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This investigation examined the clinical implications of mild vertebral fractures in older community-dwelling residents. Focusing on the locomotion health of older individuals, the earlier reported Obuse study enrolled 415 randomly sampled Japanese residents aged between 50 and 89 years, 411 of whom underwent X-ray evaluations for pre-existing vertebral fractures. A blinded assessment of vertebral fractures based on Genant's criteria was conducted on the T5-L5 spine for rating on a severity scale. Grade 1 mild fractures were not linked to age in males, but increased with aging in females. Female participants had fewer Grade 1 and 2 fractures (P = 0.003 and 0.035, respectively) but more Grade 3 fractures (P = 0.013) than did males independently of age (Grade 1, 2, and 3: 25%, 16%, and 9% in females and 40%, 22%, and 6% in males, respectively). Weak negative correlations were observed between the number of fractures and bone mineral density in females for all fracture grades (Spearman's rho: 0.23 to 0.36, P < 0.05). Our study showed that Grade 1 mild vertebral fractures in males lacked pathological significance, while in females they potentially indicated fragility fractures and were related to poor lumbopelvic alignment. [ABSTRACT FROM AUTHOR]

A 49-year-old woman underwent anatomic double-bundle anterior cruciate ligament reconstruction using a hamstring tendon. Due to knee osteoarthritis progression, total knee arthroplasty was performed 13 years after the surgery. The anteromedial (AM) bundle was composed partly of tendon-like tissue and partly of scar-like tissue. In the tendon-like part of the AM bundle, the collagen fibers were slightly loose and showed a low-frequency crimp structure with an ovoid cell shape. In contrast, the collagen arrangement in the scar-like part was irregular, edematous, and sparsely cell-dense, with an ovoid cell shape. The posterolateral bundles were generally composed of spindle-shaped cells, and the collagen was arranged in tight cohesion and had well-demarcated bundles with normal crimping. Within the tibial tunnel, the graft was mainly connected to the surrounding lamellar bone on the posterior sides, with sparser connections on the anterior and medial/lateral side. The findings of this long-term case provide valuable information to enable understanding of multiple-folded hamstring tendons. Level of evidence V. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effects of a new remnant-preserving double-bundle anterior cruciate ligament reconstruction (ACLR) technique, focused on avoiding remnant damage and preserving continuity of remnants, on graft maturity using magnetic resonance imaging (MRI). Methods: A total of 169 patients were divided into three groups: 41 in the preservation group, 70 in the resection group, and 58 in the absent group. In the preservation group, rather than passing the graft through the remnant tissue, the graft was reconstructed such that the anteromedial and posterolateral bundles sandwiched the remnant to avoid damage to the remnant and maintain its continuity. Based on 1-year postoperative MRI, the grafts were divided into three regions: distal, middle, and proximal. The signal/noise quotient (SNQ) of each region of interest was calculated to evaluate the signal intensity of the graft and was compared among the three groups. Additionally, to identify factors influencing graft maturity, a multiple regression analysis was performed with SNQ as the dependent variable and patient demographics, bone morphology, and surgical factors as independent variables. Results: In a three-group comparison of mean SNQs, the distal region was 3.3 ± 3.4, 8.9 ± 8.3, and 9.0 ± 8.6 (p < 0.001), the middle region was 5.3 ± 3.7, 10.9 ± 11.1, and 11.3 ± 10.2 (p < 0.001), and the proximal region was 6.8 ± 4.5, 11.1 ± 8.8, and 11.7 ± 10.8 (p = 0.017), in order of the preservation, resection, and absent groups, respectively. That indicated that the remnant-preserving ACLR was more hypointense than ACLR with remnant resection or absent in all three regions. Multiple regression analysis showed that remnant preservation remained the relevant factor affecting SNQ of the graft at the distal and middle levels. Conclusion: The new remnant-preserving anatomic double-bundle ACLR had significantly better graft maturity, measured by SNQ on MRI, than the remnant resection and absent groups. The remnant procedure was the relevant factor affecting graft maturity. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: This study evaluated major vascular injury risk in distal femoral osteotomy (DFO) via the subvastus approach and examined the relationship between the posterior border of the vastus medialis (VM) and the superficial femoral artery (SFA) and vein (SFV). Methods: Eighty limbs from 80 patients were evaluated using lower extremity computed tomographic venography. The positional relationship between the VM, SFA, and SFV was evaluated by measuring the angle between each structure and the horizontal reference point (VMA: VM angle, FAA (femoral arterial angle), FVA (femoral venous angle) and the distance between VM and the SFA and SFV (VMAD: VM-arterial distance, VMVD: VM-venous distance) in each axial slice (0/10/20/30/40 mm) proximal to the level of the superior patellar margin. The proximity of the posterior border of the VM and the SFA/SFV as a vertical distance, measured between the slice of the superior border of the patella and the slice where the posterior border of the VM contacted the SFA was evaluated. Single and multiple regression analyses were performed using the vertical distance as the objective variable. Results: As the slice shifted proximally, the VMA significantly increased (24.9 ± 8.5, 36.3 ± 8.8, 47.4 ± 11.8, 59.9 ± 14, 70.3 ± 13.7 degrees, respectively, p < 0.001 between all slices) and moved posteromedially from a medial direction. FAA (94.2 ± 7, 86.9 ± 9.2, 78.4 ± 9.7, 71.4 ± 9.8, 66.6 ± 10.5 degree, respectively, p < 0.001 between all slices) and FVA (100.6 ± 4.9, 98.3 ± 5.9, 93.7 ± 7.5, 88 ± 9.2, 81.1 ± 10.5 degrees, respectively, p < 0.001 between all slices) decreased and moved from a posterolateral to a posteromedial direction, while VMAD (35.4 ± 7.8, 24.1 ± 7.3, 14.3 ± 6, 8.4 ± 7, 6.2 ± 6.3 mm, respectively, p < 0.001 between all slices) and VMVD significantly decreased (42.7 ± 7.3, 32 ± 7.4, 22.4 ± 6.8, 14.5 ± 10.6, 8.7 ± 7.1 mm, respectively, p < 0.001 between all slices). The average vertical distance was 36 ± 9.3 mm (range 18.6–61.5 mm). The body height and the patellar length significantly affected the vertical distance. Conclusion: The posterior border of the VM shifted posteromedially from distal to proximal and contacted the SFA at an average of 36 mm from the suprapatellar border. Surgeons should be aware of the risk of major vascular injury during exposure and osteotomy. Level of evidence: Case series, Level IV. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the relationship between heart rate variability (HRV), a parameter of the autonomic nervous system activity (ANSA), and postoperative delirium and postoperative events. This retrospective cohort study included elderly patients aged 65 years or older who were admitted to the intensive care unit (ICU) after cardiovascular surgery. ANSA was measured using HRV parameters for 1 h at daytime and 1 h at night-time before ICU discharge. The primary endpoint was the effect of HRV parameters and delirium on mortality and readmission rates within 1 year after discharge, and the secondary endpoint was the association between HRV parameters and delirium. Cox proportional hazards models were used to examine the association between HRV parameters and postoperative events by adjusting for delirium and pre and postoperative information. A total of 71 patients, 39 without delirium and 32 with delirium, met the inclusion criteria. The incidence of death and readmission within 1 year was significantly higher in the delirium group and in the group with higher daytime HF (high frequency power) and r-MSSD (square root of the squared mean of the difference of successive NN intervals), parameters of the parasympathetic nervous system activity (PNSA), than that in other groups. Furthermore, the delirium group had significantly higher HF and r-MSSD than the nondelirium group. Even after adjusting for confounding factors in the multivariate analysis, a trend of higher daytime HF and r-MSSD was observed, indicating a significant effect on the occurrence of combined events within 1 year of discharge. ICU delirium has been associated with higher daytime HF and r-MSSD, parameters of PNSA. ICU delirium was a prognostic factor, and increased daytime PNSA may worsen the prognosis of elderly patients after cardiovascular surgery. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of a new remnant preservation technique with a focus on remnant continuity on postoperative femoral and tibial tunnel enlargement after anatomical double-bundle anterior cruciate ligament reconstruction (ACLR).Methods: A total of 150 knees were divided into three groups: Preservation Group (Group P: 49 knees), wherein the remnant continuity remained after tunnel creation; Resection Group (Group R: 47 knees), wherein the remaining remnant was resected, and Absent Group (Group A: 54 knees), wherein the remnant had no femoral attachment before tunnel creation. In Group P, the remnant maintained continuity, and the anteromedial (AM) and posterolateral (PL) bundles were positioned anterior and posterior to the remnant, respectively. Computed tomographic scans were performed at 1 week and 1 year after surgery, and the cross-sectional area of each tunnel aperture was measured. Tunnel enlargement was compared among the three groups by one-way analysis of variance (ANOVA) and the Bonferroni test. Univariate and multivariate logistic analyses were performed to identify the risk factors for tunnel enlargement in demographic and radiographic data.Result: For femoral AM tunnels, the tunnel enlargement of Group P was significantly smaller than Groups R and A (p < 0.001), femoral PL (p < 0.001 vs. R and A), tibial AM (p < 0.001 vs. R, 0.002 vs. A), and tibial PL (p < 0.001 vs. R, 0.002 vs. A). There was no significant difference between Groups R and A. Multivariate logistic analysis showed that remnant preservation was a significant factor in reducing tunnel enlargement in the femoral AM, femoral PL, tibial AM, and tibial PL.Conclusion: The new remnant-preserving anatomical double-bundle ACLR, which preserves the continuity of the remnant, prevented all bone tunnel enlargement at 1 year postoperatively.Level Of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to evaluate the risk of medial tibial cortical perforation in unicompartmental knee arthroplasty (UKA) due to peg positions on the tibial tray of the Persona Partial Knee (PPK). Methods: Preoperative CT images of 60 patients and 60 osteoarthritic knees (30 male and 30 female patients) were used. A tibial multiplanar reconstruction (MPR) image was reconstructed in preoperative planning software, and the implant was placed in a virtual osteotomy plane. In addition to PPK, Zimmer Unicompartmental Knee (ZUK) and TRIBRID (TBD) were used for evaluation. The horizontal distances from the medial tibial cortex to the anterior and posterior pegs (APCD/PPCD, respectively) were measured under neutral, 3-degree varus, 3-degree valgus and 2 mm distal positions. The differences between implants under the same positions and between positions using the same implants were compared. The percentage of total cases with APCD/PPCD of less than 3 mm and the perforation risk rate were calculated. Results: The APCD of PPK was significantly shorter at all positions except for the varus position of TBD. The PPCD of PPK was significantly shorter at all positions compared to ZUK and TBD. There were no cases with an APCD of less than 3 mm. Except for varus positions, the perforation risk rate of PPCD was significantly higher for PPK than the other two implants. Conclusion: The posterior pegs of the PPK are located more medially than the other two implants, which may result in perforation of the medial tibial cortex during implantation. Surgeons should consider the risk involved in the type of implant used. [ABSTRACT FROM AUTHOR]

Baloxavir marboxil is a new anti-influenza drug, but data on the clinical efficacy of a combination treatment of baloxavir and peramivir is scarce. We conducted a single-center retrospective analysis comparing the mortality of a combination of baloxavir and peramivir (B & P, n = 10) and peramivir without baloxavir (P-mono, n = 132) in hospitalized adults with influenza A between 2011 and 2019 in Yokohama City, Japan. Sequencing analysis was conducted in the B & P group to check the I38 mutation in polymerase acidic protein which is associated with baloxavir resistance. The 30-day mortality rates were 0 (0%) in the B & P group and 6 (4.5%) in the P-mono group, respectively, which was not statistically significant. The I38 mutation was not detected before and after the combination treatment. A combination treatment of baloxavir and peramivir might be more effective than peramivir without baloxavir and prevent the emergence of baloxavir resistance in hospitalized adults with influenza A. [ABSTRACT FROM AUTHOR]

Introduction: Fragility fractures can cause delayed wound healing after tooth extraction, which contributes to an increased risk of osteomyelitis of the jaw. We evaluated whether a history of fragility fracture was associated with increased risk of delayed wound healing after tooth extraction in older adults in Japan.Materials and Methods: Of 5352 people aged 50-89 years in the 2014 basic resident registry of the town of Obuse, the present study included 376 subjects (190 men and 186 women) who completed a structured questionnaire and measurement of the bone mineral densities (BMDs) of the bilateral femoral neck. Delayed wound healing after tooth extraction was self-reported. Fragility fractures were confirmed via examination of hospital medical records. Logistic regression analyses adjusted for age and gender were used to evaluate association of clinical variables with delayed would healing after tooth extractions. Odds ratios (ORs) and the 95% confidence intervals (CIs) of all possible associated variables for the presence of delayed wound healing were calculated.Results: Subjects with a history of fragility fractures had a significantly higher risk of delayed wound healing compared with those without previous fragility fractures (OR 2.68; 95% CI 1.11-6.46, p = 0.028). This association still remained after adjusted for all other variables (OR 2.70; 95% CI 1.10-6.60, p = 0.030). Delayed wound healing was not significantly associated with the BMD of the femoral neck.Conclusions: History of fragility fracture may be associated with increased risk of delayed wound healing after tooth extraction in Japanese men and women aged 50-89 years. [ABSTRACT FROM AUTHOR]

Recent studies have shown that protons can function as neurotransmitters in cultured neurons. To further investigate regional and neural activity-dependent proton dynamics in the brain, the development of a device with both wide-area detectability and high spatial-ltemporal resolution is necessary. Therefore, we develop an image sensor with a high spatial-temporal resolution specifically designed for measuring protons in vivo. Here, we demonstrate that spatially deferent neural stimulation by visual stimulation induced distinct patterns of proton changes in the visual cortex. This result indicates that our biosensor can detect micrometer and millisecond scale changes of protons across a wide area. Our study demonstrates that a CMOS-based proton image sensor with high spatial and temporal precision can be used to detect pH changes associated with biological events. We believe that our sensor may have broad applicability in future biological studies. Protons have been discovered to play a role in neuronal signaling, but current methods to measure pH in the brain of animal models are limited. Here the authors develop a miniaturized proton image sensor that fits into a living mouse brain and can measure pH changes at micrometer and millisecond resolution scales. [ABSTRACT FROM AUTHOR]

A Japanese man with human immunodeficiency virus (HIV) was detected 9 years ago to have a positive titer for hepatitis A virus (HAV) immunoglobulin (Ig) G, without a history of HAV infection or vaccination. His plasma HIV RNA was well-controlled on antiretroviral therapy for more than 6 years. He developed HAV infection with subsequent reduction of the HAV IgG titer. A decreasing HAV IgG in persons living with HIV might indicate the possibility of HAV reinfection and should prompt the consideration for additional vaccination. [ABSTRACT FROM AUTHOR]

This study was designed to investigate effects of heat on the bone-inducing activity of recombinant human bone morphogenetic protein (rhBMP)-2. rhBMP-2 samples were heated at 50, 70, 90, or 100 degrees C for 15 min, or 1, 2, 4, or 8 h, or autoclaved at 120 degrees C for 15 min. The bone-inducing activity of the rhBMP-2 before and after heating was assayed in in vivo and in vitro systems. For the in vivo assay, 5 microg rhBMP-2 samples were impregnated into porous collagen disks (6 mm in diameter, 1 mm thickness), freeze dried, and implanted into the back muscles of ddY mice. Three weeks later, the implant was harvested from the host and examined for ectopic new bone tissue by radiography. The new bone mass was quantified by single-energy X-ray absorptiometry. The in vitro activity of the rhBMP-2 was assayed by adding the BMP sample at a concentration of 100 ng/ml to cultures of MC3T3-E1 cells. After 48 h, the alkaline phosphatase activity was measured. After heating at 50 degrees or 70 degrees C, no significant reduction in bone-inducing activity was noted in either in vivo or in vitro assay systems unless the protein was exposed to sustained heat at 70 degrees C for 8 h, based on in vitro assay data. However, heating above 90 degrees C and for longer periods led to a decrease in the biological activity of the rhBMP-2 in a time- and temperature-dependent manner. rhBMP-2 was rendered inactive when exposed to temperatures at or in excess of 120 degrees C. [ABSTRACT FROM AUTHOR]

Bone morphogenetic proteins (BMPs) that have the potential to elicit new bonein vivo have been used in a tissue-engineering approach for the repair of bone injuries and bone defects. Although it is now possible to generate large amounts of recombinant human (rh) BMPs for medical use, the major challenge remains in the development of optimal local delivery systems for these proteins. Here we describe the development of a synthetic biodegradable polymer, poly-D,L-lactic acid -- p-dioxanone -- polyethylene glycol block copolymer (PLA-DX-PEG). This polymer exhibits promising degradation characteristics for BMP delivery systems and good biocompatibility under test conditions. PLA-DX-PEG/rhBMP-2 composite implants induced ectopic new bone formation effectively when testedin vivo, and can repair large bone defects orthotopically. This polymeric delivery system represents an advance in the technology for the enhancement of bone repair. [ABSTRACT FROM AUTHOR]