The Number and Determinants of Nutrient foramina among dry human femur bones from the East African population: A Cross-section study

Background: Nutrient foramina form important landmarks on the femur and other bones as the portal of entry for nutrient arteries. Nutrient arteries are important sources of blood supply for growing bones; and their variations may be due to congenital or acquired causes. These variations are important in anatomical comparisons, orthopaedic surgical practice and forensic medicine. Aims: This study aimed at establishing the number and determinants of the nutrient foramina among dry human femur bones from the East African population. Materials and methods: This was a cross-section study of 333 dry femur bones from the East African population, at the Galloway osteological collection of Makerere University college of health sciences. The number of nutrient foramina on the shaft of each femur, the corresponding demographic, clinical and morphometric characteristics were documented. Data were entered in an Excel sheet and exported to STATA 14 for analysis. Univariate, bivariate and multivariable analyses were performed to obtain the summary statistics and the measures of association. At all levels of analysis, a p-value of less than 0.05 was considered statistically significant. Results: Of the 333 femurs, 291 (87.4%) were from males; and 137(50.15%) were right femurs. The age ranged from 20 to 75 years with a mean age of 35 (SD± 12) years. Nutrient foramina ranged from one to four; mean of 1.4 (SD±0.5) and median of 1 (IQR: 1 to 2). Of the 333 femurs, 199 (59.8%) had one foramen, 129 (38.7%) had two foramina, four femurs had three foramina and one femur had four foramina. There was a statistically significant association between the number of nutrient foramina and the femur’s: mid-shaft circumference (p=0.014; 95%CI: 0.003 to 0.028), nationality (p=0.016; 95%CI: -0.284 to -0.030) and sex (p=0.012; 96%CI: -0.405 to -0.050). Conclusion: Nutrient foramina among femurs from the East African population range from one to four per femur, with predominantly one foramen. The key determinants of the number of foramina are: mean mid-shaft circumference, nationality and sex. These findings are significant in anatomical comparisons; forensic and orthopaedic practices. KEY WORDS: Nutrient foramina, dry human femur, East African population, morphometric characteristics.

Nonlinear Mathematical Modelling of Bone Damage and Remodelling Behaviour in Human Femur

The simulation of bone remodelling is highly complex due to the high nonlinear coupled relations between the damage and repair behaviours. In this paper, a new bone remodelling model based on the fatigue damage mechanism is proposed. Then the repair process of the human femur is simulated based on the finite element method. The results show that the new damage model can well simulate the bone damage evolution caused by overloadings. This indicates that the new mathematical model suggested in this paper can simulate the effect of external load on the cortical bone density and the related mechanical properties of the cortical bone.

Development of new metal structure for osteosynthesis of femoral fractures

We presented the results of analysis of characteristics of osteosynthesis of femur model with improved metal structure. We carried out the analysis of the literature and a patent search on the subject of the study, created a layout of this design, a prototype and tested strength characteristics using a breaking machine. We carried out the work on a bovine femur preparation, performed taking into account the maximum correspondence of the studied human femur segment. We carried out load samples for fabricated steel structures, as well as for prototypes of this design in the form of samples for shear, angular displacement and rupture, while for each sample, performed 2 versions of the location of the steel structure relative to the fracture – perpendicular to the fracture line (angle 90º), as well as with a deviation in the range of 30º (75º–105º). We detected a statistically significant increase in the load values for the new advanced steel structure at a right angle of 41 % and a variation of 56 % during the analysis of the sample for rupture. Thus, when comparing the values of the load samples of the prototype and the manufactured metal structure, we revealed an increase in the indicators of the burst sample for the new metal structure which indicates the justification of its use in clinical practice.