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PubMed1994

Bone mineral density at distal tibia using dual-energy X-ray absorptiometry in normal women and in patients with vertebral osteoporosis or primary hyperparathyroidism.

To assess the effect of age and disease on mineral distribution at the distal third of the tibia, bone mineral content (BMC) and bone mineral density (BMD) were measured at lumbar spine (spine), femoral neck (neck), and diaphysis (Dia) and distal epiphysis (Epi) of the tibia in 89 healthy control women of different age groups (20-29, n = 12; 30-39, n = 11; 40-44, n = 12; 45-49, n = 12; 50-54, n = 12; 55-59, n = 10; 60-69, n = 11; 70-79, n = 9), in 25 women with untreated vertebral osteoporosis (VOP), and in 19 women with primary hyperparathyroidism (PHPT) using dual-energy x-ray absorptiometry (DXA; Hologic QDR 1000 and standard spine software). A soft tissue simulator was used to compensate for heterogeneity of soft tissue thickness around the leg. Tibia was scanned over a length of 130 mm from the ankle joint, fibula being excluded from analysis. For BMC and BMD, 10 sections 13 mm each were analyzed separately and then pooled to define the epiphysis (Epi 13-52 mm) and diaphysis area (Dia 91-130 mm). Precision after repositioning was 1.9 and 2.1% for Epi and Dia, respectively. In the control group, at any site there was no significant difference between age groups 20-29 and 30-39, which thus were pooled to define the peak bone mass (PBM).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1996

Lack of an effect of sodium zeolite A on rat tibia histomorphometry.

Cell culture studies suggest that the aluminum silicate polymer sodium Zeolite A (SZA) increases bone cell proliferation and extracellular matrix production. This study in rats investigated the short-term (2 weeks) and long-term (18 weeks) in vivo effects of SZA on growth rate (weight gain) and tibia histomorphometry. In separate short-term experiments, female (experiment 1) or male (experiment 2) Sprague-Dawley rats grown and maintained on normal calcium diets were gavaged daily during a 2 week treatment period with 30 mg/kg, 100 mg/kg, or 500 mg of SZA/kg of rat body weight. In the long-term study (experiment 3) ovariectomized (OVX) rats were fed a low calcium diet containing 0, 1.80, and 9.00 g of SZA/kg of diet (0, 125, and 617 mg/kg of body weight, respectively). Short- and long-term treatment of growing rats with SZA resulted in a dose-dependent increase in bone aluminum. In the first experiment, growing intact female rats showed no significant SZA dose-dependent response in growth rate (weight gain) or histomorphometry of cortical bone in the tibial diaphysis or cancellous bone in the secondary spongiosa of the tibial metaphysis. In the second experiment, growing male rats, with right hind limbs immobilized by unilateral sciatic neurotomy, showed no SZA dose-dependent response in growth rate. The longitudinal growth of cancellous bone in the tibia of the denervated limb and the intact contralateral limb were not influenced by sciatic neurectomy and/or by treatment with SZA. Histomorphometry demonstrated that cortical bone mass and formation was reduced in the sciatic-sectioned limb when compared with the contralateral intact limb of vehicle-treated rats, as evidenced by significant reductions in static measurements of cortical bone area (-8.5%) and cross-sectional area (-4.8%) and in calculations of the periosteal formation rate (-33.8%) and mineral apposition rate (-31.6%), and the endocortical formation rate (-35.5%) and mineral apposition rate (-37.9%). The cancellous bone mass of denervated limbs of vehicle-treated rats was also deficient, as evidenced by decreased cancellous bone area (-39.1%) and perimeter (-31.9%). The bone mineral apposition rate was decreased (-26.7%) indicating reduced osteoblast activity. Treatment with SZA did not influence these indices in the tibiae of either sciatic-sectioned limbs or contralateral intact limbs. In the long-term experiment, OVX resulted in a dramatic 88% decrease in cancellous bone volume which was prevented by treatment with 17 beta-estradiol and not influenced by treatment with Zeolite A. The increases in osteoblast and osteoclast number following OVX were not influenced by SZA. The results indicate that SZA treatment has no anabolic effect on cortical and cancellous bone formation and mass in normal growing female rats and that this compound does not protect against osteopenia due to reduced load bearing in the growing male rat or gonadal hormone deficiency in adult female rats.

Animals↗

PubMed2006

Comparison of bone formation ingrafted periosteum harvested from tibia and calvaria.

Periosteum covers the bone surface and displays the potential to initiate bone formation, after injury to the bone. Numerous studies have demonstrated that the periosteum plays major roles in the healing process after bone fracture. Some reports have described that in the healing of long bone fractures, the periosteum forms new bone by intramembranous and endochondral ossification. Other researchers insist that healing of defects in membrane bone shows bone formation by intramembranous ossification. However, previous studies have not been able to clarify differences in bone formation patterns. We hypothesized that differences in bone formation pattern are associated with the periosteal potential for cell differentiation. The present study grafted periosteum, harvested from the tibia and calvaria, into the suprahyoid muscle, with the aim of interrupting release of factors from bone matrix. Bone formation, after grafting periosteum, harvested from the tibia and calvaria, was examined histologically and radiographically. Grafted tibial periosteum formed a large area of new bone by intramembranous and endochondral ossification, while grafted calvarial periosteum displayed intramembranous ossification. Grafted tibial periosteum formed a larger area of bone than grafted calvarial periosteum. Patterns of cell differentiation thus differ between grafted periosteum, harvested from the tibia and calvaria.

Animals↗

PubMed1985

Amelioration of oxygen-induced osteoporosis in the in vitro fetal rat tibia with a capacitively coupled electrical field.

Near-term fetal rat tibiae were grown in M.E.M. Eagle/NCTC 135/15% newborn calf serum in 5% carbon dioxide and 5, 10, 21, 35, 60, and 90% oxygen for 3, 7, 10, and 14 days. Linear growth of the explants, as measured from macrophotographs of the explants at day zero and each of the days above, was greatest in the lower oxygen concentrations and least in the higher oxygen concentrations. Breaking strengths of the tibial diaphyses were significantly reduced in those explants grown in 60 and 90% oxygen. When the fetal rat tibiae were grown in 60% oxygen for 7 days and were subjected to a capacitively coupled electrical signal (sine wave, 60 kHz, 10 V peak-to-peak output signal; current density and field in the culture dish calculated to be 5.2 microA/cm2 and 0.32 mV/cm, respectively), the breaking strengths and middiaphyseal widths were statistically significantly greater than control tibiae grown in 60% oxygen alone. It is concluded that an appropriate capacitively coupled electrical field can inhibit an oxygen-induced osteoporosis in an in vitro mammalian long bone model.

Animals↗

PubMed1992

Intraosseous infusion using the osteoport implant in the caprine tibia.

We evaluated the in vivo animal tolerance to intraosseous infusion via the Osteoport pediatric implant (model 2005PSO, Lifequest Medical, San Antonio, TX, U.S.A.) into the proximal tibia of immature goats and investigated the osseous effects of intermittent and sustained increases in intraosseous pressure (IOP). In group 1 (n = 3) autogenous whole blood was continuously infused (CI) for 5 days at flow rates producing an IOP of 30-45 mm Hg. Group 2 animals (n = 3) underwent a 5-s high-pressure infusion (HPI) of lactated Ringer solution (LRS) producing an IOP of 90-125 mm Hg twice daily for 10 days. In group 3, the Osteoports were left in place 5 (n = 2) or 10 days (n = 2) and evaluated for patency at 72-h intervals. An IOP > 35 mm Hg produced clinical evidence of bone pain. Bone mineral density was significantly increased (p < 0.05) in all implanted tibias (mean 1.04 g/cm2; range 0.87-1.21 g/cm2) compared with controls (mean 0.67 g/cm2; range 0.65-0.71 g/cm2). A nonsignificant increase (+9% to +31%) in periosteal new bone formation occurred in all implanted tibias. In the continuously infused group, there was a significant increase (p < 0.05) in cancellous new bone formation (+483%), percentage eroded bone surface (+143%), and osteoclast covered bone surface (+255%) compared with controls. HPI of LRS did not produce significant bone changes. Seemingly, the Osteoport provided a ready means of intraosseous infusion and may be associated with less complications than current methods of continual vascular access. Bone changes correlated more with the duration than the magnitude of increased intraosseous pressures.

Absorptiometry, Photon↗

PubMed1993

Intraosseous infusion of prostaglandin E2 in the caprine tibia.

We evaluated the effects of intraosseously administered prostaglandin E2 (PGE2) within the proximal metaphysis of the goat (caprine) tibia under intraosseous normotensive and hypertensive conditions. PGE2 was administered at 0.5 or 1.0 mg (1 ml vol) twice daily for 10 days via an Osteoport which had been surgically implanted within the proximal tibial metaphysis. Intraosseous hypertension was produced when venous outflow obstruction (VOO) was created by ligation of the popliteal vein, which drained the proximal tibia, and occlusion of the diaphyseal medullary space distally with bone cement. After VOO, the intraosseous pressure measured at the metaphysis increased significantly (p < 0.05) from a baseline mean of 14.9 +/- 4.2 mm Hg to 28.6 +/- 5.3 mm Hg. Serum radioimmunoassays indicated that VOO prolonged the venous drainage of PGE2 from the tibia after an infusion. Static histomorphometric analysis indicated a marked dose-dependent increase in new bone formation in all PGE2 groups at 30 days after the PGE2 infusion. Significant (p < 0.05) formation of new bone occurred, primarily at the subperiosteal and endocortical surfaces, and moderately increased the marrow cavity of cancellous new bone as compared with the VOO-only group and the controls. Bone remodeling indices were also increased by PGE2. The PGE2 infusion, combined with VOO, produced significantly more new bone formation than the PGE2 infusion alone. Intensive marrow fibrosis was associated with the active bone remodeling.

Animals↗

PubMed1995

Comparison of the effect of reamed and unreamed locked intramedullary nailing on blood flow in the callus and strength of union following fracture of the sheep tibia.

This study was performed to compare the effects of reamed and unreamed locked intramedullary nailing on blood flow in the callus and early strength of union in a fractured sheep tibia model. After the creation of a standardized short spiral fracture by three-point bending with torsion, each tibia was stabilized by the insertion of a locked intramedullary nail. Ten animals were allocated randomly into two groups: one that had reaming prior to nail insertion and one that did not. Blood flow was measured in real time with use of laser Doppler flowmetry. Endosteal perfusion was determined at the fracture site before and after nail insertion. Perfusion of the callus was measured at three locations (proximal diaphysis, fracture site, and distal diaphysis) and at three time intervals (2, 6, and 12 week follow-up). All animals were killed 12 weeks postoperatively, and the tibiae were tested to failure in four-point bending. Nailing with reaming resulted in a larger decrease in overall endosteal perfusion than nailing without reaming (p < 0.015). The presence or absence of reaming did not affect blood flow within fracture callus. Perfusion of callus was greatest at 6 weeks of follow-up. Bending strength and stiffness were the same in both groups at 12 weeks. The study demonstrated that perfusion of callus and early strength of union are similar following intramedullary nailing with or without reaming.

Animals↗

PubMed1996

Effect of human adrenomedullin on vascular resistance of the canine tibia.

An ex vivo model of a perfused canine tibia was used to investigate the effect of human adrenomedullin, a novel peptide with known vasodilator properties, on the vascular resistance of bone. Human adrenomedullin has a potent and long-lasting vasodilator effect in the canine tibia following precontraction of vascular smooth muscle by infusion of prostaglandin F2 alpha. A 0.1 ml bolus injection of 10(-5) M human adrenomedullin suppressed the pressor response of the canine tibia preparation to an infusion of norepinephrine by 43-52% for a duration of 100 minutes. An injection of 10(-6) adrenomedullin suppressed the pressor response to an infusion of norepinephrine by 22-23% for a duration of 40 minutes. These data suggest that human adrenomedullin may be a potent and long-acting vascular smooth-muscle relaxant in bone.

Acetylcholine↗

PubMed2000

Changes in bone mineral density at the proximal tibia after total knee arthroplasty: a 2-year follow-up of 28 knees using dual energy X-ray absorptiometry.

The change in bone mineral density at the proximal tibia during 2 years after total knee arthroplasty was studied in 28 knees (28 patients: 10 men and 18 women; median age: 71 years) with dual energy x-ray absorptiometry. Bone mineral density was measured at the proximal tibia at nine regions of interest below the tibial component within 1 week after the operation (baseline); measurements were repeated at 3, 6, 12, and 24 months. All but one knee was malaligned before the operation, and all but three were corrected to within the normal range of alignment after it. The mean bone mineral density of all nine regions of interest at the proximal tibia temporarily decreased by 13% (p = 0.001) during the initial 3 months, probably due to a general metabolic reaction of the skeleton to the operative trauma combined with the effect of the postoperative immobilization, and then the initial level was regained for as long as 2 years. The overall changes in mean bone mineral density to 2 years were insignificant (p > 0.05); however, a great variation (43.9% decrease to 98.0% increase) was observed on an individual basis. This change over time was significantly associated (R2 = 0.36, p = 0.002) with the level of the baseline bone mineral density, which in turn was partly related (R2 = 0.24, p = 0.009) to the amount of malalignment of the knee before the operation. Knees with high baseline levels (n = 14: 11 with varus and three with valgus alignment) displayed a decrease of 10.0 +/- 14.0% (mean +/- SD, p > 0.05) for as long as 2 years, whereas those with low baseline levels (n = 14: seven with varus and six with valgus alignment and one neutrally aligned) had an increase of 19.1 +/- 38.2% (p = 0.038). In both groups, the mean bone mineral density converged to a level of 0.75-0.95 g/cm2 at 2 years.

Absorptiometry, Photon↗

PubMed1981

Treatment of congenital pseudoarthrosis of the tibia by a free vascularized fibular graft: case report.

A free vascularized fibular graft was used to treat a case of congenital pseudoarthrosis of the tibia in a 5-year-old girl. Four weeks after the surgery, x-ray films revealed remarkable callus formation at the proximal junction of the graft and tibia. Seventeen months passed before union at this junction was completed. Union at the distal junction, on the other hand, took only 12 weeks. It was noted that the fibular graft enlarged in diameter rapidly, and at 17 months was the same size as the recipient tibia.

Child, Preschool↗

PubMed1994

Congenital pseudarthrosis of the tibia in adults treated by a free vascularized iliac crest graft.

Congenital pseudarthrosis of the tibia is a rare condition. It usually presents during early childhood, at which time the surgeon is faced with numerous challenges including difficulties in achieving union and preventing refractures and recurrences. Patients frequently end up with a severe deformity or an amputation. When an adult patient presents with previously untreated congenital pseudarthrosis of the tibia, the surgeon is faced with the additional problems of a long-standing soft tissue contracture and disuse atrophy of the limb. Two patients with congenital pseudarthrosis of the tibia were treated by free vascularized iliac crest graft. Soft tissue deformity was corrected using an external fixation device. The patients were not freely ambulatory before surgery. Union across the pseudarthrosis was achieved in both patients with a double-staged operation, within a short period of time. A functional stable painless limb with good knee and ankle motion has allowed both patients to resume bipedal gait and achieve a successful rehabilitation.

Adult↗

PubMed1996

Geometric properties of the fractured tibia stabilized by unreamed interlocking nail: development of a three-dimensional finite element model.

Based upon magnetic resonance scans of five human tibiae a three-dimensional finite element model using eight nodal isoparametric elements was developed to analyze the biomechanical properties of fracture fixation by an unreamed interlocking nail. Tension phenomena and bone implant translations occurring in the borderlines of the fracture zone, bone-implant interface, and the fixation site of the interlocking screws were analyzed with the help of link elements. The proximal fracture segment was fixed with a link element so as to produce exclusively translatory shifts corresponding to the vector of the load applied. Under condition of static load F = 500 N or axial torsion MT = 15 Nm the biomechanical properties of a nailed horizontal fracture (42-A3), a three fragment lesion (42-B2), and a comminuted midshaft fracture (42-C3) were evaluated. On condition of axial load maximum dislocations of 0.1549 mm are induced in the direction of the x-axis due to the asymmetric geometry of the human tibia which promotes medially directed translations. Independent from the fracture type present a homogenous tension profile was calculated for the whole tibia diaphysis with a sigmaEQV ranging from 24.18 to 121.14 MPa due to the relative low elastic modulus of the cortical bone compared to material characteristics of the implant. However, application of a torsional moment MT = 15 Nm induces significantly increased tension maxima in the nail-interlocking screw interface with a sigmaEQV = 7, 626 MPa. Maximum translatory movements ux = 12.59 mm and uy = 23.53 mm in the x and y plane indicate that these load conditions bear a high risk of an implant failure.

Biomechanical Phenomena↗

PubMed2001

Tibia lead levels and methodological uncertainty in 12-year-old children.

In vivo bone lead measurements with 109Cd-based K-shell X-ray fluorescence (XRF) have been used to assess long-term lead exposure in adults. Tibia lead levels were measured in 210 children (106 boys, 104 girls) of 11-12(1/2) years of age in a lead smelter town and in a control (nonexposed) town. Tibia lead levels, methodological uncertainties, and models of some of the factors influencing them are presented. 109Cd-based K-shell XRF tibia lead methodological uncertainty in children is comparable to that in adults.

Child↗

PubMed1999

Diaphyseal cross-sectional geometry of the Boxgrove 1 Middle Pleistocene human tibia.

Cross-sectional geometric analysis of the early Middle Pleistocene human tibia from Boxgrove, West Sussex, U.K. reveals a mosaic pattern relative to other archaic Homo tibiae. The specimen has relatively low percent cortical area within its cross sections. However, it exhibits the high mediolateral strength characteristic of archaic Homo tibiae. Scaled solely to tibial length it is robust, similar to those of the Neandertals and above those of early modern and pre-Late Pleistocene African and Asian humans. However, given ecogeographically-patterned variance in relative tibial length and body laterality, it is most likely that it exhibits a level of robusticity within the range encompassed by Late Pliocene to Late Pleistocene archaic Homo combined with arctic body proportions. Given its association with late interglacial cool temperate climatic indicators, the inferred body proportions of the Boxgrove hominid were probably promoted by their minimal level of cultural buffering, requiring a significant biological conservation of body heat.

Animals↗

PubMed1992

The effects of protein deficiency and fluoride on bone mineral content of rat tibia.

This study examined the effects of chronic protein deficiency and fluoride administration (10 mg/kg/day), separately or in combination, on rat tibia properties. Protein deficiency increased the bone fluoride concentration and reduced the bone mineral content (BMC) especially at the proximal or growing end which contains mainly cancellous bone. Fluoride administration also reduced BMC, but to a lesser extent, and it resulted in proximal tibia fluoride concentrations that were nearly twice those of the distal tibia. The interaction between fluoride administration and the protein content of the diet on BMC was nonsignificant, suggesting that the effects were additive, not multiplicative or synergistic. Fluoride administration, but not protein deficiency, increased bone magnesium levels. It is hypothesized that the reduction in BMC in the areas where the fluoride concentrations were the highest was due to a localized toxic effect of fluoride.

Absorptiometry, Photon↗

PubMed1976

[Influence of age of the recipient on 85Sr uptake of tibia transplants in mice (author's transl)].

The 85Sr retention of syngeneic and allogeneic tibia grafts taken from 16-day-old mice was investigated using recipients of 16 days, 12 weeks and 1 year of age. 85Sr retentions of syngeneic grafts of the tibia were generally higher than those of allogeneic ones. Additionally, there was in all grafts an increased 85Sr uptake with increasing age of the recipients. Simultaneously an increased excretion of 85Sr was observed in the older recipients. This finding may be explained by the decreasing uptake of 85Sr by the whole skeleton of the older recipients, which was recorded by the decreasing 85Sr uptake of recipient tibiae, leaving more 85Sr in the common pool to be taken up by the grafts or to be excreted. However, the proportion of 85Sr uptake of syngeneic and allogeneic grafts was also changed with age of the recipients, leading to a decrease of the ratio 85Sr in syngeneic grafts versus 85Sr in allogeneic grafts of older recipients. This points to a decrease of the immunological response with increasing age of the recipients.

Age Factors↗

PubMed1991

Tibia valga after fracture: documentation of mechanism.

Tibia valga following fracture in the proximal metaphysis of the tibia in children was previously attributed to various mechanisms. This case report offers an additional explanation based on bone scintigraphy 10 months after injury. Decreased radionuclide uptake at the lateral proximal tibial physis without evidence of increased uptake on the medial side suggests that a Salter type V injury to the lateral growth plate can occur in conjunction with a medial metaphyseal fracture, resulting in the development of tibia valga.

Child, Preschool↗

PubMed1981

Growth disturbance after physial injury of distal femur and proximal tibia studied by roentgen stereophotogrammetry.

Longitudinal growth determined by roentgen stereophotogrammetry was registered in three patients with physial injuries in distal femur and in two patients with physial injuries in proximal tibia during 18 months. The injuries in distal femur were classified as Type I, Type I kII and Type IV and in proximal tibia as Type I kII and Type IV in the different cases according to Salter and Harris. Markers of tantalum balls were implanted into the metaphysis and bony epiphysis of distal femur and proximal tibia permitting regular determination of longitudinal growth. Significant growth disturbances was registered in four patients. The Salter-Harris classification was difficult to use to predict growth disturbance after physial injuries around the knee. The roentgen stereophotogrammetric method was found useful to determine normal growth rate and after physial injuries to reveal growth disturbance leading to complete or partial growth arrest resulting in leg length discrepancy or angular deformity. This method facilitates preoperative planning if surgery is needed.

Adolescent↗