BACKGROUND In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress-shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress-shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the ten...

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disease resulting from inactivating mutations in the gene encoding the protein neurofibromin. NF1 manifests as a heritable susceptibility to tumours of neural tissue mainly located in the skin (neurofibromas) and pigmented skin lesions. Besides these more common clinical manifestations, many NF1 patients (50%) have abnormalities of...

BACKGROUND Delayed union or nonunion are frequent and feared complications in fracture treatment. Animal models of impaired bone healing are rare. Moreover, specific descriptions are limited although understanding of the biological course of pathogenesis of fracture nonunion is essential for therapeutic approaches. METHODS A rat tibial osteotomy model with subsequent intramedullary stabilizat...

FOR any given fracture the normal time to healing will vary according to the breed, age, general health, the bone involved, severity of the fracture (especially comminuted fractures), soft tissue damage and type of fixation. Delayed union can be diagnosed when no or minimal union of the bone is observed in what would be considered a “normal” healing time. “Normal” relates to that of a similar f...

Fracture healing involves the coordinated actions of multiple cytokines. Bone morphogenetic protein 9 (BMP9) is an important factor in bone formation. The present study aimed to investigate the osteogenic potential of bone marrow stem cells (BMSCs) in response to adenoviral (Ad)BMP9, and the early fracture repair properties of AdBMP9 in surgically‑created fractures in osteoporotic rats. Alkalin...

Fracture healing in diabetic individuals and in animal models of diabetes is impaired. To investigate mechanisms by which diabetes may affect fracture healing we focused on the transition from cartilage to bone, a midpoint in the fracture healing process. Femoral fractures were induced in mice rendered diabetic by multiple low dose streptozotocin treatment and compared to matching normoglycemic...

Skeletal regeneration and bone fracture repair involves complex cellular and molecular events that result in new bone formation. Many of the critical steps during bone healing are dependent on the local mechanical environment in the healing tissue. Computational models are used together with mechano-regulation algorithms to predict the influence of mechanical stimuli on the tissue differentiati...

This dissertation investigates bone fracture fixation. In the proposed method, bone fractures are stabilized using multiple bioresorbable metallic or polymer darts/nails that are inserted into bone at high velocity and which are subsequently incorporated/absorbed by the body so that removal is unnecessary. This dissertation will introduce the proposed method in detail and discuss its advantages...

Bone fracture healing is a complicated physiological regenerative process initiated in response to injury and is similar to bone development. To demonstrate whether an exogenous supply of parathyroid hormone-related protein (PTHrP) helps in bone fracture healing, closed mid-diaphyseal femur fractures were created and stabilized with intramedullary pins in eight-week-old wild-type (WT) PTHrP+/+ ...

The morbidity and mortality associated with impaired/delayed fracture healing remain high. Our objective was to identify a small nonpeptidyl molecule with the ability to promote fracture healing and prevent malunions. Prostaglandin E2 (PGE2) causes significant increases in bone mass and bone strength when administered systemically or locally to the skeleton. However, due to side effects, PGE2 i...