Consumption responses to COVID-19 payments: Evidence from a natural experiment and bank account data.

We document households' spending responses to a stimulus payment in Japan during the COVID-19 pandemic. In response to the pandemic, the Japanese government launched a universal cash entitlement program offering a sizable lump sum of money to all residents to alleviate the financial burden of the pandemic on households. The timings of cash deposits varied substantially across households due to unexpected delays in administrative procedures.

The macroeconomics of COVID-19 exit strategy: the case of Japan.

In this paper, I use a simple SIR Macro model to examine Japan's soft lockdown policies in 2021 under the COVID-19 crisis. As real-time research, this paper consists of two parts written during two different research periods. The first part, which was originally reported in February 2021, studies the Japan's second soft lockdown policy (state of emergency declaration) from January to March 2021.

Who spent their COVID-19 stimulus payment? Evidence from personal finance software in Japan.

In response to the COVID-19 crisis, governments worldwide have been formulating and implementing different strategies to mitigate its social and economic impacts. We study the household consumption responses to Japan's COVID-19 unconditional cash transfer program. Owing to frequent delays in local governments' administrative procedures, the timing of the payment to households varied unexpectedly.

Evaluation of anterior inferior iliac spine impingement after hip arthroscopic osteochondroplasty using computer simulation analysis.

Background: Anterior inferior iliac spine (AIIS) impingement is an important risk factor for revision hip arthroscopy. Although a morphological classification system is available, evaluating AIIS impingement with respect to joint kinematics remains a challenge.

Purpose: To use computer simulation analysis to ascertain the prevalence of AIIS impingement before and after osteochondroplasty.

Current risk factors for asymptomatic venous thromboembolism in patients undergoing total hip arthroplasty.

A history of venous thromboembolism (VTE) is a risk factor for newly formed VTE after total hip arthroplasty (THA). However, its morbidity and association with postoperative VTE are not clear and, therefore, were investigated in this study. Four-hundred and nineteen patients scheduled for primary THA were included.

Mechanical Strength of the Proximal Femur After Arthroscopic Osteochondroplasty for Femoroacetabular Impingement: Finite Element Analysis and 3-Dimensional Image Analysis.

Purpose: To examine the influence of femoral neck resection on the mechanical strength of the proximal femur in actual surgery.

Methods: Eighteen subjects who received arthroscopic cam resection for cam-type femoroacetabular impingement (FAI) were included. Finite element analyses (FEAs) were performed to calculate changes in simulative fracture load between pre- and postoperative femur models.

Computer-Assisted Hip Arthroscopic Surgery for Femoroacetabular Impingement.

Precise osteochondroplasty is key for success in hip arthroscopic surgery, especially for femoroacetabular impingement (FAI) caused by cam or pincer morphology. In this Technical Note, we present computer-assisted hip arthroscopic surgery for FAI, including preoperative planning by virtual osteochondroplasty and intraoperative computer navigation assistance. The important concept of this technique is that navigation assistance for osteochondroplasty is based on planning made by computer simulation analysis.

The Relationship Between the Location of Uptake on Positron Emission Tomography/Computed Tomography and the Impingement Point by Computer Simulation in Femoroacetabular Impingement Syndrome With Cam Morphology.

Purpose: To clarify the concordance rate of the location of uptake on positron emission tomography/computed tomography (PET/CT) and the impingement point demonstrated in computer simulation in femoroacetabular impingement (FAI) syndrome with cam morphology.

Methods: We included hip joints with FAI syndrome that underwent F-fluoride PET/CT. We also excluded hips with SUV <6.

Comparison of improved range of motion between cam-type femoroacetabular impingement and borderline developmental dysplasia of the hip -evaluation by virtual osteochondroplasty using computer simulation.

Background: While cam resection is essential to achieve a good clinical result with respect to femoroacetabular impingement (FAI), it is unclear whether it should also be performed in cases of borderline developmental dysplasia of the hip (DDH) with a cam deformity. The aim of this study was to evaluate improvements in range of motion (ROM) in cases of cam-type FAI and borderline DDH after virtual osteochondroplasty using a computer impingement simulation.

Methods: Thirty-eight symptomatic hips in 31 patients (11male and 20 female) diagnosed with cam-type FAI or borderline DDH were analyzed.

Reactive Osteochondromatous Lesion of the Femoral Neck in a Highly Active Preadolescent Patient: Is This the Pathogenesis of a Cam Deformity?

Here, we present a rare case of a preadolescent boy with a prominent bony bump on the femoral neck. The main histological feature was concordant with a reactive osteochondromatous lesion possibly induced by repetitive microtrauma, probably because of overtraining as a soccer goalkeeper. The nature of this pathological change is consistent with the growth of a cam deformity.

Efficacy of Alendronate for the Prevention of Bone Loss in Calcar Region Following Total Hip Arthroplasty.

Background: Bone mineral density (BMD) loss around femoral implants, particularly in the proximal femur, is a common outcome after total hip arthroplasty. Previous studies reported the prevention of postsurgical decrease in BMD with the use of osteoporosis drug therapy. This randomized study evaluated the efficacy of alendronate and alfacalcidol for preserving BMD over a long-term follow-up.

A new multiplex real-time polymerase chain reaction assay for the diagnosis of periprosthetic joint infection.

Objectives: A new multiplex real-time polymerase chain reaction (PCR) assay was developed to detect methicillin-resistant Staphylococcus (MRS) and to distinguish between gram-positive and gram-negative bacteria. In this study, we validated the sensitivity and specificity of this assay with periprosthetic joint infections (PJIs) and evaluated the utility of PCR for culture-negative PJI.

Methods: Forty-five samples from 23 infectious PJI cases and 106 samples from 64 non-infectious control cases were analyzed by real-time PCR using a LightCycler Nano system.

The Distribution of Impingement Region in Cam-Type Femoroacetabular Impingement and Borderline Dysplasia of the Hip With or Without Cam Deformity: A Computer Simulation Study.

Purpose: To identify the distribution of the impingement region in cam-type femoroacetabular impingement (FAI) or patients with borderline developmental dysplasia of the hip (DDH) using computer simulation analysis.

Methods: A total of 51 painful hip joints from 42 consecutive cases diagnosed as cam-type FAI (center edge [CE] angle ≥ 25°, alpha angle ≥ 55°) or borderline DDH (CE angle ≥ 20° and < 25°) with or without a cam deformity (alpha angle ≥ 55° or < 55°) were enrolled. ZedHip (Lexi, Tokyo, Japan) 3-dimensional computer simulation was used to identify impingement points.

Preoperative planning for implant placement with consideration of pelvic tilt in total hip arthroplasty: postoperative efficacy evaluation.

Background: In total hip arthroplasty (THA), tilting of the pelvis alters the cup placement angles. Thus, the cup angles need to be planned with consideration of the effects of pelvic tilt. In the present study, we evaluated the efficacy of preoperative planning for implant placement with consideration of pelvic tilt in THA, and the accuracy of a CT-based computer navigation for implant positioning.

Difference in Postoperative Periprosthetic Bone Mineral Density Changes Between 3 Major Designs of Uncemented Stems: A 3-Year Follow-Up Study.

Background: Although few studies have examined the direct effect of stress shielding on clinical outcomes, periprosthetic bone loss due to stress shielding is still an issue of concern, especially when physicians perform uncemented total hip arthroplasty (THA) in younger patients. Differences in femoral stem design may affect the degree of postoperative stress shielding. Therefore, the characteristics of the behavior for stress shielding of each type of femoral stem should be determined.

Computer-Assisted Rotational Acetabular Osteotomy for Patients with Acetabular Dysplasia.

Rotational acetabular osteotomy (RAO) is a well-established surgical procedure for patients with acetabular dysplasia, and excellent long-term results have been reported. However, RAO is technically demanding and precise execution of this procedure requires experience with this surgery. The usefulness of computer navigation in RAO includes its ability to perform three-dimensional (3D) preoperative planning, enable safe osteotomy even with a poor visual field, reduce exposure to radiation from intraoperative fluoroscopy, and display the tip position of the chisel in real time, which is educationally useful as it allows staff other than the operator to follow the progress of the surgery.

The current status and future prospects of computer-assisted hip surgery.

The advances in computer assistance technology have allowed detailed three-dimensional preoperative planning and simulation of preoperative plans. The use of a navigation system as an intraoperative assistance tool allows more accurate execution of the preoperative plan, compared to manual operation without assistance of the navigation system. In total hip arthroplasty using CT-based navigation, three-dimensional preoperative planning with computer software allows the surgeon to determine the optimal angle of implant placement at which implant impingement is unlikely to occur in the range of hip joint motion necessary for daily activities of living, and to determine the amount of three-dimensional correction for leg length and offset.

Evaluation of local bone turnover in painful hip by 18F-fluoride positron emission tomography.

Objective: The diagnosis of painful hip without remarkable radiographic findings is still challenging. In recent years, femoroacetabular impingement (FAI) has been recognized as an important cause of painful hip. The hypothesis of this study was that local bone turnover may be accelerated in painful hip, especially in FAI lesions.

Teriparatide Versus Alendronate for the Preservation of Bone Mineral Density After Total Hip Arthroplasty - A randomized Controlled Trial.

In this study, the effect of teriparatide for the prevention of bone mineral density (BMD) loss after THA was compared with alendronate in a randomized controlled trial. Forty-eight patients were assigned to three groups, namely, the teriparatide, alendronate, and no medication groups. Dual-energy x-ray absorptiometry (DEXA) was performed at 1 week post-surgery as a baseline reference, followed by subsequent measurements at 12, 24, and 48 weeks postoperatively.

Influence of Pelvic Tilt on Polyethylene Wear after Total Hip Arthroplasty.

We aimed to evaluate the effects of pelvic tilt on polyethylene wear after total hip arthroplasty (THA). A total of 105 joints treated with primary THA were included; conventional polyethylene (CPE) liners were used in 43 hips and highly cross-linked polyethylene (HXLPE) liners were used in the remaining 62 hips. The pelvis was tilted 6° posteriorly in the standing position as compared to the supine position, which resulted in significant increases of 1.

Use of 18F-fluoride positron emission tomography as a predictor of the hip osteoarthritis progression.

Objective: The prediction of hip osteoarthritis (OA) progression is still a difficult issue. We have adopted (18)F-fluoride positron emission tomography (PET) for the evaluation of hip osteoarthritis, and investigated the prediction utility of (18)F-fluoride PET for both pain worsening and OA progression using a logistic regression model.

Materials And Methods: A total of 57 hip joints were analyzed for progression risk factors for pain worsening and minimum joint space (MJS) narrowing by logistic regression analysis.

Prediction of femoral head collapse in osteonecrosis using 18F-fluoride positron emission tomography.

Objective: We investigated the usefulness of (18)F-fluoride PET as a predictor of femoral head collapse in patients with osteonecrosis (ON) before radiographic changes occur.

Patients And Methods: Sixty-six hips of 42 patients diagnosed with ON of the femoral head were included in this study. We evaluated the relationship between the maximum standardized uptake value (SUV(max)) in (18)F-fluoride PET and the Ficat classification.

Effects of hip joint center location and femoral offset on abductor muscle strength after total hip arthroplasty.

Objectives: The purposes of this study were 1) to examine the changes in the hip joint center (HJC) position and the femoral offset (FO) after total hip arthroplasty (THA) and 2) to investigate the effects of the HJC and FO on isometric abductor muscle strength.

Methods: We evaluated 51 patients who underwent unilateral primary THA. The FO, and horizontal and vertical distances from the HJC to the tip of the teardrop were measured and isometric hip abductor muscle strength was measured.

Bone mineral density distribution in the proximal femur and its relationship to morphologic factors in progressed unilateral hip osteoarthritis.

Although an adverse relationship between osteoporosis and osteoarthritis (OA) has been reported, it remains controversial. In most previous reports of OA, bone mineral density (BMD) changes in the subtrochanteric region have not been clarified, whilst BMD of the femoral neck and trochanteric region has been well investigated. In our current study, we investigated the BMD ratio compared to the contralateral side in the whole proximal femurs of hip OA patients.

Comparison of 18F-fluoride positron emission tomography and magnetic resonance imaging in evaluating early-stage osteoarthritis of the hip.

Objective: The imaging diagnosis of osteoarthritis (OA) of the hip, especially in its early stages, is a technically challenging but essential aspect of our increased understanding of the pathophysiology of this disorder. We recently applied 18F-fluoride PET for the detection of abnormal bone turnover in early-stage OA. In our current study, we have compared the diagnostic and analytical capabilities of 18F-fluoride PET and MRI modalities in a hip OA patient series.