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PubMed1984

Osteogenic periosteum esterase activity: a comparative morphological and cytochemical study of bone cells in situ on rat proximal tibiae and in smears.

Mononucleate phagocytes are presently thought to participate, along with osteoclasts, in bone resorption. Similar cells may also be precursors to osteoclasts. Esterase is a hydrolytic enzyme commonly found in most phagocytes and cells such as these have been shown to degrade bone matrix in vitro. Therefore, periosteal cells of remodeling proximal tibiae in rats were examined for esterase activity. Stain reactions were compared both in situ and in smears. Percentages of different cell types were obtained by counting cells in Wright-Giemsa-stained smears. Osteoclasts and mononucleate phagocyte-like cells made up approximately 20% of the isolated cells. Cells resembling preosteoblasts, mononucleate phagocytes, and osteoblasts stained for esterase activity with light to moderate intensity. Osteoclasts and mononucleate osteoclast-like cells were strongly esterase positive. The esterase was characterized as being type B by using nonorganophosphorus inhibitors of the various esterase types. The addition of esterase to the list of enzyme activities of cells in close proximity to osteoclasts lends further support to the hypothesis that mononucleate cells also participate in bone resorption.

Animals↗

PubMed1992

Intra- and extracellular localization of hyaluronic acid and proteoglycan constituents (chondroitin sulfate, keratan sulfate, and protein core) in articular cartilage of rabbit tibia.

To demonstrate the intra- and extracellular localization of hyaluronic acid (HA) in articular cartilage of the rabbit tibia, biotinylated HA binding region, which specifically binds to the HA molecule, was applied to the tissue. In comparison with the localization of HA, that of chondroitin sulfate (CS), keratan sulfate (KS), and the protein core (PC) of the proteoglycan was examined by immunohistochemistry. Strong positive staining for HA was detected in chondrocytes located in the transition between the superficial and middle zones of the tissue. Pre-treatment with chondroitinase ABC, keratanase II, or trypsin enhanced the stainability for HA in peri- and intercellular matrices. Immunohistochemistry with or without enzymatic pre-treatment demonstrated that immunoreactivity for CS, KS, and PC was distinctly discerned in chondrocytes and in the extracellular matrix located in the middle and deep zones. In particular, the immunoreactivity for KS and PC was augmented by pre-treatment with chondroitinase ABC not only in chondrocytes but in the extracellular matrix located in the middle and deep zones. Microbiochemical analysis corresponded well with histochemical and immunohistochemical results. These results suggest that HA is abundantly synthesized and secreted in chondrocytes located in the transition between the superficial and middle zones.

Aggrecans↗

PubMed1988

The ontogeny of growth hormone receptors in the rabbit tibia.

To address the question of the mode of action of GH in stimulating longitudinal bone growth, we have used a panel of anti-GH receptor monoclonal antibodies to demonstrate GH receptors in the rabbit tibia and have studied the ontogeny of these receptors. In the neonate, receptors were localized in the hypertrophic zone between the cartilage canals, a region that develops into a secondary ossification center. In support of this finding, receptors were also localized on monolayer cultures of human infant costal chondrocytes. In 20- and 50-day-old rabbits, receptors were localized on reserve and proliferative chondrocytes in the growth plate. In 50- and 130-day-old rabbits receptors were localized on proliferative chondrocytes in the condylar cartilage. In older (180-day-old) rabbits with closed growth plates, GH receptors could not be detected, even in condylar cartilage. These results support the case for revision of the somatomedin hypothesis to accommodate a direct interaction between GH and receptors on epiphyseal chondrocytes.

Aging↗

PubMed1982

Limb mechanics as a function of speed and gait: a study of functional strains in the radius and tibia of horse and dog.

Rosette strain gauges were attached to the midshaft of the radius and tibia of two horses and two dogs, which ran on a treadmill through their entire range of speed and gait. The relative magnitudes of the principal strains on the opposite cortices of each bone remained constant through the stance phase of the stride, and their orientation varied by a maximum of only 14 degrees through the entire speed range. The maximum strain rate increased linearly with speed, but the peak strain magnitude was also dependent upon the gait used, increasing incrementally by up to 59% at the transition from walk to trot, and dropping by 42% from a trot to a canter. Force transducers attached to the shoes of one horse indicated similar changes in ground load. The peak strains induced during vigorous activity are remarkably uniform in a wide range of animals. This suggests that the skeleton is scaled to provide constant safety margins between peak functional strains and those at which yield and ultimate failure occur.

Animals↗

PubMed1993

Rotation of the tibia in the normal and ligament-deficient knee. A study using biplanar photography.

The difference between physiological tibial rotation and rotatory instability of the knee, particularly the 'pivot shift' phenomenon, was investigated by analysing knee movements under both rotatory and valgus torques using 29 fresh cadaveric knees. The knee movements were measured in three dimensions using biplanar photography, when all ligaments were intact, and then after the ligaments were sequentially sectioned. The axis of the physiological tibial rotation was shown to be located about the centre of the tibial plateaux, while that of the pivot shift is located about the medial collateral ligament (MCL). When the anterior cruciate ligament (ACL) was sectioned, little or no significant change in physiological tibial rotation was observed under rotary torques, while a significant rotatory instability, including the 'pivot shift' phenomenon, was observed under a valgus torque. It was thus concluded that the rotatory instability is not simply an increase in the magnitude of the physiological rotation of the tibia, but is an abnormal tibial rotation which occurs with a different mechanism.

Adult↗

PubMed1981

Load-carrying effects on the adult beagle tibia.

The response of the skeleton to carrying extra weight while exercising was studied in 30 young adult male beagles. Following 34 wk of a caged control period, 18 dogs carried lead-weighted jackets for 1 h and 15 min, 5 d/wk for 2 yr, on a carousel-type treadmill at 3.3 kph. During the next 23 wk, the load carried was gradually increased to 130% of the animal's body weight, and then maintained for 48 wk. The other 12 dogs served as controls. The dogs remained healthy and responded to exercise showing decreased skinfolds and body weight. All dogs showed increases in both tibial mineral content and width with time; but, the exercise group increased significantly more in mineral content than the controls. It is concluded that the gradual increase in bone mineral and width of the tibia is normal in the epiphyseal-closed skeleton of a young adult beagle. Also important is the fact that the intervention of exercise with added weight will increase tibial mineral content above these normal levels.

Animals↗

PubMed1978

A technique for measuring the accumulation of 99 Tcm stannous-ethane-1-hydroxy-1, 1-diphosphonate in the canine tibia.

An experimental technique is described to measure the accumulation of 99Tcm-stannous-ethane-1-hydroxy-1, 1-diphosphonate (99Tcm-EHDP) in the canine tibia. The method involves infusion at a constant rate of known amounts of 99Tcm-EHDP into the nutrient artery supplying the tibial bone. The accumulation of the diphosphonate in bone is measured by an external sodium iodide, Nal (T1), scintillation detector. Results are presented showing that for small amounts of 99Tcm-EHDP (0.004-0.300 mg per hour) the accumulation is a nearly linear function with time for 60 minutes, after which the uptake may become variable with either a plateau formation or considerable fluctuation of activity.

Animals↗

PubMed2004

Prospective study of blood and tibia lead in women undergoing surgical menopause.

Despite the dramatic decline in environmental lead exposure in the United States during the past couple of decades, concern has been expressed regarding mobilization during menopause of existing lead stored in bone. To investigate whether bone lead concentrations decrease and blood lead levels increase, we conducted a prospective study of 91 women who were scheduled to undergo a bilateral oophorectomy for a benign condition at Mount Sinai Hospital in New York City during October 1994 through April 1999. We excluded women who were younger than 30 years of age or who were postmenopausal at the time of the surgery. We observed a small but significant increase in median blood lead levels between the baseline visit and the 6-month visit (0.4 microg/dL, p<0.0001), particularly for women who were not on estrogen replacement therapy (0.7 microg/dL, p=0.008). No significant change was observed in blood lead values between 6 and 18 months postsurgery, nor was there evidence of significant changes in tibia lead concentrations during the follow-up period. These findings do not point to substantial mobilization of lead from cortical bone during menopause.

Adult↗

PubMed2005

Distribution of type VI collagen in the cartilaginous tissue of the proximal tibia in the domestic cat.

To investigate the distribution of the early stage chondrocytes during the formation and closure of epiphyseal growth plate (EGP) of the domestic cat, we examined the EGP of proximal tibiae by immunohistochemistry for type VI collagen. In the epiphyseal cartilage without the secondary ossification center (SOC) and EGP in newborn cats aged 1 and 10 days, type VI collagen-positive chondrocytes were located around the cartilage canals and articular surface. In the epiphyseal cartilage with the SOC and EGP in young cats aged 1 to 3 months, type VI collagen-positive chondrocytes were located in the upper resting zone of the EGP, and then increased throughout the resting zone along with maturation. In the adult cats with the partially closed EGP, type VI collagen-positive chondrocytes were distributed throughout the remaining EGP. These findings indicate that the early stage chondrocytes characterized with type VI collagen are continuously located in the EGP during maturation. In addition, the increase of the early stage chondrocytes and the decrease of the reserve chondrocytes in the EGP along with maturation may cause the cessation of the longitudinal growth of the EGP, and finally bring about the EGP closure.

Acid Phosphatase↗

PubMed1977

The natural history and management of congenital short tibia with dysplasia or absence of the fibula.

Forty-three patients with unilateral congenital short tibia with partial or complete absence of the fibula are reviewed. The factors influencing the degree of leg shortening at maturity are considered. Serial radiographic measurements of leg length in fourteen patients covering an average observation period of 9-3 years support the hypothesis that the relative difference in growth between the two limbs remains remarkably constant. By estimating the percentage difference between the normal and abnormal leg lengths on the first measurable radiograph it is therefore possible to predict the likely shortening at maturity. This method of prediction allows the surgeon to make the decision to proceed to Syme's amputation or to the use of an extension prosthesis at about one year of age when the child starts to walk.

Adolescent↗

PubMed1978

The microsurgical revascularisation of resected segments of tibia in the dog.

A segment of tibia 4.5 centimetres long was removed from one hind limb of fifteen dogs. It was then replaced and the main vasculature was restored by a microsurgical technique. In eight controls the segment was replaced without such restoration. In two-thirds of the former cases the microvascular reconstruction was successful; the rate of infection was found to be reduced, bone union was guaranteed and the rate of union accelerated. Success or failure of the reconstruction was clearly demonstrated in five cases by early bone scanning using technetium-labelled polyphosphate.

Animals↗

PubMed1979

Total resection of distal femur or proximal tibia for bone tumours. Autogenous bone grafts and arthrodesis in twenty-six cases.

Resection of the distal femur or proximal tibia en bloc has been performed on twenty-six patients with primary bone tumours. The gap was filled with autogenous bone grafts stabilised with a long intramedullary nail, thus arthrodesing the knee. In two cases temporary stabilisation with a Küntscher rod and acrylic cement was adopted because of adjuvant chemotherapy. Union was achieved in twenty-four cases (92 per cent). Infection was the main and practically the only major complication, occurring in five (19 per cent) of the cases: it healed with union in three, healed with non-union in one, and led to an above-knee amputation in the fifth case. Follow-up has been from one to eight years with an average of four years.

Adolescent↗

PubMed1982

Diplopodia with double fibula and agenesis of tibia. A case report.

A 14-year-old girl with a congenitally deformed and shortened right leg and foot is described. The patient could not bear weight on the deformed limb and had to hop on the left leg. The deformed foot faced backwards and had nine toes. The right leg was shorter than the left by 26 centimetres. Radiologically, the lower end of the right femur was ill-developed and there was no knee joint. There were two fibulae and the tibia and the patella were absent. A through-knee disarticulation was done and a prosthesis fitted later. The amputated leg and foot were dissected. Many of the muscles in the leg and foot were duplicated. There were two calcanei, one talus, one navicular, two cuboids and four cuneiforms. Ther were nine metatarsals, and all the toes had three phalanges except for one which had two.

Adolescent↗

PubMed1985

Free vascularised fibular graft in the treatment of congenital pseudarthrosis of the tibia.

Five cases of congenital pseudarthrosis of the tibia successfully treated by a free vascularised fibular graft are described. Follow-up ranged from 5 to 34 months with a mean of 17.5 months. The technique, which includes radical excision of abnormal bone and soft tissue around the pseudarthrosis, also permits primary bone lengthening, and correction of deformity. The early results indicate that satisfactory bony union is achieved in a relatively short period of time.

Child↗

PubMed1985

Electrical stimulation in the treatment of congenital pseudarthrosis of the tibia.

A treatment regime using electrical stimulation in association with a variety of surgical procedures has improved the prognosis in congenital pseudarthrosis of the tibia--one of the most challenging of all orthopaedic disorders. The technique consists of correction of the tibial deformity, intramedullary fixation and cancellous bone grafting, augmented by electrical stimulation using an implanted bone-growth stimulator. Experience with 27 pseudarthroses in 25 patients is presented; of those, 20 have joined. The cases have been reviewed and the causes of failure analysed. These results offer encouragement to the orthopaedic surgeon treating this difficult condition.

Child↗

PubMed1990

The role of the tibial nutrient artery. Microsphere estimation of blood flow in the osteotomised canine tibia.

There has been a long-standing debate as to whether medullary or periosteal flow is the dominant vascular supply during the healing of diaphyseal fractures. We used radioactive microspheres to quantify blood flow to the canine tibia two weeks after an osteotomy. There was a significant contribution from the periosteum to the blood supply of healing cortical bone after nutrient artery ligation, with a reversal of flow from a centrifugal to a centripetal direction. Our study has confirmed the qualitative observations of Trueta (1974) regarding the significant recruitment of vessels from surrounding soft tissue during fracture healing. We have not studied the later stages of healing.

Animals↗

PubMed1990

Extending intramedullary rods in congenital pseudarthrosis of the tibia.

Five patients with Boyd type II congenital pseudarthrosis of the tibia underwent excision of the pseudarthrosis and double onlay bone grafting. Stability was maintained by extending intramedullary rods. Clinical union was achieved in all cases at a mean of 8.6 months (range six to 11). The rods extended by 15.7% (range 2% to 31.4%) as growth occurred. One rod was removed because of infection and a vascularised free fibular graft was subsequently performed. The extending rods provided stability while union occurred and did not require revision as the legs grew. The rods can be removed easily and have not jeopardized further surgical options.

Bone Transplantation↗

PubMed1991

Vascularised fibular graft for congenital pseudarthrosis of the tibia. Long-term results.

Five children with congenital pseudarthrosis of the tibia treated by free vascularised fibular grafts were followed up until skeletal maturity. The ipsilateral fibula was used in four cases, the contralateral fibula in one. All our cases achieved bone union, but leg length discrepancy, atrophy of the foot and ankle stiffness were frequent complications, due perhaps to the many previous operations. Vascularised fibular grafting might achieve better results if it were done as the primary procedure.

Atrophy↗