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SUMMARY:The objective of this study was to design custom-made prosthesis in a certain population, the morphometry needs to be measured. The results of this study were expected to provide basic data to design the ideal size of the total knee arthoplasty prosthesis for Indonesian population. This was an anthropometric study conducted on 100 healthy Indonesian population based on Computer Tomographic (CT) imaging on the distal femur resected surface. The parameters being used were Femoral Medio Lateral (fML) length, Femoral Antero Posterior (fAP) length, Femoral Medial Antero Posterior (fMAP) length, Femoral Lateral Antero Posterior (fLAP) length, and Femoral Aspect Ratio (FR). We found that the mean fAP and fML were 54.60±5.71 and 65.98±6.51, respectively. The morphometry of the distal femur were significantly different between male and female (male have larger build), however one of parameters showed different result: fLAP. This study showed that Indonesian people have smaller build compared with their Western counterpart. The proposed dimensions can be used as the basic data to design the ideal size of the custom-made knee arthoplasty prosthesis for Indonesian population.

Over the last few years, fused filament fabrication (FFF) has become one of the most promising and widely used techniques for the rapid prototyping process. A number of studies have also shown the possibility of FFF being used for the fabrication of functional products, such as biomedical implants and automotive components. However, the poor mechanical properties possessed by FFF-processed products are considered one of the major shortcomings of this technique. Over the last decade, many researchers have attempted to improve the mechanical properties of FFF-processed products using several strategies—for instance, by applying the short fiber reinforcement (SFR), continuous fiber reinforcement (CFR), powder addition reinforcement (PAR), vibration-assisted FFF (VA-FFF) methods, as well as annealing. In this paper, the details of all these reinforcement techniques are reviewed. The abilities of each method in improving tensile, flexural, and compressive strength are discussed.

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Purpose The purpose of this study is to investigate the influences of extruder temperatures and raster orientations on the mechanical properties of polylactic-acid (PLA) material processed by using fused filament fabrication (FFF). Design/methodology/approach In this research, the PLA specimens were first printed with nozzle or extruder temperatures of 205°C, 215°C and 225°C and then evaluated in terms of their physical, chemical and mechanical properties. An appropriate extruder temperature was then selected based on this experiment and used for the printing of the other PLA specimens having various raster orientations. A series of tensile tests were carried out again to investigate the influence of raster orientations on the tensile strength, tensile strain and elastic modulus of those FFF-processed PLA materials. In the end, the one-way ANOVA was applied for the statistical analysis and the Mohr’s circle was established to aid in the analysis of the data obtained in this experiment. Findings The result of this study shows that the chemistry, porosity, degree of crystallinity and mechanical properties (tensile strength, strain and elastic modulus) of the PLA material printed with a raster angle of 0° were all insensitive to the increasing extruder temperature from 205°C to 225°C. Meanwhile, the mechanical properties of such printed PLA material were obviously influenced by its raster orientation. In this case, a PLA material with a raster orientation parallel to its loading axis, i.e. those with a raster angle of θ = 0°, was found as the strongest material. Meanwhile, the raster configuration-oriented perpendicular to its loading axis or θ = 90° yielded the weakest PLA material. The results of the tensile tests for the PLA material printed with bidirectional raster orientations, i.e. θ = 0°/90° and 45°/−45° demonstrated their strengths with values falling between those of the materials having unidirectional raster θ = 0° and 90°. Furthermore, the result of the analysis by using a well-known Mohr’s circle confirmed the experimental tensile strengths and the failure mechanisms of the PLA material that had been printed with various raster orientations. Originality/value This study presented consistent results on the chemistry, physical, degree of crystallinity and mechanical properties of the FFF-processed PLA in responding to the increasing extruder temperature from 205°C to 225°C applied during the printing process. Unlike the results of the previous studies, all these properties were also found to be insensitive to the increase of extruder temperature. Also, the result of this research demonstrates the usability of Mohr’s circle in the analysis of stresses working on an FFF-processed PLA material in responding to the changes in raster orientation printed in this material.

Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.

Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material.In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been 2 printed with various extruder temperatures, i.e., 190 -230 C, and raster angles, i.e., 0 -90. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr's circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 C and raster angle of 0 could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.

SUMMARY:To design custom-made prosthesis in a certain population, the morphometry needs to be measured. The results of this study were expected to provide basic data to design the ideal size of the total hip arthoplasty prosthesis for Indonesian population. This was an anthropometric study conducted on sex matched 100 healthy Indonesian mongoloid race subjects based on Computer Tomographic (CT) imaging on the proximal femur. The parameters being used in this study were Femoral Head Offset (FHO), Femoral Head Position (FHP), Femoral Head Diameter (FHD), Neck-Shaft Angle (NSA), Anteroposterior Width (APW) and Mediolateral Width at 3 different locations, and Canal Flare Index (CFI). This study showed that Indonesian has smaller proximal femur morphometry as compared to Western population. The mean value of all parameters in male were larger than female. Moreover, FHO and FHP showed significant difference among male and female indicating the location of male femoral head center lies superiorly as compared to female. The dimension of femoral canal was found to be mediolaterally oval, 1.43, 1.28, and 1,34, respectively, in 3 different cutting (20 mm above and 40 mm below lesser trochanter, and isthmus). CFI of Indonesian was classified to be stovepipe femoral canal (2.99) that is the suggestion to use cemented femoral stem. This study showed that Indonesian proximal femur dimension has smaller build compared with Western counterpart. The proposed dimensions can be used as the basic data to design the ideal size of the femoral stem for Indonesian population.