosteoblasts, osteoblasts, lining cells, and the osteoid layer, with occasional immunoreactivity in osteocytes and cells of the bone marrow. Subcutaneous (sc) administration of a single injection of hPTH(1-38) at 80 microg/kg induced a rapid and transient decrease in OPG mRNA expression in both metaphyseal and diaphyseal bone. The decrease in OPG message was evident by 1 h and mRNA levels returned to baseline after 3 h. PTH analog PTH(1-31), which stimulates intracellular cAMP accumulation, inhibited OPG expression, whereas PTH analogs (3-34 and 7-34) that do not stimulate cAMP production had no effect on expression. In contrast to PTH, prostaglandin E2 (PGE2) had no effect on OPG mRNA expression in vivo in the metaphyseal bone cells, under conditions in which PGE2 does promote expression of the c-fos gene. The in vivo effects of hPTH(1-38) on OPG mRNA were confirmed in isolated primary osteoblast cultures derived from either metaphyseal or diaphyseal bone as well as in ROS 17/2.8 osteosarcoma cells. We propose that the rapid and transient decrease in OPG expression may initiate a cascade of events resulting in the differentiation of osteoclast progenitor. Such a spatially and temporally programmed effect of PTH might contribute to bone turnover.

Animals↗
PubMed1998

Biomechanical and histological evaluation of a calcium phosphate cement.

It is often difficult to achieve stable fixation of a comminuted fracture associated with a metaphyseal defect. The injection of a resorbable cement into an osseous defect may help to stabilize the fracture and to maintain osseous integrity as the cement is resorbed and replaced by bone. The purpose of the present study was to evaluate the repair of a metaphyseal defect after treatment with an injectable calcium-phosphate cement. The injectable cement undergoes isothermic curing in vivo to form a carbonated apatite (dahllite) with a compressive strength of twenty-five megapascals. Either the cement or allograft bone was placed in proximal tibial metaphyseal and distal femoral metaphyseal defects in seventy-two dogs and was evaluated from twenty-four hours to seventy-eight weeks postoperatively. Histological examination showed that the cement was osteoconductive; nearly the entire surface area was covered with bone two weeks after the injection. The resulting bone-cement composite underwent gradual remodeling over time in a pattern that was qualitatively similar to the remodeling of normal cortical and cancellous bone. Osteoclasts were found to resorb the cement and were usually associated with adjacent new-bone formation. With increasing time in vivo, the cement was penetrated by small blood vessels that became surrounded by circumferential lamellae of bone and that closely resembled evolving haversian systems. This process occurred more rapidly in the cortex than in the medulla. Mechanical testing showed that, by eight weeks, the tibiae that had been treated with cement had reached nearly 100 per cent of the torsional strength of the contralateral, control (intact) tibiae; this finding paralleled the histological observations of bone apposition to the cement and rapid restoration of the cortex. At no time was fibrous tissue present between the cement and the bone, and there was no evidence of acute inflammation. Small particles of cement were present within occasional macrophages during the process of cement resorption, but the macrophages disappeared over time and were not associated with fibrosis or unexpected resorption of bone. Resorption of the cement was incomplete in the medullary area at seventy-eight weeks, but the pattern of cement resorption and bone-remodeling suggested gradual restoration of a physiological proportion of bone and marrow in both the cortical and the medullary region with maintenance of mechanical function.

Animals↗
PubMed1976

Effects of radiation therapy on growing long bones.

Characteristic radiographic changes were seen in six of 14 children who received radiation therapy to the epiphyseal plate of a long bone. These changes, which include metaphyseal sclerosis, metaphyseal fraying, and epiphyseal plate widening, resemble rickets. In three patients, these changes were followed by development of a broad metaphyseal band of increased density. The absence of metaphyseal changes may indicate sterilization of cartilage cells and may be predictive of significant limb shortening.

Adolescent↗
PubMed1991

Extension of growth-plate cartilage into the metaphysis: a sign of healing fracture in abused infants.

The present study was carried out to determine if healing metaphyseal injury in abused infants is accompanied by an increase in the thickness of the growth-plate zone of hypertrophic cartilage and if a radiolucent extension from the growth plate into the metaphysis correlates with this histologic indicator of healing fracture. The radiologic studies of 13 infants who died with evidence of inflicted injury were reviewed. Thirteen distal metaphyseal fractures were identified. Histologically, nine of these fractures were noted to be healing and four showed no evidence of healing. The nine healing injuries were accompanied by statistically significant thickening of the zone of hypertrophic cartilage. Seven of these demonstrated localized areas of hypertrophic cartilage extension; in six of these, corresponding radiolucent extensions of the growth plate into the metaphysis were seen. The extensions tended to be single and focal with minimal osseous injury and broad and multiple with extensive injury. No similar extension was visible in the four acute injuries. Because metaphyseal injuries are notoriously difficult to date, the presence of a reliable radiologic indicator of healing metaphyseal fracture can be important in the evaluation of infant abuse. Because the radiologic findings reflect the histologic alterations, extension of the growth-plate cartilage into the metaphysis may have implications for estimating fracture age.

Child Abuse↗