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PubMed1982

Quantitation of regional chondro-osseous circulation in canine tibia and femur.

Regional osseous blood flow (OBF) to various regions of the femur and tibia was measured using radioactively labeled 15-micrometers microspheres injected into the right atrium of neonatal, skeletally immature, and skeletally mature canines. Each bone was divided into as many as 41 anatomically distinct sections to assess developmental and regional comparisons in OBF. A quantitative decrease in OBF with increasing chondro-osseous maturity was observed for both the whole bones as well as many regions within a given bone. This was particularly significant in the tibia in which OBF to the mature tibia was much lower than in the immature tibia or even the mature femur. In the immature and neonatal bones, the epiphyseal and metaphyseal regions nearest the physes had the highest flow. The physis had a statistically significant high flow rate. Furthermore, regional differences in OBF correlated well with known regional functions in both endochondral and membranous (periosteal) bone formation. OBF tended to be greater in regions of greater metabolic activity associated with hematopoiesis and endochondral osteogenesis. OBF values correlated well with regional predilections of various diseases such as acute hematogenous osteomyelitis prior to skeletal maturity and osseous metastases, and, by extrapolation, strongly support a physiological reason for delayed healing and nonunion in tibial fractures in the skeletally mature human.

Aging↗

PubMedDate not supplied

Radiographic and histologic analyses of stress fracture in rabbit tibias.

Sequential changes in remodeling of the internal structure of the tibia caused by controlled, excessive jumping and running were studied in 20 rabbits. Vascular changes and circulatory disturbances within the cortical bone occurred before osteoclastic resorption. Degeneration and necrosis of osteocytes due to circulatory disturbances also occurred. Periosteal new bone formation, found at and after 12 days of the experiment, was a compensatory reaction to support the tibia weakened by accelerated osteoclastic resorption. Small cracks appeared at the cement line and developed through the neighboring cement line of the haversian systems. At 21 days, incomplete fracture of the tibial cortex was found in two rabbits. Complete fracture through one side of the cortex was seen in one animal at the 50th day of the experiment. In this study, however, most of the tibias did not have visible fracture lines after a period of stressful exercise. This result suggests that most tibias adapt to changes in stress requirements through proper internal remodeling so that a complete fracture does not occur.

Animals↗

PubMedDate not supplied

Pathomechanics of posterior sag of the tibia in posterior cruciate deficient knees. An experimental study.

This study was an investigation of the pathomechanics of posterior sag of the tibia in knees with posterior knee instability caused by PCL deficiency. By using fresh cadaver knees, the authors hoped to define the relationship of the posterior joint capsule and the medial and lateral collateral ligaments (MCL, LCL) with posterior knee instability in the PCL deficient knee. Thirty newtons of posterior stress were applied to the knees to simulate postoperative conditions. Roentgenographic methods were then used to evaluate posterior sag and change in the distance between the origin and insertion of the PCL. Strain gauges were used to measure the actual strain of the PCL and the collateral ligaments. The PCL, the posterior capsule, and the medial and lateral collateral ligaments were sequentially divided and the above measurements were then repeated in the same way, using 30 N of applied posterior stress. When only the PCL was cut, posterior sag and medial rotation of the tibia occurred with increasing severity as flexion increased. No sagging or rotation of the tibia was observed at full extension in the knees that had isolated PCL "injury". When the posterior capsule was sectioned, no significant changes were noted in the severity of the sag or the rotation. When the MCL or LCL was divided in a PCL deficient knee, greater sag occurred with flexion and a significant sag was observed even at full extension. The MCL "injury" was associated with increased medial rotation, whereas LCL "injuries" were associated with lateral rotation of the tibia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMedDate not supplied

Tensile properties of the human femur-anterior cruciate ligament-tibia complex. The effects of specimen age and orientation.

The structural properties of 27 pairs of human cadaver knees were evaluated. Specimens were equally divided into three groups of nine pairs each based on age: younger (22 to 35 years), middle (40 to 50 years), and older (60 to 97 years). Anterior-posterior displacement tests with the intact knee at 30 degrees and 90 degrees of flexion revealed a significant effect of knee flexion angle, but not of specimen age. Tensile tests of the femur-ACL-tibia complex were performed at 30 degrees of knee flexion with the ACL aligned vertically along the direction of applied tensile load. One knee from each pair was oriented anatomically (anatomical orientation), and the contralateral knee was oriented with the tibia aligned vertically (tibial orientation). Structural properties of the femur-ACL-tibia complex, as represented by the linear stiffness, ultimate load, and energy absorbed, were found to decrease significantly with specimen age and were also found to have higher values in specimens tested in the anatomical orientation. In the younger specimens, linear stiffness (242 +/- 28 N/mm) and ultimate load (2160 +/- 157 N) values found when the femur-ACL-tibia complex was tested in the anatomical orientation were higher than those reported previously in the literature. These values provide new baseline data for the design and selection of grafts for ACL replacement in an attempt to reproduce normal knee kinematics.

Age Factors↗

PubMed1981

The treatment of osteomyelitis of the tibia with sodium salicylate. An experimental study in rabbits.

Osteomyelitis was induced in the tibiae of rabbits by injecting a suspension of Staphylococcus aureus and sodium tetradecylsulphate, a sclerosing agent. These rabbits were then divided into two groups: one group remained untreated and the other was fed a diet containing sodium salicylate. Two and four weeks after induction of osteomyelitis the tibiae taken from untreated rabbits with osteomyelitis and incubated in vitro released significantly more prostaglandin E and F than the control uninjected or uninfected tibiae. Tibiae taken from rabbits treated with sodium salicylate showed minimal radiographic changes and a significantly decreased release of prostaglandin E and F compared to the untreated rabbits. Prostaglandins are known to be potent bone resorbing agents and the results of this study suggest that they may also be involved in the destruction of bone which is characteristic of osteomyelitis. The treatment of rabbits with osteomyelitis using anti-inflammatory drugs, which block synthesis of prostaglandins, in addition to antibiotics, may prevent the destruction of bone and possible sequestration thereby decreasing the risk of chronic disease.

Animals↗

PubMed1992

Effect of dietary sodium zeolite A and graded levels of calcium and phosphorus on growth, plasma, and tibia characteristics of chicks.

Sodium zeolite A (SZA), a synthetic sodium aluminosilicate having a high ion exchange capacity, has been shown to influence Ca and P utilization in chickens. A 3 x 2 x 2 factorial arrangement of treatments was used to investigate the effect of dietary P (.41, .55, and .69% total P), Ca (.6 and 1%), and SZA (0 and .75%) on growth, plasma, and tibia characteristics of chicks from 5 to 15 days of age. Growth, feed intake, gain:feed ratio, and tibia characteristics were influenced by dietary Ca and P in a manner consistent with dietary recommendations for these macro minerals. The addition of Ca, SZA, or both exacerbated the adverse effects of feeding low-P diets, yet alleviated the adverse effects of feeding a low-Ca, high-P diet. Dietary SZA had no effect (P greater than .5) on plasma Ca or alkaline phosphatase; however, SZA reduced (P less than .01) plasma P. Dietary SZA increased (P less than .02) tibia Mn, Zn, Cu, and Al. The SZA-induced increase in tibia Al was most evident in chicks fed low levels of P (SZA by P interaction, P less than .02). The overall response to dietary SZA addition paralleled the response observed from Ca supplementation, indicating that SZA increased Ca utilization, reduced P utilization, or contributed to both of these effects. These data demonstrate that the effects of SZA are influenced by the dietary concentration of Ca and P and that the addition of SZA to diets low in P results in bone Al accumulation.

Alkaline Phosphatase↗

PubMed1992

Effects of dietary aluminum and niacin on chick tibiae.

Effects of dietary aluminum chloride and niacin on bone mineral content and bone structural measurements were studied using young male Leghorn chicks. Standard chick rations containing .8% Ca and .4 or .5% available P were fed as control diets in three experiments. Experimental diets contained .05, .1, or .3% Al, or 1.0 or 1.5% niacin, or both and were fed for 2 wk. Tibia weights were decreased by 1.5% niacin, .3% Al, and by .1% Al plus 1.5% niacin (P less than .05). Breaking strength of tibiae was decreased (P less than .05) by 1.5% niacin, .1% Al, and .1% Al plus 1.5% niacin. Ultimate stress, which is force per unit area, was decreased by .3% Al and .05% Al plus 1.5% niacin (P less than .05). Niacin had no significant effect on bone mineral content. In Experiment 3, .3% Al decreased P, Ca, Mg, and Zn content of the tibiae (P less than .05). These findings indicate that feeding high levels of supplemental niacin results in decreased bone strength in chicks with no change in mineral content of the tibiae. Aluminum fed at levels of .3% of the diet causes a decrease in bone strength with concomitant changes in bone mineral content.

Aluminum↗

PubMed1995

The effects of the interosseous membrane and partial fibulectomy on loading of the tibia: a biomechanical study.

The biomechanical basis for the treatment of delayed union of tibial fractures by partial fibulectomy has yet to be fully evaluated. To gain further insight into this problem, nine intact cadaveric lower extremities were instrumented with strain gauges on the surfaces of the tibia and fibula. The limbs were then subjected to axial loading with the ankle and subtalar joints placed in multiple positions. The specimens were loaded either through the distal femur or by direct loading of the tibial plateau. All specimens were first tested intact then after sectioning of the interosseous membrane and finally after partial fibulectomy. It was shown that during loading of the leg, the primary effects of the interosseous membrane were to stabilize the fibula and constrain its posterolateral bending. The fibular strains were not reduced to zero following sectioning of the interosseous membrane. Tibial strains measured on the anteromedial and anterolateral surfaces were consistently in relative tension, indicating a posterior bending force (anterior bowing) of the tibia. After partial fibulectomy, strains on these surfaces became relatively more compressive. With the ankle and subtalar joints in neutral position (0 degree flexion, 0 degree inversion/eversion) the strains on the anterior surface averaged approximately 10% more compressive relative to the intact condition. Tibial strains were observed to vary with the position of the ankle and subtalar joints. The fact that the anteromedial and anterolateral tibia surfaces were always in tension may explain why partial fibulectomy has not proved to be a uniformly successful treatment method for delayed union of the tibia. Furthermore, it points to the important role of "fracture personality" in the selection of treatment.

Aged↗

PubMed1992

The radial forearm flap: a biomechanical study of donor-site morbidity utilizing sheep tibia.

The use of vascularized bone grafts to reconstruct extremity and mandibular defects is now commonplace in reconstructive surgery. Fibula, scapula, iliac crest, rib, and metatarsal as well as the radial forearm osseocutaneous flaps have all been utilized for this purpose. Troublesome spiral fractures of the distal radius are the most common fractures associated with the use of the distal radius as a vascularized bone-graft donor site. This study was proposed to investigate the effect of donor-site bone loss on the strength of the radius under torsional (rotational) loading. Previous clinical series and experimental studies have not examined this aspect of distal radius loading after harvesting the bone graft. Fifty pairs of sheep tibiae were utilized in the experiment. Five pairs were used in a pilot study and 45 pairs were used in the main experiment. Five pairs of human radii were used for the control in the pilot study. The pilot study attempted to make a comparison between the human radius and the sheep tibia for experimental purposes. For the biomechanical study of donor-site defects, four study groups were examined with random assignment and matched pairs. The control group (group 1) had no alteration to the bone. Each test condition included five matched pairs of sheep tibiae. Experiment 1 compared the difference in the depth of the osteotomy defect. In doing this, one-third of the total length of the bone was removed in each of the following specimens to include (1a) 30 percent of the cross-sectional area of the total bone, (1b) 37 percent of the cross-sectional area of the total bone, and (1c) 50 percent of the cross-sectional area of the total bone. In experiment 2, the osteotomy shape was varied. Instead of the ends of the cuts being squared, the ends were beveled or rounded. Experiment 3 compared different lengths of bone removed in the osteotomy defect and included the following: In experiment 3a the diameter of the sheep tibia was measured at the incisura fibularis. This dimension was one diameter of bone, and a one-diameter length of bone was removed. In experiment 3b, a two-diameter length of bone was removed. In experiment 3c, a three-diameter length of bone was removed. In experiment 3d, a four-diameter length of bone was removed.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1992

The strain distribution in the upper tibia after insertion of two different unicompartmental prostheses.

The strain distribution in the proximal tibia in seven human autopsy specimens was investigated with strain-gauge rosettes attached on the medial proximal aspect of the tibia. The strains measured were about the same on the proximal bone and on the bone in the metaphysis. The direction of the minimal principal strain (compression) was about 45 degrees counterclockwise (left knee). After insertion of a unicompartmental prosthesis medially, a non-constrained prosthesis with a loose meniscus-bearing and a constrained prosthesis, the tensile strain was about four times higher in the most anteromedial gauge. No significant differences were found between prostheses. Tests were also performed with the two prostheses inserted into three plastic models. The constrained prosthesis was more sensitive to outward rotation of tibia versus femur, which made the femoral component climb up the slope of the tibial component and caused a marked change in the strain distribution compared to loading in the neutral position. With the other prosthesis, a malpositioning of the tibial component medially caused the meniscus bearing to lie close to the medial rim of the tibial component. An external rotation of tibia then made the system constrained and dramatically changes the strain distribution.

Biomechanical Phenomena↗

PubMed1990

Late-onset tibia vara (Blount's disease). Current concepts.

Idiopathic tibia vara or Blount's disease can be classified into three age-onset groups: (1) infantile, less than three years; (2) juvenile, four to ten years; and (3) adolescent, 11 years or older. The latter two groups comprise late-onset tibia vara, which is much less common than the infantile-onset form. In a comparison of eight juvenile-onset patients (13 knees) and seven adolescent-onset patients (nine knees), there were essentially no significant clinical, roentgenographic, or physeal-histopathologic differences. Both groups had severe obesity, mild to moderate varus deformities, and less-pronounced roentgenographic characteristics. Histopathologic analyses of the entire physis from the proximal tibia in five cases (seven knees) were essentially identical in patients with the infantile form as well as in those with slipped-capital femoral epiphyses, suggesting a common etiology. Recurrence of deformity after surgical correction occurred frequently in the juvenile onset males but not in juvenile onset females or the adolescent onset group. Incomplete correction of the varus deformity occurred more frequently in the latter group. The etiology for tibia vara appears to involve varus stress growth suppression, and disruption of endochondral ossification. The major differences between the three groups is due to the age at clinical onset, the amount of remaining growth, and the magnitude of the medial compression forces across the medial aspect of the knee.

Adolescent↗

PubMed1989

[Regional blood flow and uptake of 99mTc-MDP and 85Sr in the femur and tibia in rats: regional differences and mutual relations].

We established blood flow (by means of 85Sr-microparticles) and 24 hours 99mTc-methylendiphosphonate (MDP) catchment and that of 85Sr (at different time intervals) in five portions of femur and 4 portions of tibia in rats. 1. We detected a marked differentiation in blood flow among all measured portions with the highest values in growth active distal femur metaphysis and proximal tibia metaphysis and with the lowest value in distal terminal tibia portion. 99mTc-MDP catchment is also highest in both metaphysis parts, and in the other parts it is differentiated similarly as the blood flow. 85Sr catchment in the early phase is very high in both metaphyses, but in several weeks it decreases to very low values; in the other parts the differences are small as well as the changes in the course of several weeks. 2. There is a considerable similarity in blood flow and 99mTc-MDP, in 85Sr catchment only high initial catchment in growth active metaphysis parts corresponds with blood flow. The time course of 99mTc-MDP and 85Sr catchment in the first hours after an intravenous injection is almost identical. The experiments showed great (up to 15-fold) local differences in blood flow among growth active and the other parts of femur and tibia in rats and a similar differentiation in 99mTc-MDP catchment, suggesting a certain relationship (but not quantitative dependency).

Animals↗

PubMed1989

Bonding behavior of a glass-ceramic containing apatite and wollastonite in segmental replacement of the rabbit tibia under load-bearing conditions.

Glass-ceramic implants containing apatite and wollastonite were studied under load-bearing conditions in a segmental replacement model in the tibia of the rabbit. Alumina-ceramic implants were used as a control. A sixteen-millimeter segment of the middle of the shaft of the tibia was resected at a point distal to the junction of the tibia and the fibula. The defect was replaced by a fifteen-millimeter-long hollow, cylindrical implant that was fixed by intramedullary nailing using a Kirschner wire. Two groups of eight rabbits each (one group with a glass-ceramic implant and the other with an alumina implant) were killed twelve weeks after implantation. Two similar groups were killed twenty-five weeks after implantation. The segment of the tibia that contained the implant was excised and tension-tested. The load to failure of glass-ceramic implants containing apatite and wollastonite increased with time. The loads to failure of the glass-ceramic and alumina implants at twelve weeks after implantation were 19.8 +/- 7.06 and zero newtons, respectively. The loads to failure of glass-ceramic and alumina implants at twenty-five weeks after implantation were 126.4 +/- 32.54 and 19.6 +/- 13.92 newtons, respectively. No glass-ceramic implants broke. A calcium-phosphorus layer at the interface of the glass-ceramic and the bone was observed by scanning electron microscopy and electron-probe microanalysis. There was no interposition of soft tissue between the glass-ceramic and the bone, as observed by Giemsa surface staining.

Aluminum Oxide↗

PubMed1988

[Congenital defects of tibia and fibula].

This study comprised 7 patients with longitudinal anomalies of the knee and leg classified in accordance with the 'classification of congenital limb deficiencies' introduced by Frantz and O'Rahilly. The anomalies were paraxial hemimelia of the fibula (4 instances), paraxial hemimelia of the tibia (6 instances). In the absence of the proximal tibia, therapy consisted of knee reconstruction according to Brown. In the absence of the distal part of the tibia a proximal tibiofibular synostosis was performed. In one instance corrective osteotomy of the tibia was required in the absence of the fibula. Exarticulation according to Syme was resorted in order to cope with an incorrigible abnormal position of the foot and for leg length inequality. The therapy should aim at giving the child walking ability at a normal time. Exarticulation has to be preferred to amputation in the treatment of these patients.

Child, Preschool↗

PubMedDate not supplied

Infantile tibia vara.

We studied the applicability of Langenskiöld's classification to a predominantly nonwhite population with infantile tibia vara. Age at presentation was younger than that in previously published studies. Forty-seven tibiae averaging 6 years 7 months of follow-up had 66% good results. Poor results increased in proportion to stage at presentation. Brace treatment for early lesions was only 50% effective. Single tibial osteotomy before 4 years of age gave good results in 85% of tibiae, and multiple osteotomies gave good results between 4 and 8 years of age. One-half of tibiae treated with osteotomy developed recurrent varus. This review documents earlier stages at presentation, a more malignant course, and poorer results than Langenskiöld's series would suggest. We question the accuracy of Langenskiöld's estimate of prognosis when applied to this patient group.

Black People↗

PubMed1985

Indentation stiffness of the cancellous bone in the distal human tibia.

Total ankle arthroplasties tend to fail mainly on the tibial side. Fifteen fresh amputation specimens were used for assessment of the stiffness of the cancellous bone in the distal tibia. Because all current ankle replacements sacrifice the subchondral bone plate, the change in stiffness of cancellous bone was studied in transverse sections taken proximal to the subchondral plate of the ankle. The articular cartilage was removed from the tibial plafond, and serial 1-cm sections were taken, radiographed, and tested in compression on an Instron 1125 Universal Testing machine with the use of a 4-mm-diameter indentor. In the distal tibia, it was found that subchondral bone has an elastic modulus on the order of 300-450 MPa; removal of the subchondral bone plate reveals bone with a compressive resistance that is 30%-50% lower than with the bone plate intact; there is virtually no resistance to compression in the trabecular bone at a distance of more than 3 cm proximal to the subchondral bone plate; and stiffness characteristics in the distal tibia parallel the radiographic appearance of the trabeculae. The strongest cancellous bone in the region of the distal tibia is that near the subchondral bone plate. This material should be preserved, if possible, in the surgery for total ankle implants.

Biomechanical Phenomena↗

PubMed1980

[Anatomical investigations on the lower leg and foot in cases of hypoplasia and aplasia of the tibia (author's transl)].

Deformities associated with absence or defect of the tibia were investigated on 3 lower legs and feet. In case of bilateral hypoplasia of the tibia, the deformities are nearly identical regarding the muscles and the skeletal system. The main vessels and nerves are developed normally. The extent of malformations seems to be greater in case of aplasia of the tibia. The question, wether some abnormalities typical for a defect of the tibia exist, is discussed. For this our own observations are compared with similar cases described in the literature.

Adolescent↗

PubMedDate not supplied

The influence of physeal injury upon growth correction of deformed rat tibia.

Experimentally produced angulatory deformities of rat tibia with and without physeal injury were observed at two to three-week intervals for an eight-week period by x-ray studies, in order to estimate the spontaneous correctability of tibial deformity in growing rats. The results obtained were as follows: 1) In the retrocurvated rat tibia with intact physes or with distal physeal injury, roughly one quarter of the initial angle was corrected during the eight-week observation period, with greater correction occurring during the first five weeks in both groups. 2) Injury of the distal physis hardly influenced the correction capacity of the deformed tibia. 3) The physis and diaphysis played equally important roles in the remodelling process of rat tibia with intact physes. However, early remodelling took place on a considerably larger scale and with greater rapidity through physeal growth, and late remodelling similarly through the diaphyseal appositional growth.

Animals↗