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PubMed1996

Femoral hypoplasia-unusual facies syndrome with bifid hallux, absent tibia, and macrophallus: a report of a Bedouin baby.

A male Bedouin baby with the clinical profile of femoral hypoplasia-unusual facies syndrome is described. The phenotype includes bilateral asymmetrical lower limb hypoplasia/aplasia with short remnants of both femora, absent right tibia, bifid right big toe, dysmorphic facies, thoracic/pelvic abnormalities, macrophallus, and bilateral cryptorchidism. This report re-emphasises the previously described rare association of femoral hypoplasia-unusual facies syndrome with preaxial polydactyly and suggests that the clinical spectrum of the syndrome could be stretched further to accommodate other unusual traits, for example, macrophallus and absent tibia.

Abnormalities, Multiple↗

PubMed1990

Focal fibrocartilaginous dysplasia associated with tibia vara.

Focal fibrocartilaginous dysplasia of the tibia at the insertion of the pes anserinus (the expanded tendinous insertion of the gracilis, sartorius, and semitendinous muscles) is a rare unilateral lesion with a characteristic deformity of the proximal tibial metadiaphysis. It is associated with unilateral tibia vara in toddlers. Three cases of this entity are described, and the radiologic features are presented. Recognition of this disease is important because the response to conservative therapy is excellent.

Child, Preschool↗

PubMed1992

Bone signal abnormalities in the posterolateral tibia and lateral femoral condyle in complete tears of the anterior cruciate ligament: a specific sign?

Thirty-two patients with acute, complete tears of the anterior cruciate ligament (ACL) proved at surgery underwent examination with magnetic resonance (MR) imaging. Bone impaction sites were present in the posterolateral tibial plateau in 30 patients (94%) and in the lateral femoral condyle (LFC) in 29 patients (91%). The bone abnormalities had low signal intensity on T1-weighted images and high signal intensity on T2-weighted images when compared with the signal intensity of normal marrow. It is assumed that the bone changes occur during injury when the LFC impacts into the posterior tibia, either during the initial rotary subluxation or as the LFC recoils to return to anatomic alignment. Only one of six partial ACL tears had a bone signal change. In patients with acute knee injury, bone impaction sites in the posterolateral tibia and the LFC suggest that a complete ACL tear is present.

Anterior Cruciate Ligament Injuries↗

PubMedDate not supplied

Cortical lesions of the tibia: characteristic appearances at conventional radiography.

Lesions that involve the cortex of the tibia are fairly common in radiology practice. However, the number of diseases that involve the tibial cortex is great, and it can be difficult to arrive at a limited differential diagnosis from radiographic findings. Categorization of lesions of the tibia into those that cause cortical destruction and those that cause cortical proliferation can help narrow the broad differential diagnosis. Lesions that cause cortical destruction include nonossifying fibroma, fibrous dysplasia, osteofibrous dysplasia, aneurysmal bone cyst, giant cell tumor, eosinophilic granuloma, Ewing sarcoma, neurofibromatosis, adamantinoma, osteoblastoma, chondromyxoid fibroma, hemangioendothelioma, renal cell metastatic disease, hemangioma, and hemangiopericytoma. Lesions that cause cortical proliferation include osteochondroma, stress fracture, osteoid osteoma, periosteal osteogenic sarcoma, diaphyseal dysplasia, venous stasis, cellulitis, chronic osteomyelitis, osteopathia striatum, and melorheostosis. Conventional radiography along with clinical and pathologic data can aid in diagnosis of the wide variety of disease processes that involve the tibial cortex.

Adult↗

PubMed1996

Increased bone formation in rat tibiae after a single short period of dynamic loading in vivo.

Based on our quantum concept for mechanically adaptive bone formation, we hypothesized that a single bout of loading would increase bone formation at the endosteal surface in rat tibiae, with a maximal response 4-8 days after loading and a stimulus-response relationship for load magnitude. Bending loads were applied to right tibiae of rats at 31, 43, 53, or 65 N for a single bout of 36 or 360 cycles; bone formation was assessed 1-4, 5-8, or 9-12 days after loading. A single loading episode increased lamellar bone formation rate (BFR) in all groups (P<0.05) and was maximal 5-8 days after loading. A distinct dose-response relationship was not evident among all load magnitudes or for duration, but 65 N was significantly more osteogenic than loads of 31-53 N (P<0.05), consistent with a threshold response to loading. There was also evidence for a significant increase in BFR (P<0.05) and double-labeled surface (P<0.01) within 4 days of loading, suggesting that bone-lining cells were activated directly by the stimulus. Thus subtle changes in BFR may occur by modulating the activity of surface cells, but large modeling drifts and anabolic responses require recruitment and differentiation of osteoprogenitor cells near the bone surface.

Analysis of Variance↗

PubMed1979

Vascular reactivity of the isolated tibia of the dog.

Experiments were performed to assess the responsiveness of vessels subserving bone tissue to nerve stimulation and to exogenously administered catecholamines and acetylcholine. Tibias of mongrel dogs were isolated and dissected free; the periosteum was left intact. The main nutrient artery was prepared and cannulated. Ring electrodes were placed around the artery. The preparation was perfused at constant flow with aerated (95% O2 - 5% CO2) Krebs-Ringer solution (37 degrees C) by means of a roller pump. The perfusion pressure was continuously recorded. For each preparation, the flow rate was used at which the response to a standard dose of norepinephrine was the largest. Periarterial electrical stimulation caused frequency-dependent increases in perfusion pressure; because these responses were blocked by phentolamine, they must be due to activation of sympathetic nerves. Injections of norepinephrine caused dose-dependent increases in perfusion pressure that were abolished by phentolamine. Acetylcholine caused dose-dependent, atropine-sensitive decrease of the constrictions caused by norepinephrine infusions. These experiments demonstrate that the isolated perfused tibia of the dog is a satisfactory preparation to investigate the direct effects of sympathetic nerve stimulation and naturally occurring vasoactive amines on bone blood vessels.

Acetylcholine↗

PubMed1977

A functional analysis of fusion of the tibia and fibula in the rat and mouse.

The distal diaphyseal shafts of the rat tibia and fibula fuse postnatally, a process initiated by the seventh day with the formation of secondary cartilage that is subsequently replaced by endochondral ossification. The histological appearance of this fusion process is described. A homologous process occurs postnatally in the mouse. An analysis of some of the pertinent recent developmental, comparative and paleontological data indicated that extrinsic, biomechanical factors probably played a significant causal role in tibia-fibula fusions. The production of secondary cartilage is evoked by extrinsic forces, and these fusions were analyzed within the present concepts of intrinsic and extrinisic factors in skeletogenesis. It was concluded that the fusions currently reported fit well within the hypothesis of the functional matrix and that, such fusions between skeletal tissues are secondary, compensatory and mechanically obligatory responses to the prior demands of functionally related nonskeletal tissues and organs.

Animals↗

PubMed1984

In vivo bone strain on the dog tibia during locomotion.

Rosette and single-element strain gauges were implanted on the tibia in 2 dogs and recordings were made during locomotion on a treadmill. At foot contact and during the swing phase of locomotion, bone strains were low and directions of the principal strains were variable. There was a large shift in the directions of the principal strains at the beginning of the stance phase and bone strains were considerably higher. Peak strain occurred midway through the stance phase. At that time, the maximum principal strain (tension) was directed upwards and anteriorly between 30 and 60 degrees with respect to the long axis of the tibia. These bone strain patterns in the dog are similar to those found in sheep while both differ markedly from those found in humans.

Animals↗

PubMed1986

Change of some quantitative indices of the proximal and the distal growth cartilage of the human tibia during the period of the prenatal osteogenesis.

The zones of the tibial growth cartilage of human fetuses (6th lunar month), premature newborns (7th-8th lunar month) and mature newborns were micrometrically studied. The zone thickness, the chondrocyte number in a certain area and in the cell columns as well, and the volume density of the chondrocytes were determined. The obtained quantitative data show that the three indices undergo certain changes during the three age periods of the prenatal osteogenesis studied. They differ in the proximal and in the distal cartilages as well. The fetal tibia is found to be growing more intensively at its distal end. The quantitative processes within the growth cartilages of the tibia are more active during the earlier stages of the intrauterine period while the qualitative processes are found to be more active at the end of the intrauterine period.

Cell Count↗

PubMed1991

Morphogenesis of cartilage canals: experimental approach in the rat tibia.

This paper studies the participation of vessels in the canal morphogenesis. The proximal chondroepiphysis of the left tibia of 44 five-day-old rats was exposed and the vessels of the intercondylar fossae, near the attachment of cruciate ligaments, were cauterized. In addition to the vascular lesion this assay induced a perichondral lesion. However, the canal appeared and joined to the secondary ossification center. 36 tibiae of 4-day-old rats were removed under sterile conditions and cultured in a serum-free chemically defined medium. The cultures were carried out for as long as 15 days. A canal lumen structure was found on the first days of culture, and grew in depth to the central region of the chondroepiphysis during the culture. The secondary ossification center was not found. The vessels and mesenchymal cells observed in the control canal were not found in the culture. We suggest that the presence of vessels, perivascular cells or perichondrium does not appear to be necessary in canal morphogenesis.

Animals↗

PubMed1993

In vivo measurements of the loading conditions on the tibia of the goat.

In vivo strain measurements at 8 locations on the tibia of the goat were performed. Successive in vitro calibrations were used to determine the assumed linear relationship between the measured strain signals and the external loads (3 forces and 3 moments) at the tibia. For the reconstruction of the in vivo external loads from the strain data, a transformation matrix was created from the calibration experiments, using 'singular-value decomposition'. The method is a reliable technique for measuring in vivo loads during functional gait and gives reproducible results.

Animals↗

PubMedDate not supplied

Effects of patellar tendon adhesion to the anterior tibia on knee mechanics.

The effects of patellar tendon adhesion on the knee extensor mechanism and on the kinematics and contact areas for both the patellofemoral and tibiofemoral joints were determined for five cadaveric knees in an open kinetic chain testing configuration. Patellar tendon adhesion decreased the distance from the inferior patellar pole to the tibial tuberosity, effectively creating patella infera. When compared with the controls, knees with adhesion had medial and distal translation of the patella, as well as increased patellar flexion. Although the patellar articular contact location shifted distally, the overall contact area did not change significantly. For the tibia, adhesion resulted in significant medial, proximal, and anterior translation, and internal rotation. Adhesion also resulted in a posterior shift of the tibial contact location. For the extensor mechanism, adhesion decreased the knee extension force created by the quadriceps muscle on the tibia, indicating a decrease in the effective moment arm of the extensor mechanism. Furthermore, as a result of patellar tendon adhesion, the angle formed by the quadriceps and patellar tendons decreased, suggesting an increase in patellofemoral joint reaction force with adhesion. The increased patellofemoral joint reaction force and the altered contact location may be related to anterior knee pain after knee trauma and knee surgery. Therefore, patients should be observed for subtle patella infera, which may indicate patellar tendon adhesion.

Aged↗

PubMed2006

Health-related quality of life in patients with transtibial amputation and reconstruction with bone bridging of the distal tibia and fibula.

BACKGROUND: Bone-bridging (arthrodesis of the distal tibia and fibula) at the time of transtibial amputation is a controversial operative technique that is anecdotally reported to improve the weightbearing capacity of the residual limb and to decrease residual limb discomfort. METHODS: Thirty-two consecutive patients with multiple diagnoses had transtibial amputation with a distal tibial-fibular bone-bridge, all done by a single surgeon (MAP). At an average of 16.3 months after surgery all patients completed the Prosthetics Evaluation Questionnaire (PEQ), a validated outcomes instrument specifically created to evaluate quality of life and functional demands in patients with a lower extremity amputations. Their responses were compared with those of 17 preselected, highly functional transtibial amputees from two academic medical centers who previously had transtibial amputations using a traditional non bone-bridge operative technique; their time since amputation averaged 14.7 years. RESULTS: The "nonselected" consecutive patients with a bone-bridged residual limb scored higher (more favorable) in the Ambulation (p = 0.037) and Frustration (p < 0.001) domains of the PEQ and lower (less favorable) in the Appearance (p = 0.025) subscale. Their scores were similar in the other six domains. CONCLUSIONS: Patients of multiple ages with multiple diagnoses who had bone-bridging of the distal tibia and fibula at the time of transtibial amputation had scores on a validated outcomes instrument that were better than or comparable to those of a selected group of highly functional transtibial amputees. The results of this study suggest that bone-bridging at the time of transtibial amputation may enhance patient-perceived functional outcomes.

Adolescent↗

PubMed2004

Cement penetration and stiffness of the cement-bone composite in the proximal tibia in a porcine model.

PURPOSE: To assess the stiffness of the cement bone composite and the depth and uniformity of cement penetration into the surface of the tibial component during total knee reconstruction in a porcine model. METHODS: The effectiveness of 3 protocols were compared: 2 commonly used cementing techniques-finger-packing of cement on the cut surface followed by impaction, and coating of the undersurface of the prosthesis with cement followed by impaction-and a new method using a tibial cement-pressurising device. Cement penetration was measured by computed tomography; stiffness was determined by hydraulic penetration testing. RESULTS: Cement penetration at a depth of 1 mm was significantly greater following coating the undersurface of the prosthesis than following finger-packing (p=0.008). There was no significant difference at deeper levels or between the tibial-pressurising device group and either of the 2 other groups at any level (p>0.3 in all cases). Differences in surface stiffness by tibial plateau region were found in tibiae that had been cemented using finger-packing and in those that had had their undersurface coated, but not in tibiae that had been cemented using the tibial-pressurising device. CONCLUSION: The tibial cement-pressurising device eliminated regional differences in stiffness seen with other cementing methods. Elimination of these differences by using this device should reduce micromotion and the incidence of aseptic loosening of tibial base plates in total knee arthroplasty.

Analysis of Variance↗

PubMed2001

The femur-tibia control system in a proscopiid (Caelifera, Orthoptera): a test for assumptions on the functional basis and evolution of twig mimesis in stick insects.

The extremely slow return movements observed in stick insects (phasmids) after imposed changes in posture are termed catalepsy. In the literature, catalepsy is treated as a behavioural component of the twig mimesis observed in walking stick insects. It is produced by the high gain of the velocity-sensitive component of the relevant joint control systems and by the non-linear dependency of its time constant on movement velocity. The high gain, in turn, causes the system to work close to instability, and this may have driven the evolution of gain control mechanisms. Although these statements represent plausible assumptions, based on correlated occurrence, they remain largely hypothetical like many ideas concerning evolutionary tendencies. To test these hypotheses, we studied catalepsy and the relevant properties of the femur-tibia control system in the middle and hind legs of Prosarthria teretrirostris.cf. Prosarthria teretrirostris is a proscopiid closely related to grasshoppers and locusts. With its slender, green-to-brown body and legs, it shows clear morphological twig mimesis, which has evolved independently of the well-known twig mimesis in stick insects. The animals show clear catalepsy. The main properties of femur-tibia joint control are remarkably similar between proscopiids and stick insects (e.g. the marked sensitivity to movement velocity rather than to joint position and the non-linear dependency of the time constants of response decay on movement velocity), but there are also important differences (habituation and activity-related mechanisms of gain control are absent). Together, these results validate the main concepts that have been developed concerning the neural basis and evolution of catalepsy in stick insects and its relationship to twig mimesis, while demonstrating that ideas on the role of habituation and gain control should be refined.

Animals↗

PubMed1995

The effect of the geometry of the tibia on prediction of the cruciate ligament forces: a theoretical analysis.

This paper attempts to highlight the importance of the tibial geometry in the prediction of forces along the cruciate ligaments. A two-dimensional model of the knee which comprises the femur, the tibia and the cruciates was used. The model was subjected to an external antero-posterior force and an external axial compressive force. The analysis showed that, with a flat tibial plateau, the tension arising along either cruciate as a result of the application of an external antero-posterior force is determined solely by the inclination of the ligament to the direction of that force; it is independent of the magnitude of the external axial compressive force. A curved tibial plateau modifies the tension along either cruciate, and in the absence of an axial compressive load on the joint small changes in the geometry of the tibial surface cause slight changes (increase/decrease) in the tension. However, these changes can become considerable when a large axial compressive load is applied on the joint. A concave tibial plateau, where the tangent to the surfaces at the point of contact is inclined to the direction of the same external antero-posterior force by 7.8 degrees, can reduce the tension along either cruciate to zero, if a sufficiently large axial compressive load is applied on the joint. It was shown that the convexity of the lateral tibial plateau can provide an important protective function for the posterior cruciate ligament (PCL) at extreme positions of flexion. The analysis showed that the PCL should experience a larger force than that experienced by the anterior cruciate ligament (ACL) and hence explain why the former should be the stronger of the two. Finally, a hypothesis is proposed suggesting that bone remodelling may occur in the tibiae of the older people, causing them to become more concave with age and as a consequence provides greater protection to the cruciates in the aged, in order to compensate for decreasing strength in the older person.

Age Factors↗

PubMed1976

Effect of strontium on the epiphyseal cartilage plate of rat tibiae-histological and radiographic studies.

Following dietary administration of strontium carbonate, histological and radiographic changes in the epiphyseal cartilage plate of the rat tibiae were examined in the present study. The weight gain of the rat fed a strontium diet was less than that of the control rats. Longitudinal growth of tibiae and endochondral ossification were inhibited by strontium administration. The widths of both proximal and distal cartilage plates increased enormously as has also been shown by other investigators. Sizes of chondroblasts in columns of proximal cartilage plate in rats fed a strontium diet were smaller than those of the control rats and were not different between upper and lower parts. It is suggested that strontium inhibits bone growth through the inhibitory action on the maturation process of chondroblasts and the succeeding endochondral ossification.

Animals↗

PubMed1977

Inhibitory action of sodium salicylate on the growth of upper jaw and tibia in rats.

The inhibitory effect of sodium salicylate on the growing upper jaw and tibia was examined by the morphological measurement by radiography at different dose levels. The longitudinal growth of the tibia was greater than the sagittal growth of the upper jaw in young normal rats. The increment in length was approximately 10 mm a month in the former and 3 mm a month in the latter. Growth of these bones was reduced by successive subcutaneous injections of sodium salicylate, and the reduction of growth increased with increase of the dose administered. Sagittal growth of the upper jaw was much more sensitive to the action of salicylate, and was significantly reduced by the drug even at a dose of 100 mg/kg (P less than 0.01).

Animals↗