[Evaluation of the Japanese version of HLS-Q12 in older adults].

Objectives　The purpose of this study was to evaluate the internal consistency and factorial validity of the Japanese version of HLS-Q12 health literacy rating scale when used with older adults.Methods　A questionnaire-based mail survey was conducted among older adults living in a community. The data collection period was from January to February 2022. The Japanese version of HLS-Q12 was used to obtain data on health literacy of older adults, and the internal consistency and factorial validity of the scale were evaluated using Cronbach's alpha coefficient and confirmatory factor analysis, respectively. In addition, a Rasch model was used to conduct a detailed analysis on each questionnaire item.Results　Questionnaires were distributed among 3,572 people, out of which, 1,082 responses were received from older adults (over 65 years of age). Cronbach's alpha coefficient was 0.8 or higher, indicating no internal consistency issues. According to the confirmatory factor analysis, CFI was equal to 0.933, AGFI, 0.876, and RMSEA, 0.092; thus, all indicators met certain evaluation levels. However, deviation from one of the multiple fit criteria was confirmed for the value of RMSEA, indicating that the error between the estimated value calculated by the scale and the true value was relatively large. Analysis of each question item using the Rasch model showed that all the questions met the criteria of Infit MSQ and were suitable in their question structure.Conclusion　Following the evaluation of the HLS-Q12 scale in older adults, the scale was found to be reliable and valid at a certain level. However, the value of RMSEA indicated that it was relatively large in terms of the error between the estimated value calculated by the scale and the true value.

[Development of the Family Empowerment Scale for Parents with Toddlers].

Objectives　This study aimed to develop the Family Empowerment Scale for Parents with Toddlers (FES-P) and to examine its validity and reliability.Methods　A draft version of the scale was prepared based on a literature review and interviews with experts. Next, we conducted a web-based structured questionnaire survey of 800 parents (400 men and 400 women) with children aged 1 to 3 years, across Japan, and then verified the validity and reliability of the FES-P. The repeatability and stability by the retest method were examined as well.Results　We analyzed the data of the 825 individuals (412 men and 413 women) who answered the survey. Exploratory and confirmatory factor analyses revealed that the optimum solution that can interpret each factor could be obtained with five sub-factors and 26 question items. We confirmed that the five sub-factors were "relationships within the family," "sense of efficacy with regard to parenting," "relationships with the community," "sense of achievement as a parent," and "recognition and combined use of services." Good-fit values were obtained, with GFI=.878, AGFI=.852, CFI=.943, and RMSEA=.044, and construct validity was confirmed. The Cronbach's alpha coefficient was .96 for the entire scale and .85 to .92 for the sub-factors; the scale was deemed to have sufficient internal consistency. Further, the total score of the FES-P was positively correlated with the Family APGER score (r=.562, P<.001), scale measuring feelings about parenting (r=.620, P<.001), and generalized self-efficacy scale (r=.318, P<.001). For test-retest reliability, the intra-class correlation coefficient was r=.876 for the entire scale and r=.794 to .876 for the sub-factors, indicating stability and reproducibility.Conclusion　This study developed the FES-P, consisting of five sub-factors and 26 items and showing good validity and reliability. The five sub-factors were cross-correlated constructs. "Sense of efficacy with regard to parenting" and "sense of achievement as a parent" consisted of items related to individual empowerment, "relationships within the family" and "relationships with the community" consisted of items related to relationships with others, and "recognition and combined use of services" consisted of items related to social resources.

Prediction of the pathological fracture risk during stance and fall-loading configurations for metastases in the proximal femur, using a computed tomography-based finite element method.

BACKGROUND: It is important to assess the fracture risk associated with metastasis in the proximal femur. The study aimed to clarify the effect of tumor location on the risk of pathological fracture of the proximal femur and investigate the fracture risk not only in the stance-loading configuration (SC), but also in the fall-loading configuration (FC) using a computed tomography (CT)-based finite element (FE) method based on a simulated metastatic model. METHODS: The axial CT scans of the proximal femora of non-osteoporotic healthy men (n = 4; age range, 42-48 years) and osteoporotic post-menopausal women (n = 4; age range, 69-78 years) were obtained with a calibration phantom, from which the three-dimensional FE models were constructed. A single 15-mm-diameter spherical void simulating a tumor was created at various locations from the neck to subtrochanteric level. Nonlinear FE analyses were performed. RESULTS: The mean predicted fracture loads without spherical voids in the SC were 7700 N in men and 4370 N in women. With the void at the medial femoral neck and in the region anteromedial to lesser trochanter, the mean predicted fracture load significantly reduced to 51.3% and 59.4% in men and 34.1% and 64.5% in women, respectively. The mean predicted fracture loads without a spherical void in the FC were 2500 N in men and 1862 N in women. With the void at the medial and posterior femoral neck, the predicted fracture load was significantly reduced to 65.7% and 79.7% in men and 48.3% and 65.4% in women, respectively. CONCLUSIONS: These results showed that the risk of pathologic fracture was quite high in both the SC and FC when the lytic lesion existed along the principal compressive trabecular trajectory or posterior neck. Prophylactic intervention should be considered for metastases at these locations.

Prediction of proximal femur strength by a quantitative computed tomography-based finite element method--Creation of predicted strength data of the proximal femur according to age range in a normal population.

OBJECTIVE: The objective of this study was to investigate the factors that affect the predicted bone strength of proximal femur in Japanese population. METHODS: Participants (552 men and 273 women) in a health checkup program with computed tomography (CT) at the University of Tokyo Hospital were enrolled in this study. Three-dimensional finite element models of the proximal femur were constructed from CT data of the participants with simultaneous scans of a calibration phantom containing hydroxyapatite rods. Multiple regression analysis was performed to analyze the relationship between the predicted bone strength and clinical factors. RESULTS: Average predicted strength of proximal femur was lower in women than in men in all age ranges. Predicted bone strength in women under both stance and fall configurations significantly decreased with age, and that in men had the tendency to decrease with age. Body weight positively affected the predicted bone strength in both men and women. CONCLUSIONS: This is the first cross-sectional analysis of the predicted bone strength of the proximal femur in Japanese population of wide age range. Age and body weight critically affected bone strength of proximal femur determined by quantitative CT-based finite element method, in particular in women, under both stance and fall configurations.

Effect of low-intensity pulsed ultrasound stimulation on gap healing in a rabbit osteotomy model evaluated by quantitative micro-computed tomography-based cross-sectional moment of inertia.

BACKGROUND: It has been previously demonstrated that low-intensity pulsed ultrasound stimulation (LIPUS) enhances formation of the medullary canal and cortex in a gap-healing model of the tibia in rabbits, shortens the time required for remodeling, and enhances mineralization of the callus. In the current study, the mechanical integrity of these models was confirmed. In order to do this, the cross-sectional moment of inertia (CSMI) obtained from quantitative micro-computed tomography scans was calculated, and a comparison was made with a four-point bending test. METHODS: This parameter can be analyzed in any direction, and three directions were selected in order to adopt an XYZ coordinate (X and Y for bending; Z for torsion). RESULTS: The present results demonstrated that LIPUS improved earlier restoration of bending stiffness at the healing site. In addition, LIPUS was effective not only in the ultrasound-irradiated plane, but also in the other two planes. CONCLUSIONS: CSMI may provide the structural as well as compositional determinants to assess fracture healing and would be very useful to replace the mechanical testing.

[Prediction of bone strength using a quantitative computed tomography based finite element method].

Clinically available methods for estimating bone strength include bone densitometry techniques such as dual energy X-ray absorptiometry and quantitative computed tomography, and other diagnostic imaging procedures such as radiographic imaging. These techniques evaluate regional bone density and morphology, which are partly related to fracture risk, but are of limited value for quantifying structural strength. Therefore, it is necessary to develop a noninvasive method for accurate quantitative structural analysis that incorporates information on both morphology and bone density in a three-dimensional distribution. Computed tomography-based finite element method (CT/FEM), which incorporates information on both the three-dimensional architecture and bone density distribution, could possibly achieve precise assessment of the strength of the bone. We focused on a CT/FEM to quantify structural strength, developing a nonlinear CT/FEM to achieve accurate assessment of strength in the proximal femur and lumbar vertebrae. Here, we describe the CT/FEM.

Comparison of ultrasound speed in articular cartilage measured by different time-of-flight methods.

The purpose of this study was to investigate whether different time-of-flight (TOF) methods including amplitude-related methods, which determine tissue borders from the reflected wave itself, and the cross-correlation method, which requires reference signals to determine borders, influence speed of sound (SOS) values for articular cartilage. Left femoral condyle samples from a 6-month-old pig and a 3-year-old pig were used. Radiofrequency signals from the cartilage surface and cartilage-bone interface were acquired using the ultrasound transducer for nine points in each sample. TOF was calculated by three amplitude-related methods (peak amplitude, peak envelope, signal phase) and a cross-correlation method. Cartilage thickness was measured microscopically, and SOS was calculated at each point. Mean (± standard deviation) SOSs in cartilage from the 9-point measurement by the four TOF methods were 1488 ± 51, 1488 ± 48, 1487 ± 54, and 1466 ± 51 m/s (for peak amplitude, peak envelope, signal phase, and cross-correlation methods, respectively) for the 6-month-old pig, and 1709 ± 107, 1717 ± 104, 1713 ± 105, and 1695 ± 138 m/s, respectively, for the 3-year-old pig. Paired t testing identified no significant differences between the amplitude-related methods and the cross-correlation method, although SOS values yielded by the amplitude-related methods tended to be higher than those from the cross-correlation method. These results suggest that amplitude-related methods of TOF measurement and the cross-correlation method are equivalently applicable to articular cartilage SOS measurement when a wave is clearly reflected from cartilage. TOF methods should thus be considered in studies on SOS measurement.

Measurement of mechanical properties on gap healing in a rabbit osteotomy model until the remodeling stage.

BACKGROUND: The most important issue in the assessment of fracture healing is to acquire information about the restoration of the mechanical integrity of bone. Many researchers have attempted to monitor stiffness either directly or indirectly for the purpose of assessing strength, as strength has been impossible to assess directly in clinical practice. The purpose of this study was thus to determine the relationship between bending stiffness and strength using mechanical testing at different times during the healing process. METHODS: Unilateral, transverse, mid-tibial osteotomies with a 2-mm gap were performed in 28 rabbits. The osteotomy site was stabilized using a double-bar external fixator. The animals were divided into four groups (n=7/group/time point; 4, 6, 8 and 12 weeks). A series of images from micro-computed tomography of the gap was evaluated to detect the stage of fracture healing and a 4-point bending test was performed to measure stiffness and strength. Relative stiffness and strength values were also acquired from calculation of ratios relative to those of the non-osteotomized contralateral bones. FINDINGS: Formation of cortex and medullary canal at the gap was seen in the 12-week group and would represent the remodeling stage. In addition, the relationship between stiffness and strength remained almost linear until at least 12 weeks. However, stiffness recovered much more rapidly than strength. INTERPRETATION: Strength was not fully restored until the later stages of fracture healing. However, the current study demonstrated that stiffness could be monitored as a surrogate marker of strength until at least the remodeling stage.

Measurement of articular cartilage thickness using a three-dimensional image reconstructed from B-mode ultrasonography mechanical scans feasibility study by comparison with MRI-derived data.

The present study aimed to develop a method to measure three-dimensional (3-D) thickness of cartilage (Tc) at the femoral condyle using B-mode ultrasonography (US) and to clarify the feasibility of US in clinical evaluations of articular cartilage by comparing the results with 3-D measurement values using magnetic resonance imaging (MRI) and assessing repeatability. The medial surface of the right knees of two healthy male volunteers (age, 37 and 59 years) and the knees on affected side of three male patients with osteoarthritis (OA) (age, 73, 81 and 83 years) were scanned using B-mode US with the knee flexed at 120°. The range of the angle of probe rotation for the arm was 0-80° and B-mode images (total, 101 images) were acquired every 0.8°. MRI of the knees was also performed using the double echo steady-state sequence. Both US and MRI images were used to create 3-D models of medial femoral condyle articular cartilage. Tc was determined at points 1 mm apart from one another in the US model (Tc-US) and MRI model (Tc-MRI). Tc-US was compared with Tc-MRI and the repeatability of Tc-US was assessed by mean Tc in the specific region of interest of the femoral condyle. Tc-US correlated significantly with Tc-MRI both in volunteers and in OA patients (p < 0.0001 each) and coefficients of correlation were 0.976 and 0.964 for volunteers and OA patients, respectively. The coefficient of variance for mean Tc-US was 4.90%. Our results show that 3-D US measurements of femoral cartilage are reproducible and correlate strongly with MRI measurements.

Evaluation of the accuracy of articular cartilage thickness measurement by B-mode ultrasonography with conventional imaging and real-time spatial compound ultrasonography imaging.

The present study aimed to quantify the thickness of articular cartilage (Tc) in vitro using both conventional and real-time spatial compound B-mode ultrasonography (US) with a clinically used transducer and to evaluate the accuracy of measurement by comparing the results with values obtained microscopically. Femoral condyle samples were obtained from a 6-month-old pig and a 3-year-old pig. B-mode US images with conventional imaging and real-time spatial compound imaging (RTSCI) of osteochondral blocks were acquired. Tc determined using US (Tc-US) was measured from line data parallel to US beam direction acquired from B-mode images with an objective method for determining cartilage surface and bone-cartilage interfaces at the peak brightness values. Tc was also determined under microscopy (Tc-optical) using the corresponding points from US measurement. Tc-US was compared with Tc-optical to assess accuracy. Tc-US correlated significantly with Tc in both conventional imaging and RTSCI (r = 0.961, 0.976, respectively). Bland-Altman plots showed mean differences between Tc-optical and Tc-US were -0.0073 mm and 0.0139 mm with standard deviations of 0.171 mm and 0.131 mm for conventional imaging and RTSCI, respectively. Our results show that Tc-US measurement using B-mode US allows accurate measurement of Tc. Considering correlation coefficients between Tc-US and Tc-optical, RTSCI US may offer higher accuracy for measuring Tc than conventional methods when an objective tissue border determination algorithm is used, even though both showed good accuracy in our study.

Prediction of proximal femur strength using a CT-based nonlinear finite element method: differences in predicted fracture load and site with changing load and boundary conditions.

The annual occurrence of hip fracture due to osteoporosis as of 2002 had reached 120,000 in Japan. The increase has been very rapid. From a biomechanical perspective, hip fractures are thought to be caused in real settings by different directions of loading. Thus, clarification of the loading directions under which the proximal femur is most vulnerable to fracture would be helpful for elucidating fracture mechanics and establishing preventive interventions. The purpose of the current study was to clarify the influence of loading direction on strength and fracture site of the proximal femur using the CT-based nonlinear FE method to determine loading directions under which the proximal femur is most vulnerable to fracture. Contralateral femora were analyzed in 42 women with hip fracture (mean age, 82.4 years), comprising 20 neck fractures and 22 trochanteric fractures. Within 1 week after fracture, quantitative CT of the contralateral femur was performed in each patient and 3-dimensional FE models were created. One stance loading configuration (SC) and four different fall loading configurations (FC) were assigned. Nonlinear FE analysis was performed. Differences in fracture loads depending on differences in loading direction were analyzed and correlations among fracture loads in different loading directions were assessed. Next, fracture sites were also analyzed. Mean predicted fracture load in the SC was 3150 N. Mean fracture loads were 2270 N in FC1, 1060 N in FC2, 980 N in FC3, and 710 N in FC4. The correlation between predicted fracture loads in SC and those in each FC was significant with a correlation coefficient of 0.467-0.631. Predicted fracture sites in the SC appeared at the subcapital region in all patients and were categorized as neck fracture. However, trochanteric fractures occurred in all fall configurations except FC1. In FC1, a significant correlation was seen between real fracture type and predicted type. The current investigation could contribute to the acquisition of useful knowledge allowing the establishment of more efficacious means of preventing hip fractures.