Association between pre-operative complications, comorbidities, and in-hospital mortality in a hip fracture cohort: a register study in a tertiary hospital in Brazil.

PURPOSE: The incidence of hip fractures is increasing exponentially due to an aging Brazilian population. Older people had significant comorbidities which increases the risk of post-operative mortality. Our purpose was to examine the association between pre-operative infections and comorbidities on the risk of post-operative in-hospital mortality after proximal femur fracture surgery's, beyond that, to evaluate the association between comorbidities and time to surgery. METHODS: This is a population-based cohort retrospective study, using medical records of all six year consecutive surgical procedures for correction of hip fracture in a tertiary teaching Hospital in Brazil. The exclusion criteria aimed to exclusively allocate patients who had their first hip fracture secondary to low-energy trauma. Multivariate logistical regression was performed and receiver operating characteristic (ROC) curve with area under curve (AUC) to evaluate the sensitivity and specificity of the model. p-value < 0.05 was considered significant. RESULTS: Final sample was composed by 856 consecutive patients with 81 years of median and 164 patients were excluded. The median length of hospital say was five days with - l mortality at 3.6%. Significant variables for increased mortality included the presence of pre-operative infection (odds ratio (OR): 3.9(1.12-8.54), chronic obstructive pulmonary disease (COPD) (OR: 3.83(1.36-10.82)), and systemic arterial hypertension (SAH) (OR: 4.1(1.18-14.25)). Development of pre-operative infection was associated with a delay to surgery (OR: 1.1 (1.08-1.13)). CONCLUSIONS: In older people with proximal femur fracture, the presence of pre-operative infection, COPD and SAH were the strongest risk factor for post-operative in-hospital mortality. Pre-operative infection was associated with statistically significant delay to surgery.

The effects of low-level laser irradiation on bone tissue in diabetic rats.

Diabetes mellitus (DM) leads to a decrease in bone mass and increase the risk of osteoporosis and in this context, many treatments have shown to accelerate bone metabolism. It seems that low-level laser therapy (LLLT) is able of stimulating osteoblast activity and produced increased biomechanical properties. However, its effects on bone in diabetic rats are not fully elucidated. The aim of this study was to evaluate the effects of LLLT on bone formation, immunoexpression of osteogenic factors, biomechanical properties and densitometric parameters in diabetic rats. Thirty male Wistar rats were randomly distributed into three experimental groups: control group, diabetic group, and laser-treated diabetic group. DM was induced by streptozotocin (STZ) and after 1 week laser treatment started. An 830-nm laser was used, performed for 18 sessions, during 6 weeks. At the end of the experiment, animals were euthanized and tibias and femurs were defleshed for analysis. Extensive resorptive areas as a result of osteoclasts activity were noticed in DG when compared to control. Laser-treated animals showed an increased cortical area. The immunohistochemical analysis revealed that LLLT produced an increased RUNX-2 expression compared to other groups. Similar RANK-L immunoexpression was observed for all experimental groups. In addition, laser irradiation produced a statistically increase in fracture force, bone mineral content (BMC) and bone mineral density compared to DG. The results of this study indicate that the STZ model was efficient in inducing DM 1 and producing a decrease in cortical diameter, biomechanical properties and in densitometric variables. In addition, it seems that LLLT stimulated bone metabolism, decreased resorptive areas, increased RUNX-2 expression, cortical area, fracture force, BMD, and BMC. Further studies should be developed to provide additional information concerning the mechanisms of action of laser therapy in diabetic bone in experimental and clinical trials.