Repeatability of a Multi-segment Foot Model with a 15-Marker Set in Normal Children

Background

The use of three-dimensional multi-segment foot models (3D MFMs) is increasing since they have superior ability to illustrate the effect of foot and ankle pathologies on intersegmental motion of the foot compared to single-segment foot model gait analysis. However, validation of the repeatability of the 3D MFMs is important for their clinical use. Although many MFMs have been validated in normal adults, research on MFM repeatability in children is lacking. The purpose of this study is to validate the intrasession, intersession, and interrater repeatability of an MFM with a 15-marker set (DuPont foot model) in healthy children.

Methods

The study included 20 feet of 20 healthy children (10 boys and 10 girls). We divided the participants into two groups of 10 each. One group was tested by the same operator in each test (intersession analysis), while the other group was tested by a different operator in each test (interrater analysis). The multiple correlation coefficient (CMC) and intraclass correlation coefficient (ICC) were calculated to assess repeatability. The difference between the two sessions of each group was assessed at each time point of gait cycle.

Results

The intrasession CMC and ICC values of all parameters showed excellent or very good repeatability. The intersession CMC of many parameters showed good or better repeatability. Interrater CMC and ICC values were generally lower for all parameters than intrasession and intersession. The mean gaps of all parameters were generally similar to those of the previous study.

Conclusions

We demonstrated that 3D MFM using a 15-marker set had high intrasession, intersession, and interrater repeatability in the assessment of foot motion in healthy children but recommend some caution in interpreting the hindfoot parameters.

A Compressed-Sensing Based Blind Deconvolution Method for Image Deblurring in Dental Cone-Beam Computed Tomography

In cone-beam computed tomography (CBCT), reconstructed images are inherently degraded, restricting its image performance, due mainly to imperfections in the imaging process resulting from detector resolution, noise, X-ray tube's focal spot, and reconstruction procedure as well. Thus, the recovery of CBCT images from their degraded version is essential for improving image quality. In this study, we investigated a compressed-sensing (CS)-based blind deconvolution method to solve the blurring problem in CBCT where both the image to be recovered and the blur kernel (or point-spread function) of the imaging system are simultaneously recursively identified. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate the feasibility of using the algorithm for image deblurring in dental CBCT. In the experiment, we used a commercially available dental CBCT system that consisted of an X-ray tube, which was operated at 90 kV_p and 5 mA, and a CMOS flat-panel detector with a 200-μm pixel size. The image characteristics were quantitatively investigated in terms of the image intensity, the root-mean-square error, the contrast-to-noise ratio, and the noise power spectrum. The results indicate that our proposed method effectively reduced the image blur in dental CBCT, excluding repetitious measurement of the system's blur kernel.

Clinical significance and morphological analysis of the os subfibulare using radiologic assessment in patients with chronic lateral ankle instability

Category:

Ankle

Introduction/Purpose:

Although os subfibulare has been associated to various clinical problems in patients with chronic lateral ankle instability (CLAI), there are a few studies on the analysis of morphological characteristics of os subfibulare. The purpose of this study is to analyze morphologic characteristics of the os subfibulare and to evaluate the clinical significance of the os subfibulare in patients with CLAI.

Methods:

Among 252 patients who visited our training hospital with the symptom of lateral ankle instability for more than 1 year after sustaining ankle injury, 71 patients with os subfibulare who underwent magnetic resonance imaging (MRI) of the ankle were included in this study. For each patient, the simple radiologic assessment was also performed. The shape and size of ossicles were measured on a sagittal MR images. The location of the subfibular ossicle was classified into 3 zones by relation with the attachment site of the anterior talofibular ligament. The talofibular impingement, in which ossicles impinged to the talar articular surface.

Results:

The most common shape of ossicles was oval, and the most common site of ossicles was ATFL attach site. 61% of patients showed talofibular joint impingement on axial MR images, whereas 28 cases showed normal congruency of the talofibular joint. Forty-eight cases in 71 patients with CLAI had an enlarged fibular shape instead of a contralateral fibula on simple radiographs. The age; sex; the shape, location, and size of the ossicle; talofibular articular impingement; and history of major trauma were associated with surgical treatment in statistical analysis.

Conclusion:

The morphological analysis of the os subfibulare revealed that the ossicle manifested radiographic differences based on its size, location, and morphology. Based on the findings of our study, we suggest it is crucial to understand the morphologeical characteristics of the os subfibulare in patients with CLAI and to establish the treatment plan accordingly.

Inter-segment foot motion in girls using a three-dimensional multi-segment foot model

BACKGROUND

Several multi-segment foot models (MFMs) have been introduced for in vivo analyses of dynamic foot kinematics. However, the normal gait patterns of healthy children and adolescents remain uncharacterized. We sought to determine normal foot kinematics according to age in clinically normal female children and adolescents using a Foot 3D model.

METHODS

Fifty-eight girls (age 7-17 years) with normal function and without radiographic abnormalities were tested. Three representative strides from five separate trials were analyzed. Kinematic data of foot segment motion were tracked and evaluated using an MFM with a 15-marker set (Foot 3D model). As controls, 50 symptom-free female adults (20-35 years old) were analyzed.

RESULTS

In the hindfoot kinematic analysis, plantar flexion motion in the pre-swing phase was significantly greater in girls aged 11 years or older than in girls aged <11 years, thereby resulting in a larger sagittal range of motion. Coronal plane hindfoot motion exhibited pronation, whereas transverse plane hindfoot motion exhibited increased internal rotation in girls aged <11 years. Hallux valgus angles increased significantly in girls aged 11 years or older. The foot progression angle showed mildly increased internal rotation in the loading response phase and the swing phase in girls aged <11 years old.

CONCLUSION

The patterns of inter-segment foot motion in girls aged 11 years or older showed low-arch kinematic characteristics, whereas those in girls aged 11 years or older were more similar to the patterns in young adult women.

Slow gait speed after bilateral total knee arthroplasty is associated with suboptimal improvement of knee biomechanics

PURPOSE

The aim of this study was to investigate gait speed changes 2 years after bilateral total knee arthroplasty (TKA) and identify kinetic and kinematic factors associated with such changes by comparing patients with age- and sex-matched controls.

METHODS

The study group included 34 female patients with end-stage knee osteoarthritis (OA) who underwent bilateral TKA and 42 age- and sex-matched controls without knee pain or OA. Standard TKA was performed on all arthritic patients with placement of posterior stabilized fixed-bearing implants. Kinetic and kinematic parameters were evaluated using a commercial optoelectric gait analysis system. Gait speed, kinetic and kinematic changes and determinants of speed were assessed via principal component analysis and multiple regression analysis.

RESULTS

The average gait speed of an arthritic patient was 90.2 ± 18.4 cm/s and improved to 96.0 ± 12.3 cm/s after TKA (p = 0.032). However, the speed remained slower than that of controls (111.2 ± 8.2 cm/s, p < 0.001). With regard to kinetics, the peak knee extension moment (KEM) generated by the quadriceps was unchanged after TKA and weaker than that of controls (p < 0.001). The proportions of KEM contributing to the total sagittal moment were also smaller in the pre-/post-operative groups than in the control group (13-14% vs. 19%). On the other hand, the ankle plantar flexion moment (APFM) was increased after TKA (p = 0.007) and its proportion of the total sagittal moment was greater than in controls (46% vs. 42%). With regard to kinematics, knee range of motion (ROM) improved after TKA (p = 0.025), but was smaller than that of controls (p < 0.001). In controls, gait speed was determined principally by hip and knee joint moments. However, in the TKA group, speed was determined by the knee ROM and APFM.

CONCLUSIONS

Despite showing improvement, the gait speed of TKA patients remained slower than that of controls. Slow gait speed after bilateral TKA was associated with suboptimal improvement of knee biomechanics. Quadriceps strengthening exercises and the achievement of greater ROM during gait are advised for the further improvement of gait speed.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

Clinical Implication of Os subfibulare

Category:

Ankle, Sports, Trauma

Introduction/Purpose:

Os subfibulare, defined as a separated ossicle of the distal fibular, has been linked to various clinical problems such as subfibulare pain and chronic lateral ankle instability. However, whether os subfibulare is congenital or traumatic remains unclear. The objectives of this study were: 1) to determine the incidence of os subfibulare development after ankle sprain in children and adolescents in a single primary care orthopedic clinic, and 2) to evaluate clinical implication of os subfibulare associated with ankle sprain in children and adolescents

Methods:

Among 896 pediatric patients (age ranging from 3 to 16 years) who visited a single primary care unit after sustaining ankle inversion injury, 627 patients who were followed up for over 2 weeks were included in this study. For each pediatric patient, physical examination and radiographic examination (anteroposterior, lateral, and mortise view of the bilateral ankle) were performed. The incidence of os subfibulare was evaluated based on initial radiographic examination. To analyze the incidence of new os subfibulare formation after ankle inversion injury, radiographs of 193 patients who were followed up for more than 6 months were evaluated according to the grade of injury.

Results:

At initial visit, 1% of examined ankles (13 from 1,254 ankles of 627 patients) showed well corticated ossicle not related to initial injuries. We cannot recognize the existence of accessory ossification center of the fibula in our study population. Overall incidence of os subfibulare at final follow up after ankle inversion injury was 23.9% (150/627). Os subfibulare at final follow up was correlated with initial injury grade (OR: 8.0, p = 0.001). In patients with initial avulsion fragment, 64.9% (61/94 cases) had residual ossicle at the final radiograph after being followed up for more than 6 months. As for the morphology of ossicle, 54 cases with wafer bone fragment at the time of initial injury showed oval or round shape ossicles at final radiograph.

Conclusion:

The incidence of os subfibulare at the initial radiograph was about 1%. The chance of ossicle formation after ankle inversion injury was substantially high in pediatric population. Based on the findings of our study, we carefully suggest that majority, if not all, of os subfibulare would be posttraumatic in pediatric period. Therefore, ankle inversion injury in children should be managed more actively to reduce the chance of posttraumatic os subfibulare formation.

Comparison of Multisegmental Foot and Ankle Motion Between Total Ankle Replacement and Ankle Arthrodesis in Adults

BACKGROUND

Total ankle replacement (TAR) and ankle arthrodesis (AA) are usually performed for severe ankle arthritis. We compared postoperative foot segmental motion during gait in patients treated with TAR and AA.

METHODS

Gait analysis was performed in 17 and 7 patients undergoing TAR and AA, respectively. Subjects were evaluated using a 3-dimensional multisegmental foot model with 15 markers. Temporal gait parameters were calculated. The maximum and minimum values and the differences in hallux, forefoot, hindfoot, and arch in 3 planes (sagittal, coronal, transverse) were compared between the 2 groups. One hundred healthy adults were evaluated as a control.

RESULTS

Gait speed was faster in the TAR ( P = .028). On analysis of foot and ankle segmental motion, the range of hindfoot sagittal motion was significantly greater in the TAR (15.1 vs 10.2 degrees in AA; P = .004). The main component of motion increase was hindfoot dorsiflexion (12.3 and 8.6 degrees). The range of forefoot sagittal motion was greater in the TAR (9.3 vs 5.8 degrees in AA; P = .004). Maximum ankle power in the TAR (1.16) was significantly higher than 0.32 in AA; P = .008). However, the range of hindfoot and forefoot sagittal motion was decreased in both TAR and AA compared with the control group ( P = .000).

CONCLUSION

Although biomechanical results of TAR and AA were not similar to those in the normal controls, joint motions in the TAR more closely matched normal values. Treatment decision making should involve considerations of the effect of surgery on the adjacent joints.

LEVEL OF EVIDENCE

Level III, case-control study.

Chemical stability of morphine and methadone, and of methadone in combination with acepromazine, medetomidine or xylazine, during prolonged storage in syringes

OBJECTIVE

To assess the chemical and physical stability of morphine and methadone stored in syringes for 12 months and of methadone when mixed with acepromazine, medetomidine or xylazine.

METHODS

A high-performance liquid chromatography (HPLC) technique was developed and validated for the analysis of morphine and methadone. Morphine and methadone were dispensed into syringes and stored at 25°C/60% relative humidity (RH) and 40°C/75% RH. Solutions containing mixtures of methadone combined with acepromazine, medetomidine or xylazine were stored in syringes at 25°C/60%RH. At initiation, after 1 week and then 1, 3, 6, 9 and 12 months, samples were analysed by HPLC for the quantification of the morphine or methadone. Measured concentrations were assessed as a function of storage time and temperature using linear regression statistics to calculate stability.

RESULTS

When stored at 40°C/75%RH as pre-dispensed syringes, severe physical and chemical changes were observed after the third month for both morphine and methadone. In contrast, at 25°C/60%RH both drugs remained chemically stable for 12 months, with concentration variations not exceeding a 5% change from initiation as stipulated in VICH stability guidelines. When in combination with acepromazine or xylazine, methadone also remained chemically stable, but the combination with medetomidine failed stability criteria prior to 6 months. Precipitation compromised the physical stability of methadone in all unsealed syringes prior to 9 months' storage.

CONCLUSION

Pre-dispensing morphine or methadone into unsealed syringes compromises the drugs' physical stability. Mixing of methadone with other drugs can degrade its chemical stability.

Inter-segmental motions of the foot: differences between younger and older healthy adult females

BACKGROUND

Although accumulative evidence exists that support the applicability of multi-segmental foot models (MFMs) in evaluating foot motion in various pathologic conditions, little is known of the effect of aging on inter-segmental foot motion. The objective of this study was to evaluate differences in inter-segmental motion of the foot between older and younger adult healthy females during gait using a MFM with 15-marker set.

METHODS

One hundred symptom-free females, who had no radiographic evidence of osteoarthritis, were evaluated using MFM with 15-marker set. They were divided into young (n = 50, 20-35 years old) and old (n = 50, 60-69 years old) groups. Coefficients of multiple correlations were evaluated to assess the similarity of kinematic curve. Inter-segmental angles (hindfoot, forefoot, and hallux) were calculated at each gait phase. To evaluate the effect of gait speed on intersegmental foot motion, subgroup analysis was performed according to the similar speed of walking.

RESULTS

Kinematic curves showed good or excellent similarity in most parameters. Range of motion in the sagittal (p < 0.001) and transverse (p = 0.001) plane of the hallux, and sagittal (p = 0.023) plane of the forefoot was lower in older females. The dorsiflexion (p = 0.001) of the hallux at terminal stance and pre-swing phases was significantly lower in older females. When we compared young and older females with similar speed, these differences remained.

CONCLUSIONS

Although the overall kinematic pattern was similar between young and older females, reduced range of inter-segmental motion was observed in the older group. Our results suggest that age-related changes need to be considered in studies evaluating inter-segmental motion of the foot.

Platelet-Derived Growth Factor Receptor-Positive Pericytic Cells of White Adipose Tissue from Critical Limb Ischemia Patients Display Mesenchymal Stem Cell-Like Properties

Background

The pericytes in the blood vessel wall have recently been identified to be important in regulating vascular formation, stabilization, remodeling, and function. We isolated and identified pericyte-like platelet-derived growth factor receptor beta-positive (PDGFRβ+) cells from the stromal vascular fraction (SVF) of adipose tissue from critical limb ischemia (CLI) patients and investigated their potential as a reliable source of stem cells for cell-based therapy.

Methods

De-identified subcutaneous fat tissues were harvested after amputation in CLI patients. Freshly isolated SVF cells and culture-expanded adipose-derived stem cells (ADSCs) were quantified using flow cytometry. A matrigel tube formation assay and multi-lineage differentiation were performed to assess pericytic and mesenchymal stem cell (MSC)-like characteristics of PDGFRβ+ ADSCs.

Results

PDGFRβ+ cells were located in the pericytic area of various sizes of blood vessels and coexpressed mesenchymal stem cell markers. PDGFRβ+ cells in freshly isolated SVF cells expressed a higher level of stem cell markers (CD34 and CXCR4) and mesenchymal markers (CD13, CD44, CD54, and CD90) than PDGFRβ– cells. In vitro expansion of PDGFRβ+ cells resulted in enrichment of the perivascular mesenchymal stem-like (PDGFRβ+/CD90+/CD45–/CD31–) cell fractions. The Matrigel tube formation assay revealed that PDGFRβ+ cells were located in the peritubular area.

Conclusions

PDGFRβ+ ADSCs cells demonstrated a good multilineage differentiation potential. Pericyte-like PDGFRβ+ cells from the SVF of adipose tissue from CLI patients had MSC-like characteristics and could be amplified by in vitro culture with preservation of their cell characteristics. We believe PDGFRβ+ cells in the SVF of adipose tissue can be used as a reliable source of stem cells even in CLI patients.

Sex differences in knee joint loading: Cross-sectional study in geriatric population

This study investigated sex differences in knee biomechanics and investigated determinants for difference in a geriatric population. Age-matched healthy volunteers (42 males and 42 females, average age 65 years) without knee OA were included in the study. Subjects underwent physical examination on their knee and standing full-limb radiography for anthropometric measurements. Linear, kinetic, and kinematic parameters were compared using a three-dimensional, 12-camera motion capture system. Gait parameters were evaluated and determinants for sex difference were evaluated with multiple regression analysis. Females had a higher peak knee adduction moment (KAM) during gait (p = 0.004). Females had relatively wider pelvis and narrower step width (both p < 0.001). However, coronal knee alignment was not significantly different between the sexes. Multiple regression analysis revealed that coronal alignment (b = 0.014, p < 0.001), step width (b = -0.010, p = 0.011), and pelvic width/height ratio (b = 1.703, p = 0.046) were significant determinants of peak KAM. Because coronal alignment was not different between the sexes, narrow step width and high pelvic width/height ratio of female were the main contributors to higher peak KAM in females. Sex differences in knee biomechanics were present in the geriatric population. Increased mechanical loading on the female knee, which was associated with narrow step width and wide pelvis, may play an important role in future development and progression of OA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1283-1289, 2017.

Serum 25-hydroxyvitamin D cutoffs for functional bone measures in postmenopausal osteoporosis

This study sought to determine the minimal serum 25-hydroxyvitamin D [25(OH)D] concentration required to maintain bone health in postmenopausal women with low bone mass. A serum 25(OH)D concentration of 20 ng/mL rather than 30 ng/mL was appropriate for bone health.

INTRODUCTION

There is no consensus on the minimal serum 25-hydroxyvitamin D [25(OH)D] concentration required to maintain bone health. The aim of this study was to investigate the relationship between 25(OH)D measured via liquid chromatography-mass spectrometry (LC-MS/MS), which is the current gold standard, and biochemical markers of bone turnover, PTH, and bone mineral densitometry (BMD).

METHODS

The medical records of 750 postmenopausal women newly diagnosed with osteoporosis or osteopenia at Samsung Medical Center from 2009 to 2014 were investigated. Subjects were divided into four groups according to serum 25(OH)D concentration: <10, 10-20, 20-30, and ≥30 ng/mL. Serum concentrations of bone-specific alkaline phosphatase (BS-ALP), carboxy-terminal cross-linking telopeptide of type 1 collagen (CTx), intact PTH (iPTH), and BMD were compared among the four groups using analysis of covariance. Thresholds of 25(OH)D were then assessed using spline plots and locally weighted regression smoothing (LOESS) plots.

RESULTS

25(OH)D was negatively correlated with serum BS-ALP, CTx, and iPTH. Only femur neck and total femur BMD had significant positive relationships with 25(OH)D. Cutoff values of 11.9 and 9.7 ng/mL were estimated from the spline plots of femur neck and total femur BMD, respectively. For iPTH, the LOESS plot showed a steep decrease to a serum 25(OH)D concentration of about 20 ng/mL, followed by a plateau.

CONCLUSIONS

According to this study, a serum 25(OH)D concentration of 20 ng/mL, rather than 30 ng/mL, was appropriate for bone health.

Inter-segmental motions of the foot in healthy adults: Gender difference

BACKGROUND

Multi-segment Foot Models (MFM) have increased in use for both clinical and research applications; however, little is known about the gender differences of inter-segmental motions within the foot and ankle during gait. The objectives of this study were to analyze the gender differences of inter-segmental foot motion during gait in healthy young adults using a MFM with a 15-marker set.

METHODS

One hundred healthy adults (50 males, 50 females) between 20 and 35 years of age who had normal function and no radiographic abnormality, were evaluated. Inter-segmental angles (ISA) (hindfoot, forefoot, and hallux) were calculated at each time point. The ISAs at specific phases of the gait cycle, the change in ISAs between the phases, and the range of motion for each ISA across the entire gait cycle were compared between genders.

RESULTS

The kinematic curve of the inter-segmental foot motions showed a characteristic pattern during the whole gait cycle. Although the hallux of female was aligned in a more valgus angulation during gait, the overall patterns of the inter-segmental foot motions were quite similar for both genders. Most differences in the inter-segmental foot motions between men and women were observed in the range of motion. Considering the stance phase of gait-cycle, the range of motion in the sagittal and transverse plane of the hindfoot was greater in females than in males. The sagittal range of motion of the hallux was also greater in females, mainly due to higher plantar flexion.

CONCLUSIONS

The gender differences of the inter-segmental foot motion were investigated during gait in healthy young adults using a MFM with a 15-marker set. Females had a larger range of motion in the sagittal plane of the hallux and in the sagittal and transverse plane of the hindfoot.

Alzheimer's disease with cerebrovascular disease: current status in the Asia-Pacific region

BACKGROUND

There is growing awareness of the coexistence of Alzheimer's disease and cerebrovascular disease (AD+CVD), however, due to lack of well-defined criteria and treatment guidelines AD+CVD may be underdiagnosed in Asia.

METHODS

Sixteen dementia specialists from nine Asia Pacific countries completed a survey in September 2014 and met in November 2014 to review the epidemiology, diagnosis and treatment of AD+CVD in Asia. A consensus was reached by discussion, with evidence provided by published studies when available.

RESULTS

AD accounts for up to 60% and AD+CVD accounts for 10-20% of all dementia cases in Asia. The reasons for underdiagnosis of AD+CVD include lack of awareness as a result of a lack of diagnostic criteria, misdiagnosis as vascular dementia or AD, lack of diagnostic facilities, resource constraints and cost of investigations. There is variability in the tools used to diagnose AD+CVD in clinical practice. Diagnosis of AD+CVD should be performed in a stepwise manner of clinical evaluation followed by neuroimaging. Dementia patients should be assessed for cognition, behavioural and psychological symptoms, functional staging and instrumental activities of daily living. Neuroimaging should be performed using computed tomography or magnetic resonance imaging. The treatment goals are to stabilize or slow progression as well as to reduce behavioural and psychological symptoms, improve quality of life and reduce disease burden. First-line therapy is usually an acetylcholinesterase inhibitor such as donepezil.

CONCLUSION

AD+CVD is likely to be under-recognised in Asia. Further research is needed to establish the true prevalence of this treatable and potentially preventable disease.

Inter-Segmental Foot Kinematics During Gait in Elderly Females with Symptomatic and Asymptomatic Hallux Valgus

Category:

Basic Sciences/Biologics

Introduction/Purpose:

Hallux valgus (HV) is a common condition that may lead to considerable pain and disability. While a number of gait analyses of people with and without HV have been performed using planter pressures, the results to date are not in agreement. In the last two decades, several multi-segmental foot models (MFMs) have been introduced for the in vivo analysis of dynamic foot kinematics. Although there are some investigations about triplanar multisegmental of patients with HV, there were lack of age and gender matched comparison of inter-segmental foot motions in previous reports. The objective of this study was to find the effect of hallux valgus deformity on inter-segmental motion of the foot by comparisons with age and gender controlled healthy adults using a multi-segmental foot model (MFM) with 15-marker set.

Methods:

Eighteen female symptomatic hallux valgus patients (SHV group) and 50 female symptom-free older female participants who had normal function of the foot and ankle and no radiographic evidence of osteoarthritis were included in this study. Symptom-free participants were divided into asymptomatic hallux valgus group (AHV, n=14) and control group (CON, n=36). For radiographic examinations, hallux valgus angle was measured using standing anteroposterior radiograph of the foot. The temporal gait parameters such as the cadence, speed, stride length, step width, step time, and proportion of stance phase were calculated. Segmental foot kinematics evaluated using a 3D MFM of a 15-marker set (Foot3D model). Inter-segmental angles (ISA) (hindfoot relative to tibia, forefoot to hindfoot, and hallux to forefoot) were calculated at each time points (100 time points for whole gait cycle). The ISAs (position) at specific phases of gait cycle, the change of ISA (motion) between phases and range of ISAs during the whole gait cycle were calculated and compared among groups.

Results:

Basic demographic data was no significant difference among groups except HV angle and foot width. The speed, stride length were significantly lower in SHV group. The proportion of the stance phase in a gait cycle was longer SHV group. Range of motion (ROM) of sagittal plane of hallux and transverse plane of forefoot was lower in SHV group. Significantly different finding in SHV group included more dorsiflexed position of hallux segment, reduced forefoot abduction motion during terminal stance and loss of push off during preswing(Figure 1). However, when we compared AHV group and CON group, there was no difference in temporal gait parameters and ROM of inter-segmental motions of foot. Hallux segment was in more valgus position and the forefoot segment was in more pronated position in AHV group than in CON group.

Conclusion:

Symptomatic hallux valgus patients showed different gait parameters & inter-segmental motion during gait when compared with age-matched controls. Asymptomatic hallux valgus does not affect gait & inter-segmental motion during gait except that the hallux segment was in more valgus position and the forefoot segment was in more pronated position. The results of this study suggest that effect of moderate hallux valgus itself on foot kinematics might be limited while pain or arthritic change of the joint might cause changes in gait in patients with symptomatic HV.

Inter-Segmental Foot Motions in Children and Adolescents Using a Three-Dimensional Multi-Segment Foot Model

Category:

Basic Sciences/Biologics

Introduction/Purpose:

In the last two decades, several multi-segmental foot models (MFMs) have been introduced for the in vivo analysis of dynamic foot kinematics. However, the literature has not yet sufficiently described normal gait patterns in normal children and adolescents. Normal range of gait pattern should be established before applying gait analysis clinically in order to assess and treat pathological gait patterns. The purpose of this study is to suggest normal foot kinematics of clinically normal children and adolescents using three dimensional multi-segment foot model (3D MFM). Using this data, we will be able to distinguish between normal and abnormal gait more precisely in pediatric population and to evaluate gait improvement by certain treatment methods.

Methods:

One-hundred fifteen children and adolescents without anatomical or functional abnormalities of foot were involved. Fifty-seven individuals were boys and 58 were girls. The mean age was 11.4 years (range: 7-17). We divided the pediatric subjects into two groups; age between 7 to 10 years (Prepuberty) when the foot is still growing and age of 11 or older (Puberty) when the gait pattern is thought to be similar with that of adults. The Difference of gait kinematics of the two groups was analyzed. Using 12 sets of 3D optical motion capture cameras, gait motion data were collected while the subjects were walking. In 5 separate experiments, gait analysis was performed for 3 different kinds of stride. Foot segment kinematics were measured and analyzed by Foot 3D Multi-Segment Software program (Motion Analysis Co., Santa Rosa. CA). We performed student’s t-test to analysis the difference between the groups.

Results:

The basic demographic data showed that there was no significant difference in proportion of stance phase among groups. There are some significant difference of foot motion between prepuberty and puberty (Figure 1). Both boys and girls in puberty showed approximately 4.5 degrees greater big toe motion in sagittal plane than in prepuberty. Mostly, increase of dorsiflexion angle was evident. Hallux valgus angles did not show significant difference in boys, but girls showed marked increase in puberty. In forefoot motion analysis, there were significant difference in sagittal, coronal and transverse plane between prepuberty and puberty girl, but did not show significant difference in boys. Sagittal plane of hindfoot motions increased in both boys and girls in puberty and coronal plane hindfoot motion showed increased pronation in puberty.

Conclusion:

The results suggest that sagittal motion of the great toe mainly involves plantar flexion and increase in hallux valgus angle is evidently greater in females than in males throughout growth development. Increase in sagittal plane motion and valgus angle of the big toe rapidly increased in puberty, while increase in sagittal motion of forefoot and hindfoot were gradual. In summary, authors identified children’s normal gait pattern and especially, difference between boys and girls and changes according to age groups in this study.

Repeatability of a Multi-Segment Foot Model with a 15-Marker Set in Healthy Children

Category:

Basic Sciences/Biologics

Introduction/Purpose:

Recently, 3D multi-segment foot models using 15 marker set(Foot 3D model) was proposed . Our team demonstrated that this model had comparable intra-session/inter-session repeatability with other MFMs making it suitable for evaluation of segmental foot motion during gait. And also we have shown that this model had high intra-session/inter-session repeatability in the assessment of foot motion in healthy adults. Compared with adults, children have some specific character of gait. Mechanical axis of lower extremity and gait has changed over the course of growing up. And children has small bones and soft skin comparing with adults, so these can be some factors that induce bias of analysis. Then despite of verification of high intra- session/inter-session repeatability of Foot 3D model in healthy adults, it is necessary to validate the intra-session/inter-session repeatability of this model in healthy children.

Methods:

Participating subjects is made up of 40 feet of twenty healthy children (10 males, 10 females) of 10-15 years old. We utilized multi-segment foot model with 15-marker set used in previous study for healthy adults. We divided participants into two groups in tens. One group was tested by same operator in each test and the other group changed the operator in each test. The former is for inter-session analysis and the latter is for inter-rater analysis. In this study, we analyzed the intra-session, inter- session, and inter-rater repeatability. Coefficients of multiple correlation (CMC) and intra-class correlation (ICC) were calculated in order to assess the intra-session, inter-session and inter-rater session repeatability. The difference between the two sessions of each group was assessed for each time points of the gait cycle.

Results:

There is no significant difference pattern in gait analysis graph (Figure 1). The mean intra-session CMC (±Standard deviation) was 0.933 (± 0.034). The intra-session CMC values of all parameters were interpreted as excellent or very good repeatability. The intra-session ICC values of all parameters were interpreted as excellent. The mean inter-session CMC (±SD) was 0.794 (± 0.123). The mean inter-session ICC (±SD) was 0.866 (± 0.086). The inter-session ICC values of all parameters were interpreted as excellent except hindfoot rotation parameter. Inter-rater CMC (±Standard deviation) was 0.766 (± 0.214). The mean inter-rater ICC (±SD) was 0.839 (± 0.203). The inter-rater ICC values of all parameters were interpreted as good or excellent. Mean gap of all parameters is larger than the value of previous study for healthy adults.

Conclusion:

In this study, we used a multi-segment foot models using 15 marker set in order to evaluate segmental foot motion in healthy children as in case of adults. And we demonstrated that this model had high intra-session, inter-session and inter-rater repeatability in the assessment of foot motion except some cautions. We believe that our study for children is very important to understand the gait of childhood and this Foot 3D model can be applicable in clinical settings, which require further elucidation.

Weight-Bearing 3D Foot Model Reconstruction From Standing Radiographs Using Deformable Surface Fitting Method

Category:

Basic Sciences/Biologics

Introduction/Purpose:

Although weight-bearing CT of the foot and ankle definitely reflect the morphology of joint and foot deformity, it is hard to obtain the standing CT due to difficulty of availability. The purpose of this study is to introduce a semi- automatic method based on a deformable surface fitting for achieving the weight-bearing 3D model reconstruction from standing radiographs for foot and ankle.

Methods:

Our method is based on a Laplacian surface deformation framework using a template model of foot bones. As pre- processing step, we obtained template surface meshes having the average shapes of foot bones from standing CT images (Planmed Verity® CT scanner) in 10 normal volunteers. First, 3D standing CT was obtained by Planmed Verity® CT scanner and used as gold standard of reconstruction for one patient with flatfoot. Second, in the reconstruction step, the surface meshes are deformed following guided user inputs (talus 6, calcaneus 8 in lateral, talus 6, calcaneus 6 in anteroposterior standing radiograph) with geometric constraints to recover the target shapes of patients while preserving average bone shape and smoothness as much as possible. Finally, we compared reconstructed 3D model to original standing CT images.

Results:

In this study, the comparison results indicate that the obtained reconstruction is close to the actual standing foot and ankle geometry. We present the accuracy and robustness of our method via comparison between the reconstructed 3D models and the original bone surfaces

Conclusion:

Weight-bearing 3D foot model reconstruction from standing radiographs is concise and the effective method for analysis of foot joint alignment and deformity.

Exposure to the BPA-Substitute Bisphenol S Causes Unique Alterations of Germline Function

Concerns about the safety of Bisphenol A, a chemical found in plastics, receipts, food packaging and more, have led to its replacement with substitutes now found in a multitude of consumer products. However, several popular BPA-free alternatives, such as Bisphenol S, share a high degree of structural similarity with BPA, suggesting that these substitutes may disrupt similar developmental and reproductive pathways. We compared the effects of BPA and BPS on germline and reproductive functions using the genetic model system Caenorhabditis elegans. We found that, similarly to BPA, BPS caused severe reproductive defects including germline apoptosis and embryonic lethality. However, meiotic recombination, targeted gene expression, whole transcriptome and ontology analyses as well as ToxCast data mining all indicate that these effects are partly achieved via mechanisms distinct from BPAs. These findings therefore raise new concerns about the safety of BPA alternatives and the risk associated with human exposure to mixtures.