Injury
-
Although several systemic and local factors are known to impair fracture healing, there is still no explanation, why some patients with sufficient fracture stability, showing none of the existing risk factors, still fail to heal normally. An investigation of local gene expression patterns in the fracture gap of patients with non-unions could decisively contribute to a better understanding of the pathophysiology of impaired fracture healing. For the first time, this study compares the expression of a large variety of osteogenic and chondrogenic genes in patients with regular and failed fracture healing. ⋯ The differences in gene expression pattern indicate a change in the composition and structure of the extracellular matrix, and a possible turn in the healing programme towards fibrous scar tissue formation, leading to non-union.
-
The incidence of children's forearm fractures is increasing worldwide. This is different from the declining trend observed in the overall injury rate, and the reason for the increase is not known. Diaphyseal forearm fractures comprise 3-6% of all paediatric fractures, and they offer a challenge to their treatment. The purpose of this study was to evaluate the incidence of diaphyseal both-bone forearm fractures in children during the last decade in Northern Finland. Another objective was to study the background factors, treatment, and re-displacement of these fractures. ⋯ There was an accelerating increase in the incidence of paediatric diaphyseal both-bone forearm fractures during the last decade. Trampoline was the most important and still increasing reason for these fractures. The mean age of the patients was increasing. Increasing proportion of diaphyseal both-bone forearm fractures was treated operatively. Re-displacement was unusual amongst operated cases.
-
Whilst the majority of fractures heal normally, it is estimated that ∼10% of fractures exhibit some level of delayed or impaired healing. Although radiography is the primary diagnostic tool to assess the progression of fracture healing, radiographic features only qualitatively correlate with tissue level increases in mineral content and do not quantitatively measure underlying biological processes that are associated with the progression of healing. Specific metaloproteinases have been shown to be essential to processes of both angiogenesis and mineralised cartilage resorption and bone remodelling at different phases of fracture healing. ⋯ Using a standard mid-diaphyseal murine model of femoral fracture, MMP9 and MMP13 proteins and enzymatic activity levels were quantified in the urine of mice across the time-course of fracture healing and compared to the mRNA and protein expression profiles in the calluses. Both urinary MMP9 and MMP13 protein and enzymatic activity levels, assessed by Western blot, zymogram and specific MMP fluorometric substrate assays, corresponded to mRNA expression and immunohistologic assays of the proteins within callus tissues. These studies suggest that urinary levels of MMP9 and MMP13 may have potential as metabolic markers to monitor the progression of fracture healing.
-
Review
Chondrocytes or adult stem cells for cartilage repair: the indisputable role of growth factors.
Articular cartilage is easily injured but difficult to repair and cell therapies are proposed as tools to regenerate the defects in the tissue. Both differentiated chondrocytes and adult mesenchymal stem cells (MSCs) are regarded as cells potentially able to restore a functional cartilage. ⋯ Depending on the cell type chosen to restore cartilage, the effect of growth factors will vary. In this review, the roles of these factors in the maintenance of the chondrocyte phenotype are discussed and compared with those of factors involved in the repair of cartilage defects, using chondrocytes or adult mesenchymal stem cells.