Detection of biomagnetic signals from induced pluripotent stem cell-derived cardiomyocytes using deep learning with simulation data.

The detection of spontaneous magnetic signals can be used for the non-invasive electrophysiological evaluation of induced pluripotent stem cell-derived cardiomyocytes (iPS-CMs). We report that deep learning with a dataset that combines magnetic signals estimated using numerical simulation and actual noise data is effective in the detection of weak biomagnetic signals. To verify the feasibility of this method, we measured artificially generated magnetic signals that mimic cellular magnetic fields using a superconducting quantum interference device and attempted peak detection using a long short-term memory network. We correctly detected 80.0% of the peaks and the method achieved superior detection performance compared with conventional methods. Next, we attempted peak detection for magnetic signals measured from mouse iPS-CMs. The number of detected peaks was consistent with the spontaneous beats counted using microscopic observation and the average peak waveform achieved good similarity with the prediction. We also observed the synchronization of peak positions between simultaneously measured field potentials and magnetic signals. Furthermore, the magnetic measurements of cell samples treated with isoproterenol showed potential for the detection of chronotropic effects. These results suggest that the proposed method is effective and has potential application in the safety assessment of regenerative medicine and drug screening.

Indication for Achilles Tenotomy in Congenital Clubfoot: Effectiveness of Using the Tibio-Plantar Fascia Angle as a Radiographic Parameter.

Congenital clubfoot is one of the most common deformities in children, and currently, the Ponseti method is used worldwide because of its favorable short-term results. With the Ponseti method, the indication for Achilles tenotomy is traditionally based on only physical examination findings; however, some surgeons have also utilized plain radiographs. Because using physical examinations to determine the degree of hindfoot dorsiflexion for the indication of tenotomy can lead to underestimation. We developed and utilized the effectiveness of the tibio-plantar fascia angle (Ti-P angle) in the lateral maximum dorsiflexion view in determining the need for Achilles tenotomy. A retrospective analysis of consecutive 26 patients with congenital idiopathic clubfeet (37 feet) was performed. Whether Achilles tenotomy was indicated was determined based on physical examination for a former period (Group P). For the latter period, whether tenotomy was indicated was determined by referencing radiographs (Group X). No significant differences were found in any of the background factors or severity between Group P and Group X. Cases with larger tibiocalcaneal and Ti-P angles were more likely to require Achilles tenotomy or additional soft tissue release. An angle of more than 72° of the Ti-P angle demonstrated adequate specificity for the indication of Achilles tenotomy. The radiographic lateral tibio-plantar fascia angle is useful for deciding whether a tenotomy needs to be performed.

Langenskiöld Procedure for Treatment of Partial Growth Arrest of Distal Ulna After Septic Osteomyelitis: A Case Report.

Background: Although cases of impaired long bone growth due to bone and joint infections in childhood are sometimes reported, few cases of growth impairment of the ulna due to septic osteomyelitis have been described. We report herein a case of ulnar partial physeal arrest treated using the Langenskiöld procedure. Materials and Methods: A boy developed septic osteomyelitis of the right distal ulna at age 2 years 6 months. Osteomyelitis subsided after antibiotic treatment and external immobilization. As a result of impaired growth of the ulna along the long axis, shortening and trumpet-shaped deformity of the metaphysis gradually appeared. Computed tomography revealed a bony bridge, and premature epiphyseal closure due to osteomyelitis was diagnosed. The Langenskiöld procedure was performed at 4 years 4 months old. Results: As of 2 years 9 months later, no further ulnar shortening has occurred and morphological remodeling has been confirmed. Conclusions: The treatments employed for ulnar shortening include ulnar lengthening by callotasis as well as stapling of the distal radial epiphyseal line or radial shortening osteotomy. In this case, the Langenskiöld procedure proved effective because the patient was still young with growth potential and the area of the bony bridge after osteomyelitis-induced epiphyseal line damage was <30%.

Hybrid Fixation for Paediatric Femoral Supracondylar Fracture during Circular External Fixation of the Lower Limb.

AIM: To describe the novel hybrid fixation technique for paediatric femoral supracondylar fracture during circular external fixation of the lower limb. BACKGROUND: The Ilizarov external fixator is commonly used for various orthopaedic conditions. Difficulties associated with external fixation have previously been described. A fall while using a circular external fixator can cause ipsilateral fracture. Such fractures are ideally treated conservatively, but it is difficult to fix the frame itself. No study has reported the treatment of paediatric femoral supracondylar fracture during circular external fixation. Herein, we describe a novel hybrid fixation technique that was successfully used to treat paediatric femoral supracondylar fracture in three paediatric patients with circular external fixators. TECHNIQUE: The fracture was manually manipulated and reduced by slight hyperextension of the lower extremity under general anaesthesia. After confirmation of good reduction, a stockinette, a cast padding, and a thin core cast were applied to the ipsilateral thigh. The hinge parts were attached to the medial and lateral sides of the proximal ring. The rods were connected to the medial and lateral hinges, and the half ring was connected to the ventral side of the proximal end. Under fluoroscopic confirmation, the thin core cast of the thigh and rods were connected by cast rolled in a figure-of-eight manner. The hinges were locked with the knee joint slightly flexed. CONCLUSION: The minimally invasive hybrid fixation technique enables conservative treatment of paediatric femoral supracondylar fracture during circular external fixation of the lower limb with no complications, and early exercise and recovery. CLINICAL SIGNIFICANCE: This novel hybrid fixation technique will be an effective method for paediatric femoral supracondylar fracture in patients with a circular external fixator. HOW TO CITE THIS ARTICLE: Oka Y, Kim W-C, Yoshida T, et al. Hybrid Fixation for Paediatric Femoral Supracondylar Fracture during Circular External Fixation of the Lower Limb. Strategies Trauma Limb Reconstr 2020;15(3):179-183.

Effectiveness of medial-wedge insoles for children with intoeing gait who fall easily.

OBJECTIVES: This study aims to investigate the effectiveness of orthosis therapy using a medial-wedge insole (MWI) with a height of 5 mm and an arch support for children with intoeing gait who are prone to falling. PATIENTS AND METHODS: Between January 1997 and July 2014, a total of 51 children (24 males, 27 females; mean age 5.0 years; range, 3 to 8 years) who were treated for an intoeing gait symptom of easily falling using the MWI (toe-in gait group) were included. The effectiveness of the MWI was evaluated based on the scores reported by children and their parents on a scale. Physical findings of the study group were also compared with a control group consisting of seven healthy children (4 males, 3 females; mean age 5.2 years; range, 3 to 6.2 years). Foot stability with and without MWI were assessed. RESULTS: The MWI was found to be effective in 80.8% of the toe-in gait group. Bilateral sum of the internal rotation angle of the hip (IRAB) was significantly higher (136±17°) (p=0.007) and bilateral sum of thigh foot angle (TFAB) significantly lower (-27±21°) (p<0.001) before using MWI in the toe-in gait group, compared to the control group. The maximum range of motion of the foot in six children in the toe-in gait group significantly decreased from 14.1±5.0° without MWI to 8.2±3.0° with MWI (p=0.002) in the gait analysis. CONCLUSION: These study results suggest that MWI is effective in reducing the risk of falling in children with intoeing gait, mainly due to the internal torsion of the tibia or femur. In addition, it appears to be effective in improving the maximum range of motion of the foot.

Monitoring of Callus Maturation and Measurement of Resistance Rates Using Bioelectrical Impedance for Patients Treated With an External Fixator.

Evaluation of callus maturation and the decision to remove an external fixator depend on radiographic and clinical findings, which are subjective. Callus fracture or recurrent deformity may occur after premature removal of a fixator. The authors applied a technique to measure bioelectrical impedance to assess callus maturation. This study included 27 limbs that underwent deformity correction or callus distraction using a fixator. Mean patient age at the time of surgery was 17.2 years. Overall impedance during callus maturation was measured from after completion of correction or distraction to removal of the fixator. Temporal changes in impedance values were measured, and maximum and final values were compared with initial values. The resistance rates were compared by age (<15 or ≥15 years), correction site (femur or tibia), and treatment method (noncontact or contact). Mean overall impedance increased gradually. Compared with initial values, maximum and final impedance values were 1.21 times and 1.15 times higher, respectively. Resistance rates by age, correction site, and treatment method were significantly higher in patients 15 years and older, in the tibia, and in the contact group, respectively. Overall impedance tended to increase during callus maturation but varied among patients. Therefore, resistance rates were calculated to classify differences for individual patients. Age and treatment method were important predictors of resistance rates. These data by age, correction site, and treatment method, which assume overall impedance from after completion of correction or distraction, can serve as a useful index to determine when a fixator should be removed. [Orthopedics. 2018; 41(1):54-58.].

Modyfied wedge osteotomy for osteoarthritis of elbow secondary to osteochondritis dissecans in adolecent with multiple epiphyseal dysplasia. A case report.

Multiple epiphyseal dysplasia (MED) may be complicated by osteochondritis dissecans (OCD), most commonly reported in the knee, but involvement of the elbow is very rare. Optimal treatment for MED-associated elbow OCD and treatment outcome have not been established. This report describes the case of an adolescent male patient with elbow OCD treated by arthroscopic drilling at a previous clinic. Progression of osteoarthritis and radial head subluxation were observed. Resection of the osteophytes and modified wedge osteotomy of the lateral condyle were then performed, and a favorable result was obtained by decompression and sufficient congruency of the radiohumeral joint.

Acetabular anteversion angle from early stage of Perthes disease to adolescence.

OBJECTIVE: This study aimed to assess acetabular anteversion angle (AAA) from the early stage of Perthes disease to adolescence. METHODS: Twenty-five patients treated conservatively were examined. Changes in AAA from initial to final measurement were compared between the two groups (G-group: Stulberg classes I and II; P-group: classes III and IV). RESULTS: In the G-group, AAA decreased significantly in the affected hip compared with the unaffected hip, whereas AAA decreased in both hips in the P-group. CONCLUSION: Acetabular retroversion may occur only in the affected hip or in both hips; in the latter case, the treatment outcome may be poor.

Assessment of lateral subluxation in Legg-Calvé-Perthes disease: a time-sequential study of magnetic resonance imaging and plain radiography.

Lateral subluxation of the femoral head is one of the poor prognostic factors of Legg-Calvé-Perthes disease. The aim of this study was to investigate the cause of lateral subluxation of the femoral head on the basis of the changes over time on MRI. Twenty-four patients with unilateral Legg-Calvé-Perthes disease were analyzed retrospectively. Lateral subluxation was measured as the tear drop distance on radiographs. We focused on joint fluid, medial articular cartilage thickening, and abnormal lesion on MRI. Lateral subluxation continued significantly in patients with poor results. Among the MRI findings, the presence of an abnormal lesion was associated significantly with the continuous lateral subluxation.

Detection of early changes after growth plate injury using MRI.

BACKGROUND: To elucidate the association between growth plate injury size and the beginning of physeal growth disturbance by MRI. METHODS: Thirty-two 5-week-old male Japanese white rabbits were used. Injuries were made to the right tibial proximal growth plate central region with a 3.0-mm and a 1.2-mm drill. The left tibia was used as a control. MRI (7.04 Tesla [T], gradient echo: repetition time [TR], 71.68 ms; echo time [TE], 3.60 ms; proton-density weighted imaging: TR, 2000 ms; TE, 12 ms) of the growth plates was performed at 1, 4, 8, 10, and 12 weeks postinjury. Tibia length, histology, radiography, and microcomputed tomography (µCT) were studied. RESULTS: MRI showed that at 10 and 12 weeks postinjury in the 3.0-mm group, the medial and lateral growth plates in the noninjured regions were significantly reduced compared with the controls (P < 0.05). At 12 weeks postinjury in the 1.2-mm group, medial and lateral growth plates in the noninjured regions were significantly reduced (P < 0.05). Tibia length and histological growth plate height of injured side in both groups were significantly shorter than controls at 12 weeks postinjury (P < 0.05). Comparison with the controls showed no significant difference at any of the time periods in either the 3.0- or 1.2-mm group according to the radiographic studies (P > 0.05). Bony bridges developed in all the subjects of the 3.0-mm group and in five of eight subjects of the 1.2-mm group, as shown by µCT images. CONCLUSION: This study suggested that growth plate injury size was associated with the timing of the beginning of physeal growth disturbance.

A new method for the estimation of age at death by using electrical impedance: A preliminary study.

Estimation of age at death is an important part of physical and forensic anthropology. The aim of this study was to investigate whether bioelectrical impedance analysis (BIA) of long bones can be used in the field of forensic medicine as a method to estimate age at death. BIA is easy to use and allows repeat measurements to be taken over time, and the equipment is inexpensive and portable. Impedance values (Z values) in 378 long bones (humeri, radii, femora, tibiae) of 40 male (233 bones) and 26 female (145 bones) autopsy cadavers were measured using two wire electrodes (connected to an alternating current device and a measuring device) inserted into the metaphyses of long bones. Computed tomography of the greater trochanter of the femur was also analyzed to evaluate bone mineral density (BMD). The results showed that Z values could be used to estimate age in males, and with an age cut-off point of 50 years in females. When estimating age at death from femur and tibia in males by using BIA, it is not necessary to consider the length of subjects. And it was thought that Z values reflected BMD. Among the long bones, the tibia is the most suitable and easy to use for Z value measurement. Z value measurement is a useful method for quantitative evaluation of age at death that can be performed quickly with inexpensive, portable equipment.

The time of the insult/triggering event in Legg-Calvé-Perthes' disease determined by incubation period modeling and the age distribution of children with Perthes'.

The time when the insult/triggering event occurs in Legg-Calvé-Perthes' (LCPD) is unknown. the purpose of this study was to determine, using the mathematical tool of incubation period modeling, the time of such event and the incubation period for LCPD. We reviewed 2,911 children with LCPD from 10 different centers around the world. They were divided into two groups: those from India (505 children, mean age 8.1 ± 2.3 years) and those from other than India (2,406 children, mean age 5.8 ± 2.2 years). A simple distribution with an excellent fit to the data was ln(y) = a + bx + cxln(x), where y is the proportion of children with LCPD at age of diagnosis x (r(2) = 0.994 for non-Indian and 0.959 for Indian children). The age of the triggering event was 1.32 years for non-Indian and 2.77 years for Indian children; the median incubation period was 4.30 years non-Indian and 5.33 years for Indian patients. Knowing the incubation period and age of triggering event narrows the number of potential etiologies in LCPD. this study does not support a prenatal triggering event as postulated in the past. similar incubation periods with different ages at diagnosis supports a common insult which occurs at different ages in different populations dependent upon local factors such as geographic location and ethnicity.

Use of a rugby helmet brace for postoperative treatment of muscular torticollis.

Prior to 1992, our postoperative management for congenital muscular torticollis consisted of either plaster cast immobilization or no immobilization, depending on the patient's age and the degree of contracture. However, some patients required further surgery and developed complications. In 1992, we produced rugby helmet braces for postoperative management. The purpose of this study was to compare the clinical results of the previous postoperative management with the results achieved using rugby helmet braces. Twenty-five children aged younger than 6 years underwent caudal partial resection of the sternocleidomastoid muscle. Twelve children aged 6 years and older underwent cranial tenotomy. These 37 patients were divided into 2 groups: no immobilization or plaster immobilization (group A; n=19) and rugby helmet braces (group B; n=18). Canale's method was used for evaluation of clinical results. In group A, the results were good in 12 patients, fair in 4, and poor in 3, whereas all 18 patients in group B had good results. Two patients in group A required further surgery, and complications were observed in 5 patients. In group B, alopecia areata was observed in 1 patient.The rugby helmet brace is easy to put on and remove, providing good retention and allowing for physiotherapy. It provides a useful method of postoperative management for congenital muscular torticollis.

Assessment of distraction callus in rabbits by monitoring of the electrical impedance of bone.

BACKGROUND AND PURPOSE: Evaluation of distraction callus is important for determination of the optimal time for removal of external fixation. We attempted to determine whether there might be a relationship between the electrical impedance of bone and callus maturation, with a view to using impedance as a way of knowing when to remove a fixator. METHODS: We applied an external lengthener to the right tibia of 24 rabbits and performed distraction at 1 mm/day for 10 days. Radiographs were taken and measurement of overall impedance between fixation pins was performed weekly after distraction. At weeks 2, 4, 6, and 8 after distraction (n = 6 each), resistivity of the bone to electrical conductivity was measured before killing. Cross-sectional area of the conduction pathway in callus and maximum bending stress were measured after excision of the tibia. RESULTS: The overall impedance increased statistically significantly from 1 to 6 weeks after completion of distraction. The resistivity of bone decreased over 4 weeks and the cross-sectional area of callus decreased significantly over 6 weeks, while the maximum bending stress increased significantly over the same time. We observed a negative correlation between the cross-sectional area of callus and maximum bending stress. INTERPRETATION: The impedance values, which are related to changes in electrical conductivity and the conduction pathway, increased due to the changes in the cross-sectional area of callus, despite the reduction in bone resistivity. Since the cross-sectional area of callus was correlated with maximum bending stress and the impedance values increased with the callus-remodeling process, we suggest that temporal increases in overall impedance reflect callus maturation.

Measurement of bone electrical impedance in fracture healing.

BACKGROUND: Although external fixation is widely used for fractures and limb lengthening, evaluation of the time for removing the external fixator is dependent upon radiographic examinations and clinical findings, and a useful method has yet to be established clinically. This study aimed to measure the bone electrical impedance (Z values) non-invasively by using external fixation pins as electrodes, and clarify the relationship with bone union. METHODS: Thirty rabbits received the external fixation at the right tibia and were assigned to a control group (group C; n = 5) and a fractured group (group F; n = 25). Z values were measured once a week following surgery. The animals of group F were assigned to 5 groups (weeks 2, 3, 4, 5, and 6 after osteotomy, each n = 5). The resistivity (rho) of the electrical property between electrodes was measured prior to euthanasia, and fracture cross-sectional area (FrA) of the conduction pathway and maximum bending stress (Bmax) were measured following excision of the tibia. RESULTS: Although Z values in group F increased through 5 weeks after surgery, Z values in group C remained constant at 3 weeks, and significant differences were observed between groups at 4, 5, and 6 weeks. The rho values and FrA in group F decreased through 5 weeks; while Bmax increased, reaching a plateau at 5 weeks. CONCLUSIONS: Narrowing of conduction pathway due to the decrease in the contour of fracture area accompanying bone remodeling resulted in an increase of Z values. Both Z values and Bmax in group F reached a peak at 5 weeks, this was believed to be the optimal time for removal of external fixation. These results suggest that measurement of Z values makes it possible to evaluate bone union.

[Bone fracture and the healing mechanisms. Fracture treatment using electrical stimulation].

In 1953, Iwao Yasuda reported on the piezoelectricity of bone and the electrical stimulation of callus formation. Subsequently, various methods of electrical stimulation have been investigated, and the enhancement of callus formation by electrical stimulation is likely to have broad clinical applications for not only the repair of fractures, but also for nonunion and pseudoarthrosis. Recently, these outcomes have been validated by significant double blind clinical trials, and the electrical currents in bone were investigated at the molecular level. Moreover, the application of impedance measurements obtained upon electrical stimulation as a means to evaluate bone maturation was examined. This paper reports on the current methods of electrical stimulation, the fundamental effects on bone formation, and further clinical applications.

Evaluating bone union of distal radius fractures by measuring impedance values.

The measurement of impedance is a noninvasive and simple quantitative technique for evaluation of fracture healing. Fractures of the distal radius are the most common long bone fractures, accounting for approximately 20% to 25% of all acute fractures. External fixators have been applied clinically to treat unstable distal radius fractures. The evaluation of radiological findings and clinical signs are current standard methods and are effective in assessing fracture union of the distal radius, but these methods are dependent on subjective elements. For the objective methods, previous studies have shown that measurement of bone mineral density, ultrasound, quantitative computed tomography, and acoustic emission are useful in evaluating bone union. However, due to the complexity and high radiation dose associated with these methods, are seldom used clinically. This study was undertaken to examine the correlation between bone union and impedance at the site of digital radius fractures treated with an external fixator, using an alternating current electrical stimulator and a digital oscilloscope.

Efficacy of titanium dioxide photocatalyst for inhibition of bacterial colonization on percutaneous implants.

The purpose of this study was to evaluate the efficacy of titanium dioxide photocatalyst in inhibition of bacterial colonization on percutaneous implants. Titanium dioxide photocatalyst was prepared by direct oxidization of pure titanium substrate, and a comparative study with pure titanium was performed. The bactericidal ability of the photocatalyst was examined using methicillin-resistant Staphylococcus aureus (MRSA) suspensions in a colony-forming assay according to the Japanese Industrial Standards committee standard. After exposing the MRSA suspension on sample plates to ultraviolet A (UVA) light, the number of surviving bacteria was estimated. Next, an animal model for inhibition of colonization was examined in vivo. Pins were inserted into the femurs of rabbits, were infected with 10(8) colony-forming units of MRSA suspension, and were illuminated with UVA light for 60 min daily; the number of colonizing bacteria was estimated after 7 days. The bactericidal ability of the photocatalyst was apparent after 60 min, when the bacteria had almost disappeared. The number of colonizing bacteria on photocatalytic pins was decreased significantly in vivo. The photocatalyst was effective even against resistant bacterial colonization. Clinically, the incidence of percutaneous implant infection such as pin tract infection in external fixation could be reduced using the titanium photocatalyst.

Experience of bone bridge resection and bone wax packing for partial growth arrest of distal tibia.

Two patients with a partial growth arrest of the distal tibia were treated by bone bridge resection and bone wax packing technique. Their average age at the time of surgery was 7 years, both had been injured in an accident, and each had been treated with percutaneous pinning and a plaster cast. Unfortunately, partial growth arrest of the distal tibia occurred, and the ankle varus deformity gradually progressed. About 1 year after initial treatment, bone bridge resection and bone wax packing were performed. The average follow-up period was 80 months. There was no reformation of the bone bridge or recurrence of deformity, and gradual improvements in clinical and radiographic findings were observed. Although fat is typically used as an interpositional material after bone bridge resection, there are problems with its use, including a lack of hemostasis and the absence of intrinsic stability. Bone wax is readily available and commonly used in medical applications to control bleeding. It is considered a useful plug, it is inexpensive, and it is not associated with complications.