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PubMed1991

Development of a three-dimensional finite element model of a human tibia using experimental modal analysis.

The modal analysis of a human tibia consisted of characterizing its dynamic behavior by determining natural frequency, damping ratio and mode shapes. Two methods were used to perform the modal analysis: (1) a finite element method (structural model); (2) an experimental modal analysis (modal model). The experimental modal model was used to optimize the structural model. After optimization, differences in results between the two models were found to be due only to mechanical properties and mass distribution. The influences of boundary conditions and geometric properties (such as inertia and length) were eliminated by the finite element model itself. The percent relative error between the two methods was approximately 3%, corresponding to the standard deviation of the measured frequencies. For the frequency range considered, the mode shapes were bending modes in two different vibration planes (latero-medial and sagittal), with a slight torsion effect due to the twisted geometry of the tibia.

Biomechanical Phenomena↗

PubMed1991

Three-dimensional acceleration of the tibia during walking and running.

Measurements of tibial acceleration during walking and running were obtained by means of a triaxial accelerometer. The accelerometer was fixed to the free end of a Steinmann pin inserted into the right tibia of one volunteer subject. The patterns of tibial acceleration showed little step-to-step variation within each experimental condition. Following foot strike and depending upon footwear, the resultant tibial acceleration reached between 2.7 and 3.7 g during walking. The tibia experienced maximal accelerations of 10.6 g during running. The high values of tibial acceleration recorded in the antero-posterior (AP) and medio-lateral (ML) directions clearly revealed the importance of measuring all three components of acceleration to quantify the magnitude of the shock experienced by the lower limbs during locomotor activities.

Acceleration↗

PubMed1977

Preventive treatment of congenital pseudarthrosis of tibia.

If an osteotomy is carried out in a child with congenital angulation of the tibia with segmental sclerosis, a pseudarthrosis develops in many cases. This should be prevented by a bone-graft operation along the concave side of the tibia. The results described illustrate this contention.

Bone Transplantation↗

PubMed1987

Non-invasive method of measuring resonant frequency of a human tibia in vivo. Part 1.

We describe a method for measuring resonant frequency of a human tibia in vivo. Although the main reason for this measurement is the assessment of a fractured tibia, we emphasize the special instrumentation required; in particular the novel techniques which are used to overcome the difficulty of obtaining results through skin and soft tissue.

Acoustics↗

PubMed1984

Constructional peculiarities of the human tibia defined by reference to ultrasound measurement data.

The distribution of the acoustic properties of the human tibia was studied by the method of ultrasound probing. This enabled the determination of some constructional peculiarities of the tibia. A considerable non-uniformity of ultrasound propagation velocity has been revealed along the entire length of the bone. The uniform velocity fields were longitudinally orientated in the diaphysis whereas in the epiphyseal parts of the bone they had a cross-sectional orientation. Isorapid zones formed spiral structures positioned at an angle of 6.7 +/- 0.5 degrees to the bone axis. Moreover, right-wound spiral was characteristic of the left bone but left-wound spiral of the right. A new parameter--acoustic stiffness of the construction is suggested. In the proximal third of the bone its acoustic stiffness was more pronounced in the sagittal plane; in the middle part it was best defined in the direction of the angular zones of the bone, but in the distal part it had a clearly marked frontal orientation. A statistically valid distinction of ultrasound velocity in the cross-sectional and longitudinal zones of separate bones has been established in all the bones studied.

Biomechanical Phenomena↗

PubMed1991

Modulation of the membrane surrounding particulate cement and polyethylene in the rabbit tibia.

Twenty-nine mature New Zealand white, female rabbits were divided into four groups. Using sterile technique, a 6 mm drill hole was made in the tibia 1 cm distal to the knee joint. The marrow was scooped out underneath the hole. The right tibia received Simplex particulate cement polymer (PMMA) (groups 1 and 2) or polyethylene particles (UHMWP) (groups 3 and 4). The left leg functioned as a prepared but non-implanted control. All animals were fed a standard diet; those in groups 1 and 3 received plain water, while groups 2 and 4 drank water in which sodium naproxen was dissolved (1.375 mg/ml). Animals were killed after 16 wk. The implant area was harvested and grown in tissue culture. The cumulative collection of tissue culture supernatants over 3 d was assayed for prostaglandin E2 (PGE2) via radioimmunoassay. PGE2 production was significantly higher in the membrane harvested from the right side containing particulate cement with no sodium naproxen (group 1) compared with controls (P less than 0.05). The ratio of PGE2 values for the right divided by the left side yielded higher values in group 1, compared with groups 2, 3 or 4 (P less than 0.01). Previous studies have suggested that particulate debris and PGE2 production are associated with arthroplasty loosening. This experiment has demonstrated that PGE2 production by the membrane surrounding particulate debris can be suppressed by the administration of oral sodium naproxen. Because non-steroidal anti-inflammatory drugs are known to inhibit prostaglandin synthesis in man, these agents may prove useful in retarding the bone loss associated with early prosthetic loosening.

Animals↗

PubMed1996

Evaluation of guided bone regeneration in rabbit tibia using bioresorbable and non-resorbable membranes.

The aim of this study was an evaluation of the possibility of bone regeneration in connection with implant placement, using a new bioresorbable membrane (Guidor Matrix Barrier) used previously in periodontal tissues regeneration. The study compared the bone regeneration obtained around Bonefit-ITI implants inserted in rabbit tibia using Guidor membranes, Gore-Tex membranes and in control sites. Microscopic analysis was performed after 6, 9 and 12 weeks. It was possible to see that the amount of bone around implants covered by Guidor and Gore-Tex membranes was roughly equivalent in all experimental sites at the 6-, 9- and 12-week time intervals. Also, all control sites healed completely. It could be concluded from this study that: (1) rabbit tibia cannot be recommended in research connected with guided bone regeneration, as all control sites healed in the same way as the test sites; (2) in no case did the presence or the degradation of the resorbable membrane prevent the formation of new bone; (3) no inflammatory reaction was present around the bioresorbable and the non-resorbable membranes; (4) bone formed in all cases on the outer surface of the non-resorbable membranes; (5) large Guidor membrane fragments were present in the 6-week specimens, while in the 12-week specimens only small fragments were recognizable; (6) Guidor membranes can be used in guided bone regeneration.

Animals↗

PubMed1993

Establishment of a growth hormone responsive chondrogenic cell line from fetal rat tibia.

Reproducible effects of growth hormone (GH) on primary isolated cells in monolayer are highly dependent on the culture conditions and/or the fraction of GH responsive cells. To study the effect of GH at the cellular level, a homogenous cell line with both GH responsiveness and chondrogenic properties was established. Primary isolated cells from 18-day-old fetal rat tibia were subcultured using a strict protocol for passages (every third day and a seeding density of 15,000/cm2). Of six established cell lines, one fetal tibia cell line No. 5 (FTC 5) expressed adipogenic and chondrogenic properties at a low frequency. Cells from FTC 5 were subcultured in soft agar suspension with the addition of bovine GH (100 ng/ml). After 14 days in culture eight monoclonal cell lines were established from individual large colonies. Two subclones, FTC 5:3 and FTC 5:6, expressed a chondrogenic phenotype as demonstrated by chondrocyte foci, alcian blue staining and production of type II collagen. Further characterization of FTC 5:3 revealed specific binding of bovine GH with an affinity of 1.7 x 10(9) M-1, and approximately 7300 receptors/cell. Northern blot analysis of FTC 5:3 with a 32P-labeled RNA probe complementary to an extracellular part of the rat GH receptor, revealed two major labeled bands (4.0 and 1.2 kilobases). Both GH and insulin-like growth factor-I (IGF-I) stimulated 3H-thymidine uptake in FTC 5:3 (194 +/- 28% and 405 +/- 127% over control, respectively), while proteoglycan synthesis, as measured by [35S]sulphate uptake, was stimulated by IGF-I only (101 +/- 18% over control).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Ossicles anterior to the proximal tibia.

Ossicles anterior to the anterior tibia are most usually seen in relation to the tibial tuberosity. While these are usually taken to represent sequelae of previous Osgood-Schlatter disease, they may, on occasion, represent normal variants in ossification of the tuberosity. Ossicles superior to the tuberosity may have similar origins. Representative examples are presented, as is a very large ossicle separated from the anterior tibia by a prolongation of the knee joint space. Theories of causation of such ossicles are discussed.

Accidents, Occupational↗

PubMedDate not supplied

The influence of clodronate on the torsional strength of the growing rat tibia in immobilization osteoporosis.

The purpose was to investigate whether the reduction in bone mechanical strength induced by immobilization could be prevented by a bisphosphonate compound, clodronate. The torsional breaking strength of the tibia was measured using a specially constructed torsion machine. Maximum torque capacity, maximum angle of deformation, and rigidity of the bone were calculated from a load-deformation curve. The study was performed in two experiments, one with rats having their right hind leg immobilized, the other with freely moving animals. In both experiments, the rats were treated with either clodronate or pure vehicle. Thus, the following groups, consisting of growing male Sprague-Dawley rats, were included: immobilized groups receiving clodronate (20 rats), immobilized group receiving vehicle only (20 rats), nonimmobilized group receiving clodronate (10 rats), and nonimmobilized group receiving vehicle only (10 rats). The rats to receive clodronate were injected daily with clodronate tetrahydrate s.c., 10 mg/kg body weight for 21 days, the others having the same volume of 0.9% NaCl (2 ml/kg body weight). On the third day of injection the right hind leg of the rats in the immobilization groups were immobilized with a plaster cast. Eighteen days later the animals were sacrificed, the tibias were submitted to torsional testing, and the ash weights of the femurs were determined. Clodronate treatment had an increasing effect on immobilized bone ash weight and all mechanical parameters, in the contralateral leg on ash weight, and maximum torque capacity, when compared with the respective leg of the immobilized, vehicle-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2005

Immunohistochemical analysis of Sox9 expression in periosteum of tibia and calvaria after surgical release of the periosteum.

Sox9 is a transcription factor belonging to the SRY family of high-mobility box proteins, and plays a major role in endochondral ossification. Sox9 is a potent activator of the type-2 collagen pheno-type marker of articular cartilage. Regulation of osteogenic molecular signals in periosteal bone formation has not yet been elucidated yet. The purpose of the present study was to analyze histologically the bone formation in surgically released and repositioned periosteum, and to determine expression of Sox9 and type-2 collagen in periosteal bone formation of tibia and calvaria. After surgery, the released tibial periosteum formed ectopic cartilage. At 7 days, a combination of endochondral and intramembranous ossification was apparent. Some fibroblasts derived from the released periosteum showed Sox9 expression. Chondrocytes and cartilage matrix both displayed type-2 collagen expression. At 7 days, an additional new bone was formed on the calvaria. Osteoblasts and fibroblasts derived from released calvarial periosteum did not express Sox9 or type-2 collagen. Sox9 was not expressed throughout the process periosteal bone formation on the calvaria. It is concluded that we revealed Sox9 and type-2 collagen expression in periosteal cells after periosteum release and that the generative potential of periosteal cells of calvaria is different from that of tibia.

Animals↗

PubMed2005

Effect of hydroxyapatite-coated tibial components on changes in bone mineral density of the proximal tibia after uncemented total knee arthroplasty: a prospective randomized study using dual-energy x-ray absorptiometry.

Sixteen patients scheduled for an uncemented total knee arthroplasty (TKA) were randomized to receive a tibial component either with (n = 8) or without (n = 8) hydroxyapatite (HA) coating. In 4 regions of interest, prospective measurements of bone mineral density (BMD) using dual-energy x-ray absorptiometry were performed in the proximal tibia. Two years after the operation, the only significant change in BMD was in the lateral tibial condyle, where BMD had increased by 6.1% (95% confidence interval: 2.3%-9.9%) in patients with tibial components without HA. The intragroup changes (0-24 months) in the uncoated group and HA-coated group were significantly different (P = .003) in these regions of interest. There was no significant effect of HA coating on bone remodeling pattern of the proximal tibia.

Absorptiometry, Photon↗

PubMed2004

Subchondral giant-cell tumor of the proximal tibia: arthroscopic treatment for accelerated articular cartilage and meniscal degeneration in two patients.

Giant-cell tumor most commonly occurs in the distal femur and proximal tibia and characteristically involves the subchondral bone. Incomplete resection leads to recurrence rates of up to 50%. Intralesional curettage, adjuvant treatments, and polymethyl methacralate (PMMA) reconstruction is the current mainstay of treatment and has produced recurrence rates of less than 10%. Achieving adequate curettage while preserving the articular cartilage of the tibial plateau poses a significant challenge, especially when the tumor involves the subchondral bone. We report on 2 cases, both with symptomatic full-thickness tibial articular cartilage loss and one with a meniscal tear, after curettage, phenol cautery, and PMMA reconstruction of giant-cell tumor of the proximal tibia. Arthroscopic chondroplasty and planing of the exposed cement was performed in both cases, theoretically reducing focal areas of stress concentration that could lead to further meniscal damage and injury to the femoral condyle articular surface in weight-bearing. Partial meniscectomy for a complex meniscal tear was performed in one case. Eighteen months postoperatively, both patients were asymptomatic, working full-time, and participating in light physical activity. Repetitive heavy loading of the knee, such as running, was prohibited, and long-term follow-up is warranted to assess for further joint degeneration and need for total knee arthroplasty.

Adult↗

PubMed2005

Loading induces site-specific increases in mineral content assessed by microcomputed tomography of the mouse tibia.

Adaptation to mechanical loading has been studied extensively in cortical, but not cancellous bone. However, corticocancellous sites are more relevant to osteoporosis and related fracture risk of the hip and spine. We tested the hypotheses that adaptation in a long bone would be greater at cancellous than cortical sites and would depend on the term of daily in vivo cyclic axial loading. We applied compressive loads to the adolescent, 10-week old, male C57BL/6 mouse tibia to examine the skeletal response immediately prior to attainment of peak bone mass. Adaptation was quantified at the completion of either 2-week (n = 8) or 6-week (n = 12) loading terms by directly comparing volumetric bone mineral content between loaded and contralateral limbs by microcomputed tomography. The increase in mineral content was site specific with a greater response found in the corticocancellous proximal metaphysis (14%) than the cortical mid-shaft (2%) after 6 weeks of loading. Furthermore, bone volume fraction and average trabecular thickness of cancellous bone in the proximal tibia increased after 6 weeks by 15% and 12% respectively. Diaphyseal response was only evident proximal to the mid-shaft as indicated by an 8% increase in maximum principal moment of inertia. Both loading terms produced similar results for mineral content, volume fraction, and moments of inertia. Our finding that non-invasive loading increases the bone volume and fraction at a corticocancellous site by as much as 15% motivates exploring the use of mechanical loading to attain greater peak bone mass and inhibit osteoporosis.

Animals↗

PubMed2005

Non-invasive axial loading of mouse tibiae increases cortical bone formation and modifies trabecular organization: a new model to study cortical and cancellous compartments in a single loaded element.

Systematic study of bones' responses to loading requires simple non-invasive models in appropriate experimental animals where the applied load is controllable and the changes in bone quantifiable. Herein, we validate a model for applying axial loads, non-invasively to murine tibiae. This allows the effects of mechanical loading in both cancellous and cortical bone to be determined within a single bone in which genetic, neuronal and functional influences can also be readily manipulated. Using female C57Bl/J6 mice, peak strains at the tibial mid-shaft were measured during walking (<300 micro epsilon tension) and jumping (<600 micro epsilon compression) with single longitudinally oriented strain gauges attached to the bone's lateral and medial surfaces. Identically positioned gauges were also used to determine, for calibration, the strains engendered by external applied compressive tibial loading between the flexed knee and ankle ex vivo. Applied loads between 5 and 13 N produced strains of 1150-2000 micro epsilon on the lateral surface, and in vivo repetitions of these loads on alternate days for 2 weeks produced significant load magnitude-related increases in cortical bone formation that were similar in mice at 8, 12 and 20 weeks of age. Micro-CT scans showed that loading significantly increases trabecular bone volume in 8 week old mice, but modifies trabecular organization with decreases in trabecular bone volume in 12 and 20 week old mice. This model for loading the tibia has several advantages over other approaches, including scope to study the effects of loading in cancellous as well as cortical bone, against a background of either disuse or of treatment with osteotropic agents within a single bone in normal, mutant and transgenic mice.

Adaptation, Physiological↗

PubMed2005

Side-to-side differences in cortical bone mineral density of tibiae in young male athletes.

The importance of physical activity in the development and maintenance of bone mineral density (BMD) is widely accepted. However, the effects on cortical BMD have not been clarified in detail. The present study examined bilateral asymmetries in cortical BMD of the tibia using peripheral quantitative computed tomography. Subjects comprised 37 young male athletes and 57 controls (age range, 18-28 years). BMD and geometrical indices were determined in bilateral tibiae. Cortical and trabecular BMD were calculated at the diaphysis and distal metaphysis, respectively. Cortical width, periosteal cross-sectional area, and cross-sectional moment of inertia were calculated using tomographic data of the tibial diaphysis. In athletes, the non-dominant leg showed greater cortical BMD than the dominant leg (mean difference, 5.42%; P < 0.0001). Cortical width and moment of inertia were also greater in the non-dominant leg. Periosteal area displayed no significant difference between legs. The control group exhibited similar results except for cortical BMD. No differences in trabecular BMD were noted between legs in either athletes or controls. These results implies the existence of mechanisms for the mechanical adaptation of cortical BMD. Dominant leg is used for mobility or manipulation whereas the non-dominant leg contributes to support the actions of the dominant leg. Loading differences in bilateral legs in young athletes might affect the remodeling rate leading to the side-to-side differences in cortical BMD.

Adolescent↗

PubMed2006

Effect of impact exercise and its intensity on bone geometry at weight-bearing tibia and femur.

INTRODUCTION: Physical activity is known to enhance the mechanical competence of bone. However, information about the optimal type of exercise is limited. The aim of this study was to evaluate the contribution of jumping exercise to changes in bone geometry. METHODS: We carried out a 12-month population-based trial with 120 women (aged 35-40 years), randomly assigned to an exercise group or to a control group. The exercise regimen consisted of supervised, progressive high-impact exercises three times per week and an additional home program. The intensity of impact loading was assessed as the magnitude of acceleration peaks using an accelerometer-based body movement monitor. The activity was analyzed as the daily number of impacts within five acceleration ranges (0.3-1.0g, 1.1-2.4g, 2.5-3.8g, 3.9-5.3g and 5.4-9.2g; g=acceleration of gravity, 9.81 m/s(2)). Bone geometry was assessed with spiral quantitative computed tomography (QCT) scanner at mid-femur, proximal tibia and distal tibia. RESULTS: Thirty-nine women (65%) in the exercise group and 41 women (68%) in the control group completed the study. QCT and physical activity data were available from 65 subjects. The exercise group showed a significant 0.2% (p=0.033) higher gain in bone circumference compared to the control group at mid-femur. Subgroup analyses revealed geometric changes indicating up to a 2.5% increment in bone strength in favor of the most active exercisers (>66 exercise sessions during the 12 months) compared to the least active exercisers (<19 sessions). In pooled groups, the changes in cortical attenuation and cross-sectional moment of inertia correlated positively (p<0.05-p<0.01) with the number of impacts exceeding 1.1g, while changes in cortical thickness (p<0.05) and bone circumference (p<0.05-p<0.01) were positively associated with impacts 3.9g, or more. The number and intensity of impacts during the 12 months were the most significant predictors of changes in bone geometry explaining up to 36% of changes. CONCLUSIONS: Bone geometry adapts to impact exercise and the adaptation is most marked at the mid-femur. The changes in bone geometry are associated with the number and intensity of daily impacts while the redistribution of bone mineral appears to be the main mechanism in the skeletal adaptation to varying intensities of exercise.

Adult↗

PubMed2005

Distraction osteogenesis for segmental bone defect. Physeal change after acute bone shortening followed by gradual lengthening in a rabbit tibia model.

We investigated physeal change after acute bone shortening followed by distraction osteogenesis in a rabbit tibia model. Distraction osteogenesis was performed on acutely shortened right rabbit tibia after removing a diaphyseal segment until distraction reached the length of the excised segment. Sixty animals were divided into three groups (n=20) according to the amount of shortening (20, 30, and 40% of original length) and radiographic, immunohistochemical, and histomorphometric analyses were performed to evaluate the physeal activity. The results showed no differences between groups and all animals could recover the original length without growth retardation. There was no notable venous congestion or lymphatic kinking associated with acute shortening. These results suggest that distraction osteogenesis at the primary site of shortening may have little adverse effects on the growth plate, when the shortening can provide sufficient soft tissue without vascular compromise and the amount of lengthening does not exceed that of shortening.

Animals↗