Bone matrix, cellularity, and structural changes in a rat model with high-turnover osteoporosis induced by combined ovariectomy and a multiple-deficient diet.

In estrogen-deficient, postmenopausal women, vitamin D and calcium deficiency increase osteoporotic fracture risk. Therefore, a new rat model of combined ovariectomy and multiple-deficient diet was established to mimic human postmenopausal osteoporotic conditions under nutrient deficiency. Sprague-Dawley rats were untreated (control), laparatomized (sham), or ovariectomized and received a deficient diet (OVX-Diet).

Differences of bone healing in metaphyseal defect fractures between osteoporotic and physiological bone in rats.

Discrepancies in bone healing between osteoporotic and non-osteoporotic bone remain uncertain. The focus of the current work is to evaluate potential healing discrepancies in a metaphyseal defect model in rat femora. Female Sprague-Dawley rats were either ovariectomized (OVX, n=14) and combined with a calcium-, phosphorus- and vitamin D3-, soy- and phytoestrogen-free diet or received SHAM operation with standard diet rat (SHAM, n=14).

Allogenous bone with collagen for repair of deep osteochondral defects.

Background: A scaffold for treatment of deep osteochondral defects should be stable, integrate well, and provide a surface for chondrocytes. To meet these demands, a biphasic scaffold of allogenous sterilized bone with a collagen surface was developed. Integration was tested in the sheep model.

Implications of combined ovariectomy/multi-deficiency diet on rat bone with age-related variation in bone parameters and bone loss at multiple skeletal sites by DEXA.

Background: Osteoporosis is a multi-factorial, chronic, skeletal disease highly prevalent in post-menopausal women and is influenced by hormonal and dietary factors. Because animal models are imperative for disease diagnostics, the present study establishes and evaluates enhanced osteoporosis obtained through combined ovariectomy and deficient diet by DEXA (dual-energy X-ray absorptiometry) for a prolonged time period.

Material/methods: Sprague-Dawley rats were randomly divided into sham (laparotomized) and OVX-diet (ovariectomized and fed with deficient diet) groups.

Biphasic scaffolds for repair of deep osteochondral defects in a sheep model.

Background: To oppose the disadvantages of autologous osteochondral transplantation in the treatment of deep osteochondral defects such as donor site morbidity, size limitation, and insufficient chondral integration, we developed two biphasic scaffolds of either hydroxylapatite/collagen (scaffold A) or allogenous sterilized bone/collagen (scaffold B) and tested their integration in a sheep model.

Methods: We collected chondral biopsies from 12 sheep for the isolation of chondroblasts and cultured them for 4 wk. We created defects at the femoral condyle and implanted either scaffold A or B with chondrocytes or cell free.

The changing landscape of therapeutic strategies for recurrent ovarian cancer.

Advanced epithelial ovarian cancer, cancer of the fallopian tube and primary peritoneal cancer have a poor prognosis and a high rate of disease recurrence following primary therapy. Recurrent ovarian cancer is currently classified according to sensitivity to platinum-based chemotherapy. Data on targeted therapy provide evidence of improvement with systemic treatment in addition to chemotherapy.

A new animal model for implant-related infected non-unions after intramedullary fixation of the tibia in rats with fluorescent in situ hybridization of bacteria in bone infection.

There is no adequate animal model to mimic the difficult clinical situation of infected non-union of the tibia after intramedullary stabilization. The purpose was to establish an animal model of implant-related infected non-unions of the tibia in rats. Furthermore, it was evaluated if detection of bacteria by fluorescent in situ hybridisation (FISH) technique is possible in bone infection.

Effects of gentamicin and gentamicin-RGD coatings on bone ingrowth and biocompatibility of cementless joint prostheses: an experimental study in rabbits.

Antimicrobial coatings are of interest as a means to improve infection prophylaxis in cementless joint arthroplasty. However, those coatings must not interfere with the essential bony integration of the implants. Gentamicin-hydroxyapatite (gentamicin-HA) and gentamicin-RGD (arginine-glycine-aspartate)-HA coatings have recently been shown to significantly reduce infection rates in a rabbit infection prophylaxis model.

Bond strength of an alkylene bis(dilactoyl)-methacrylate bone adhesive: a biomechanical evaluation in sheep.

The purpose of this study is to assess the mechanical efficacy of an alkylene bis(dilactoyl)-methacrylate-based degradable bone adhesive in 36 sheep. Bone segmentation with osteotomies of the metaphyseal ulna was performed and adhesive was applied into the osteotomy gaps in 18 sheep. The remaining 18 animals served as controls.

Enhancement of bone formation in hydroxyapatite implants by rhBMP-2 coating.

The combination of hydroxyapatite (HA) implants serving as osteoconductive scaffold with growth factors is an interesting approach for the improvement of bone defect healing. The purpose of this study was to test whether recombinant human bone morphogenetic protein-2 (rhBMP-2) coating of solid HA-implants improves bone formation in a cortical bone defect. Cylindrical trephine mill defects (diameter: 9.

Development of a bioresorbable self-hardening bone adhesive based on a composite consisting of polylactide methacrylates and beta-tricalcium phosphate.

In this work, a novel bioresorbable bone adhesive based on radically polymerizable polylactide with methacrylate endgroups known from polymethylmethacrylate (PMMA) cements and varying amounts of bioresorbable/biodegradable lactide moieties was developed. The swelling and degradation properties as well as the hardening time, viscosity, and adhesion properties (tension and shear resistance) were subsequently measured in vitro and optimized. For a broad use in surgery the handling properties, the shelf life and the storage temperature are important issues.

Diagnosis of osteoporosis with vitamin k as a new biochemical marker.

Osteoporosis is a metabolic bone disease characterized by reduced bone quality and quantity. As a consequence, patients are at risk for fractures, subsequent immobility, and higher mortality especially among elder patients. Because of the high incidence of complications and the associated financial burden for the health system, new parameters for diagnostic and therapeutic purposes are urgently needed.