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Background We hypothesized that 3 weeks of preoperative rehabilitation could improve postoperative pain in patients undergoing total knee arthroplasty (TKA). Aim: This study aimed to evaluate the effects of 3 weeks of preoperative rehabilitation on postoperative pain after TKA. Methods This prospective cohort study included 29 subjects (41 knees) divided into two groups: the preoperative rehabilitation group included 14 subjects (20 knees) and the control group included 15 subjects (21 knees). All subjects were scheduled for unilateral or bilateral TKA. The preoperative rehabilitation group completed a 90-min rehabilitation program 3 days per week for 3 weeks before their TKA. The rehabilitation included body weight exercise, resistance exercise, and cycle ergometer exercise. The control group did not undergo any rehabilitation prior to TKA. We assessed the patients using Western Ontario and McMaster Universities’ Osteoarthritis Index (WOMAC) and recorded their physical activity of walking, standing, sitting, and lying down at study entry and/or before TKA and 1 month after TKA. Results The WOMAC total and WOMAC pain scores were significantly lower after 3-weeks of rehabilitation, but before TKA and 1 month after surgery were significantly lower in the preoperative rehabilitation group than in the control group. The time spent walking, standing, sitting, and lying down for 12 h did not change after TKA in the preoperative rehabilitation group. In contrast, in the control group, the time spent in walking and standing positions decreased and the time in the sitting position increased after TKA (p < 0.05). Conclusion: We found that 3-week preoperative training reduced knee pain and helped maintain physical activity after surgery in patients with severe osteoarthritis who underwent TKA.

Spinal fusion surgery is often performed with pelvic fixation to prevent distal junctional kyphosis. The inclusion of spinopelvic fixation has been reported to induce progression of hip joint arthropathy in a radiographic follow-up study. However, its biomechanical mechanism has not yet been elucidated. This study aimed to compare the changes in hip joint moment before and after spinal fusion surgery.This study was an observational study and included nine patients (eight women and one man) who were scheduled to undergo spinopelvic fusion surgery. We calculated the three-dimensional external joint moments of the hip during gait, standing, and climbing stairs before and 1 year after surgery.During gait, the maximum extension moment was 0.51 ± 0.29 and 0.63 ± 0.40 before and after spinopelvic fusion surgery (p = 0.011), and maximum abduction moment was 0.60 ± 0.33 and 0.83 ± 0.34 before and after surgery (p = 0.004), respectively. During standing, maximum extension moment was 0.76 ± 0.32 and 1.04 ± 0.21 before and after spinopelvic fusion surgery (p = 0.0026), and maximum abduction moment was 0.12 ± 0.20 and 0.36 ± 0.22 before and after surgery (p = 0.0005), respectively. During climbing stairs, maximum extension moment was - 0.31 ± 0.30 and - 0.48 ± 0.15 before and after spinopelvic fusion surgery (p = 0.040), and maximum abduction moment was 0.023 ± 0.18 and - 0.02 ± 0.13 before and after surgery (p = 0.038), respectively.This study revealed that hip joint flexion-extension and abduction-adduction moments increased after spinopelvic fixation surgery in the postures of standing, walking, and climbing stairs. The mechanism was considered to be adjacent joint disease after spinopelvic fusion surgery including sacroiliac joint fixation.

Recently, the number of adult spinal deformity surgeries including sacroiliac joint fixation (SIJF) by using an S2 alar iliac screw or iliac screw has increased to avoid the distal junctional failure. However, we occasionally experienced patients who suffered from hip pain after a long instrumented spinal fusion. We hypothesized that long spinal fusion surgery including SIJF influenced the hip joint as an adjacent joint. The aim of this paper was to evaluate the association between spinal deformity surgery including SIJF and radiographic progression of hip osteoarthritis (OA). This study was retrospective cohort study. In total, 118 patients who underwent spinal fusion surgery at single center from January 2013 to August 2018 were included. We measured joint space width (JSW) at central space of the hip joint. We defined reduction of more than 0.5 mm/year in JSW as hip OA progression. The patients were divided into two groups depending on either a progression of hip osteoarthritis (Group P), or no progression (Group N). The number of patients in Group P and Group N was 47 and 71, respectively. Factor that was statistically significant for hip OA was SIJF (p = 0.0065, odds ratio = 7.1, 95% confidence interval = 1.6–31.6). There were no other significant differences by the multiple logistic regression analysis. This study identified spinal fixation surgery that includes SIJF as a predictor for radiographic progression of hip OA over 12 months. We should pay attention to hip joint lesions after adult spinal deformity surgery, including SIJF.

We evaluated the effectiveness of a high-intensity preoperative resistance and endurance training program in improving physical function among patients scheduled for total knee arthroplasty. This non-randomized controlled trial included 33 knee osteoarthritis patients scheduled to undergo total knee arthroplasty at a tertiary public medical university hospital. Fourteen and nineteen patients were non-randomly assigned to intervention and control groups, respectively. All patients underwent total knee arthroplasty and a postoperative rehabilitation program. The intervention group participated in a preoperative rehabilitation program comprising high-intensity resistance and endurance training exercises to increase lower limb muscle strength and endurance capacity. The control group received only exercise instruction. The primary outcome was the 6-min walking distance, which was significantly higher in the intervention group (399 ± 59.8 m) than in the control group (348 ± 75.1 m) 3 months post-surgery. There were no significant differences between the groups 3 months post-surgery in muscle strength, visual analog scale, WOMAC-Pain, range of motion of knee flexion, and extension. A 3-week preoperative rehabilitation program combining muscle strengthening and endurance training improved endurance 3 months after total knee arthroplasty. Thus, preoperative rehabilitation is important for improving postoperative activity.

Adult spinal fusion surgery improves lumbar alignment and patient satisfaction. Adult spinal deformity surgery improves saggital balance not only lumbar lesion, but also at hip joint coverage. It was expected that hip joint coverage rate was improved and joint stress decreased. However, it was reported that adjacent joint disease at hip joint was induced by adult spinal fusion surgery including sacroiliac joint fixation on an X-ray study. The mechanism is still unclear. We aimed to investigate the association between lumbosacral fusion including sacroiliac joint fixation and contact stress of the hip joint.A 40-year-old woman with intact lumbar vertebrae underwent computed tomography. A three-dimensional nonlinear finite element model was constructed from the L4 vertebra to the femoral bone with triangular shell elements (thickness, 2 mm; size, 3 mm) for the cortical bone's outer surface and 2-mm (lumbar spine) or 3-mm (femoral bone) tetrahedral solid elements for the remaining bone. We constructed the following four models: a non-fusion model (NF), a L4-5 fusion model (L5F), a L4-S1 fusion model (S1F), and a L4-S2 alar iliac screw fixation model (S2F). A compressive load of 400 N was applied vertically to the L4 vertebra and a 10-Nm bending moment was additionally applied to the L4 vertebra to stimulate flexion, extension, left lateral bending, and axial rotation. Each model's hip joint's von Mises stress and angular motion were analyzed.The hip joint's angular motion in NF, L5F, S1F, and S2F gradually increased; the S2F model presented the greatest angular motion.The average and maximum contact stress of the hip joint was the highest in the S2F model. Thus, lumbosacral fusion surgery with sacroiliac joint fixation placed added stress on the hip joint. We propose that this was a consequence of adjacent joint spinopelvic fixation. Lumbar-to-pelvic fixation increases the angular motion and stress at the hip joint.

Accurate gluteus medius (GMd) volume evaluation may aid in the analysis of muscular atrophy states and help gain an improved understanding of patient recovery via rehabilitation. However, the segmentation of muscle regions in GMd images for cubic muscle volume assessment is time-consuming and labor-intensive. This study automated GMd-region segmentation from the computed tomography (CT) images of patients diagnosed with hip osteoarthritis using deep learning and evaluated the segmentation accuracy. To this end, 5250 augmented pairs of training data were obtained from five participants, and a conditional generative adversarial network was used to identify the relationships between the image pairs. Using the preserved test datasets, the results of automatic segmentation with the trained deep learning model were compared to those of manual segmentation in terms of the dice similarity coefficient (DSC), volume similarity (VS), and shape similarity (MS). As observed, the average DSC values for automatic and manual segmentations were 0.748 and 0.812, respectively, with a significant difference (p < 0.0001); the average VS values were 0.247 and 0.203, respectively, with no significant difference (p = 0.069); and the average MS values were 1.394 and 1.156, respectively, with no significant difference (p = 0.308). The GMd volumes obtained by automatic and manual segmentation were 246.2 cm3 and 282.9 cm3, respectively. The noninferiority of the DSC obtained by automatic segmentation was verified against that obtained by manual segmentation. Accordingly, the proposed GAN-based automatic GMd-segmentation technique is confirmed to be noninferior to manual segmentation. Therefore, the findings of this research confirm that the proposed method not only reduces time and effort but also facilitates accurate assessment of the cubic muscle volume.

Background and objectives Gait can be severely affected by pain, muscle weakness, and aging resulting in lameness. Despite the high incidence of lameness, there are no studies on the features that are useful for classifying lameness patterns. Therefore, we aimed to identify features of high importance for classifying population differences in lameness patterns using an inertial measurement unit mounted above the sacral region. Methods Features computed exhaustively for multidimensional time series consisting of three-axis angular velocities and three-axis acceleration were carefully selected using the Benjamini–Yekutieli procedure, and multiclass classification was performed using LightGBM (Microsoft Corp., Redmond, WA, USA). We calculated the relative importance of the features that contributed to the classification task in machine learning. Results The most important feature was found to be the absolute value of the Fourier coefficients of the second frequency calculated by the one-dimensional discrete Fourier transform for real input. This was determined by the fast Fourier transformation algorithm using data of a single gait cycle of the yaw angular velocity of the pelvic region. Conclusions Using an inertial measurement unit worn over the sacral region, we determined a set of features of high importance for classifying differences in lameness patterns based on different factors. This completely new set of indicators can be used to advance the understanding of lameness.

We report multi-photon luminescence and Laser Ablation–Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) as a non-destructive and sensitive method of visualizing the concentration and distribution of activator ions doped to a crystal host, respectively. Here, LA-ICPMS is able to detect concentrations that are less than 0.1%. Using these methods and a large 110-mm diameter Czochralski method-grown cerium-doped lithium calcium aluminum fluoride (Ce3+:LiCaAlF6 or Ce:LiCAF), we observed that Ce is distributed non-uniformly with varying concentrations across the diameter of the crystal boule. We further verify quantitatively that luminescence intensity increases in proportion to doping density. Ultraviolet (UV, 290-nm wavelength) laser emissions from areas of the Ce:LiCAF crystal having different doping distributions and concentrations reveal that a uniform doping distribution leads to a higher slope efficiency, lower laser threshold and a potentially higher damage threshold even though the doping concentration is low compared to areas with high but non-uniform doping. Our results show a means of improving laser performance by aiming to achieve a uniform doping distribution; and multi-photon luminescence and LA-ICPMS are powerful tools that could aid in this process. Improved laser performance could lead to new breakthroughs in laser output energies especially in the UV region for many applications.

Introduction: Hip dislocation rates in patients with combined total hip arthroplasty (THA) and spinal deformity fixation are significantly higher than those of THA alone. Nevertheless, there are no treatment recommendations for patients who undergo THA and require a spine deformity correction later. Methods: Twenty-eight patients underwent spinal fixation surgery for adult spinal deformity. Sagittal spinopelvic alignment was analyzed on lateral radiographs taken preoperatively and postoperatively in the sitting and standing positions. Univariate linear regression analysis was conducted to identify the factors affecting the pelvic inclination in the sitting position after spinal fixation. Multiple regression analysis was conducted to determine the most efficient combination of radiographic parameters for predicting postoperative pelvic inclination while sitting. Results: There were significantly weak associations between postoperative sacral slope (SS) in the sitting position and the following factors: the number of vertebral levels fused (β = 0.30, p = 0.003); the presence of sacral fixation (β = 0.22, p = 0.01); the presence of sacroiliac joint fixation (β = 0.24, p = 0.008); and preoperative SS while standing and sitting (β = 0.21, p = 0.01 and β = 0.34, p = 0.001). Postoperative lumbar lordosis (LL) while standing was strongly associated with postoperative SS in the sitting position (β = 0.67, p

Acetabular component revision in the presence of severe bone loss is difficult for reconstructing an acetabular component in the anatomical hip center. Various treatment options are available, although often the acetabular defect cannot be corrected with a single option alone. Precise assessment of the bone loss and a suitable combination of methods are needed. Here we report a case of multiple failures with impaction bone grafting reconstruction for an acetabular bone defect of American Academy of Orthopedic Surgeons classification type III. We finally reconstructed the acetabulum with three femoral head allografts and a Kerboull-type acetabular reinforcement device. The allograft was a casted, jet-type helmet-like shape. A year later the patient was able to walk without a cane and perform light agricultural work. Accurate evaluation of the acetabular bone loss and appropriate reconstruction is important.

In the previous paper, an elastoplastic damper utilizing continuous plastic bending of thin metal rods was developed. In this paper, an improved damper that is improved a winding mechanism of the metal rods of the elastoplastic damper for a larger resisting force and a compound damper that is added a friction mechanism as a fale-safe mechanism to the elastoplastic damper are proposed. The trial dampers were made and the resisting force characteristics and fatigue strength of the dampers were measured. The seismic responses of an L-shaped pipe supported by the dampers were also measured using an electrohydraulic shaking table.

In this paper, a new type of elastoplastic damper utilizing continuous plastic bending of thin metal rods is proposed in order to obtain an elastoplastic damper which yields damping even for a small displacement. The seismic responses of a piping system supported by the elastoplastic damper were calculated using a continuous system simulation language and the effects of the damper on the deflection of the piping system are discussed. The trial damper was made using a thin copper rod, and the resisting force characteristics and fatigue strength of the damper were measured. The seismic responses of an L-shaped pipe supported by the trial elastoplastic damper were measured using an electrohydraulic shaking table. The experimental results were compared with the calculated results.