Tendons are critical to mobility, and are susceptible to degeneration through injury and ageing. Type I collagen is the most abundant protein in vertebrates; it is the main structural protein of the extracellular matrix in numerous musculoskeletal tissues, including tendons. Type I collagen predominantly is a heterotrimer, which consists of two alpha-1 chains and one alpha-2 chain (α1)2(α2) encoded by the COL1A1 and COL1A2 genes, respectively. However, type I collagen can form homotrimers (α1)3 which are protease-resistant, and are associated with age-related musculoskeletal diseases, fibrotic and connective tissue pathologies. Transforming growth factor beta (TGFβ) enhances collagen (I) gene expression, is involved in tendon mechanobiology and repair processes, while its effect on homotrimer formation is unknown. Our aim is to investigate the relative expressions of collagen (I) α1 and α2 polypeptide chains in tenocytes (tendon fibroblasts) stimulated with TGFβ. Included RT-qPCR to measure the relative expression of COL1A1 and COL1A2 genes. [14C]-proline metabolic labelling was used to measure the expression of the collagen (I) α1 and α2 polypeptide chains. These techniques were performed in equine superficial digital flexor tendon (SDFT) tenocytes (n=3) and murine tail tendon tenocytes (n=3) with different concentrations of TGFβ (0.01 ng/ml-100 ng/ml).Introduction
Materials and Methods
All children with a fracture of both bones of the forearm who underwent general anaesthetic manipulation and plaster (GAMP) at the Launceston General Hospital over a four-year period from 2005–2008 were reviewed. Casting technique was determined according to the treating surgeon, with three casting techniques used: flexion, extension and a mid-flexed position. The primary end-point was defined as re-manipulation or progression to open reduction and internal fixation. The secondary end-point of residual angulation was also assessed. A total of 123 patients with 124 fractures were treated with GAMP. Seventy-seven cases were treated in a traditional flexion cast, 28 in extension and 19 were treated in a dorsoradial slab in a mid-flexed position. Ten patients required repeat intervention. Six failures were initially cast in flexion, four were in the mid flexed position and none of the fractures in the extension group required re-manipulation. The difference between the groups was statistically significant (p<0.001). There was significantly greater residual angulation at follow up in the flexed group compared to the extension group for both the radius (p=0.049) and the ulna (p=0.046) Closed reduction and cast immobilisation with the elbow extended is a safe and more effective technique in maintaining position in both bone forearm fractures in children.
