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Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_22 | Pages 10 - 10
1 Dec 2017
Hotchen AJ Garcia-Pulido P Gojanur A Stohr K
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Aims

This case series aims to describe the clinical consequences of juxta-physeal sub-acute osteomyelitis in children, specifically growth and limb deformity.

Methods

All children diagnosed with osteomyelitis between 2014 and 2016 at a single University Teaching Hospital in the UK were included. Juxta-physeal sub-acute osteomyelitis was identified using magnetic resonance imaging obtained within 48-hours of presentation. These cases were followed up prospectively on a regular basis in the outpatient clinic. Any clinical evidence of limb or growth deformity was evaluated using long-leg standing radiographs.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 278 - 278
1 May 2010
Holstein J Klein M Garcia P Histing T Laschke M Scheuer C Meier C Pohlemann T Menger M
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The immunosuppressive drug rapamycin (RAPA) prevents rejection in organ transplantation by inhibiting interleukin-2-stimulated T-cell division. RAPA has also been suggested to possess strong anti-angiogenic activities linked to a decrease in production of vascular endothelial growth factor (VEGF). Because VEGF is a key growth factor in fracture healing, the present study was conducted to analyze the effect of RAPA on bone repair.

For the herein introduced study 35 SKH-1Hr mice were treated by a daily intraperitoneal (i.p.) injection of RAPA (1.5mg/kg/d) from the day of fracture until sacrifice. Two or five weeks after fracture, animals were killed and bone healing was analyzed using radiological (n=16 at 2 weeks; n=16 at 5 weeks), biomechanical (n=2x8), and histomorphometric (n=2x8)

Methods: At 2 weeks additional animals were studied to achieve tissue for protein biochemical analysis of VEGF and proliferating cell nuclear antigen (PCNA; n=3). Additional 34 mice, which received the vehicle only, served as controls. Analyses in controls were similar to those of RAPA-treated animals.

X-ray analyses demonstrated that RAPA treatment inhibits callus formation after 2 weeks of fracture healing. The radiologically observed lack of callus formation after RAPA treatment was confirmed by histomorphometric analyses, which revealed a significantly diminished callus size and a reduced amount of bone formation when compared to vehicle-treated controls. Biomechanical testing further demonstrated that RAPA significantly reduces torsional stiffness of the callus (11.5±5.9% of the contralateral unfractured femur vs. 28.3±13.9% in controls; p< 0.05). Of interest, this was associated with a decrease of callus VEGF and PCNA expression. After 5 weeks of fracture healing, however, the negative impact of RAPA on fracture healing was found blunted and the radiological, histomorphometric and biomechanical differences observed after 2 weeks could not longer be detected.

We demonstrate that RAPA treatment leads to a severe alteration of early fracture healing. The negative action of RAPA on fracture repair at 2 weeks is most probably due to an inhibition of VEGF expression within the callus as suggested by the results of the Western blot analysis, demonstrating during the early phase of fracture healing a significantly reduced expression of VEGF and PCNA after RAPA treatment. This indicates a substantial alteration of cell proliferation and angiogenic vascularization during initial fracture healing. Since T-cells contribute to delayed fracture healing, RAPA may promote bone healing at later stages due to a reduction of interleukin-2-stimulated Tcell division.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 72 - 73
1 Mar 2010
Holstein JH Schmalenbach J Herrmann M Obeid R Ölkü I Garcia P Histing T Menger MD Pohlemann T Claes L
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Deficiencies of folate and vitamin B6 and B12 as well as increased methionine serum concentrations have been indicated to disturb bone metabolism, most probably due to an induction of hyperhomocysteinemia (HHCY). However, there is a complete lack of information on whether these metabolic changes affect fracture healing.

Therefore, the aim of this study was to analyze the impact of a methionine-enriched (n=13) and a B vitamin-deficient diet (n=14) on bone repair in mice. Controls were fed by the accordant standard diet (n=12 and n=13). Four weeks after stable fixation of a closed femoral fracture, animals were sacrificed to prepare bones for histomorphometric and biomechanical analyses. In addition, blood samples were obtained to evaluate serum concentrations of homocysteine (HCY), folate, and vitamin B12.

Quantitative analysis of blood samples revealed significantly increased serum concentrations of HCY associated with significantly decreased serum concentrations of folate and vitamin B12 in animals fed with the methionine-enriched diet or the B vitamin-deficient diet when compared to controls. Biomechanical evaluation showed no significant differences in bending stiffness between bones of the experimental and those of the control groups. In accordance, the histomorphometric analysis demonstrated a comparable size and tissue composition of the callus in all groups analyzed.

We conclude that a methionine-enriched and a B vitamin-deficient diet leads to HHCY, however, without affecting bone repair in mice.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 70 - 71
1 Mar 2010
Holstein J Fiedler M Becker S Matthys R Garcia P Histing T Menger M Pohlemann T
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During the last decades numerous studies have reported the critical impact of physical activity on bone repair. While most studies have evaluated the tissue response to the local mechanical environment within the fracture gap, there is a lack of information on the systemic role of physical activity during fracture healing. Therefore, the aim of this study was to standardize the mechanical environment in the fracture gap by developing a rotationally and axially stable murine fracture model, and thereby to analyze the systemic influence of physical activity on early bone repair.

After stable fixation of a closed femoral fracture, mice (n=18) were housed in cages supplied with running wheels (running distance > 500m/d). At 2 weeks animals were sacrificed and bones were prepared for histomorphometric (n=7), biomechanical (n=7), and protein biochemical analyses (n=4). Additional mice (n=22), which were housed in standard cages, served as controls.

Histomorphometric evaluation showed no influence of increased physical activity on bone repair in terms of callus size and tissue composition. Accordingly, also biomechanical testing of the callus revealed no differences between both groups in rotational stiffness, peak rotation angle, and load at failure. Western blot analyses demonstrated no alterations in callus expression of proliferating cell nuclear antigen (PCNA) and vascular endothelial growth factor (VEGF) after daily running when compared to controls.

We conclude that increased physical activity under standardized mechanical conditions in the fracture gap does not affect early bone repair in mice.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 152 - 153
1 Mar 2009
Suarez-Suarez M Ferrero-Manzanal F Salas-Bustamante A Alvarez-Rico M deCos-Juez J Garcia-Gonzalez P Meana-Infiesta A Acebal-Cortina G Murcia-Mazon A
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INTRODUCTION: In guided tissue regeneration a membrane is used for defect isolation to protect it against invasion from surrounding tissues and to keep intrinsic healing factors ‘in situ’. This technique has been successfully used in maxillo-facial surgery, but short experience has been reported in long-bone defects, with synthetic membranes and with variable results. In the other hand, calcification and ossification inside the arterial wall have been described.

OBJECTIVE: The aim of the study was to evaluate the use of cryopreserved aorta allografts as membranes for guided tissue regeneration in comparison with expanded poly-tetra-fluoro-ethylene (e-PTFE) synthetic membranes.

MATERIAL & METHODS: Prospective, randomized, blinded study in 15 New-Zeland rabbits. 10 mm mid-diaphyseal defects were created in both radii: 10 defects were covered with a cryopreserved aortic allograft as a tube, 10 with an e-PTFE membrane and 10, with no barrier membrane, served as controls. Animals sacrifice at 6–12–24–30 months. Studies: X-rays, CT, MR, morpho-densitometric analysis, electronic and optical microscopy. Immuno-cytochemistry on tissues and arterial wall cells cultured.

RESULTS: None of the control defects healed. Nine defects covered with an artery completely reconstituted, but only six of those covered with e-PTFE, with a nearly normal cortical-medullar pattern and with progressive increasing in density and thickness of medullar and cortical to values similar to those of the normal bone. Histological studies showed no inflammatory response to the arterial graft, direct union between the artery and the regenerated bone and even mature bone between the elastic laminae of the arterial wall, suggesting superior biocompatibility properties. Immuno-cytochemistry and ultrastructural studies suggest that arterial allografts could act not only as membrane barriers, with additional osteoinductive properties due to trans-differentiation of viable arterial wall cells (endothelial, smooth muscle and/or tissue specific stem cells) towards osteoblastic cells, and also due to ossification secondary to changes in proteins of the arterial extracellular matrix. This could be the application of the process of arterial wall calcification and ossification (usually seen in arteriosclerosis, gender, diabetes or kidney failure) for regeneration of long-bone defects.

CONCLUSION: Cryopreserved aortic allografts can be used as membrane barriers for guided bone regeneration, with superior results to e-PTFE membranes.