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PubMed1995

Effect of bone cylinder length on distraction osteogenesis in the rabbit tibia.

The viability and osteogenic potential of bone cylinders for bone transport was investigated in one tibia of 18 mature male New Zealand rabbits. The length of the bone cylinder was equal to or twice that of the diameter of the tibia. The cylinder was cut subperiosteally with an externally cooled oscillating saw from a lateral approach, after a specific unilateral external fixator had been applied. To simulate bone transport, one end of the cylinder was fixed to the distal bone stump by a cerclage wire and healing and revascularization was prevented by an interposed expanded polytetrafluoroethylene membrane. The periosteum was re-adapted and sutured, and distraction began 10 days postoperatively at 0.25 mm/12 hours for 22 days. New bone formation in the distraction gap was quantified by dual energy x-ray absorptiometry and by computer-assisted histomorphometry of polyfluorochrome-labeled undecalcified bone sections and corresponding microradiographs. In half of the animals with each size cylinder, osseous bridging occurred, so the findings on distraction osteogenesis are reported only for the remaining nine animals. Generally, centripetal mineralization of the gap with two distinct zones of ripening bone structures and a central radiolucent fibrocartilaginous zone could be distinguished. Neither absorptiometry nor histomorphometry showed significant differences in the overall amount of this new bone formation for the bone cylinders of two different lengths. However, osteogenesis was significantly greater at the proximal end than at the cylinder. New bone was formed predominantly from endosteal sites in the smaller cylinders and from periosteal sites in the larger cylinders. Histologically, there was complete necrosis of both sizes of cylinders, followed by revitalization through newly formed vascular channels.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1995

Cortical bone perfusion in plated fractured sheep tibiae.

The limited contact dynamic compression plate and partial contact plate were designed to decrease contact with cortical bone in an attempt to decrease cortical ischemia, remodeling, and eventual porosis under the plate after use of standard dynamic compression plates. This study quantified cortical bone blood flow beneath the plate with these three different designs in a sheep tibia fracture model. In 18 skeletally immature sheep, the right tibia was fractured and then was internally fixed with an interfragmentary screw and a dynamic compression plate, limited contact dynamic compression plate, or partial contact plate. At 12 weeks, cortical bone perfusion was assessed with laser Doppler flowmetry in nine areas beneath the plate. The baseline (before fracture) cortical bone cell flux averaged 100 +/- 60 mV. After fracture, this decreased to 60 +/- 48 mV (p < 0.0003); immediately after plating, the perfusion averaged 29 +/- 25 mV (p < 0.01). Cortical bone perfusion then increased to 106 +/- 52, 165 +/- 71, and 163 +/- 71 mV at 2, 6, and 12 weeks after fracture (p < 0.001 for all when compared with values after plating). No significant differences in cortical perfusion were seen between the types of plate. Cortical porosity under the plate was assessed with digital density analysis of microradiographs of this region. No significant difference was seen between the types of plate in this analysis or in biomechanical and disulphine blue perfusion analysis. Thus, no significant advantage was seen for the new plate designs used in this model. This lack of advantage may be a result of the immature animals used in the study, the protocol for blood flow measurement, the invasive periosteal stripping employed to create the fracture, or all three. However, as advantages with the new plate designs have been seen in other studies, this area warrants further investigation.

Analysis of Variance↗

PubMed1996

Late changes in bone mineral density of the proximal tibia following total or partial medial meniscectomy. A randomized study.

The adaptive bone remodeling in the proximal tibia following medial meniscectomy was measured quantitatively by dual photon absorptiometry. Thirty-three patients who had undergone a meniscectomy (randomized to either total [n=19] or partial [n=14] meniscectomy) performed by open joint surgery approximately 12 years earlier were included in the study. Bone mineral density was measured in the previously injured legs and in the healthy contralateral legs in areas located medially and laterally in the cortical bone of the subchondral plates and below in the trabecular bone of the medial and lateral tibial condyles. The distribution of bone mineral within the proximal tibia showed a characteristic and significant pattern. In the trabecular bone of the healthy contralateral knees, bone mineral density was 15% higher in the medial tibial condyles compared with the values laterally; a total or partial meniscectomy increased this difference to 25%. With regard to the cortical bone of the subchondral plates, the bone mineral density in the healthy knees was 24.8-29.4% higher medially than laterally, whereas after total and partial meniscectomy the differences were, respectively, 37.7 and 41.4%. No significant differences in the distribution of bone mineral density, at either cortical or trabecular measuring sites, were found between totally and partially meniscectomized knees.

Absorptiometry, Photon↗

PubMed1996

Spatial distribution of CD44 and hyaluronan in the proximal tibia of the growing rat.

CD44 has been described as a cell surface hyaluronan receptor present on a variety of different cells, and it is generally assumed to be prevalent in most connective tissues that contain hyaluronan. A major aim of this study was to test that presumption by localizing CD44 and hyaluronan within several tissues of the proximal tibia of the growing rat. Comparison of these profiles would reveal whether CD44 and hyaluronan co-localize with high fidelity, as would be expected if CD44 were a major hyaluronan binding protein. Using in situ hybridization and immunohistochemistry, CD44 was identified on osteoclasts, chondroclasts, osteocytes, hematopoietic marrow cells, synovial cells, and connective tissue fibroblasts (ligaments, tendons, and fascia). Although the majority of osteocytes expressed CD44, reduced expression was observed for osteoblasts and ostcoprogenitor cells. Additionally. CD44 was not detected on chondrocytes from epiphyseal and metaphyseal growth cartilages or in meniscal fibrocartilage. Using biotinylated G1 domain from aggrecan and link protein, hyaluronan was observed in the maturational and hypertrophic zones of all growth cartilages, the synovium and other fibroblastic connective tissues, regional areas of the periosteum and endosteum (around osteoblasts, osteoprogenitor cells, and osteoclasts), osteocyte lacunae, and surrounding blood vessels. In regions of co-localization for CD44 and hyaluronan, it seems that CD44 is a likely hyaluronan binding protein in several tissues of the proximal tibia. However, it does not appear to be the predominant hyaluronan binding protein in growing cartilages of the weanling rat.

Aggrecans↗

PubMed1996

Interaction of tobramycin and pH in cultured chick tibiae.

The toxicity of tobramycin at concentrations released from antibiotic-impregnated polymethylmethacrylate beads was determined using cultured embryonic chick tibiae. Because previous results from this laboratory have shown that osteoblast metabolism is inhibited at low pH and because of the potential for a low local pH in infected bone, the antibiotic was tested in medium with pH values from 6.8 to 7.4. Bone metabolism was evaluated by measuring the rates of glycolysis (lactate production), protein synthesis ([3H]proline uptake), and collagen synthesis ([3H]proline hydroxylation). Tobramycin at the concentrations released from the beads (1.0-1.5 mg/ml) contributed to lowering the pH of the medium. At pH 7.4, the antibiotic produced as much as a 30, 39, and 48% decrease in glycolysis, protein synthesis, and collagen synthesis, respectively. Tibiae exposed to tobramycin for 3 days, followed by 2 days without the antibiotic, showed only a partial recovery from its toxic effects. Although tobramycin was relatively less toxic in an acidic environment, the overall metabolic activity of the bones was poorest when the tobramycin concentration was high (2.0 mg/ml) and pH was low (6.8). The results of this study support the following conclusions: (a) tobramycin at high concentrations is toxic to bone, (b) a combination of high tobramycin concentration and low pH in the bone microenvironment may greatly inhibit bone metabolism, and (c) treatment and prevention of osteomyelitis by means of tobramycin-impregnated beads may be augmented by preventing the pH from decreasing in traumatized areas.

Animals↗

PubMed2006

In vivo cyclic axial compression affects bone healing in the mouse tibia.

Abundant evidence exists that fracture healing can be influenced by mechanical loading. However, the specific loading parameters that are osteogenic remain unknown. We hypothesized that the bone healing response in mouse tibial osteotomies would be different with a short delay before loading compared to immediate load application, as well as with higher and lower load magnitudes applied. Eighty 12-week-old mice underwent osteotomy of the left tibia followed by intramedullary nailing. Mice were divided into six groups based on days delayed until application of load (0 days or 4 days) and amplitude of cyclic load (0.5N, 1N, or 2N). Loading regimens were applied at 1 Hz for 100 cycles per day, 5 days per week for 2 weeks, using an external device that applied axial compression to the tibia. Bone healing was assessed by both microcomputed tomography (CT) and four-point bend testing. A short delay followed by cyclic application of a relatively low load led to improved fracture healing, as determined by increased callus strength, but this enhancement disappeared as load amplitudes increased. Load initiation immediately following fracture inhibited healing, regardless of the magnitude of load applied. MicroCT measurements of calluses in the early healing stage did not predict the mechanical strength of the fractures. These findings confirm that controlled, noninvasive cyclic loading can improve the strength of healing callus. However, application of load immediately after fracture appears to be detrimental to healing. Load magnitude also plays a critical role, and must be taken into account in future studies and clinical applications. As the loading parameters necessary to enhance fracture healing become refined, external compression may be used as a potent stimulus for treating fractures with decreased biological capacity.

Animals↗

PubMed2006

Mechanical and radiological assessment of the influence of rhTGFbeta-3 on bone regeneration in a segmental defect in the ovine tibia: pilot study.

Limitations in the use of autologous bone graft, which is the gold standard therapy in bone defect healing, drive the search for alternative treatments. In this study the influence of rhTGFbeta-3 on mechanical and radiological parameters of a healing bone defect in the sheep tibia was assessed. In the sheep, an 18-mm long osteoperiosteal defect in the tibia was treated by rhTGFbeta-3 seeded on a poly(L/DL-lactide) carrier (n = 4). In a second group (n = 4), the defect was treated by the carrier only, in a third group (n = 4) by autologous cancellous bone graft, and in a fourth group (n = 2) the defect remained blank. The healing process of the defect was assessed by weekly in vivo stiffness measurements and radiology as well as by quantitative computed tomographic assessment of bone mineral density (BMD) every 4 weeks. The duration of the experiment was 12 weeks under loading conditions. In the bone graft group, a marginally significant higher increase in stiffness was observed than in the PLA/rhTGFbeta-3 group (p = 0.06) and a significantly higher increase than in the PLA-only group (p = 0.03). The radiographic as well as the computed tomographic evaluation yielded significant differences between the groups (p = 0.03), indicating the bone graft treatment (bone/per area, 83%; BMD, 0.57 g/cm(3)) performing better than the PLA/rhTGFbeta-3 (38%; 0.23 g/cm(3)) and the PLA-only treatment (2.5%; 0.09 g/cm(3)), respectively. Regarding the mechanical and radiological parameters assessed in this study, we conclude that rhTGFbeta-3 has a promoting effect on bone regeneration. However, under the conditions of this study, this effect does not reach the potential of autologous cancellous bone graft transplantation.

Absorbable Implants↗

PubMed2002

Replantation of a crush amputation of distal tibia followed by lengthening with Ilizarov circular external fixator: two-year follow-up.

A 20-year-old male sustained a severe crush injury to his left leg, resulting in amputation of the foot at the level of the distal tibia. Despite 12-h warm ischemia, replantation was attempted after radical debridement, bone shortening, and proximal fasciotomies. The replanted part survived totally. Four months later, a 13-cm shortness of the extremity was managed by 10-cm lengthening with distraction osteogenesis, using Ilizarov's circular external fixator and by means of a special shoe. Two-year follow-up of the patient revealed acceptable functional and sensorial recovery. Success of replantation despite the excessive warm-ischemia time was attributed to the sparse muscle content of the distal tibia and foot. Fasciotomies performed on the proximal segment of the leg ensured the patency of anastomoses by maintaining adequate blood flow distally despite increasing edema after the crush injury. Debridement and bone shortening at the proximal stump eliminated the vein and nerve grafts to bridge the gap. In conclusion, considering the functional outcome of our case, replantation of distal parts of a lower extremity should be attempted first, even if the nature of the injury is unfavorable and the ischemia time is longer than the documented ischemia-tolerance.

Adult↗

PubMed1993

The relationship between the rotation possibilities between femur and tibia and the lengths of the cruciate ligaments.

The system of the anterior (a) and posterior (p) cruciate ligaments and their distances between attachments to the femur (f) and tibia (t), respectively, as found in the knee joint of tetrapods is considered as a crossed four-bar linkage. Starting from a flat or curved tibial articulating surface the shape of the femoral articulating surfaces in principle can be derived (Huson, 1974; Menschik, 1974). The point of intersection (S) of the cruciate ligaments is the instantaneous centre of rotation and describes a curve during knee angulation; the centrode. Two centrodes are distinguished: S1 with the tibia stationary and S2 with the femur stationary. During leg bending the centrodes roll over each other, without sliding. Four series of knee-joint simulations were made. In series A, the femoral bar (distance between cruciate ligaments) was varied, in series B, the anterior cruciate ligament (so the length of a ligament). In series C and D, combinations of bar lengths were varied. The maximum leg rotation range was calculated from the lengths of the bars of the cruciate ligament system for each of the series A ... D. Also the leg rotation range for which the knee joint is mechanically stabilized by the cruciate ligaments was calculated. The stabilization criterium chosen was that a cruciate ligament may not become perpendicular (> 78.5 degrees) to the articulating surfaces. It was found that the cruciate ligaments alone cannot stabilize the knee joint adequately over the whole required range of leg movement. External structures are required to obtain full stabilization. As the femoral and tibial articulating surfaces never lie at the centrodes, considerable sliding occurs between them. It is suggested that a uniformly distributed sliding is essential for lubrication and so for a proper knee-joint functioning.

Animals↗

PubMed1996

Distributed processing on the basis of parallel and antagonistic pathways simulation of the femur-tibia control system in the stick insect.

In inactive stick insects, sensory information from the femoral chordotonal organ (fCO) about position and movement of the femur-tibia joint is transferred via local nonspiking interneurons onto extensor and flexor tibiae motoneurons. Information is processed by the interaction of antagonistic parallel pathways at two levels: (1) at the input side of the nonspiking interneurons and (2) at the input side of the motoneurons. We tested by a combination of physiological experiments and computer simulation whether the known network topology and the properties of its elements are sufficient to explain the generation of the motor output in response to passive joint movements, that is resistance reflexes. In reinvestigating the quantitative characteristics of interneuronal pathways we identified 10 distinct types of nonspiking interneurons. Synaptic inputs from fCO afferents onto these interneurons are direct excitatory and indirect inhibitory. These connections were investigated with respect to position and velocity signals from the fCO. The results were introduced in the network simulation. The motor output of the simulation has the same characteristics as the real system, even when particular types of interneurons were removed in the simulation and the real system.

Animals↗

PubMed1991

[Results of the surgical treatment of chronic hematogenous osteomyelitis of the tibia. A series of 122 cases].

Between 1968 and 1987 the authors treated 122 cases of chronic haematogenous osteomyelitis of the tibia by operation. The procedures used were drilling, sequestrectomy, and saucerisation, with bone resection in 2 cases. Operation was combined with chemotherapy for between 10 and 60 days. Eleven patients, thought to be healed, were lost to follow-up after 4 months. The remainder were reviewed for between 4 and 288 months, 97 for more than one year. After the first operation 102 patients healed completely, while 20 relapsed. Of these, 12 were treated by further operation and 8 by drainage of the abscess. Two patients relapsed twice and another 4 times. When last seen 110 patients were healed, 6 had an intermittent discharge and 6 had a permanent sinus. Special features of chronic osteomyelitis of the tibia are discussed, including destructive lesions of the knee and tibio-tarsal joints, a high incidence of axial deformity, indications for particular surgical approaches, the use of cancellous grafts and arguments against bone resection. The lesions carry a relatively good prognosis.

Adolescent↗

PubMed1992

Osteofibrous dysplasia of the tibia treated by bracing.

Osteofibrous dysplasia of the tibia in children will commonly recur after surgical resection. The use of a leg brace until puberty offers a useful method of conservative management. Seven female patients, age three months to nine years at the time of brace treatment, have been followed for 3.5 to 18 years, an average of nine years, with evidence of satisfactory healing of the lesions in all. Three of the cases had recurred after surgery, two with fibular grafts and one required leg lengthening. The use of a brace to control bowing of the tibia while awaiting spontaneous regression is advised until epiphyseal closure.

Braces↗

PubMed1992

Case report 699. Primary localized skeletal cryptococcosis (torulosis) of the right tibia at its proximal end.

The case of a 58-year-old man with a normal immune status with primary localized skeletal cryptococcosis of the right tibia was presented. Radiologically it appeared as an osteolytic lesion with marginally indistinct borders in the epimetaphyseal region of the proximal tibia. Histologically, necrotizing granulomatous inflammation was associated with a prominent fibrohistiocytic reaction. The presence of cryptococci was confirmed by special stains. Clinicopathological features and the therapeutic aspects of this rare infective bone lesion were discussed. It is uncommon today, particularly in developed countries, to encounter a localized skeletal fungal infection. Therefore, radiologists and pathologists generally may be unfamiliar with the appearance of the lesion and tend not to consider the possibility of fungal osseous disease in the differential diagnosis. Unless it is remembered that fungal infection may cause a localized bone lesion with varied histological responses, the diagnosis may be overlooked, and bacteriologic proof may not be sought.

Bone Diseases↗

PubMed1995

Scanning electron microscopy-electron probe microanalysis study of the interface between apatite and wollastonite-containing glass-ceramic and rabbit tibia under load-bearing conditions after long-term implantation.

Glass-ceramic implants containing oxy- and fluoroapatite [Ca10(PO4)6(O, F2)] and beta-wollastonite (CaSiO3) were studied under load-bearing conditions in a segmental replacement model in the tibia of the rabbit. A 16-mm segment of the middle of the tibial shaft was resected at a point distal to the junction of the tibia and the fibula. The defect was replaced by a 15 mm-long hollow, cylindrical implant that was fixed by intramedullary nailing using Kirschner wire. The implants were 9 mm in diameter and 15 mm long bearing a central hole 3.05 mm in dianeter. The rabbits used were killed 6 months, 1 year, 18 months, and 2 years after implantation. The interface between the bone and the glass-ceramic was investigated by scanning electron microscopy-electron-probe microanalysis (SEM-EPMA). None of the glass-ceramic implants broke, and the glass-ceramic had bonded directly to the bone tissue without any intervening soft tissue. A calcium-phosphorus layer (Ca-P layer) was observed at the glass-ceramic/bone interface. This layer was 30-100 microns thick at 6 months after implantation, 60-110 microns thick at 1 year after implantation, 80-200 microns thick at 18 months, and 120-350 microns thick at 2 years. At the lateral surface of the glass-ceramic uncovered by the bone, the calcium-phosphorus layer was 50-80 microns thick at 6 months after implantation, 250-450 microns thick at 1 year, 300 approximately 400 microns thick at 18 months, and 300 microns thick at 2 years. The thickness of the calcium-phosphorus layer increased moderately after long-term implantation. However, it was difficult to estimate the rate of increase in the thickness of calcium-phosphorus layer.

Animals↗

PubMed1983

Radiology of postnatal skeletal development. VIII. Distal tibia and fibula.

Initially the distal tibial physis is a relatively transverse structure. As the epiphysis matures, undulations develop within the physis and lappet formation occurs peripherally. Within the first two years a significant physeal undulation develops anteriorly above the medial malleolus. This undulation must not be misinterpreted as premature epiphyseodesis following distal tibial fracture. Secondary ossification in the distal tibia begins centrally and initially expands to fill the area over the tibial plafond. At the lateral side of the tibial epiphysis the ossification center may be wedge-shaped. The medial margin adjacent to the medial malleolus is often irregular and may show small peripheral foci of ossification. By seven to eight years, the secondary center extends into the medial malleolus, with complete distal extension often not occurring until adolescence (although usually complete by ten to eleven years). The malleolar tip may exhibit an accessory ossification center. However, this center also may be a traumatic avulsion in the symptomatic patient. Physiologic epiphyseodesis begins over the medial malleolus and subsequently extends laterally. This pattern of closure appears to predispose to fracture of the lateral portion of the distal tibial epiphysis (fracture of Tillaux), as well as to triplane fractures. The articular surface curves onto the lateral side of the distal tibia to form an articulation with the lateral malleolus (distal tibiofibular joint). A similar extension occurs along the medial side of the fibula. These surfaces extend proximally as a recess to the level of the distal tibial physis, at which point the syndesmosis begins. The initially transverse distal fibular physis becomes a convoluted structure, with extensive peripheral lappet formation. Within these regions of physeal overlap there may be small areas of accessory ossification (both medially and laterally) that should not be misinterpreted as fractures. This overlapping also minimizes specific physeal separation and displacement (especially when compared to the incidence of distal tibial physeal injuries). Stress views may be necessary to show such an undisplaced fracture. The fibular physis normally is level with the tibial articular surface or distal extent of the tibial ossification center, especially after the second year of life (however, it may be more proximal in infants). As in the medial malleolus, there may be accessory ossification at the tip of the fibula. While this usually is a normal variant of secondary ossification, occasionally it also may result from trauma. Extensive porosity of the distal fibular metaphysis predisposes to buckling or torus injuries that may have severe, multiangular deformation.

Adolescent↗

PubMed1991

Quantitative comparison of the histological effects of particulate polymethylmethacrylate versus polyethylene in the rabbit tibia.

Fourteen mature female New Zealand White rabbits underwent implantation of Simplex polymethylmethacrylate (PMMA) powder or particulate (average 67 microns) ultrahigh-molecular-weight polyethylene (UHMWPE) through a drill hole in the proximal right tibia. The left tibia functioned as a prepared but nonimplanted control. Animals were killed after 16 weeks. Histological examination of the bone-implant interface in the particulate PMMA group disclosed a florid foreign-body reaction with the presence of giant cells and histiocytes. The particulate UHMWPE group demonstrated positively birefringent UHMWPE fragments, rimmed by foreign-body giant cells and histiocytes, embedded in a loose connective tissue stroma. UHMWPE interfaces were thicker and contained more histiocytes and fibrocytes; PMMA interfaces contained more marrow cells and lymphocytes. This study underscores the importance of biomaterial debris in the process of aseptic loosening of cemented joint arthroplasties.

Animals↗

PubMed1977

To what extent is the tibia-calcaneum angle a reliable measurement of the triceps surae length? Radiological correction of the torque-angle curve (III).

Previous papers gave some methods for the reliable measurement of the tibia-calcaneum angle. It is of common use to evaluate the physical properties of triceps surae on the basis of torque-angle curves. However this method is reliable only if each tibia-calcaneum angle corresponds to a defined distance between the insertions of the muscle in subjects of the same height. Evidence is given by radiological measurements that this correspondance is correct in normal children. However, this is no longer true in certain cerebral palsied children because of abnormal translation of the calcaneum and/or abnormal ratio of bone sizes. In this case the torque-angle curves do not define properly the torque-length curves. A method of correction is given. This correction may be as high as 15 degrees.

Ankle Joint↗

PubMed1979

[Differential diagnosis of a metastasizing adamantinoma of the tibia and fibula (author's transl)].

A case of an adamantinoma of the tibia and fibula is described in a 10-year-old girl who died after 17 years with pulmonary metastasis. For a long time, an exact diagnosis couldn't be made. Histologically the lesion was called chronic osteomyelitis (Brodie's abscess), synovial sarcoma and spindle cell sarcoma. The revision of the histological sections revealed a fibrous dysplasia-like pattern in the first lesion of the tibia with tiny foci of an epitheloid-like pattern. This had could be the key to the right diagnosis, because sometimes adamantinoma of long bones is associated with a fibrous dysplasia-like pattern. The reason for misinterpretation of the histological features is seen in the typical variable histological pattern of this tumor (basaloids, squamoid, spindled and tubular pattern). In this connection is refered to the necessity to correlate the histological feature with the X-ray in making diagnosis in bone pathology.

Adult↗