SEARCH · PubMed Health

Results for “Tibia”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMedDate not supplied

Pseudarthrosis of the rabbit tibia: a model for congenital pseudarthrosis?

The purpose of this study was to create a rabbit model of a pseudarthrosis of the tibia by passively constricting circumferential diaphyseal growth. A circumferential strip of Marlex mesh was placed around both tibiae of eight growing rabbits. It was sutured as a circumferential tube on the experimental tibia and not sutured together on the control side. The experimental tibiae developed significant narrowing, cystic changes, and sclerosis. Five of 11 experimental tibiae went on to pathological fracture, compared to no fractures in the eight control tibiae. The mesh was sutured together around both tibiae in another six rabbits. Release of the band 6 weeks later allowed healing of the narrowed tibiae, with or without an experimentally produced fracture. We conclude a passive constriction phenomenon may contribute to the development of congenital pseudarthrosis of the tibia. Removal of the band improved the chances of healing, which has implications for the treatment of children.

Animals↗

PubMed1991

The influence of various calcium and phosphorus levels on tibia strength and eggshell quality of pullets during peak production.

One thousand and eighty DeKalb XL pullets were randomly allocated to nine treatments and arranged in a 3 x 3 factorial to determine the effects of three levels of dietary calcium (2.75, 3.75, and 4.25%) and three levels of dietary available phosphorus (.30, .40, and .50%) on eggshell quality and tibia weight, tibia breaking strength, tibia ash, and bone mineral content of pullets during peak production. Feed consumption increased as dietary calcium or phosphorus increased. Increasing dietary calcium caused a significant linear increase in egg specific gravity, but dietary phosphorus had no significant effect on egg specific gravity. Calcium and phosphorus levels did not significantly affect egg production, body weight, plasma chloride, or phosphorus. Ionized calcium increased significantly as dietary calcium increased. Tibia breaking strength, tibia weight, tibia ash, and bone mineral content increased significantly with increasing dietary calcium. Dietary phosphorus had no significant effect on these parameters. However, when 2.75% calcium was fed, reducing dietary phosphorus significantly decreased tibia weight, tibia ash, and bone mineral content.

Animals↗

PubMed1989

Effect of muscle flap coverage on bone blood flow following devascularization of a segment of tibia: an experimental investigation in the dog.

Severe tibial fractures may be associated with soft tissue loss, devascularization of cortical bone, and significant morbidity. Local rotational muscle flap coverage is used to obtain coverage of acute open tibial fractures and to treat chronic osteomyelitis of the tibia. The purpose of this study was to determine (a) the longitudinal and cross-sectional regional blood flow characteristics of the canine tibia and (b) whether a muscle flap was superior to vascularized skin coverage in restoring blood flow to devascularized canine tibial cortex. A 2.5-cm segment of tibia between two standardized osteotomies was devascularized. The segment was replaced anatomically and stabilized with a plate. The animals were divided into two experimental groups: (a) skin coverage (n = 8), and (b) muscle flap coverage (n = 8). Thirty-one days postoperatively Ce141 microspheres were injected to measure bone blood flow. The tibial diaphysis was divided into proximal, middle (devascularized), and distal segments. The unoperated leg was used as a control. In the control tibiae, the middle segment was less vascular than either the proximal or distal segment and no difference between anterior and posterior cortical blood flow was observed. Blood flow to the devascularized segment of tibia was significantly greater when it was covered with a muscle flap (p less than 0.025). The most significant increase in bone blood flow in the muscle flap coverage group versus the skin coverage group occurred in the anterior cortex of the tibia (p less than 0.005). This may be clinically important since the soft tissues over the anterior tibia are commonly deficient following open fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Influence of age, sex, and method of rearing on tibia length and mineral deposition in broilers.

Two experiments were conducted to determine linear growth and mineral deposition in the tibiae of Vantress x Arbor Acres broilers. In Experiment 1, birds were maintained in battery brooders for 21 days then housed in floor pens from Day 22 to 70. In the second experiment, birds were reared either in battery brooders and grow-out cages or floor pens from Day 1 to 63. Males and females were maintained separately. Birds in both trials were weighted at weekly intervals and three birds of each sex per treatment were euthanatized weekly to obtain tibia samples. Tibiae were cleaned of muscle and connective tissues, dried, extracted with diethyl ether, measured for length in centimeters, weighed, and ashed. Results from both experiments show a curvilinear response for weight gain, bone length, and bone ash weight. In some cases, sex by week or week by rearing interactions (P less than .001) were observed. As expected, males had greater weight gain and bone length than females. In Experiment 2, birds grown in floor pens had greater (P less than .05) bone length, tibia weight, and tibia ash weight than cage-reared birds, but percentage tibia ash was not different between the two rearing systems. Tibia growth and mineral deposition were influenced by gender and rearing systems. Bone ash weight data for females in both trials had a response curve that approached a sigmoidal shape. Response curve for males tended to be more quadratic, indicating a significant (P less than .003) week by week by sex interaction. Thus, there was evidence for bone growth differences not only between rearing systems, but also between sexes, the latter not unexpected.

Age Factors↗

PubMed1988

Limb lengthening by low rate epiphyseal distraction. An experimental study in the caprine tibia.

Low-rate epiphyseal distraction of the left proximal tibia using a modified bilateral Hoffmann external fixation device, was accomplished in 14 goats (age 6-7 months). Daily distraction at a rate of 0.5 mm was continued for 5.5 weeks. Epiphysiolysis occurred after 5-9 days. After distraction had been discontinued, the external device was left in situ for fixation for 4 weeks. The animals in group 1 (n = 6), group 2 (n = 3), and group 3 (n = 5) were killed at 4, 16, and 32 weeks, respectively, from the end of the distraction period. The proximal growth plate of the elongated tibia appeared radiolucent at the conclusion of the study but was less distinct and reduced in height as compared with the control leg. The gained length at the end of the distraction period was on the average 2.2 cm (11.9%). This gain in length was reduced with further growth. In group 3, the final gain in length was reduced to half. A reduced cortical thickness of the bone within the area subjected to distractional force was observed. This finding is attributable to stress protection. An interesting observation comparing control and operated tibia was an increase of the cross-sectional diameter of the elongated bone. Both tibiae of all animals were tested mechanically. The torsional strength of the elongated tibiae as compared with controls was on the average 29% in group 1, 79% in group 2, and 95% in group 3. We conclude that leg lengthening by low-rate epiphyseal distraction in the proximal tibia is a justifiable alternative to other lengthening procedures in individuals approaching adolescence. In juveniles, lengthening by epiphyseal distraction may result in reduction in the longitudinal growth.

Animals↗

PubMed1990

Stress protection by external fixation of the rabbit tibia.

Osteopenia of the tibia and femur caused by an external fixator in the tibia was studied in 14 rabbits. Eight rabbits were treated with a complete unilateral external fixator in one tibia, whereas the other tibia served as control. The other 6 animals had one leg operated on with inserting of all the pins but without the frame. This technique was chosen to compare osteopenia caused by stress protection and the effect of the pins. After 6 weeks, we found a 7 percent reduction in the bone mineral content in the tibial diaphyseal segment between the pins of the external fixator and no bone loss in the tibia that were operated on with only pins. In the femurs, there was a smaller decrease in the bone mineral content: respectively 3.2 percent (complete frame) and 2.9 percent (only pins). On all the operated on tibiae, there was an increase in the bone mineral content around the pins both proximally and distally.

Animals↗

PubMed1989

Effect of dietary sodium zeolite A and excess calcium on growth and tibia calcium and phosphorus concentration in uninfected and Eimeria acervulina-infected chicks.

Two identical trials were conducted with 5 to 14-day-old broiler chicks. Sodium zeolite A (NZA, 0 and .75%) and Ca (1.0 and 1.5%) were fed to both uninfected and Eimeria acervulina-infected chicks resulting in a 2 x 2 x 2 factorial arrangement of treatments. Coccidial infection reduced weight gain and gain:feed (P less than .01), and tibia ash, Ca, and Ca:P ratio (P less than .05). Excess dietary Ca reduced (P less than .05) weight gain and tibia ash in uninfected chicks but had no effect (P greater than .10) in coccidiosis-infected chicks (Ca x coccidiosis interaction, P less than .05). Addition of NZA to diets with excess Ca further decreased (P less than .05) weight gain and tibia ash in both uninfected and E. acervulina-infected chicks. Tibia Ca, as a percentage of dry fat-free tibia, was reduced (P less than .05) by the addition of NZA. This effect was not observed when tibia Ca was expressed as a percentage of ash. These results suggest that NZA may exacerbate the adverse effects of excess dietary Ca.

Aluminum Silicates↗

PubMed1990

Influence of vitamin D3, 1 alpha-hydroxyvitamin D3, and 1,25-dihydroxyvitamin D3 on eggshell quality, tibia strength, and various production parameters in commercial laying hens.

Four hundred 53-wk-old Hyline W36 laying hens were randomly allocated to 10 treatments. The effects of feeding two vitamin D3 metabolites, 1 alpha-hydroxyvitamin D3 [1 alpha-(OH) D3] and 1,25-dihydroxyvitamin D3 [1,25-(OH)2 D3], each at five dietary levels (0, .75, 1.50, 3.00, and 4.50 micrograms/kg of feed) were determined on eggshell quality and tibia strength in commercial laying hens (Experiment 1). In Experiment 2, 1,440 Hyline W36 65-wk-old laying hens were used to determine the effects of four levels of vitamin D3 (0, 500, 1,000, and 1,500 ICU vitamin D3/kg) and three levels of dietary 1,25-(OH)2 D3 (0, .5, and 1.0 microgram/kg of feed) on eggshell quality, tibia strength, and egg production. In Experiment 1, neither 1,25-(OH)2 D3 nor 1 alpha-(OH) D3 affected eggshell quality or production criteria. Tibia weight was increased by adding either 1,25-(OH)2 D3 or 1 alpha-(OH) D3. In Experiment 2, 1,25-(OH)2 D3 increased percentage of shell, shell weight, and egg breaking strength when 0 ICU D3/kg was fed but had no effect at higher levels of vitamin D3. Egg production, feed consumption, and egg weight were also increased with supplemental 1,25-(OH)2 D3 when 0 ICU D3/kg was fed. Tibia weight and tibia breaking strength were also increased by adding 1,25-(OH)2 D3 to the diet. The commercial laying hen metabolizes sufficient 1,25-(OH)2 D3 from dietary vitamin D3 to maintain shell quality but not enough to maintain tibia strength.

Animals↗

PubMed1989

Adolescent tibia vara.

Adolescent tibia vara is less common and less well described when compared to infantile tibia vara. Yet, the two share a significant number of features related to their epidemiology and histology. The two diseases differ most in their radiographic appearance. It does not, however, necessarily follow that their etiologies cannot be similar. By its epidemiology and histology, adolescent tibia vara appears to be related to repetitive trauma in the form of abnormal force directed on the medial tibial growth plate due to obesity, the adolescent growth spurt, or residual, incompletely corrected physiologic varus. Such forces may give growth plate suppression by the Heuter Volkman principle similar to what is thought to occur in infantile tibia vara. In the infant, this results in typical radiologic findings related to an epiphyseal ossification center which is cartilagenous and moldable and results in progressive medial wedging. In the adolescent, however, this ossification center is bony and, therefore, will not deform under stress. The growth plate, however, still responds with decreased growth resulting in varus deformity. Thus, adolescent tibia vara, by definition not related to trauma or infection, may in fact reflect the same pathologic process at work as in infantile tibia vara.

Child↗

PubMed1986

[Osteomyelitic pseudarthrosis of the tibia with loss of substance treated with a graft of the opposite fibula].

Dragan Dj./Re. No. 2755/76, 5,5-year-old boy, referred to this hospital with signs of bipolar osteomyelitis, destruction and fistulisation of the left tibia and talocrural arthritis. Staphylococcus albus and streptococcus haemoliticus were isolated from the fistula. Osteomyelitis was treated with an adequate therapy including long usage of Lincocin. In Feb. and Oct. of 1977 a sequestrotomy of the mid portion of the tibia and transmedular fixation using Ratschmann's nail were performed. The process resulted in pseudarthrosis of the mid portion of the tibia with loss of bone substance in the length of 2.5 cm and talocrural arthrosis and deformed foot. The boy walking support. In July 1980, in the stage of "ripe" pseudarthrosis a complete resection of pseudoarthrosis with sclerotic portions of tibia to healthy bone was performed. The mid part of the right tibia was resected subperiostally and was grafted centromedularlly into the upper and lower medular channel of the left tibia. Two Kirschner's needles were implanted centromedularlly so as to strengthen the bone osteosynthesis. Complete union of the grafted fibula with treppassage of the medular channel occurred with its tibilisation and growth in length and width. In July 1982, the concave foot was corrected using Bertrand's method. The present difference in the length between the two legs is 4.5 cm which is corrected by the use of padded shoes. Lengthening of the leg is planned to be performed before he reaches the age of 14.

Child↗

PubMed1990

Effect of weight-bearing on healing of cortical defects in the canine tibia.

UNLABELLED: It has been generally accepted that mechanical stimulation is an important factor in the promotion of formation of bone. Fracture-healing consists of periosteal bridging of the fracture, which achieves stability, and proliferation of endosteal bone to fill the defects between the ends of the bone. To evaluate the effect of weight-bearing on bone-healing, an operatively created defect in the tibial cortex was chosen as an experimental model. In one set of dogs (Group 1), a bilateral defect in the tibial cortex was created and weight-bearing was permitted on one tibia but not on the opposite one. In Group 2, a bilateral defect in the tibial cortex was made and weight-bearing was allowed on both tibiae. A third group of dogs of similar age (Group 3) had no tibial defects. Quantitative histomorphometry was used to measure formation and porosity of bone. Weight-bearing was measured with both static and dynamic techniques. Significantly less woven bone formed in the defects in the non-weight-bearing tibiae than in the weight-bearing tibiae. This appeared to be due to a disuse response in the underloaded tibiae, in which less bone formed, rather than to the formation of more bone in the weight-bearing tibiae. The data suggest that weight-bearing is a permissive factor, not a stimulus, for formation of woven bone in a tibial defect. CLINICAL RELEVANCE: This animal model supports the concept that lack of weight-bearing decreases the amount of woven bone that is formed in a healing tibial defect. The results of this study indicate that weight-bearing increases the formation of bone in fracture-healing.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1979

The timing of the onset of osteogenesis in the tibia of the embryonic chick.

Haematoxylin, Alcian Blue-Chlorantine Fast Red (ABCR) and the Ralis osteoid-specific stain were employed to closely follow the histogenesis of the tibia of the embryonic chick so as to provide an accurate description of the onset of ossification. An overview of the major cytological events preceding osteogenesis in the tibia was obtained from hindlimbs of embryos of H. H. (Hamburger and Hambilton, '51) stages 16-26 (2.5-5 days of incubation) stained with ABCR. A description of the cytological changes in the periosteum as it develops from the perichondrium and an analysis of the timing of the onset of osteoid deposition was obtained from the tibiae of accurately aged and staged embryos of H. H. stages 28-32 (5.5-8 days). These tibiae were stained specifically for the detection of osteoid: the freshly-secreted, unmineralized product of fully-differentiated osteoblasts. The perichondrium transformed into a bi-layered periosteum at H. H. late stage 29 (6.5 days) while osteoid was first detected adjacent to the hypertrophic cartilage of H. H. stage 30 (6.5-7 days) tibial diaphyses. These results, correlated with the immunoflourescent studies of Von der Mark et al. ('76a,b), which revealed the presence of Type I (bone-type) collagen-synthesizing cells in the perichondria of tibiae from embryos of H. H. stage 28 (5.5-6 days), demonstrated that the onset of determination of cells for osteogenesis and the cytodifferentiation of the periosteum are not temporally coupled.

Animals↗

PubMed1992

Repetitive loading, in vivo, of the tibia and femora of rats: effects of a single bout of treadmill running.

The presence of microdamage in the tibiae and femora of rats following repetitive loading in vivo was investigated by subjecting 48 male rats, aged 12 weeks, to treadmill running (26.8 m.min-1 on 10% grade) for 0.56 hours (5,000 cycles, E1), 1.13 hours, (10,000 cycles, E2), 2.27 hours (20,000 cycles, E3), and 3.4 hours (30,000 cycles, E4) with Group C as control. Following exercise, tibiae and femora were excised and the right limbs were tested in torsion at 180 degrees.sec-1. Transverse sections were cut from the proximal, mid- and distal diaphysis of left tibiae and femora, bulk stained in basic fuchsin, cut to 50 microns thick, and examined for the presence of microdamage. Following these periods of loading, tibiae and femora showed no evidence of microdamage initiation, as evidenced by light microscopy, or corresponding alterations in mechanical properties. It was concluded that the magnitude of loading produced by single bouts of intensive exercise, which encompassed up to 30,000 loading cycles, was insufficient to initiate fatigue microdamage in tibiae or femora of rats.

Animals↗

PubMed1977

Magnesium and the mineral metabolism of chick embryo tibiae in organ culture.

Using bone organ culture techniques, three concentrations of magnesium were evaluated for their effects on the mineral mass of embryonic chick tibiae incubated for 3 days with or without a metabolic inhibitor (1 mM iodoacetic acid) added to the media. Varying the medium Mg level from 0.3 to 3.0 mM had little effect on the net increase in mineral in live bones (without the inhibitor), but in dead tibiae (with the inhibitor) there was a marked net decrease in mineral deposition with increasing Mg concentration. Bone Mg mass varied directly with the level of Mg in the medium regardless of whether or not the tibiae were inhibited. Responsiveness to parathyroid hormone (PTH) with regard to mineral loss and increased lactate production was not affected by Mg even in tibiae incubated in Mg-free media. However, PTH-treated bones cultured in Mg-free media had a significantly elevated Mg mass, suggesting that the hormone may have a Mg-conserving effect on bone during severe Mg deficiency. The findings of this study support the hypothesis that bone cells regulate the level of Mg to which newly forming mineral is exposed and that PTH-responsiveness in embryonic chick tibiae is not dependent on the ambient Mg concentration.

Animals↗

PubMed1992

Characterization of in vivo strain in the rat tibia during external application of a four-point bending load.

This paper describes a technique for characterizing strains and stresses induced in vivo in the rat tibia during application of an external four-point bending load. An external load was applied through the muscle and soft tissue with a four-point bending device, to induce strain in a 11 mm section of the right tibiae of ten adult female Sprague-Dawley rats. Induced strains were measured in vivo on the lateral surface of the tibia. Inter-rat difference, leg positioning and strain gage placement were evaluated as sources of variability of applied strains. Beam bending theory was used to predict externally induced in vivo strains. Finite element analysis was used to quantify the magnitude of shear stresses induced by this type of loading. There was a linear relationship between applied load and induced in vivo strains. In vivo strains induced by external loading were linearly correlated (R2 = 0.87) with the strains calculated using beam bending theory. The finite element analysis predicted shear stresses at less than 10% of the longitudinal stresses resulting from four-point bending. Strains predicted along the tibia by finite element analysis and beam bending theory were well-correlated. Inter-rat variability due to tibia size and shape difference was the most important source of variation in induced strain (CV = 21.6%). Leg positioning was less important (CV = 9.5%).

Animals↗

PubMed1991

Repetitive loading, in vivo, of the tibiae and femora of rats: effects of repeated bouts of treadmill-running.

Twenty-four male rats, aged 12 weeks, were subjected to approximately 20,000 loading cycles per day of treadmill running (2 h/day, 26.8 m/min and 10% gradient) for 5 (group A) and 10 days (group B); with corresponding controls (C5) and (C10). Rats in groups B and C10 were given weekly doses of tetracycline from 4 days prior to training. Following training, right tibiae and femora were tested to failure in torsion at 180 degrees/s. Sections were cut from the distal, mid and proximal diaphysis of left bones, bulk-stained in basic fuchsin and two transverse sections (50 microns) were cut and examined for the presence of microdamage and fluorescence. Results for mechanical testing showed a significant reduction in stiffness of tibiae (P less than 0.01) for groups A and B and a significant increase in twist angle (P less than 0.01) for group A when compared with controls. No evidence of microdamage was observed from histological analysis. But, labelling demonstrated reduced appositional growth of the periosteal and endosteal surface at the mid-diaphysis of exercised tibiae (P less than 0.01). These tibiae also showed fewer regions of, measurable, appositional growth than controls (P less than 0.05). Exercised femora showed increased appositional growth at the endocortical surface of the mid-diaphysis (P less than 0.05). Reductions in stiffness of exercised tibiae were significantly correlated with cross-sectional area.

Animals↗

PubMed1987

Static measurement of tibia vara. Reliability and effect of lower extremity position.

The purpose of this study was to examine the reliability of tibia vara measurements and to determine the effects of lower extremity position on such measurements. A manual goniometer was used to measure tibia vara in both lower extremities of 20 healthy subjects while they assumed three different positions: double-limb stance (DLS) with subtalar joint position uncontrolled (Condition 1), DLS with subtalar joint positioned in neutral (Condition 2), and single-limb stance with subtalar joint position uncontrolled (Condition 3). Intraclass correlation coefficients (p less than .05) revealed that tibia vara measurements were reliable both within and between raters with mean absolute differences between repeated measures of 2 to 3 degrees. An analysis of variance and a Newman-Keuls post-hoc test (p less than .05) showed that Condition 3 produced the greatest value of tibia vara followed by Conditions 1 and 2, respectively. The results of this study suggest that lower extremity position is an important consideration when measuring tibia vara and determining whether treatment intervention is indicated.

Adult↗

PubMed1986

A three-dimensional finite element analysis of the upper tibia.

A three-dimensional finite element model of the proximal tibia has been developed to provide a base line for further modeling of prosthetic resurfaced tibiae. The geometry for the model was developed by digitizing coronal and transverse sections made with the milling machine, from one fresh tibia of average size. The load is equally distributed between the medial and lateral compartments over contact areas that were reported in the literature. An indentation test has been used to measure the stiffness and the ultimate strength of cancellous bone in four cadaver tibiae. These values provided the statistical basis for characterising the inhomogeneous distribution of the cancellous bone properties in the proximal tibia. All materials in the model were assumed to be linearly elastic and isotropic. Mechanical properties for the cortical bone and cartilage have been taken from the literature. Results have been compared with strain gage tests and with a two-dimensional axisymmetric finite element model both from the literature. Qualitative comparison between trabecular alignment, and the direction of the principal compressive stresses in the cancellous bone, showed a good relationship. Maximum stresses in the cancellous bone and cortical bone, under a load which occurs near stance phase during normal gait, show safety factors of approximately eight and twelve, respectively. The load sharing between the cancellous bone and the cortical bone has been plotted for the first 40 mm distally from the tibial eminence.

Aged↗