Reapplication of the Pavlik Harness for Treatment of Developmental Dysplasia of the Hip After Initial Pavlik Harness Failure

OBJECTIVE

The Pavlik harness (PH) has been widely used as the standard treatment for infants with developmental dysplasia of the hip (DDH). When the initial application of the PH fails, alternative treatments, such as closed reduction, open reduction, and reapplication of the PH will be considered. Compared with other treatments, reapplication of the PH offers certain advantages, including simplicity and reduced physical, and psychological stress, on both infants and caregivers. This study aims to investigate the effectiveness of reapplying the PH in patients with DDH.

METHODS

This study included patients with DDH (complete dislocation) who were treated by reapplication of PH between 1988 and 2012. Patients who were able to follow-up for more than 5 years were included. We examined the reduction rate and several factors to identify indicators associated with successful reduction during reapplication, including age, sex, side of hip dislocation, and the presence of the Ortolani sign. At the final follow-up, hip development was assessed using the Severin classification, whereas avascular necrosis (AVN) was evaluated using the Kalamchi classification and the Salter criteria.

RESULTS

A total of 56 patients (48 females and 8 males) and 57 hips were included in this study. The mean age at first and second application of PH was 4.2 months old (range: 0.12 to 6.4), and 5.8 months old (3.0 to 11.4), respectively. The reduction rate was 49% (28 out of 57 hips). Among the successfully reduced hips, the AVN rate was 3.6% (1 out of 28 hips). The Severin classification revealed 27 hips in class I and 1 hip in class III. Statistical analysis indicated a significantly higher proportion of left hip involvement in the reduction group (85% vs 41%, χ 2 test, P < 0.001). Although not statistically significant, the rate of positive Ortolani sign tended to be higher in the reduction group (61% vs 38%, χ 2 test, P = 0.06).

CONCLUSION

The reapplication method demonstrated a 49% reduction rate and a low AVN rate of 3.6% in our study. It is worth considering for patients who fail the initial PH treatment, particularly in cases of left-side dislocation and a positive Ortolani sign during the initial application.

Feasibility and safety study of wearable cyborg Hybrid Assistive Limb for pediatric patients with cerebral palsy and spinal cord disorders

Introduction

The wearable cyborg Hybrid Assistive Limb (HAL) is the world's first cyborg-type wearable robotic device, and it assists the user's voluntary movements and facilitates muscle activities. However, since the minimum height required for using the HAL is 150 cm, a smaller HAL (2S size) has been newly developed for pediatric use. This study aimed to (1) examine the feasibility and safety of a protocol for treatments with HAL (2S size) in pediatric patients and (2) explore the optimal method for assessing the efficacy of HAL.

Methods

This clinical study included seven pediatric patients with postural and motor function disorders, who received 8-12 sessions of smaller HAL (2S size) treatment. The primary outcome was the Gross Motor Function Measure-88 (GMFM-88). The secondary outcomes were GMFM-66, 10-m walk test, 2- and 6-min walking distances, Canadian Occupational Performance Measure (COPM), a post-treatment questionnaire, adverse events, and device failures. Statistical analyses were performed using the paired samples t-test or Wilcoxon signed-rank test.

Results

All participants completed the study protocol with no serious adverse events. GMFM-88 improved from 65.51 ± 21.97 to 66.72 ± 22.28 (p = 0.07). The improvements in the secondary outcomes were as follows: GMFM-66, 53.63 ± 11.94 to 54.96 ± 12.31, p = 0.04; step length, 0.32 ± 0.16 to 0.34 ± 0.16, p = 0.25; 2-MWD, 59.1 ± 57.0 to 62.8 ± 63.3, p = 0.54; COPM performance score, 3.7 ± 2.0 to 5.3 ± 1.9, p = 0.06; COPM satisfaction score, 3.3 ± 2.1 to 5.1 ± 2.1, p = 0.04.

Discussion

In this exploratory study, we applied a new size of wearable cyborg HAL (2S size), to children with central nervous system disorders. We evaluated its safety, feasibility, and identified an optimal assessment method for multiple treatments. All participants completed the protocol with no serious adverse events. This study suggested that the GMFM would be an optimal assessment tool for validation trials of HAL (2S size) treatment in pediatric patients with posture and motor function disorders.

Transcranial Direct Current Stimulation over the Temporoparietal Junction Modulates Posture Control in Unfamiliar Environments

The temporoparietal junction (TPJ), which integrates visual, somatosensory, and vestibular information to form body schema, is involved in human postural control. We evaluated whether or not the transcranial direct current stimulation (tDCS) of the TPJ can modulate postural control on an unstable surface with eyes closed, during which the updating of body schema is needed to maintain balance. Sixteen healthy subjects participated in this study. The order of the three types of tDCS (anodal, cathodal, and sham) over the right TPJ was counterbalanced across the participants. We evaluated dynamic posture control while the participants were standing on a stable surface with eyes open and an unstable surface with eyes closed. Anodal tDCS enhanced postural control on an unstable surface with eyes closed during and after stimulation, but cathodal tDCS deteriorated postural control during stimulation. Neither anodal nor cathodal tDCS altered postural control while the participants were on a stable surface with eyes open. Anodal tDCS may enhance postural control with non-vision and altered tactile perception by activating the TPJ, which integrates multisensory inputs to update the body schema, whereas cathodal tDCS has the opposite effect. tDCS over the TPJ may facilitate the updating of body schemas to accommodate changes in sensory inputs and help develop novel approaches to prevent falls.

Prevalence of anemia and iron deficiency and its association with body mass index in elite Japanese high school long-distance runners

OBJECTIVES

Anemia is a common condition in long-distance runners (LDRs). Recently, not only iron deficiency (ID) but also energy deficiency has been considered as a risk factor for anemia in athletes but no evidence has yet been established. The aim of this study was to investigate the prevalence of anemia and ID and the influence of body mass index (BMI) on anemia in high-school LDRs.

METHODS

The participants were 406 male and 235 female elite Japanese LDRs who competed in the All-Japan High-School Ekiden Championship 2019. They submitted their anthropometric data and results of a blood test within five days after the competition. The prevalence of anemia and ID and the influence of BMI on anemia were assessed retrospectively.

RESULTS

Mean hemoglobin concentrations (Hb) were 14.8 ± 0.9 g/dl in males and 13.2 ± 0.9 g/dl in females. The prevalence of anemia (Hb < 14 g/dl in males and < 12 g/dl in females) was significantly higher in males (16.3%) than females (6.4%), but males also showed higher prevalence of non-iron deficiency anemia (NIDA) than females (11.6% and 3.0%, respectively). No significant gender difference was found in the prevalence of iron deficiency anemia (IDA) (4.7% in males and 3.4% in females). ID (serum ferritin level < 25 ng/ml) was significantly more prevalent in females (37.4%) than males (18.5%). A binary logistic regression analysis revealed that low BMI was a contributor to anemia in females (odds ratios: 0.577 (95% CI: 0.369-0.901), p = 0.012).

CONCLUSION

In Japanese high-school LDRs, one in six males was anemic, but most males did not have ID. Conversely, one-third of females were diagnosed with ID. Lower BMI was identified as a risk for anemia in females, suggesting that leanness may also lead to anemia in females.

Radiologic Changes After 10 Years Postreduction in Developmental Dysplasia of the Hip Treated With Different Reduction Methods and Risk Factors for Osteoarthritis

BACKGROUND

This study examined how radiologic indices at 10 years postreduction change over time and influence the final outcome through a comparative study of 3 reduction methods for developmental dysplasia of the hip, including the Pavlik harness, closed reduction, and open reduction (OR).

METHODS

Patients treated from 1990 to 2000 for dysplasia of the hip and followed up for >20 years were included in this study. Radiologic indices at 10 years postreduction and final follow-up (average 24 years postreduction) were measured in the 3 groups. The relative joint space of <66% compared with the healthy side was defined as positive osteoarthritis (OA) at the final follow-up. The relationship between OA and factors such as age, sex, method of reduction, radiologic indices, and Severin and Kalamchi classifications at 10 years postreduction were examined. Clinical evaluation was performed using the modified Harris Hip Score; a score of ≥80 was defined as good performance at the final follow-up.

RESULTS

Sixty-five patients (totaling 74 hips) were included. There were no significant differences in radiologic indices between the 10-year postreduction time and final follow-up. Excluding 9 bilateral patients, based on the relative joint space, 21% of the patients (13/56 hips), were positive for OA. Univariate analysis showed that the incidence of positive OA was significantly associated with OR and Kalamchi grade 4 at 10 years postreduction. The modified Harris Hip Score was 80 or higher in 90% of the cases at the final follow-up.

CONCLUSIONS

No significant changes in hip morphology were observed at 10 years postreduction. The Kalamchi classification at 10 years postreduction and OR were significantly associated with the incidence of OA at the final follow-up. Therefore, patients who undergo OR and/or display Kalamchi grade 4 have a high risk of developing OA and would require individual instructions for their daily lives to prevent further progression of OA and longer follow-up.

LEVEL OF EVIDENCE

Level Ⅲ-case-control study.

Effects of bone marrow-derived mesenchymal stem cell transplantation in piglet Legg-Calve-Perthes disease models: a pilot study

This preliminary study investigated the efficacy and safety of bone marrow-derived mesenchymal stem cell transplantation in a piglet Legg-Calve-Perthes disease (LCPD) model. The LCPD model was induced in two Landrace piglets (6- and 7-week-old, weighing 12 and 17 kg, respectively) by ligaturing the femoral neck. In the first piglet, the natural LCPD course was observed. In the second piglet, 4 weeks after ligaturing the femoral neck, simple medium and medium containing 2.44 × 107 bone marrow-derived mesenchymal stem cells were transplanted into the right and left femoral heads after core decompression, respectively. Plain radiographs were obtained every 4 weeks, and the epiphyseal quotient was calculated by dividing the maximum epiphysis height by the maximum epiphysis diameter. The piglets were sacrificed at 14 weeks postoperatively. The femoral heads were extracted and evaluated grossly, pathologically, and by using computed tomography. The transplanted cell characteristics were evaluated using flow cytometry. Flattening of the epiphysis was observed in both femoral heads of the first piglet and only in the right hip of the second piglet. The epiphyseal quotients immediately and at 14 weeks postoperatively in the right femoral head of the second piglet were 0.40 and 0.14, respectively, while those of the left femoral head were 0.30 and 0.42, respectively. Hematoxylin and eosin staining did not reveal physeal bar or tumor cell formation. The transplanted cells were 99.2%, 65.9%, 18.2%, and 0.16% positive for CD44, CD105, CD29, and CD31, respectively. Core decompression combined with bone marrow-derived mesenchymal stem cell transplantation prevented epiphyseal collapse.

Association between Self-reported Overtraining Syndrome and Symptoms in High School Track and Field Athletes

Diagnosing overtraining syndrome is challenging and it is often correlated with other diseases, especially those related to low energy availability. Therefore, we investigated the prevalence of overtraining syndrome-like symptoms and correlative factors in 389 female and 572 male national-level high school track and field athletes. They were asked to complete a survey regarding their history of overtraining syndrome-like symptoms, injuries, and diseases. The survey results revealed that 13.4% (52/389) of female and 13.3% (76/572) of male athletes had a history of overtraining syndrome-like symptoms. Logistic regression analysis showed that training hours per day (odds ratio, 1.74; 95% confidence interval, 1.12-2.71) was an associated factor in female athletes, while rest days per week (odds ratio, 0.61; 95% confidence interval, 0.37-1.00), skipping meals (odds ratio, 3.73; 95% confidence interval, 1.50-9.29), and having snacks/light meals on a regular basis (odds ratio, 0.46; 95% confidence interval, 0.26-0.83) were the associated factors in male athletes. In conclusion, athletes with overtraining syndrome-like symptoms may be prone to injuries and diseases. Hence, although overtraining syndrome is difficult to diagnose, further attention should be paid to minimize overtraining syndrome-related risks.

Controlling Behavior, Sex Bias and Coaching Success in Japanese Track and Field

Coaching athletes is a complex and lengthy process. Recently, attention has been given to coaches over-controlling behavior toward the athletes' personal lives and possible sex bias, but the impact of these behaviors on coaching success is unclear. An anonymous survey was answered by 412 track and field coaches (male: 369; female: 43), comprising questions regarding controlling behaviors, sex bias, and personal background. A Chi-square test and logistic regression were performed to determine the factors related to the coach's characteristics and their success in coaching athletes (to national vs. non-national level). The results showed that controlling behaviors and sex-bias-related beliefs were present. The coaches who coached national-level athletes were more likely to be older, more experienced, and were national level athletes themselves. More national-level coaches reported controlling behaviors but fewer held sex bias beliefs than the non-national level coaches. However, the strength of these beliefs (scores for controlling behavior and sex bias) was not related to the coaching success.

Awareness and Knowledge of Medical Issues Related to Female Athletes Among Track and Field Coaches

Introduction

Little is known regarding medical knowledge pertaining to female athletes among track and field coaches and their interactions with female athletes regarding medical problems.

Methods

Participants were track and field coaches (369 males and 43 females) with Japan Sport Association certification and they completed an anonymous survey on their knowledge of medical problems pertinent to female athletes including whether the coaches knew about the female athlete triad and relative energy deficiency in sports; their feelings about female athletes' use of contraceptive pills; whether they speak about menses with the female athletes; and whether they have a gynecologist for consultation regarding their medical problems.

Results

Females coaches were significantly more likely to be aware of the triad (odds ratio (OR), 3.44; p = 0.003); to have access to a physician able to address the gynecological problems of female athletes (OR, 9.22; p < 0.001); and to talk to their female athletes about menses (OR, 2.30; p = 0.015) than their male counterparts. Coaches with more experience tended to be aware of the triad and relative energy deficiency in sports compared with those with ≤5 years of experience.

Conclusion

Females coaches are aware of the triad, talk about menses with their female athletes, and have access to a physician who can address gynecological problems with compared to male counterparts. Educating all coaches on these problems is essential to provide adequate support to female athletes.

Influence of commuting methods on low back pain and musculoskeletal function of the lower limbs in elementary school children: A cross-sectional study

BACKGROUND

Lower limb flexibility is known to be decreased in those living in mountainous areas, and musculoskeletal growth is often influenced by lifestyle factors. The purpose of this study was to determine the relationship between the means of transportation to school and lower limb musculoskeletal function and low back pain.

METHODS

During routine medical examinations conducted in two cities in a prefecture in 2016, a questionnaire was administered. The parents of 15,259 students who attended elementary school answered questions evaluating the following parameters: (1) anteflexion limit in the standing posture, (2) crouching failure, (3) one leg standing failure, (4) low back pain during lumbar extension, (5) lower limb alignment abnormalities, and (6) flat foot. Students were divided into a walking commuting group (13,569 students) and a vehicle commuting group (1690 students), and findings were compared between the two groups using chi-square tests.

RESULTS

In the walking and vehicle commuting groups, anteflexion limit in the standing posture was present in 23.3% and 26.1% of students, respectively (p = 0.013). Crouching failure was present in 4.6% and 7.3% of students (p < 0.001); one leg standing failure in 5.3% and 8.5% of students (p < 0.001); low back pain in 5.0% and 7.1% of students (p < 0.001); positive leg alignment abnormalities in 7.3% and 8.0% of students (p = 0.260); and flat foot in 7.4% and 8.7% of students (p = 0.067), respectively. Significant differences were observed in all four of the failure measures. No significant differences were observed in the two methods evaluating morphological abnormalities.

CONCLUSIONS

The decreased walking duration and increased sitting duration associated with vehicle commuting had little effect on lower limb morphology but could induce lower limb dysfunction and low-back pain in children. Thus, supplemental walking should be instated for children who commute by car.

Feasibility and Safety of a Novel Leg Exercise Apparatus for Venous Thromboembolism Prophylaxis after Total Joint Arthroplasty of the Lower Extremities-A Pilot Study

Venous thromboembolism (VTE) is a severe complication in orthopedic surgeries. Herein, we developed a novel leg exercise apparatus (LEX) to encourage postoperative limb movement in bedridden patients to prevent VTE. We aimed to evaluate its feasibility and safety in individuals at risk of VTE. Twenty patients (four men, 16 women) who underwent total joint arthroplasty in the lower extremity were enrolled in this prospective study. Exercise using the LEX was performed for 5 min at 30 cycles/min, four times/day during postoperative days 1–7. Clinical assessments included the evaluation of vital signs, venous ultrasonography, and blood tests within seven days postoperatively, and adverse events (pulmonary embolism and cerebral hemorrhage) were monitored. Overall, 16/20 (80%) patients completed the 7-day exercise regimen. There were no cases of severe adverse events, changes in vital signs, or lower-extremity deep vein thrombosis in patients who performed exercises with the LEX. Thus, the results of this pilot study show that this novel apparatus may be a safe and feasible tool for VTE prophylaxis after joint arthroplasty of the lower extremities.

Effect of temporary school closure due to COVID-19 on musculoskeletal function in elementary school children

Objective: In 2020, coronavirus disease-2019 (COVID-19) became the cause of a pandemic. In response, the Japan Sports Agency issued warnings about secondary damage to health, such as the threat to physical and mental well-being due to the lack of exercise in this situation. In this study, we report on cross-sectional and longitudinal examinations of standing trunk flexion to evaluate how temporary long-term school closures affected musculoskeletal function in elementary school students. Patients and Methods: All children in one public elementary school in T-city during the school years 2019 and 2020 were included in this study. A digital forward flexion meter was used to measure standing trunk flexion. Results: In this study, 284 (284/289: 98.3%) and 266 (266/274: 97.1%) children in school years 2020 and 2019, respectively, were found to have valid data for cross-sectional analysis. The standing trunk flexion did not show significant differences between grades or sexes. In the longitudinal analysis, the results of the comparison of standing trunk flexion in children for two consecutive years revealed significant differences only between grades 3 and 4 (P<0.05) and between girls in grades 3 and 4 (P<0.01), but no significant differences in other grades or among boys or girls were observed. Conclusion: Initially, we expected that there would be a difference in the results of functional assessment using standing trunk flexion depending on the period of absence from school. However, the results of this study showed no significant changes in standing trunk flexion. Moreover, since children's musculoskeletal functions may be affected by various factors during the COVID-19 pandemic, they should be carefully monitored in the future.

Factors that affect menarche in Japanese national-level track-and-field athletes

OBJECTIVES

The minimum body mass index (BMI) required to menarche and the relationship between the training onset age of sports and menarche is not fully understood. The aim of this study is to elucidate the minimum BMI required to attain menarche in female adolescent athletes competing at a national level, and to determine how the occurrence of menarche is associated with training onset age in track-and-field athletes.

METHODS

Overall, 134 sprinters and 44 long-distance (LD) runners of ninth-grade females at a national level were enrolled and an anonymous questionnaire was administered.

RESULTS

As BMI increased, the proportion of athletes who had attained menarche increased. The BMI cutoff values for menarche were 17.3 and 17.1 kg/m² for sprinters and LD runners, respectively. Menarche had not occurred in almost 50% of the LD runners who began training at elementary school, and among LD runners, those who began training at elementary school had 18.4 higher odds of not attaining menarche until the age of 15 years as opposed to those who started training after elementary school.

CONCLUSIONS

The BMI cutoff values could be an indicator for menarche in sprinters and LD runners. For LD runners, starting to compete at elementary school could be a risk factor for delayed menarche.

Cardiac function at diagnosis is important prognostic factor in patients with cardiac sarcoidosis -from Japanese nationwide questionnaire survey-

Background

Sarcoidosis is a systemic non-caseating granulomatous disease of unknown etiology. Cardiac involvement (cardiac sarcoidosis, CS) has been reported to be an important prognostic factor in this disease because of heart failure and/or ventricular arrhythmia, and corticosteroid therapy is usually prescribed to prevent cardiac events. However, little is known about the relationship of cardiac function and concomitant corticosteroid therapy on later cardiac events in CS.

Objective

We evaluated the relationship between prognosis and left ventricular ejection fraction (LVEF) at the time of diagnosis in CS patients from the Japanese nationwide questionnaire survey.

Methods

Total of 757 Japanese patients from 57 hospitals who diagnosed CS were examined. Patients who unsatisfied the criteria of the Japanese new guidelines, or who underwent cardiac transplantations were excluded, and 420 patients (287 females, mean age 60±13 years old, median follow-up periods 1864 days [interquartile range: 845–3159 days]) were analyzed. The relationship of adverse events (all-cause death, cardiovascular death, and appropriate ICD [Implantable Cardioverter Defibrillator] discharge) and LVEF (with corticosteroid 84%) (low LVEF: LVEF≤35% n=98 [with corticosteroid in 78%], moderate LVEF: LVEF 35–50% n=104 [with corticosteroid in 93%], normal LVEF: 50≤LVEF n=218 [with corticosteroid in 83%]) were evaluated respectively.

Results

89 CS patients developed all-cause death (n=50), cardiovascular death (n=30) or appropriate ICD discharge (n=48). The frequency of corticosteroid therapy was not different in the each LVEF group, but Kaplan-Meier analysis revealed that all-cause death, cardiovascular death, and all cardiovascular adverse events were more observed in lower LVEF group (log-rank p&lt;0.0001). Furthermore, multivariate Cox hazard analysis revealed that LVEF was a most important independent prognostic factor in CS.

Conclusion

This Japanese nationwide questionnaire survey data showed that initial LVEF was an independent and strong prognostic predictor in CS, therefore primary prevention would be needed even after starting corticosteroid in patients with decreased cardiac function.

Funding Acknowledgement

Type of funding source: None

Long time clinical course of cardiac sarcoidosis with corticosteroid therapy -from Japanese nationwide questionnaire survey-

Background

Sarcoidosis is a systemic inflammatory syndrome of unknown etiology and cardiac involvement has been reported to be an important prognostic factor in this disease. An autopsy study has reported that the frequency of this cardiac involvement (cardiac sarcoidosis: CS) varies in the different countries and races and very frequent in Japanese patients. We therefore performed the nationwide questionnaire survey and try to clarify the clinical characteristics and corticosteroid effect in CS, especially focused on arrhythmic events in this disease.

Methods

Total of 757 Japanese patients from 57 hospitals who diagnosed CS were examined. Patients who unsatisfied the criteria of the Japanese new guidelines, or who underwent cardiac transplantations were excluded, and 420 patients (287 females, median follow-up periods 1864 days [interquartile range: 845–3159 days]) were analyzed. The clinical outcome and corticosteroid effect were evaluated.

Results

Clinical characteristics at diagnosis was as follows: female dominant (68%), mean age of 60±13 years old, mean left ventricular ejection fraction was 49±16%. Arrhythmic events were very frequently observed as an initial cardiac manifestation in 263 patients (62%) of CS, of which atrioventricular block (AVB) in 174 (41%), ventricular tachycardia (VT) in 73 (17%) and AVB with VT in 17 (4%) (Figure 1A). Pacemaker was implanted in 166 patients (40%) and defibrillators was 137 patients (33%). Corticosteroid was prescribed in 144 (83%) of 174 patients with AVB and in 62 (85%) of 73 patients with VT. Initial dose was mean 47.9 mg and maintenance dose of mean 7.3 mg. Corticosteroid improved VT as good as AVB (27% vs. 29%). However, corticosteroid sometimes worsened VT events compared with AVB (10% vs. 2%) (Figure 1B). During the course of follow-up, 32 patients were needed to increase corticosteroid in 23 of AVB and 10 of VT cases. However, there were no difference in mortality between the groups, whether or not to increase corticosteroid. All survival rate was 92% (5-year mortality), 83% (10-year mortality) and free from all cause death and defibrillator charge was 81% (5 year), 71% (10 year).

Conclusion

Fatal arrhythmia is commonly observed in CS as a primary symptom. Corticosteroid sometimes worsen ventricular arrhythmia and appropriate defibrillator discharge was common. Thus, careful attention for activating ventricular arrhythmia would be needed during the follow-up period even after corticosteroid therapy.

Funding Acknowledgement

Type of funding source: None

Long-term follow up ventricular tachycardia patients with preserved cardiac function -from Japanese cardiac sarcoidosis nationwide questionnaire survey-

Background

Prior ventricular tachycardia (VT) and low left ventricular ejection fraction (LVEF) are the most important prognostic factors in cardiac sarcoidosis (CS). Recently diagnosis of CS was renewed according to Japanese new guidelines. Patients with preserved cardiac function often have VT events, thus new guidelines recommends to assess the implantable cardioverter defibrillator (ICD) implantation for CS patients with preserved LVEF (35%≤LVEF&lt;50%). However, the long-term prognosis of CS patients with preserved LVEF is unclear.

Objective

In CS patients with preserved LVEF, we evaluated the prognosis between VT manifestation and non-VT manifestation groups at CS diagnosis from Japanese nationwide questionnaire survey.

Methods

Total of 757 Japanese patients from 57 hospitals who diagnosed CS were examined. Patients who unsatisfied the criteria of the Japanese new guidelines, who had LVEF≤35%, LVEF&gt;50%, or who underwent cardiac transplantations were excluded. 104 patients with LVEF 35–50% (67 females, mean age 60±15 years old, median follow-up periods 2134 days [interquartile range: 758–2935 days]) were analyzed. The prognosis between VT manifestation and non-VT manifestation groups at CS diagnosis were evaluated.

Results

30 patients had VT manifestation at CS diagnosis and 24 patients (80%) received ICDs. 74 patients had no VT manifestation at CS diagnosis and 19 patients (44%) received ICDs during follow up period. All-cause mortality was not different between two groups (Figure). Appropriate ICD therapy of non-VT manifestation group was significantly lower compared with that of VT manifestation group (log-rank p=0.001), however considerable number (n=7, 15%) of non-VT manifestation group had appropriate ICD therapy event during follow-up period. Cox hazard analysis revealed that concomitant non-sustained VT (NSVT) with atrioventricular block (AVB) was a predictor of appropriate ICD therapy in non-VT manifestation group.

Conclusion

This nationwide survey showed that considerable number of CS patients with preserved LVEF had VT events, independent of VT manifestation. Concomitant NSVT with AVB was a predictor of VT events, and ICD implantation should be assessed.

Funding Acknowledgement

Type of funding source: None

Progressive age and other factors affecting scoliosis severity in cerebral palsy patients

Objective: This study aimed to investigate the age at which scoliosis progresses to a severe condition and identify the factors related to severe scoliosis in patients with cerebral palsy. Patients and Methods: This retrospective study included 51 patients aged ≥15 years. The Cobb angle was measured over time using radiographs. Patients were divided into the following groups according to their final Cobb angle: <60°, 60°-100°, and ≥100°. The age at which the Cobb angle was ≥20° in the patients was compared among the groups. Moreover, the age at which a significant difference in the Cobb angle occurred in the groups was considered the age at which the scoliosis worsened. Association of the final Cobb angle with factors such as the location of curve, Gross Motor Functional Classification System (GMFCS), capability of turning over, orthosis use, hip dislocation, tracheotomy, and gastric fistula was examined. Results: The mean age at which the Cobb angle was ≥20° was significantly lower in the ≥100° group. From 9 years of age, a significant difference was noted in the Cobb angle between the <60° group and ≥100° group. Between 13-19 years, a significant difference in the Cobb angle was observed among the three groups. Furthermore, GMFCS, capability of turning over, hip dislocation, and gastric fistula were the factors showing a significant difference among the three groups. Conclusion: Scoliosis progressed to the severe form (Cobb angle ≥100°) at 9 years of age. Moreover, scoliosis is aggravated during the growth period. Severe cerebral palsy with low motor function levels and problems with internal functions was considered the cause of scoliosis deterioration.

Four-year musculoskeletal examinations among elementary and junior high school students across a single city

Objective: In 2016, Japan started conducting musculoskeletal examinations that included “limb status” of students as an essential item. Our institution implemented a unified musculoskeletal examination for all public elementary and junior high schools in T-city. In this study, we aimed to report the progress in the past 4 years.

Patients and Methods: The Tsukuba Childhood Locomotive-Organ Screening Sheet (T-CLOSS), which is a questionnaire that includes some nationwide-recommended questions, was prepared and distributed to students. Results of the questionnaires were analyzed, and the orthopedic surgeon conducted examinations for the extracted items. From these questionnaires, the ratio of each item, rate of advisory for screening, and content of the advisory were investigated.

Results: During 2016–2019, musculoskeletal examinations were conducted in every public schools, with nearly 20,000 students in T-city. The consultation advisory rate was 6.7% in 2019. Of the 524 students who received the third screening recommendation, the actual consultation rate was 248 (40.8%). After the third screening, the proportion of students requiring treatment and outpatient visits was 46.7% (n=248), which accounted for 1.2% of all elementary and junior high school students in the city.

Conclusion: We reported the results of 4-year musculoskeletal examinations in a city. In our screening, we distributed a uniform questionnaire throughout the city, and orthopedic surgeons performed secondary examinations of identified students in all schools. This appears to be an advanced effort to prevent musculoskeletal impairment in students. We hope to conduct more sophisticated musculoskeletal examinations using our results, aiming at early detection, early treatment, and improvement of musculoskeletal function in elementary and junior high school students.

Characteristics and diagnostic factors associated with fresh lumbar spondylolysis in elementary school-aged children

PURPOSE

We often encounter elementary school-aged children with fresh lumbar spondylolysis and non-union of bone. They may have factors that impede healing, and treatment outcomes need improvement. The purpose of this study was to investigate elementary school-aged patients with fresh lumbar spondylolysis and to identify characteristics that can aid in prompt diagnosis and proper therapy.

METHODS

We retrospectively compared the characteristics of fresh lumbar spondylolysis in elementary school-aged children with those of older patients. We included patients aged 6-18 years with lower back pain and evidence of bone marrow oedema of lumbar pedicles on magnetic resonance imaging (MRI). The elementary school-aged group (group E) included 100 patients aged 6-12 years, and the senior group (group S) included 251 patients aged 13-18 years. We recorded patient sex, duration of lower back pain, injured site (lumbar level, unilateral/bilateral), presence of contralateral pars defect with evidence of high signal change on MRI (short tau inversion recovery), presence of spina bifida occulta (SBO), and follow-up treatment interruption rate.

RESULTS

One-third of the patients in group E were female, and there was an even smaller proportion of females in group S. L5 lumbar spondylolysis was more common in group E. The treatment interruption rate was lower in group E. L5 SBO and contralateral pars defect were more common in group E.

CONCLUSION

L5 lumbar spondylolysis, L5 SBO, and contralateral pars defect were important diagnostic factors in elementary school-aged patients. Identification of these characteristics will aid in prompt diagnosis and proper therapy.

Use of nutritional supplements by elite Japanese track and field athletes

BACKGROUND

While scientific evidence supports the efficacy of only limited nutritional supplements (NS) on sports performance, the use of NS is widespread in athletes. Given the serious issues of health damage or unintended Anti-Doping Rule Violations due to ingestion of contaminated NS in sports, accurately understanding NS practices by athletes is crucial. This study therefore elucidated the use of NS by elite Japanese track and field (TF) athletes.

METHODS

The subjects were 574 Japanese TF athletes, including 275 junior athletes (under 20 years) and 299 senior athletes, who participated in international competitions from 2013 to 2018. Data on NS use were collected through pre-participation medical forms obtained from all entrants before their participation in competitions. NS users were requested to report the product names and primary components of all NS they were taking.

RESULTS

The overall prevalence of NS use was 63.9%. The mean number of NS products used per athlete was 1.4. The prevalence was significantly higher in women (69.2%) than in men (59.6%) (p = 0.018) and significantly higher in senior athletes (68.9%) than in junior athletes (58.9%) (p = 0.012). The prevalence of NS use was higher in long-distance runners (75.8%) and lower in jumpers (52.3%) and throwers (49.2%) than other disciplines (p < 0.001). The most prevalent components were amino acids (49.3%), followed by vitamins (48.3%), minerals (22.8%), and protein (17.8%).

CONCLUSIONS

Approximately two-thirds of elite Japanese TF athletes reported the use of NS, and NS practices varied by gender, age, and discipline.

Determining the relationship between physical status and musculoskeletal injuries in children: a cohort study

Background: In Japan, in 2016, the School Health and Safety Act was revised and examination of extremities in addition to scoliosis became mandatory. Musculoskeletal examinations were subsequently started using a mark sheet-type questionnaire. In the present study, we aimed to analyze the relationship between physical findings and musculoskeletal problems and propose a preventive strategy for musculoskeletal injuries. Methods: In 2017, a total of 4,073 elementary and middle school students underwent direct musculoskeletal examination. In a direct examination, the following elements were included: torticollis; scoliosis; stiffness of the shoulder, elbow, hip, knee, and ankle; flexion and extension in standing position; flat foot; hallux valgus; and alignment of the upper and lower extremities. Of the 4,073 students who underwent direct examination in early 2017, only 3,754 were able to complete the mark sheet-type questionnaires in early 2018. A prospective longitudinal analysis of the data gathered was performed. Results: A total of 396 (11%) students had injuries. The ankle sprain/non-ankle sprain group comprised 119 (3%)/3,635 (97%) students, while the fracture/non-fracture group comprised 105 (2.8%)/3,650 (97.2%) students, respectively. Comparing the sprain group with the non-sprain group, ankle stiffness significantly correlated with ankle sprain in the univariable and multivariable analyses. Injuries occurred more frequently among boys, older students, students with stiff bodies, and students who were involved in sports activities of longer duration. Conclusion: Ankle stiffness was assumed to be a risk factor for ankle sprain. Stretching of the ankle might be effective for preventing ankle sprain. However, further interventional studies are needed to confirm this finding.

Probing Few-Body Nuclear Dynamics via ^{3}H and ^{3}He (e,e^{'}p)pn Cross-Section Measurements

We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9  (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500  MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350  MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250  MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500  MeV/c.

Safety and immediate effects of Hybrid Assistive Limb in children with cerebral palsy: A pilot study

PURPOSE

Early intervention is effective for developing motor ability and preventing contractures and deformities in patients with cerebral palsy (CP). Gait training using the newly developed Hybrid Assistive Limb (HAL) shows promise as an intervention to prevent deterioration in walking ability and deformities in pediatric CP patients. The purpose of this pilot study was to examine the safety and immediate effects on walking ability after gait training using the HAL in pediatric CP patients.

METHODS

Nineteen patients (six females, 13 males; mean age 8.5 years; mean height 120.5 cm; mean weight 23.2 kg) were enrolled. The Gross Motor Functional Classification Scale level was I in two patients, II in two, III in eight, and IV in seven. The HAL was used for a single session of gait training. The primary outcome was safety of the HAL for use in pediatric CP patients. The secondary outcome was the immediate effect after gait training with HAL, evaluated by passive range of motion (ROM) and gait parameters, including gait speed (m/s), step length (cm), and cadence (step/min).

RESULTS

All 19 patients were able to carry out the gait training without any severe adverse events. Significant improvements were observed for mean internal/external rotation and abduction angles of the hip joint, and ankle dorsiflexion angles (n = 19). Significant improvements were observed for mean gait speed and step length based on expansion of the hip flexion-extension range (n = 11).

CONCLUSION

Gait training using the HAL is safe and can produce immediate improvements in ROM and walking ability in pediatric patients with CP.

Prophylactic pinning should be considered in patients at risk for slipped capital femoral epiphysis

Background: The use of prophylactic contralateral pinning for slipped capital femoral epiphysis (SCFE) remains controversial. This study evaluated the outcome of SCFE treatment and examined the use of prophylactic pinning.

Methods: The study included 44 patients (33 men, 11 women; 54 hips [right, 31; left, 23]), with mean age of 12.9 (7.3–29) years, who underwent treatment between 1986 and 2017, with follow-up for more than 6 months. Patients were divided into 3 groups: group 1 had bilateral SCFE at first presentation, group 2 developed contralateral side SCFE during follow-up, and group 3 had unilateral SCFE until final follow-up. Three patients who received prophylactic pinning were excluded. Univariate and multivariate logistic analyses were performed.

Results: Overall, 93% (50/54) of hips underwent positional reduction and in situ fixation and 7.4% (4/54) underwent open reduction. Mean follow-up period was 4.8 (0.5–25) years. Groups 1, 2, and 3 had 7, 3, and 31 cases, respectively. Sex, age, and follow-up period showed no significant differences among the groups. The Rohrer index was significantly higher in group 1, the affected side posterior sloping angle (PSA) was significantly higher in group 3, and the contralateral side PSA and percentage with endocrinopathy were significantly higher in group 2. In multivariate logistic analysis, age, sex, Rohrer index, affected side PSA, and endocrinopathy were significantly correlated with bilateral SCFE.

Conclusion: We recommend prophylactic contralateral side pinning in patients with risk factors of obesity, high PSA before slipping, and endocrinopathy. Careful observation until growth plate closure is required in patients without risk factors.

Relationship between exercise time and musculoskeletal problems in children

Objectives: The purpose of this study was to evaluate the relationship between exercise time and musculoskeletal problems and to determine the appropriate amount of exercise for children in both lower- and higher-grade levels of elementary and junior high schools.

Materials and Methods: Mark-sheet-type questionnaires were distributed to and collected from all elementary and junior high schools in two cities. We collected 22,494 questionnaires in total. The relationship between exercise time and musculoskeletal problems was analyzed. The χ² test and multivariate logistic regression analysis were used for statistical analyses.

Results: The mean exercise time in school, in addition to physical education time, was 3.1 hours per week. In 56% of the children, the exercise time was less than 2 hours per week, and in 13% of the children, the exercise time was more than 10 hours per week. Although the rate of sports injury increased with an increase in exercise time, the duration of one-leg stand (a test of balance and muscle strength) also increased with an increase in exercise time. The cut-off values for sports injuries in boys/girls were 2.9/2.9 hours, 4.0/2.9 hours, and 7.5/4.2 hours in lower grade elementary school, higher grade elementary school, and junior high school, respectively.

Conclusions: Although an appropriate amount of exercise improves one’s physical health and ability, excessive exercise leads to musculoskeletal problems. Approximately 7 hours/week of exercise is recommended for junior high school students. In elementary school, the exercise time should be carefully decided as the musculoskeletal system of the students is still immature.

Proposal of a New Type of Innominate Osteotomy without the Use of Bone Graft in Children: A Preliminary Study

Good long-term outcomes have been reported for the Salter innominate osteotomy (SIO), which is widely used to correct developmental dysplasia of the hip (DDH) in children. In this study, we describe the procedure and early outcomes of a new pelvic osteotomy termed “angulated innominate osteotomy” (AIO).

Ephrin type-A receptor 2 on tumor-derived exosomes enhances angiogenesis through the activation of MAPK signaling

Exosomes are potent players in the development of metastases and they play an important role in cancer angiogenesis and exacerbation. However, it is unclear how proteins on exosomes affect development of blood vessel networks. In this study, we focused on relationships between membrane proteins on exosomes and angiogenesis using human umbilical vein endothelial cells (HUVEC). Lung tumor cell-derived exosomes induced tube formation and growth of endothelial cells in vitro in a dose-dependent manner involving MAPK activation, but this was not seen in normal lung epithelial cells. Ephrin type-A receptor 2 (EphA2) was identified by proteomic analysis and an inhibition assays showed it is a major MAPK activator on exosomes. Thus EphA2 on exosomes participates in angiogenesis as a ligand of the ephrin signaling pathway. These results support the development of novel therapeutic strategies such as blockade of remote cancer communications through exosomes.

Cross-Sectional Survey of Childhood Acetabular Development in Japan

Introduction:

We aimed to clarify childhood acetabular development and to identify the incidence of children’s hip dysplasia in Japan using radiographs of the contralateral hip.

Methods:

We performed radiological cross-sectional evaluation of hip development in 211 patients (106 boys, 211 hips) in different age groups (age range: 3–9 years). We excluded patients who complained of bilateral coxalgia at the first visit or had received a diagnosis of acetabular dysplasia. We measured the acetabular index (AI), center-edge angle (CEA), and acetabular head index (AHI) in plain radiographs taken at the first visit.

Results:

A significant correlation was found between age and CEA in boys, but other parameters had no significant correlation. The mean AI values in boys and girls were 18 ± 3° and 20 ± 4° (p < 0.01), respectively, and the mean CEA values were 25 ± 5° and 24 ± 5° (p = 0.43), respectively. The mean AHI values in boys and girls were 83 ± 6% and 81 ± 7%, respectively (p < 0.01). Two of the 120 children (66 boys and 54 girls) aged ≥6 years old had a hip CEA < 15°; both were girls.

Conclusions:

We found decreased acetabular development in girls, and 4% (2/54) of girls without any history of dislocation belonged to Severin’s group III. Acetabular dysplasia was observed more frequently in children from Japanese than in those from other countries. Girls with less than two standard deviations in hip dysplasia indices had an AI of 28°, an AHI of 67%, and a CEA of 14°. These reference values may be useful as prognostic indicators for hip dysplasia and OA in adulthood.

Improvement and sustainability of walking ability with hybrid assistive limb training in a patient with cerebral palsy after puberty: a case report

[Purpose] Cerebral palsy is one of the most common causes of childhood physical disability affecting motor development. Gait training with a wearable-robot, such as the Hybrid Assistive Limb, has been reported to improve gait ability in patients with chronic motor disabilities; however, there are no reports concerning the sustained improvement of walking ability with its use in patients with cerebral palsy. We present our observations for the use of Hybrid Assistive Limb gait training in a postpubescent cerebral palsy patient. [Participant and Methods] A 17-year-old male with spastic cerebral palsy could only ambulate slightly using a crouch gait posture and with the aid of a walker. Hybrid Assistive Limb training was performed thrice weekly for 4 weeks (total of 12 sessions) along with concurrent daily physical therapy. The follow-up period was 7 months after the intervention. [Results] The intervention resulted in improvements in the patient’s gait speed, proportion of the stance phase in a gait cycle, step length, and the flexion angle of the knees at initial contact and during late stance phase, which was sustained for 7 months following the intervention. [Conclusion] Our observations suggest that Hybrid Assistive Limb training may effectively improve and sustain walking ability even among postpubescent cerebral palsy patients who have a decreased walking ability.

Newly developed hybrid assistive limb for pediatric patients with cerebral palsy: a case report

[Purpose] The effect of fitness training on improving walking ability in cerebral palsy is controversial. However, gait training with a wearable robot (hybrid assistive limb) has been reported to improve gait ability in patients with cerebral palsy. For pediatric patients, a smaller, lighter-weight hybrid assistive limb has been newly developed. We describe the immediate effect of this newly developed smaller hybrid assistive limb on the gait ability of a pediatric patient with cerebral palsy and examine its safety and feasibility. [Participant and Methods] An 11-year-old male with spastic cerebral palsy (height, 130 cm; weight, 29.0 kg) who could ambulate using an elbow crutch participated in this study. A single session of hybrid assistive limb training comprising pre-exercise of the hip and knee joints and walking for 20 minutes was conducted. [Results] The intervention immediately improved his gait speed, stride length, and cadence according to the 10-m walking test. Co-contraction of agonist/antagonist muscles during walking improved, and the flexion angle of the right hip during the swing phase increased, which resulted in symmetry of movement of both legs. [Conclusion] Gait training using the new, smaller hybrid assistive limb for a pediatric patient was safe and feasible, and the newly developed hybrid assistive limb has the potential to immediately improve walking ability even among young children with cerebral palsy.

Feasibility and safety of Robot Suit HAL treatment for adolescents and adults with cerebral palsy

To investigate whether Robot Suit HAL treatment (HAL-T) is safe and feasible for gait disorders in adolescents and adults with cerebral palsy (CP). We tested HAL-T in adolescents and adults with bilateral spastic CP (four men, four women; mean age: 18.2 years). Three participants were classified as level III under the Gross Motor Function Classification System (GMFCS), and five were classified as level IV. The participants underwent HAL-T twice per week for 4 weeks. The outcome measures, which were assessed before and after HAL-T, included comfortable gait speed (CGS), step length (SL), cadence, and GMFCS level. Adverse events were noted. All participants completed the HAL-T sessions despite some mild adverse events occurring. The mean increases in CGS, SL, and cadence were 0.19 ± 0.14 m/s (p = 0.006), 0.09 ± 0.08 m (p = 0.020), and 18.0 ± 15.9 steps/min (p = 0.015), respectively. HAL-T is safe and feasible for gait disorders in patients with CP. HAL-T can significantly improve CGS, SL, and cadence and may be effective for improving walking ability in adolescents and adults with CP.

Anorexia and supracondylar fracture of the femur following surgery for bilateral lower limb joint contracture in a case of severe cerebral palsy with mental retardation: a case report

Objective: Postoperative management of children having cerebral palsy (CP) with mental retardation is difficult. This report presents a case of severe CP with mental retardation, which resulted in anorexia and condylar fracture of the femur following a surgery for bilateral lower limb joint contracture.

Case report: A 14-year-old male was diagnosed with CP having severity of Gross Motor Functional Classification System Level V, and severe mental retardation. Due to bilateral spasticity in hip adduction, knee flexion, and valgus of the feet, tenotomies of the adductors of both hips, bilateral lengthening of the hamstrings and bilateral tenotomy of the peroneal tendons were performed. At 4 weeks postoperatively, knee casts were used; thereafter, knee extension braces were attached for 12 weeks. After surgery, he showed severe anorexia for 8 weeks and weight loss of 8.8 kg (from 35.2 kg to 26.4 kg) during the 4 months of hospitalization. Six months postoperatively, he was diagnosed with supracondylar fracture of the right femur.

Discussion: Severe CP with mental retardation requires attention to the physical symptoms caused by stress related to the hospitalization, surgery, fixation by casts, and braces. Moreover, care must be taken not to increase the risk of fracture by fixation or immobility of the postoperative cast, because it can lead to the progression of low bone mineral density.

Dominance of Tensor Correlations in High-Momentum Nucleon Pairs Studied by (p,pd) Reaction

The isospin character of p-n pairs at large relative momentum has been observed for the first time in the ^{16}O ground state. A strong population of the J,T=1,0 state and a very weak population of the J,T=0,1 state were observed in the neutron pickup domain of ^{16}O(p,pd) at 392 MeV. This strong isospin dependence at large momentum transfer is not reproduced by the distorted-wave impulse approximation calculations with known spectroscopic amplitudes. The results indicate the presence of high-momentum protons and neutrons induced by the tensor interactions in the ground state of ^{16}O.

A novel exercise device for venous thromboembolism prophylaxis improves venous flow in bed versus ankle movement exercises in healthy volunteers

PURPOSE

Venous thromboembolism prophylaxis is crucial. To facilitate active ankle movement in postoperative and bedridden patients, we developed a novel leg exercise apparatus (LEX). We investigated the effect of the LEX by comparing increases in lower extremity venous flow during different modes of exercise using the LEX.

METHODS

In eight healthy participants, we measured venous flow volume and velocity in the femoral vein using duplex ultrasonography at 1, 10, 20, and 30 min after completing three modes of 1-min LEX exercises. The exercises involved (1) rapid single motion (ankle dorsi-plantar flexion; 60 cycles/min); (2) slow single motion (30 cycles/min); and (3) slow combined leg motion.

RESULTS

Flow volumes after modes 1, 2, and 3 were 1.63-, 1.39-, and 1.53-fold above baseline at 30 min, respectively. Short periods of rapid single motion, with the LEX, improved postexercise lower extremity venous flow volumes at 30 min and mean venous flow velocity at 20 min, compared to slow single motion exercise. Even at slow speeds, combined-motion improved flow volume compared to single motion.

CONCLUSION

Short periods of rapid single motion exercise, with the LEX, improved postexercise venous flow volumes in the lower extremities at 30 min and mean venous flow velocity at 20 min. These effects were greater than those produced by slow single motion exercises. However, even at slow speeds, combined-motion exercises improved flow volume compared to single motion. Therefore, LEX may prove effective at preventing thromboembolism in postoperative and bedridden patients.

Use of Hybrid Assistive Limb (HAL®) for a postoperative patient with cerebral palsy: a case report

Background

The Hybrid Assistive Limb (HAL^®) is an exoskeleton wearable robot suit that assists in voluntary control of knee and hip joint motion. There have been several studies on HAL intervention effects in stroke, spinal cord injury, and cerebral palsy. However, no study has investigated HAL intervention for patients with cerebral palsy after surgery.

Case presentation

We report a case of using HAL in a postoperative patient with cerebral palsy. A 15-year-old boy was diagnosed with spastic diplegia cerebral palsy Gross Motor Function Classification System level IV, with knee flection contracture, equinus foot, and paralysis of the right upper extremity with adduction contracture. He underwent tendon lengthening of the bilateral hamstrings and Achilles tendons. Although the flexion contractures of the bilateral knees and equinus foot improved, muscle strength decreased after the soft tissue surgery. HAL intervention was performed twice during postoperative months 10 and 11. Walking speed, stride, and cadence were increased after HAL intervention. Post HAL intervention, extension angles of the knee in stance phase and hip in the pre-swing phase were improved. In the gait cycle, the proportion of terminal stance in the stance and swing phase was increased.

Conclusions

Hybrid Assistive Limb intervention for postoperative patients with cerebral palsy whose muscle strength decreases can enhance improvement in walking ability. Further studies are needed to examine the safety and potential application of HAL in this setting.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3311-z) contains supplementary material, which is available to authorized users.

Soft-tissue release for hip subluxation and dislocation in cerebral palsy

Objective: This study aimed to evaluate the effectiveness of soft-tissue release on hip subluxation and dislocation in cerebral palsy as well as activities of daily living after surgery.

Patients and Methods: Soft-tissue release was performed in 13 patients (19 hips) with cerebral palsy. Of them, 10 had spastic quadriplegia and three had spastic diplegia. Mean ages were 8.6 years at surgery and 13.8 years at the last investigation. The mean follow-up period was 5.2 years. Hip subluxation and dislocation severities were analyzed before and after surgery and at the final investigation as migration percentage on radiographs. Postoperative activities of daily living were also evaluated in 12 patients.

Results: Seven hips classified as mild and moderate preoperatively were classified as good, mild, and moderate at the last investigation. Nine of 12 hips classified as severe preoperatively continued to be severe at the last investigation. However, three of 12 hips classified as severe preoperatively improved at the last investigation. There was a positive correlation between preoperative migration percentage and that at the last investigation. Daily activities improved postoperatively in 12 patients.

Conclusions: Early treatment is necessary to prevent hip dislocation and improve hip subluxation. However, several patients with severe subluxation might experience improvement with soft-tissue release alone. Soft-tissue release is effective for treating hip dislocation and subluxation in cerebral palsy and improving daily activities.

The correlation between Salter's criteria for avascular necrosis of the femoral head and Kalamchi's prognostic classification following the treatment of developmental dysplasia of the hip

AIMS

The aim of this study was to evaluate the correlation between Salter's criteria and Kalamchi's classification of avascular necrosis in patients treated for developmental dysphasia of the hip (DDH).

PATIENTS AND METHODS

The study involved a retrospective analysis of 123 patients (123 hips) with DDH treated by operative and non-operative reduction before the age of two years, with a minimum follow-up of ten years. Salter's criteria (S1 to S4) were determined from radiographs obtained at one to two years post-reduction, whilst the Kalamchi grade was determined from radiographs obtained at ten or more years of age. Early post-reduction radiographs were also used to evaluate the centre-head distance discrepancy (CHDD) and the occurrence of a dome-shaped deformity of the proximal femoral metaphysis (D-shaped metaphysis). The prognosis was described as good (Kalamchi grade K0 or KI), fair (Kalamchi grade KII) or poor (Kalamchi grade KIII or KIV) for analysis and correlation with the early Salter criteria, CHDD and D-shaped metaphysis.

RESULTS

S1 and S2 criteria were predictive of a poor prognosis. The outcome following S3, S4 and S3 + S4 varied; 18 (40%) had a good prognosis, 17 (38%) a fair prognosis and ten (22%) a poor prognosis. A CHDD ≥ 10% and a D-shaped metaphysis were also predictive of a poor prognosis.

CONCLUSION

The Salter criteria were predictive of the Kalamchi grade of avascular necrosis in patients with DDH aged ten or more years after reduction of the hip. Cite this article: Bone Joint J 2017;99-B:1115-20.

Location of fractures and the characteristics of patients with atypical femoral fractures: analyses of 38 Japanese cases

The purpose of this study was to determine fracture location and the characteristics of patients with atypical femoral fractures (AFFs). We studied 38 AFFs in 34 patients admitted to our institution between November 2007 and July 2013. The diagnostic criteria for the AFFs were based on 2014 American Society of Bone and Mineral Research guidelines. We classified the fracture location as proximal, middle, or distal to trisect the femoral diaphysis from just distal to the lesser trochanter to just proximal to the supracondylar flare. Bowing was defined as a line through the inside of the tip of the great trochanter and a condylar center that was outside the medullary cavity. We investigated the fracture's location, existence of coronal bowing, and bisphosphonates (BPs), glucocorticoids (GCs), and proton pump inhibitors therapy. We analyzed associations between fracture location and demographic and clinical factors. Twelve fractures were proximal, 25 were middle, and one was distal. Nineteen limbs showed femoral bowing. Thirty-one patients received BP treatment-20 patients received alendronic acid, eight risedronic acid, and three minodronic acid. Fourteen patients received a GC, and 16 received a proton pump inhibitor. There was a significant association between coronal bowing and middle fracture locations, GC therapy and proximal fracture locations, and older age and middle fracture locations. Tall height and heavy weight had an association with proximal fracture location, and short height and light weight had an association with middle fracture location. In conclusion, we provide evidence supporting a causal relationship between BP-related severely suppressed bone turnover and AFFs. We also provide evidence supporting additional influences from altered distribution of mechanical stress with femoral bowing and various factors, such as GC therapy, age, body weight, and height, which might negatively affect bone intensity and quality and result in fracture.

Effects of Cyclic Tensile Forces on the Expression of Vascular Endothelial Growth Factor (VEGF) and Macrophage-colony-stimulating Factor (M-CSF) in Murine Osteoblastic MC3T3-E1 Cells

It has been reported that vascular endothelial growth factor (VEGF), expressed by osteoblasts, can induce osteoclast recruitment and thus affects bone remodeling. The purpose of this study was to investigate the effects of cyclic tensile forces on the expression of VEGF and macrophage-colony-stimulating factor (M-CSF) in osteoblastic MC3T3-E1 cells. VEGF and M-CSF gene expression and protein concentration were determined by real-time PCR and enzyme-linked immunoassay. The expression of VEGF and M-CSF mRNA in the experimental group was higher than in the control group. The increase in the concentration of VEGF and M-CSF protein in the experimental group was time-dependent. Moreover, gadolinium (an S-A channel inhibitor), but not nifedipine (L-Type Ca2+ channel blocker), treatment reduced the concentration of VEGF and M-CSF mRNA and protein in the experimental groups. These findings suggest that cyclic tensile forces increase the expression of VEGF and M-CSF in osteoblastic MC3T3-E1 cells via a stretch-activated channel (S-A channel).

A novel apparatus for active leg exercise improves venous flow in the lower extremity

BACKGROUND

Venous thromboembolism is a serious complication associated with major orthopedic surgery to the lower extremities. Although active ankle exercise is recommended, patients with postoperative pain may have difficulty moving their ankles. Therefore, we developed a novel leg exercise apparatus (LEX) to facilitate active ankle movement during the early postoperative period. We describe how LEX facilitates active movement of the leg, and thereby increases venous flow in the lower extremities.

METHODS

The femoral venous flow volume and velocity in 8 healthy volunteers (5 men, 3 women; mean age 22.4 years; age range 22-26 years), were measured using duplex ultrasonography. Measurements were repeated 1, 3, 5, and 10 minutes after the completion of 1 minute of active ankle exercise using LEX, and during a 10-minute period of intermittent pneumatic compression (IPC) device use.

RESULTS

The flow volume after 1 minute of LEX exercise increased 2.63-fold from baseline; elevated values persisted for 10 minutes. Flow volume at 10 minutes was increased 1.71-fold from baseline. The corresponding values during IPC did not differ from resting values. The mean velocity 1 minute after LEX exercise increased 2.34-fold from baseline; in contrast, mean velocity 1 minute after the start of IPC had decreased 0.90-fold (P=0.009).

CONCLUSIONS

A 1-minute period of LEX exercise improved venous flow in the lower extremities, compared with continuous use of IPC. Use of LEX might facilitate improved ankle mobility, and therefore reduced risk of thromboembolism, in postoperative patients.

The use of a novel in-bed active Leg Exercise Apparatus (LEX) for increasing venous blood flow

OBJECTIVE

The incidence of pulmonary embolism (PE) and leg deep vein thrombosis (DVT) has increased in recent years in association with aging and an increase in the number of bedridden individuals. We developed an active in-bed leg exercise apparatus labeled the Leg Exercise Apparatus (LEX) for DVT prevention. We compared the effect of leg exercises performed using the LEX to conventional active ankle exercises on increased blood flow.

MATERIALS & METHODS

The subjects were eight healthy adult volunteers [five men and three women, aged 20-34 (mean 27.0) years]. Subjects performed two types of exercise; exercise 1 consisted of leg exercises using the LEX, while exercise 2 consisted of in-bed active plantar flexion/dorsiflexion exercises without the device. Measurements were taken 1, 5, 10, 20, and 30 minutes after exercise including common femoral vein blood flow, mean blood flow velocity, maximum blood flow velocity, and vessel diameter using Doppler ultrasound. Statistical procedures included timed measurement data analysis using a linear mixed model. A Bonferroni correction was used for multiple comparisons.

RESULTS

Compared to resting levels, blood flow reached a maximum value 1 minute after exercise for both exercise types, with a significantly greater increase after exercise 1 (1.76-fold increase) compared to exercise 2 (1.44-fold increase) (p = 0.005). There was a significant difference (p = 0.03) between the two exercises for all values from 1 minute to 30 minutes following exercise. There was no significant difference between exercises for peak or mean blood flow velocity. Compared to resting levels, blood vessel diameter reached a maximum value of 1.47-fold greater at 5 minutes post-exercise for exercise 1 and a maximum value of 1.21-fold greater at 1 minute post-exercise for exercise 2.

CONCLUSIONS

Exercise using the LEX increased lower leg venous blood flow and vessel diameter. We propose that the LEX may serve as a new DVT prevention tool.

Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg

[Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named “LEX” was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (−)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (−) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention.

Generation of a sensitive TNFR2-specific murine assays system

Tumor necrosis factor (TNF)/TNF receptors (TNFR1/TNFR2) are considered to be potential drug targets to treat refractory diseases, including autoimmune diseases and malignant tumors. However, their specific functions, especially in the case of TNFR2, are poorly understood. In this study, we constructed a mouse TNFR2 (mTNFR2)-mediated biological assay system that shows no effects of mouse TNFR1 (mTNFR1) in order to screen mTNFR2-selective stimulating agents. Mouse TNFR1(-/-)R2(-/-) preadipocytes were transfected with the gene encoding the mTNFR2/mouse Fas (mFas) chimeric receptor in which the extracellular and transmembrane domains of mTNFR2 were fused to the intracellular domain of mFas. Our results demonstrated that this cell line exhibits highly sensitive mTNFR2-mediated cytotoxic effects. We propose that this mTNFR2-mediated biological assay system would be a useful tool to screen for mTNFR2-selective stimulating agents.