Polymeric Orthosis with Electromagnetic Stimulator Controlled by Mobile Application for Bone Fracture Healing: Evaluation of Design Concepts for Medical Use

Background: The occurrence of bone fractures is increasing worldwide, mainly due to the health problems that follow the aging population. The use of additive manufacturing and electrical stimulators can be applied for bioactive achievements in bone healing. However, such technologies are difficult to be transferred to medical practice. This work aims to develop an orthosis with a combined magnetic field (CFM) electrostimulator that demonstrates concepts and design aspects that facilitate its use in a real scenario. Methods: A 3D-printed orthosis made of two meshes was manufactured using PLA for outer mechanical stabilization mesh and TPU for inner fixation mesh to avoid mobilization. A CFM stimulator of reduced dimension controlled by a mobile application was coupled onto the orthosis. The design concepts were evaluated by health professionals and their resistance to chemical agents commonly used in daily activities were tested. Their thermal, chemical and electrical properties were also characterized. Results: No degradation was observed after exposure to chemical agents. The CMF achieved proper intensity (20–40 µT). The thermal analysis indicated its appropriate use for being modelled during clinical assessment. Conclusion: An orthosis with a coupled electrostimulator that works with a combined magnetic field and is controlled by mobile application was developed, and it has advantageous characteristics when compared to traditional techniques for application in real medical environments.     

Evaluation of Load Distribution in a Mandibular Model with Four Implants Depending on the Number of Prosthetic Screws Used for OT-Bridge System: A Finite Element Analysis (FEA)

In full-arch implant rehabilitations, when the anterior screw abutment channel compromises the aesthetic of the patient, the OT-Bridge system used with its Seeger rings may provide the necessary retention of the prosthesis. However, no studies have evaluated the forces generated at the Seeger level during loading. This Finite Element Analysis aims to investigate the mechanical behavior of Seeger rings in a mandibular model with four implants and an OT-Bridge system, used without one or two anterior prosthetic screws. A 400 N unilateral load was virtually applied on a 7 mm distal cantilever. Two different variables were considered: the constraint conditions using two or three screws instead of four and the three different framework materials (fiberglass reinforced resin, cobalt-chrome, TiAl6V4). The FEA analysis exhibited tensile and compressive forces on the Seeger closest to the loading point. With the resin framework, a tension force on abutment 3.3 generates a displacement from 5 to 10 times greater than that respectively expressed in metal framework materials. In a full-arch rehabilitation with four implants, the case with three prosthetic screws seems to be a safer and more predictable configuration instead of two. Considering the stress value exhibited and the mechanical properties of the Seeger, the presence of only two prosthetic screws could lead to permanent deformation of the Seeger in the screwless abutment closest to the loading point.     

Regional disparities in cardiac rehabilitation volume throughout Japan based on open data from a National Database of Health Insurance Claims

Objective: This study assessed the regional disparities and the associated factors in the implementation of cardiac rehabilitation in Japan.Materials and Methods: Regional disparities were investigated by comparing the number of cardiac rehabilitation units in each of 47 prefectures in Japan based on the National Database of Health Insurance Claims Open Data published by the Ministry of Health, Labour, and Welfare. The relationships between the numbers of inpatient and outpatient cardiac rehabilitation units and the numbers of registered instructors of cardiac rehabilitation, board-certified physiatrists, and board-certified cardiologists were examined.Results: The region with the highest and lowest numbers of inpatient units showed 11,620.5 and 1,650.2 population-adjusted cardiac rehabilitation units adjusted per 100,000 population, respectively, corresponding to a 7.0-fold difference. Meanwhile, 4,865.3 and 238.6 units were present in the regions with the highest and lowest numbers of outpatient units, respectively, corresponding to a 20.4-fold regional disparity. Our analysis showed that the population-adjusted number of inpatient cardiac rehabilitation units was significantly associated with the population-adjusted numbers of registered instructors of cardiac rehabilitation (r=0.647, P<0.001) and board-certified cardiologists (r=0.445, P=0.002) but only marginally associated with the population-adjusted number of board-certified physiatrists (r=0.329, P=0.024). Moreover, the population-adjusted number of outpatient cardiac rehabilitation units was significantly associated with the population-adjusted numbers of registered instructors of cardiac rehabilitation (r=0.406, P=0.005) and board-certified cardiologists (r=0.450, P=0.002) but not with the population-adjusted number of board-certified physiatrists (r=0.078, P=0.603).Conclusion: Large regional disparities were observed during the implementation of cardiac rehabilitation. Increased numbers of cardiac rehabilitation instructors and cardiac rehabilitation practices are expected to eliminate these regional differences in cardiac rehabilitation practices.     

The hamstrings are more impacted than the quadriceps after severe ankle sprain

Ankle sprains (AS) are common in the military population, with a prevalence 5 to 8 times higher than that for civilians. The aim of this study was to evaluate in patients with severe AS the impact of disuse on thigh muscle induced by unloading and immobilization due to care. This study focused on muscle trophicity and dynamometric strength. In this observational prospective study, assessments were repeated at 3 visits: close to injury, 15 and 30 days following the sprain. The injured limb was compared to the contralateral limb. A dynamometer assessment was used to monitor changes in strength and fatigue of the thigh muscles of both limbs. Isometric and isokinetic concentric evaluation of peak torque (PTiso and PTdyn), total work (Wt), and peak torque time integral (IPT) of thigh muscles. Full follow-up was obtained in 30 subjects. The injured limbs showed significant deficits in the mean (SD). The quadriceps PTiso and IPT deficits were −12.6% ± 1.9% (P < .0001) and −13.27% ± 1.8% (P < .0001), respectively. The quadriceps PTdyn showed a significant deficit since V2 (−12.2.5% ± 2.0). The quadriceps Wt presented a significant deficit of −4.2% ± 2.4 (P < .0007) at 1 month. The hamstring PTdyn deficit presented a mean loss of −16.5% ± 2.4% (P < .0001). The hamstring Wt deficit was −13.7% ± 2.3% (P < .001). The analysis of variance showed that the grade of the sprain had a significant effect on the quadriceps PTq deficit (P < .016) but not the type of discharge. Our study showed that disuse leads to a significant deficit in the strength of knee muscles within 1 month. It is noteworthy that the hamstrings are more affected than the quadriceps. The rehabilitation protocol to prevent the risk of iterative ankle injuries and secondary knee injuries should incorporate early training of both quadriceps and hamstrings.     

Effects of tissue plasminogen activator on medium-term functional independence: A propensity score-matched analysis

This study revealed the effects of tissue plasminogen activator (tPA) on medium-term functional independence in patients with stroke. We retrospectively examined 240 patients from April 2016 to March 2019 and selected 68 who met our criteria. After adjusting the functional status at the onset by propensity score matching, the functional independence measure (FIM) on admission to and discharge from the convalescent rehabilitation wards was compared between the groups classified by the presence or absence of tPA. Twelve pairs were derived by propensity score matching. Upon admission to the convalescent rehabilitation ward, the median score of the FIM was significantly higher in the tPA group than in the non-tPA group (P = .028). Patients in the tPA group had higher median FIM scores at discharge than those in the non-tPA group (P = .060). The difference in the independence level of activities of daily living (ADL) between the groups with and without tPA may gradually decrease with continuous inpatient rehabilitation. However, the tPA group tended to have high levels of independence in ADL at the time of discharge.