Introduction:. Blount's disease can be defined as idiopathic proximal tibial vara. Several etiologies including the mechanical theory have been described. Obesity is the only causative factor proven to be associated with Blount disease. Varus deformity is also a clinical feature of rickets and 31% of children with vitamin D deficiency rickets presented with varus deformities to the local Metabolic Bone clinics. The aim of this study is to assess if there is an association between vitamin D and Blount's disease. We hypothesize that children with Blount disease are more likely to be vitamin D deficient. Method:. This a retrospective study of pre-operative and post-operative patients with Blount's disease who were screened for vitamin D deficiency. Patients with known vitamin D deficiency and rickets were excluded. The study patients had the following blood tests: calcium, phosphate, alkaline phosphatase, parathyroid hormone and 25-hydroxyvitamin D. Body mass index (BMI) was also assessed. Results:. We recruited 50 patients. The mean age of these patients was 10.4 years (SD 3.88) with average BMI of 28.7 (SD 10.2). Fifty two % were overweight. Thirty (60%) patients were diagnosed with infantile, 16(32%) adolescent and 4(8%) juvenile Blount disease. Eight (16%) patients were found to be vitamin D depleted (less than 20 ng/ml). Of these eight patients, six had insufficient 25-hydroxyvitamin D levels (12–20 ng/ml) and while the other two were vitamin D deficient (less than 12 ng/ml). Conclusion:. Vitamin D deficiency is a public health problem worldwide. This study confirms that the prevalence of Vitamin D deficiency in children with Blount's disease is similar to healthy children and infants living in Johannesburg. There is no evidence that Vitamin D deficiency is a factor in causing Blount's disease. Routine screening for Vitamin D deficiency in children with Blount disease is not recommended

Purpose. Up to 70% of the differences in human bone mass have been attributed to genetic background. These differences are associated with alterations in the biomechanical properties, micro-architecture and remodeling of bone as well as its susceptibility to fracture and its capacity for repair. In previous work it was shown that C57Bl6 mice carrying one copy of the parathyroid hormone related protein (PTHrP+/−) gene developed osteopenia by four months of age. The current study was designed to determine if the haploinsufficient phenotype was maintained on a C3H background. Method. PTHrP+/+ and PTHrP+/− mice on C57Bl6 and C3H backgrounds were euthanised between 6 and 18 months of age. The femurs were harvested, fixed in 4% paraformaldehyde overnight and scanned on a Skyscan 1172 equipped with a 10kV X-ray source and a 10 megapixel camera at a resolution 5μm. The amount and quality of cortical and trabecular bone was quantified from 2D images and 3D reconstructions using CTAn, CTvol and CTVox software. The undecalcified specimens were embedded at low temperature in MMA, sectioned at 5 μm and stained with Von Kossa and Toluidine Blue to distinguish mineralized from unmineralized tissue. Results. A novel application of CTAn was developed to automatically and consistently separate cortical from trabecular bone for high throughput, independent quantification. At all ages, PTHrP+/− mice on the C57Bl6 background had less trabecular bone, which was of poorer quality, than their wild type counterparts. In contrast, no difference was seen between PTHrP+/− and PTHrP+/+ mice on the C3H background at any age. No difference in cortical thickness was seen between PTHrP+/− and PTHrP+/+ mice on either background at any age, although the femoral cortices of the C3H mice were consistently thicker than those of the C57Bl6 mice. Conclusion. The osteopenic phenotype of young adult PTHrP+/− mice on a C57Bl6 background is lost when the mutation is bred onto a C3H background. This suggests that some other osteogenic agent can compensate for the lack of PTHrP during bone development in the C3H mice

Aims

Orthopaedic infection is a potentially serious complication of elective and emergency trauma and orthopaedic procedures, with a high associated burden of morbidity and cost. Optimization of vitamin D levels has been postulated to be beneficial in the prevention of orthopaedic infection. This study explores the role of vitamin D in orthopaedic infection through a systematic review of available evidence.