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Abstract Background We evaluated the relationship between the weight-bearing line (WBL) ratio and anatomical femorotibial angle (FTA) by simulated open wedge high tibial osteotomy (OWHTO). This study evaluated the correlation between the ‘‘Fujisawa point’’ and FTA, and identified factors which caused deviations between the two measurement methods. We hypothesized that the Fujisawa point corresponded with 170° of the FTA. Methods Preoperative antero-posterior full-length lower limb radiographs of 82 patients were obtained for the OWHTO to place the WBL ratio at a target of 62.5% of the width of the tibial plateau (Fujisawa point). The coronal alignment was measured pre- and post-planning. The patients were divided into two groups by the post-planning FTA: a correspondence group (168.5°≦FTA≦171.5°) and a non-correspondence group (FTA

In this study, best-fit fatigue curves are constructed considering material properties and loading modes. Three common fatigue test methods (rotating bending, axial load-controlled and strain-controlled) are compared, and their scopes of applications are clarified. The best-fit fatigue curves are given as a function of tensile strength and have been constructed based on the strain-controlled fatigue test data. The comparison of the best-fit fatigue curves with the axial load-controlled test data reveals that both deviated from each other for the carbon and low-alloy steels and the austenitic stainless steel. Therefore, the best-fit fatigue curves are reconstructed considering the data by the rotating bending fatigue test and the axial load-controlled fatigue test. In the case of the carbon and low-alloy steels, the best-fit fatigue curves are classified by two kinds of microstructures. In the case of the austenitic stainless steel, the best-fit fatigue curves are classified by two kinds of loading modes. Finally, design factors based on the reliability of best-fit fatigue curves are specifically presented.

Abstract Background To investigate the relationship between femoral or tibial torsion and hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), or mechanical medial proximal tibial angle (mMPTA) in patients with medial knee osteoarthritis (OA). Methods A total of 75 knees were enrolled. Femoral and tibial torsions were measured by superimposing the axial planes of computed tomography images. The relationship between femoral or tibial torsion and HKA, mLDFA, or mMPTA on radiographs was examined. Results The mean femoral torsion was 12.2 ± 8.5° internally; femoral internal and external torsions were observed in 70 and 5 knees, respectively. The mean tibial external torsion was 18.0 ± 7.4° externally; tibial external torsion was observed in all 75 knees. Femoral internal and tibial external torsions increased with lower mMPTA (r = 0.33, P = 0.003; r = − 0.32, P = 0.005, respectively) but were not related to HKA or mLDFA. Conclusion Femoral and tibial torsions were correlated with varus inclination of the proximal tibia in patients with medial knee OA.

Abstract Background The association of glycated albumin (GA) with mortality is unclear in chronic hemodialysis patients with diabetes. We investigated the usefulness of GA by comparing it with hemoglobin A1c (HbA1c) in this patient population. Research design and methods This was a multi-center, prospective cohort study of 841 Japanese chronic hemodialysis patients with diabetes. There were 235 women and 606 men included, with a mean age of 64 years. The primary and secondary endpoints were the incidence of all-cause and cause-specific mortality, respectively. The hazard ratios of GA and HbA1c for the endpoints were estimated using the values at baseline and during the study period. Results During the mean follow-up period of 3.1 years, there were 184 deceased cases, in which 30 and 154 resulted from atherosclerotic cardiovascular disease (ASCVD) and non-ASCVD, respectively. The hazard ratio for a 1% increase in GA was 1.033 (95% confidence interval 1.006–1.060, p = 0.017) for all-cause mortality with a statistical significance when GA was treated as a time dependent variable, but not when the baseline levels or the mean levels during the follow-up period were used in the analysis (p = 0.815 and 0.517, respectively). GA was a significant predictor for ASCVD-related mortality in the above 3 models, but was not for non-ASCVD mortality. Higher levels of HbA1c were only associated with ASCVD-related mortality when HbA1c was treated as a time-dependent variable. Conclusions GA may be useful compared to HbA1c for predicting all-cause and ASCVD-related mortality in Japanese patients with diabetes undergoing chronic hemodialysis.

Background: The carotid bulb has a high density of baroreceptors that play an important role in maintaining blood pressure. We hypothesized that atherosclerosis of the carotid bulb would reflect the severity of orthostatic hypotension more accurately than would atherosclerosis of other carotid artery segments. Methods: This cross-sectional study included 198 non-diabetic adults. We measured the cardio-vascular ankle index as an index of arterial stiffness, intima-media thickness in each carotid artery segment (internal carotid artery, carotid bulb, distal and proximal portions, respectively, of the common carotid artery) as a measure of atherosclerosis, and heart rate variability as a measure of cardiac autonomic function. The sit-to-stand test was used to assess severity of orthostatic hypotension. Results: Intima-media thickness of the carotid bulb was correlated with orthostatic systolic blood pressure change (r = −0.218, p = 0.002), cardio-ankle vascular index (r = 0.365, p < 0.001) and heart rate variability parameters. Multivariate regression analysis revealed that among all of the segments, only intima-media thickness of the carotid bulb was an independent predictor of orthostatic systolic blood pressure change (p = 0.022). Conclusion: Atherosclerosis of the carotid bulb was associated with severity of orthostatic hypotension, arterial stiffening and cardiac autonomic dysfunction than that of other carotid artery segments.

Purpose: The purpose of this study was to investigate the surgical outcomes of total hip arthroplasty (THA) through direct anterior approach (DAA) performed by beginners by comparing the outcomes after the introduction of DAA-THA between using a normal operating table and a traction table. Methods: The total subjects were 200 patients, there were 120 cases from the introduction of three surgeons using a normal table and 80 cases from two surgeons using a traction table. The surgical procedure was standardized, and a surgeon skilled in DAA entered the operating room and instructed the novice surgeons of DAA in all cases. Results: The mean operative time was no significant difference between the two groups ( p = 0.093). The difference in slope of the operative time was no significant difference between the two groups ( p value = 0.089). The mean fluoroscopy time and the mean blood loss were significant difference between the two groups ( p < 0.05). The difference in slope of the fluoroscopy time and blood loss were significant difference between the two groups ( p < 0.05). There were no intraoperative complications and no reoperations for any reason. Conclusions: At the facility with a surgeon skilled in DAA, the use of a traction table in DAA did not increase the complication rate compared with the use of a normal operating table when the exclusion criteria for DAA were set and surgery was performed using intraoperative fluoroscopy under supervision by a skilled surgeon.

Cable television (CATV) systems generally consist of a headend, trunk cables, distribution cables in the neighborhood, drop cables to a home and in-house wiring, and terminal equipment. Coaxial cables bring a CATV signal to customer premises through a service drop, an overhead or underground cable. Hermetic inline amplifiers are used to amplify the attenuated CATV signal due to propagation loss or splitting the coaxial cable. They are usually installed on utility poles. Therefore, maintenance methods for inline amplifiers on utility poles are important issues in CATV operations. This paper proposes a new maintenance system for inline amplifiers in CATV systems, and develops a prototype implementation. The proposed system consists of an amplifier gain analyser to measure amplification performance of inline amplifiers, a special smartphone application, and a cloud server. The proposed amplifier gain analyser is composed of three functions: a generation of high frequency signals for testing, measurement of the test signal gain, and wireless communication based on Bluetooth Low Energy (BLE). We develop a signal generation circuit for a test signal and a smoothing circuit for converting the high frequency test signals into DC signals. The amplifier gain analyser can evaluate an amplifier gain by comparing an input test signal from the signal generation circuit and an output test signal from an inline amplifier. The measurement function uses Nordic nRF51822, which is a System on Chip (SoC) for BLE because Nordic nRF51822 has some AD converter ports for evaluating the DC signals. The smartphone application employs BLE communication function to collect the measured amplifier gain from the amplifier gain analyser. Therefore, we developed a special data collection application for iOS. The data collection application has a central function of BLE, and can find a target peripheral device that is the amplifier gain analyser in this paper. Therefore, technicians of CATV systems can easily check the operational status of inline amplifiers on utility poles. Additionally, the smartphone application can upload the measured information to a cloud storage server. We employ Google App Engine and use Cloud Datastore to implement the cloud storage service. Therefore, our storage service has flexibility for various kinds of information.

For opening wedge high tibial osteotomy (OWHTO), it is recommended that the osteotomy line is parallel to the medial tibial posterior slope (TPS) in the sagittal view and that the alignments are simultaneously controlled in the coronal and sagittal views. Here combined computed tomography (CT)-based and image-free navigation systems were used for intraoperative reference during OWHTO. Using the CT-based navigation, 2 entry points for insertion of Kirschner wires were preoperatively set up and an accurate osteotomy plane was intraoperatively duplicated. Preoperative planning anticipated a femorotibial angle of 170°, representing a weight-bearing ratio of 62.5%, on the whole-leg radiograph. The original TPS in the sagittal view was aimed to be preserved postoperatively. The hip-knee-ankle (HKA) correction angle was preoperatively measured on the whole-leg radiograph, and the HKA angle and flexion angle were intraoperatively monitored in real time using the image-free navigation. We have introduced an operative technique for OWHTO using CT-based and image-free navigation systems. We expect that this method, with the osteotomy plane parallel to the tibial plateau plane in the sagittal view and simultaneous control of coronal and sagittal alignments, will enable actuation of accurate alignment in the 2 planes and lead to improvements in patient activity in future.

Displaced tibial intercondylar eminence fractures require early reduction and stable fixation to prevent nonunion, knee instability, and a lack of extension. Many types of surgical procedure are recommended including arthrotomy or an arthroscopic technique to stabilize the fracture segment using Kirschner wire, screws, staples, and suture fixation. However, contemporary arthroscopic techniques and devices can facilitate intra-articular surgery and have been applied to the treatment of this fracture. In our current report, we describe a simple suture fixation method under arthroscopy for the treatment of tibial intercondylar eminence fractures. We treated eight knees of eight patients. One patient had a Type II fracture and seven patients had a Type III fracture according to Meyer's classification. Following the arthroscopic inspection of concomitant injuries, debridement of hematoma, and reduction of the fragment, two nonabsorbable sutures (Ethibond No. 2, Johnson & Johnson, Somerville, NJ, USA) were advanced through the suture passer device, which is used to penetrate the anterior cruciate ligament (ACL) near to the insertion site of the displaced fragment. Two surgical sutures were pulled out by the suture retriever from the anterior proximal tibia hole and were fixed to the tibia cortex bone with a double-spike plate. At follow-up, radiographic examinations showed that bone union was achieved in all cases. All but one patient could resume normal activities with no restrictions and no ligamentous instability. All knees had a negative Lachman's test and showed a gain of stable ligament function by KT2000 arthrometer evaluation. One patient had an insignificant extension limitation and experienced slight pain after walking but these symptoms were minimal. In conclusion current arthroscopic surgery techniques for tibial intercondylar fractures can be easily performed and reproducibly achieve secure fixation and early mobilization of the knee.

Background: We aimed to report an unusual case of a subchondral insufficiency fracture that occurred at the non-weight-bearing portion of the lateral posterior femoral condyle (LPFC). Case presentation: An 82-year-old woman with severe knee pain was diagnosed with a subchondral bone defect in the non-weight-bearing portion of the LPFC. The patient underwent total knee arthroplasty with an intramedullary stem and an augmentation block. Twelve months post-operatively, her Knee Society score and knee injury and osteoarthritis outcome score improved from 34 to 92 and 136 to 316, respectively. Reports on subchondral insufficiency fractures at the portion are extremely limited. No surgical treatments or histological reports on subchondral insufficiency fractures at the portion have been published. Conclusions: In our case, pre-operative valgus alignment and a combination of factors, including sex, low bone mineral density and physical activity, and lifestyle, might have resulted in the subchondral insufficiency fracture at the location.

We propose a new method for the specific nonlinear and nonconvex global optimization problem by using a linear relaxation technique. To simplify the specific nonlinear and nonconvex optimization problem, we transform the problem to the lower linear relaxation form, and we solve the linear relaxation optimization problem by the Branch and Bound Algorithm. Under some reasonable assumptions, the global convergence of the algorithm is certified for the problem. Numerical results show that this method is more efficient than the previous methods.

In this paper, we propose an interference reduction routing protocol for ad-hoc networks. The interference is one of the degradation factors in wireless communications. In the ad-hoc network, some nodes communicate simultaneously. Therefore, these communications cause interference each other, and some packets are corrupted due to interference from another node. In the proposed protocol, each node estimates required transmission power according to hello messages. Therefore, the node can transmit a data packet with minimum required transmission power. Consequently, the interference against neighbor nodes can be reduced. From simulation results, we can find that the proposed protocol can reduce the number of control messages and can improve the throughput performance.

Wireless technology is becoming a leading option for future Internet access. Transmission Control Protocol (TCP) is one of the protocols designed on the basis of the transmission characteristics in wired networks. It is known that the TCP performance deteriorates drastically under a wireless communication environment. On the other hand, many wireless networking standards such as IEEE 802.11a, 802.11b, and 802.11g have multirate capability. Therefore, adaptive rate control methods have been proposed for ad hoc networks. However, almost methods require the modification of the request to send (RTS) and clear to send (CTS) packets. Therefore, the conventional methods are not compatible with the standardized system. In this paper, we propose adaptive rate control mechanisms for ad hoc networks. Our mechanisms are based on the RTS/CTS mechanisms. However, no modifications to the RTS and CTS packets are required in the proposed method. Therefore, our proposed method can attempt to satisfy the conventional IEEE 802.11 standards. Moreover, an adequate transmission rate is selected based on an estimated TCP throughput performance. From simulation results, it is observed that the proposed method can improve the throughput performance without any modification of packet structures.

Wireless sensor networks are envisioned to consist of many small devices that can sense the environment and communicate the data as required. The most critical requirement for widespread sensor networks is power efficiency since battery replacement is not viable. Many protocols attempt to minimize the power consumption by using complex algorithms. However, it is difficult to perform these complex methods since an individual sensor node in sensor networks does not have high computational capacity. On the other hand, many sensor nodes should transfer the data packet to the sink node that collects the required data. Therefore, the operations of the sensor nodes over the route are terminated; it is difficult to deliver the data packet to the sink node even if some sensor nodes are active. In this paper, we propose a simple power-aware routing protocol for sensor networks. Our proposed protocol is based on the ad hoc on-demand distance vector (AODV) protocol, which is one of the reactive routing protocols. In addition, we introduce forwarder nodes in the sensor networks in order to extend the lifetime of the entire sensor network. From the simulation results, we evaluate the performance of the protocols and clarify the effect of forwarder nodes on the sensor networks.

Abstract Background The changes in synovial fluid biomarkers after intra‐articular injection of hyarulonic acid (IA HA) remain controversial. We investigate the changes in the properties of synovial fluid (SF) and clinical symptoms before the first and fifth IA HA. Methods A total of 73 patients (73 knees) with symptomatic knee osteoarthritis were treated with five weekly intra‐articular injections of HA and 55 patients (55 knees) were analyzed. The SF total volume, viscosity, and levels of HA, chondroitin 4‐sulfate (C4S), chondroitin 6‐sulfate (C6S), keratin sulfate, and interleukin (IL)‐6 were measured before the first and fifth injections. Clinical evaluations were performed using the American Knee Society score for physician‐based outcome measurements and Knee injury and Osteoarthritis Outcome Score for patient‐based outcome measurements before the first and fifth injections. Results The SF viscosity and levels of HA were significantly increased, and the total SF volume and levels of chondroitin 4‐sulfate, chondroitin 6‐sulfate, and interleukin‐6 were significantly decreased. The physician‐based and patient‐based outcome scores were improved. Conclusions Our findings speculate that HA injections significantly modulate levels of intra articular biomarkers which may indicate beneficial effect for articular cartilage and synovium membrane.

We extend work by Pei-Ping and Gui-Xia, 2007, to a global optimization problem for more general functions. Pei-Ping and Gui-Xia treat the optimization problem for the linear sum of polynomial fractional functions, using a branch and bound approach. We prove that this extension makes possible to solve the following nonconvex optimization problems which Pei-Ping and Gui-Xia, 2007, cannot solve, that the sum of the positive (or negative) first and second derivatives function with the variable defined by sum of polynomial fractional function by using branch and bound algorithm.

The chirp signal exp(iπ(x-y)2) is a typical example of CAZAC (constant amplitude zero autocorrelation) sequence. Using the chirp signals, the chirp z transform and the chirp-Fourier transform were defined in order to calculate the discrete Fourier transform. We define a transform directly from the chirp signals for an even or odd number N and the continuous version. We study the fundamental properties of the transform and how it can be applied to recursion problems and differential equations. Furthermore, when N is not prime and N=ML, we define a transform skipped L and develop the theory for it.

Rapidly destructive coxarthrosis (RDC) is rare and develops unusual clinical course. Recent studies suggest multiple possible mechanisms of the development of RDC. However the exact mechanism of RDC is still not clear. The difficulty of the study on RDC is attributed to its rareness and the fact that the data before the onset of RDC is normally unavailable. In this report, we presented the patient having the radiographic data before the onset who had rapid osteoarthritis (OA) development after contralateral THA, which meets the current criteria of RDC. We thought that the increased posterior tilt of the pelvis after THA reinforced the stress concentration at pre-existed anterior acetabular cyst, thereby the destruction of the cyst was occurred. As a result the rapid OA was developed. We think that there is the case of rapid osteoarthritis developing due to alternating load concentration by posterior pelvic tilt on preexisting anterior acetabular cyst such as our patient among the cases diagnosed as RDC without any identifiable etiology. The recognition of sagittal alignment changes and anterior acetabular cyst may play important role in prediction and prevention of the rapid hip osteoarthritis development similar to RDC.