Hyperon Polarization along the Beam Direction Relative to the Second and Third Harmonic Event Planes in Isobar Collisions at sqrt[s_{NN}]=200 GeV

The polarization of Λ and Λ[over ¯] hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at sqrt[s_{NN}]=200  GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild p_{T} dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagrees with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and p_{T} dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy.

Biomechanical evaluation of novel intra- and extramedullary assembly fixation for proximal humerus fractures in the elderly

Purpose: A novel intra- and extramedullary assembly fixation method was introduced, which achieved good clinical results in complex proximal humeral fractures; however, evidence of its comparability with traditional fixation is lacking. This biomechanical study aimed to compare it with traditional fixation devices in osteoporotic proximal humeral fractures. Methods: Three-part proximal humeral fractures with osteopenia were created on 12 pairs of fresh frozen humerus specimens and allocated to three groups: 1) lateral locking plate, 2) intramedullary nail, and 3) intra- and extramedullary assembly fixation. The specimens were loaded to simulate the force at 25° abduction. Thereafter, an axial stiffness test and a compound cyclic load to failure test were applied. Structural stiffness, number of cycles loaded to failure, and relative displacement values at predetermined measurement points were recorded using a testing machine and a synchronized 3D video tracking system. Results: In terms of initial stiffness and the number of cycles loaded to failure, the intra- and extramedullary assembly fixation group showed notable improvements compared to the other groups (p <0.017). The mean relative displacement value of measurement points in the intra- and extramedullary assembly fixation group was smaller than that in the other two groups. However, there was no significant difference until 10,000 cycles. The mean relative displacement of the intramedullary nail group (3.136 mm) exceeded 3 mm at 7,500 cycles of loading. Conclusion: In this test model, axial fixation can provide better mechanical stability than non-axial fixation. The intra- and extramedullary assembly fixation is better able to prevent the varus collapse for elderly proximal humeral fractures with posteromedial comminution.

Erratum: Global Polarization of Ξ and Ω Hyperons in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 126, 162301 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.126.162301.

[Analysis of factors associated with proximal junctional kyphosis after surgery for Lenke type 5 adolescent idiopathic scoliosis]

Objective: To investigate the risk factors associated with the development of proximal junctional kyphosis (PJK) after posterior spinal fusion for in children with Lenke type 5 adolescent idiopathic scoliosis (AIS). Methods: It was a retrospective case-control study that included medical records of 98 children with Lenke type 5 AIS who underwent posterior orthopedic surgery under general anesthesia at the Honghui Hospital Affiliated to Xi'an Jiaotong University from January 2013 to December 2018. There were 23 males and 75 females with a mean age of (14.5±2.2) years (10-18 years). Patients were divided into PJK and non-PJK groups according to whether the posterior junctional angle (PJA) was greater than 10° and increased for more than 10° from the preoperative period at the the last follow-up. Univariate analysis was used to analyze the correlation of general data of the children with occurrence of PJK after the operation. Multivariate logistic regression analysis was used to analyze the risk factors of postoperative PJK. Results: There were 35 cases in the PJK group and 63 cases in the non-PJK group. The PJK and non-PJK groups were followed up for (35.6±7.3) months and (36.4±7.5) months, respectively, and the difference was not statistically significant (P=0.637). There was no statistically significant difference between the two groups in general data such as gender, age, and body mass index (all P>0.05), while there were statistically significant differences between the two groups in upper instrumented vertebrea (UIV) location and junctional area posterior ligamentous complex (PLC) injury (all P<0.05). The results of univariate analysis showed that UIV location at T10-T12, junctional area PLC injury, preoperative coronal thoracic curve (TC), preoperative and final follow-up PJA, and preoperative and final follow-up pelvic incidence-lumbarlordosis (PI-LL) were correlated with postoperative PJK (OR=2.50, 5.37, 0.92, 1.12, 1.32, 1.06, 3.35, all P<0.05). Multifactorial logistic regression analysis showed that UIV located at T10-T12 (OR=2.346, 95%CI: 1.582-3.481, P=0.001), junctional area PLC injury (OR=5.112, 95%CI: 1.283-20.418, P=0.023) and last follow-up PI-LL (OR=1.826, 95%CI: 1.558-24.745, P=0.012) were risk factors for the occurrence of postoperative PJK in children with Lenke type 5 AIS. Conclusions: Postoperative UIV fixation to the thoracolumbar segment, PLC injury in the junctional area and excessive postoperative PI-LL in children with Lenke type 5 AIS may be the risk factors for the occurrence of PJK after the operation. It is suggested that avoidance of UIV selection to the thoracolumbar segment, intraoperative protection of the PLC located near the UIV and restoration of a good PI-LL relationship may reduce the incidence of PJK.

[Predictive value of left ventricular ejection fraction reserve assessed by SPECT G-MPI for major adverse cardiovascular event in patients with coronary artery disease]

Objective: To evaluate the prognostic value of left ventricular ejection fraction (LVEF) reserve assessed by gated SPECT myocardial perfusion imaging (SPECT G-MPI) for major adverse cardiovascular event (MACE) in patients with coronary artery disease. Methods: This is a retrospective cohort study. From January 2017 to December 2019, patients with coronary artery disease and confirmed myocardial ischemia by stress and rest SPECT G-MPI, and underwent coronary angiography within 3 months were enrolled. The sum stress score (SSS) and sum resting score (SRS) were analyzed by the standard 17-segment model, and the sum difference score (SDS, SDS=SSS-SRS) was calculated. The LVEF at stress and rest were analyzed by 4DM software. The LVEF reserve (ΔLVEF) was calculated (ΔLVEF=stress LVEF-rest LVEF). The primary endpoint was MACE, which was obtained by reviewing the medical record system or by telephone follow-up once every twelve months. Patients were divided into MACE-free and MACE groups. Spearman correlation analysis was used to analyze the correlation between ΔLVEF and all MPI parameters. Cox regression analysis was used to analyze the independent factors of MACE, and the optimal SDS cutoff value for predicting MACE was determined by receiver operating characteristic curve (ROC). Kaplan-Meier survival curves were plotted to compare the difference in the incidence of MACE between different SDS groups and different ΔLVEF groups. Results: A total of 164 patients with coronary artery disease [120 male; age (58.6±10.7) years] were included. The average follow-up time was (26.5±10.4) months, and a total of 30 MACE were recorded during follow-up. Multivariate Cox regression analysis showed that SDS (HR=1.069, 95%CI: 1.005-1.137, P=0.035) and ΔLVEF (HR=0.935, 95%CI: 0.878-0.995, P=0.034) were independent predictors of MACE. According to ROC curve analysis, the optimal cut-off to predict MACE was a SDS of 5.5 with an area under the curve of 0.63 (P=0.022). Survival analysis showed that the incidence of MACE was significantly higher in the SDS≥5.5 group than in the SDS<5.5 group (27.6% vs. 13.2%, P=0.019), but the incidence of MACE was significantly lower in the ΔLVEF≥0 group than in theΔLVEF<0 group (11.0% vs. 25.6%, P=0.022). Conclusions: LVEF reserve (ΔLVEF) assessed by SPECT G-MPI serves as an independent protective factor for MACE, while SDS is an independent risk predictor in patients with coronary artery disease. SPECT G-MPI is valuable for risk stratification by assessing myocardial ischemia and LVEF.

Measurements of the Elliptic and Triangular Azimuthal Anisotropies in Central ^{3}He+Au, d+Au and p+Au Collisions at sqrt[s_{NN}]=200 GeV

The elliptic (v_{2}) and triangular (v_{3}) azimuthal anisotropy coefficients in central ^{3}He+Au, d+Au, and p+Au collisions at sqrt[s_{NN}]=200  GeV are measured as a function of transverse momentum (p_{T}) at midrapidity (|η|<0.9), via the azimuthal angular correlation between two particles both at |η|<0.9. While the v_{2}(p_{T}) values depend on the colliding systems, the v_{3}(p_{T}) values are system independent within the uncertainties, suggesting an influence on eccentricity from subnucleonic fluctuations in these small-sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems.

Observation of Directed Flow of Hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in sqrt[s_{NN}]=3 GeV Au+Au Collisions at RHIC

We report here the first observation of directed flow (v_{1}) of the hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in mid-central Au+Au collisions at sqrt[s_{NN}]=3  GeV at RHIC. These data are taken as part of the beam energy scan program carried out by the STAR experiment. From 165×10^{6} events in 5%-40% centrality, about 8400 _{Λ}^{3}H and 5200 _{Λ}^{4}H candidates are reconstructed through two- and three-body decay channels. We observe that these hypernuclei exhibit significant directed flow. Comparing to that of light nuclei, it is found that the midrapidity v_{1} slopes of _{Λ}^{3}H and _{Λ}^{4}H follow baryon number scaling, implying that the coalescence is the dominant mechanism for these hypernuclei production in the 3 GeV Au+Au collisions.

Beam Energy Dependence of Triton Production and Yield Ratio (N_{t}×N_{p}/N_{d}^{2}) in Au+Au Collisions at RHIC

We report the triton (t) production in midrapidity (|y|<0.5) Au+Au collisions at sqrt[s_{NN}]=7.7-200  GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider. The nuclear compound yield ratio (N_{t}×N_{p}/N_{d}^{2}), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity (dN_{ch}/dη) and follows a scaling behavior. The dN_{ch}/dη dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0%-10% most central collisions at 19.6 and 27 GeV, with a significance of 2.3σ and 3.4σ, respectively, giving a combined significance of 4.1σ. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller p_{T} acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.

Measurement of Sequential ϒ Suppression in Au+Au Collisions at sqrt[s_{NN}]=200 GeV with the STAR Experiment

We report on measurements of sequential ϒ suppression in Au+Au collisions at sqrt[s_{NN}]=200  GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC) through both the dielectron and dimuon decay channels. In the 0%-60% centrality class, the nuclear modification factors (R_{AA}), which quantify the level of yield suppression in heavy-ion collisions compared to p+p collisions, for ϒ(1S) and ϒ(2S) are 0.40±0.03(stat)±0.03(sys)±0.09(norm) and 0.26±0.08(stat)±0.02(sys)±0.06(norm), respectively, while the upper limit of the ϒ(3S) R_{AA} is 0.17 at a 95% confidence level. This provides experimental evidence that the ϒ(3S) is significantly more suppressed than the ϒ(1S) at RHIC. The level of suppression for ϒ(1S) is comparable to that observed at the much higher collision energy at the Large Hadron Collider. These results point to the creation of a medium at RHIC whose temperature is sufficiently high to strongly suppress excited ϒ states.

Beam Energy Dependence of Fifth- and Sixth-Order Net-Proton Number Fluctuations in Au+Au Collisions at RHIC

We report the beam energy and collision centrality dependence of fifth and sixth order cumulants (C_{5}, C_{6}) and factorial cumulants (κ_{5}, κ_{6}) of net-proton and proton number distributions, from center-of-mass energy (sqrt[s_{NN}]) 3 GeV to 200 GeV Au+Au collisions at RHIC. Cumulant ratios of net-proton (taken as proxy for net-baryon) distributions generally follow the hierarchy expected from QCD thermodynamics, except for the case of collisions at 3 GeV. The measured values of C_{6}/C_{2} for 0%-40% centrality collisions show progressively negative trend with decreasing energy, while it is positive for the lowest energy studied. These observed negative signs are consistent with QCD calculations (for baryon chemical potential, μ_{B}≤110  MeV) which contains the crossover transition range. In addition, for energies above 7.7 GeV, the measured proton κ_{n}, within uncertainties, does not support the two-component (Poisson+binomial) shape of proton number distributions that would be expected from a first-order phase transition. Taken in combination, the hyperorder proton number fluctuations suggest that the structure of QCD matter at high baryon density, μ_{B}∼750  MeV at sqrt[s_{NN}]=3  GeV is starkly different from those at vanishing μ_{B}∼24  MeV at sqrt[s_{NN}]=200  GeV and higher collision energies.

[Effectiveness of three-dimensional visible technique without fluoroscopy versus two-dimensional fluoroscopy in reduction of unstable pelvic fractures]

Objective

To compare the reduction qualities of three-dimensional visible technique without fluoroscopy and two-dimensional fluoroscopy for unstable pelvic fractures during operations.

Methods

The clinical data of 40 patients with unstable pelvic fractures, who met the selection criteria in three clinical centers between June 2021 and September 2022, were retrospectively analyzed. According to the reduction methods, the patients were divided into two groups. Twenty patients in trial group were treated with unlocking closed reduction system combined with three-dimensional visible technique without fluoroscopy; 20 patients in control group with unlocking closed reduction system under two-dimensional fluoroscopy. There was no significant difference in the gender, age, injury mechanism, Tile type of fracture, Injury Severity Score (ISS), and the time between injury to operation between the two groups ( P>0.05). The qualities of fracture reduction according to the Matta criteria, operative time, intraoperative blood loss, fracture reduction time, times of fluoroscopy, and System Usability Scale (SUS) score were recorded and compared.

Results

All operations were successfully completed in both groups. According to the Matta criteria, the qualities of fracture reduction were rated as excellent in 19 patients (95%) in trial group, which was better than that in the control group (13 cases, 65%), with a significant difference ( χ ²=3.906, P=0.048). The operative time and intraoperative blood loss had no significant differences between the two groups ( P>0.05). The fracture reduction time and times of fluoroscopy were significantly less in trial group than in control group ( P<0.05), and SUS score in trial group was significantly higher in trial group than in control group ( P<0.05).

Conclusion

Compared to using unlocking closed reduction system under two-dimensional fluoroscopy, three-dimensional visible technique without fluoroscopy can significantly improve the reduction quality of unstable pelvic fractures without prolonging the operative time, and is valuable to reduce iatrogenic radiation exposure for patients and medical workers.

Chronic pain conditions and risk of suicidal behavior: a 10-year longitudinal co-twin control study

BACKGROUND

Understanding the relationship between chronic pain conditions and suicidal behavior-suicide attempt, other intentional self-harm, and death by suicide-is imperative for suicide prevention efforts. Although chronic pain conditions are associated with suicidal behaviors, these associations might be attributed to unmeasured confounding or mediated via pain comorbidity.

METHODS

We linked a population-based Swedish twin study (N=17,148 twins) with 10 years of longitudinal, nationwide records of suicidal behavior from health and mortality registers through 2016. To investigate whether pain comorbidity versus specific pain conditions were more important for later suicidal behavior, we modeled a general factor of pain and two independent specific pain factors (measuring pain-related somatic symptoms and neck-shoulder pain, respectively) based on 9 self-reported chronic pain conditions. To examine whether the pain-suicidal behavior associations were attributable to familial confounding, we applied a co-twin control model.

RESULTS

Individuals scoring one standard deviation above the mean on the general pain factor had a 51% higher risk of experiencing suicidal behavior (odds ratio (OR), 1.51; 95% confidence interval (CI), 1.34-1.72). The specific factor of somatic pain was also associated with increased risk for suicidal behavior (OR, 1.80; 95% CI, 1.45-2.22]). However, after adjustment for familial confounding, the associations were greatly attenuated and not statistically significant within monozygotic twin pairs (general pain factor OR, 0.89; 95% CI, 0.59-1.33; somatic pain factor OR, 1.02; 95% CI, 0.49-2.11) CONCLUSION: Clinicians might benefit from measuring not only specific types of pain, but also pain comorbidity; however, treating pain might not necessarily reduce future suicidal behavior, as the associations appeared attributable to familial confounding.

How to improve the biomechanical stability of endosteal augmentation for proximal humerus fracture with osteopenia? A cadaveric study

BACKGROUND

Endosteal augmentation enhances the stability of osteoporotic proximal humeral fracture fixation, but the optimal configuration is unknown. The purpose of this study was to compare the biomechanical properties of different lengths of fibula with or without calcar screw in osteoporotic proximal humeral fracture.

METHODS

Three-part proximal humeral fractures with osteopenia were created on 20 pairs of fresh-frozen humeri specimens and allocated to four groups: (1) locking plate with a 6-cm fibular strut allograft, (2) locking plate with a 6-cm fibular strut allograft and additional calcar screws, (3) locking plate with a 12-cm fibular strut allograft，and (4) locking plate with a 12-cm fibular strut allograft and additional calcar screws. Specimens were loaded to simulate the force at 25° abduction. Thereafter, an axial stiffness test and a compound cyclic load to failure test were applied. Structural stiffness, number of cycles loaded to failure and relative displacement values for 5000 cycles at predetermined measurement points were recorded using a testing machine and a synchronized 3D video tracking system.

FINDINGS

In terms of initial stiffness, number of cycles loaded to failure, and relative displacement values, the groups with 12-cm fibular strut showed obvious improvement compared to the groups with 6-cm fibular strut irrespective of the influence of calcar screw implementation. Further, the groups implemented with calcar screws also showed promising biomechanical stability irrespective of fibular length.

INTERPRETATION

Lateral locking plate with longer endosteal fibular augmentation and calcar screw can significantly improve biomechanical stability for elderly proximal humeral fractures with posteromedial comminution.

Age-Related changes in the morphological features of medial column of the proximal humerus in the Chinese population

Background

Age-related changes in the medial column (MC) of the proximal humerus have a major impact on fracture management; however, the changes in the morphological features remain unclear. This study aimed to investigate the age-related changes in the morphological features of MC and present the morphological grading.

Methods

One hundred computed tomography (CT) images of the proximal humerus of 100 individuals (19-95 years) were retrospectively obtained. The individuals were categorized into five age groups to quantify the differences among different ages; the youngest group (18-44 years) served as the baseline group. Parameters of the morphological features were measured on CT images with multiplanar reconstruction based on an explicit definition of MC, including length, thickness, width, oblique thickness (D_SM), humeral head diameter (D_HM), and ratio (R_SM) of D_SM to D_HM. The morphological grading of MC was presented based on the value of R_SM deviating different standard deviations (SD) from the mean value in the baseline group.

Results

Significant negative correlations were observed between age and the morphological parameters of MC (r ranged from -0.875 to -0.926; all P < 0.05), excluding D_HM (r = 0.081, P = 0.422). Significant differences in the values of morphological feature parameters were detected among the five age groups (all P < 0.001). The highest mean values of morphological feature parameters were observed in the youngest group (18-44 years), which decreased gradually with increasing age until the lowest mean values were observed in the oldest group (≥90 years) (all P < 0.05). The morphological features of MC were categorized into three grades based on the value of R_SM deviating 1.5 SD or 3 SD from the mean value in the baseline group.

Conclusion

Our study shows that the parameter values of morphological features of MC decreased with increasing age. The morphological features of MC could be categorized into three grades. Our findings may provide a more comprehensive insight into age-related changes in the morphological features of MC that facilitate risk stratification and optimize the management of proximal humeral fractures.

Collision-System and Beam-Energy Dependence of Anisotropic Flow Fluctuations

Elliptic flow measurements from two-, four-, and six-particle correlations are used to investigate flow fluctuations in collisions of U+U at sqrt[s_{NN}]=193  GeV, Cu+Au at sqrt[s_{NN}]=200  GeV and Au+Au spanning the range sqrt[s_{NN}]=11.5-200  GeV. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar LHC measurements, viscous hydrodynamic calculations, and trento model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.

Treatment of elderly comminuted proximal humeral fracture using endosteal anatomical support system: A case report

INTRODUCTION

Intramedullary anatomical medial strut with allograft bone (IAMSAB), which accommodates the shape of the proximal humeral cavity and provides rotational stability and direct support to the medial column, was successfully introduced to augment Lateral locking plate (LLP) in the treatment of elderly comminuted proximal humeral fractures. Based on the LLP-IAMSAB construct, a newly titanium endosteal anatomical support system (EASS) was developed.

CASE PRESENTATION

Reported here is a single case of a highly comminuted proximal humeral fracture. The fractures were treated with EASS. The patient's fracture healed properly. The 24-month follow-up demonstrated no pain and a good functional outcome, with no signs of reduction loss, absorption of greater tuberosity, varus displacement and avascular necrosis of humeral head.

CLINICAL DISCUSSION

The newly developed EASS had several special considerations contributing to satisfactory surgical outcome. The flat plane construct of the proximal end of the EASS directly support humeral head to prevent varus displacement of the humeral head, instead of the purchase between the screw thread and the cancellous bone inside the humeral head in the nail or plate fixation. Medial anatomical shape of proximal end helps to reduce medial cortex reduction. Greater tuberosity support block with rotator cuff suture fixation might promote greater tuberosity healing and prevent its absorption. However, there is no similar construct in the nail or plate fixation.

CONCLUSION

The newly developed endosteal anatomical support system might be a promising option in the treatment of elderly comminuted proximal humeral fractures. Although the effectiveness of this system requires additional evaluation upon more patients being treated with this surgical method, the newly developed EASS may serve as a humeral head-preserving method for elderly patients with comminuted proximal humeral fractures.

Is the reconstruction of medial support important for revision following failed treatment of femoral trochanteric fractures? a retrospective comparative study

BACKGROUND

Hip-preserving revision in patients with failed treatment of femoral trochanteric fracture is still a major challenge. Whether the medial support reconstruction could benefit the patients and improve the success rate of hip-preserving revision is still controversial. Hence, the purpose of this study was to evaluate the clinical significance and prognosis of medial support reconstruction during the hip-preserving revision of failed femoral trochanteric fracture treatment.

METHODS

Patients with failed femoral trochanteric fractures treatments addressed by hip-preserving revision at our hospital from January 2014 to December 2020 were analyzed retrospectively. 31 patients were included and divided into a medial support group (n = 16) and a non-medial support group (n = 15). The fracture healing rate was the primary measurement. In addition, the differences in Oxford Hip Score (OHS), quality of life, surgical trauma, and complications were also evaluated.

RESULTS

The fracture healing rate (100%, 16/16 vs. 66.67%, 10/15), the OHS (42.06 ± 4.12 vs. 30.93 ± 11.56, M ± SD), and the mental component score of the 12-item Short-Form Survey (SF-12) (54.48 ± 5.38 vs. 47.90 ± 3.47, M ± SD), were significantly better and the incidence of complications [0(0/16) vs. 40%(6/15)] was significantly lower in the medial support group than the non-medial support group (p < 0.05). No significant differences in the physical component score of the SF-12, surgical trauma and reduction in collodiaphyseal angle of affected femur were observed between groups.

CONCLUSIONS

The reconstruction of medial support seems important for revision following failed treatment of femoral trochanteric fractures. Due to the medial augmentation and improvement of the mechanical stability for proximal femur, the patients might benefit from fracture healing prognosis and functional.

Augmented Stability in Leaving Original Internal Fixation with Multidimensional Cross Locking Plate through Mini-Open Femoral Anterior Approach for Aseptic Femoral Shaft Nonunion: A Retrospective Cohort Study

OBJECTIVE

Aseptic femoral shaft nonunion constitutes approximately 1%-10% of all femoral shaft fractures treated with intramedullary nail (IMN) fixation, possibly attributable to the lack of anti-rotational stability. Although a lateral locking plate (LP) with retainment of original IMN has shown the most success, lateral LP inflicts significant surgical trauma on patients. Therefore, the Multidimensional Cross Locking Plate (MDC-LP) was designed based on a mini-open femoral anterior approach. We aim to report and compare the technical aspects and clinical outcomes of using anterior MDC-LP or lateral LP with retention of original IMN for the treatment of aseptic femoral shaft nonunion.

METHODS

In this single center retrospective cohort study, records of 49 patients who had undergone revision of femoral shaft aseptic nonunion with anterior MDC-LP or lateral LP while retaining the original IMN from January 2015 to October 2019 were retrospectively reviewed. Information on patients' demographics, clinical data, and surgical outcomes were gathered and analyzed. X-ray and CT scans were used for bone union evaluation and the lower extremity functional scale (LEFS) was used for follow-up functional evaluation. For quantitative data, the Student's t-test was used if the data were normally distributed. The Mann-Whitney U-test was used for non-normally distributed data. For qualitative data, the Chi-square test was used for comparisons.

RESULTS

Twenty-seven patients were treated with anterior MDC-LP, and 22 patients were treated with lateral LP. There are no significant differences in age, sex, BMI, time since initial femoral shaft fracture, initial fracture type (close/open), nonunion type, or nonunion location between patients' group. Among patients treated with anterior MDC-LP, an average of 2-months advantage in time to union was observed (4.09 months vs. 6.8 months in the lateral LP group: P = 0.000), smaller incision was required for MDC-LP installment (7.7 cm vs 17.1 cm in lateral LP group: P = 0.000).

CONCLUSIONS

For the treatment of aseptic femoral shaft nonunion with retainment of original IMN, anterior MDC-LP via mini-open femoral anterior approach described in this study is a better option than lateral LP for achieving faster bone union and satisfactory functional outcome with less surgical trauma.

Evidence for Nonlinear Gluon Effects in QCD and Their Mass Number Dependence at STAR

The STAR Collaboration reports measurements of back-to-back azimuthal correlations of di-π^{0}s produced at forward pseudorapidities (2.6<η<4.0) in p+p, p+Al, and p+Au collisions at a center-of-mass energy of 200 GeV. We observe a clear suppression of the correlated yields of back-to-back π^{0} pairs in p+Al and p+Au collisions compared to the p+p data. The observed suppression of back-to-back pairs as a function of transverse momentum suggests nonlinear gluon dynamics arising at high parton densities. The larger suppression found in p+Au relative to p+Al collisions exhibits a dependence of the saturation scale Q_{s}^{2} on the mass number A. A linear scaling of the suppression with A^{1/3} is observed with a slope of -0.09±0.01.

Measurements of Proton High-Order Cumulants in sqrt[s_{NN}]=3 GeV Au+Au Collisions and Implications for the QCD Critical Point

We report cumulants of the proton multiplicity distribution from dedicated fixed-target Au+Au collisions at sqrt[s_{NN}]=3.0  GeV, measured by the STAR experiment in the kinematic acceptance of rapidity (y) and transverse momentum (p_{T}) within -0.5<y<0 and 0.4<p_{T}<2.0  GeV/c. In the most central 0%-5% collisions, a proton cumulant ratio is measured to be C_{4}/C_{2}=-0.85±0.09 (stat)±0.82 (syst), which is 2σ below the Poisson baseline with respect to both the statistical and systematic uncertainties. The hadronic transport UrQMD model reproduces our C_{4}/C_{2} in the measured acceptance. Compared to higher energy results and the transport model calculations, the suppression in C_{4}/C_{2} is consistent with fluctuations driven by baryon number conservation and indicates an energy regime dominated by hadronic interactions. These data imply that the QCD critical region, if created in heavy-ion collisions, could only exist at energies higher than 3 GeV.

Measurements of _{Λ}^{3}H and _{Λ}^{4}H Lifetimes and Yields in Au+Au Collisions in the High Baryon Density Region

We report precision measurements of hypernuclei _{Λ}^{3}H and _{Λ}^{4}H lifetimes obtained from Au+Au collisions at sqrt[s_{NN}]=3.0  GeV and 7.2 GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider, and the first measurement of _{Λ}^{3}H and _{Λ}^{4}H midrapidity yields in Au+Au collisions at sqrt[s_{NN}]=3.0  GeV. _{Λ}^{3}H and _{Λ}^{4}H, being the two simplest bound states composed of hyperons and nucleons, are cornerstones in the field of hypernuclear physics. Their lifetimes are measured to be 221±15(stat)±19(syst)  ps for _{Λ}^{3}H and 218±6(stat)±13(syst)  ps for _{Λ}^{4}H. The p_{T}-integrated yields of _{Λ}^{3}H and _{Λ}^{4}H are presented in different centrality and rapidity intervals. It is observed that the shape of the rapidity distribution of _{Λ}^{4}H is different for 0%-10% and 10%-50% centrality collisions. Thermal model calculations, using the canonical ensemble for strangeness, describes the _{Λ}^{3}H yield well, while underestimating the _{Λ}^{4}H yield. Transport models, combining baryonic mean-field and coalescence (jam) or utilizing dynamical cluster formation via baryonic interactions (phqmd) for light nuclei and hypernuclei production, approximately describe the measured _{Λ}^{3}H and _{Λ}^{4}H yields. Our measurements provide means to precisely assess our understanding of the fundamental baryonic interactions with strange quarks, which can impact our understanding of more complicated systems involving hyperons, such as the interior of neutron stars or exotic hypernuclei.

Probing the Gluonic Structure of the Deuteron with J/ψ Photoproduction in d+Au Ultraperipheral Collisions

Understanding gluon density distributions and how they are modified in nuclei are among the most important goals in nuclear physics. In recent years, diffractive vector meson production measured in ultraperipheral collisions (UPCs) at heavy-ion colliders has provided a new tool for probing the gluon density. In this Letter, we report the first measurement of J/ψ photoproduction off the deuteron in UPCs at the center-of-mass energy sqrt[s_{NN}]=200  GeV in d+Au collisions. The differential cross section as a function of momentum transfer -t is measured. In addition, data with a neutron tagged in the deuteron-going zero-degree calorimeter is investigated for the first time, which is found to be consistent with the expectation of incoherent diffractive scattering at low momentum transfer. Theoretical predictions based on the color glass condensate saturation model and the leading twist approximation nuclear shadowing model are compared with the data quantitatively. A better agreement with the saturation model has been observed. With the current measurement, the results are found to be directly sensitive to the gluon density distribution of the deuteron and the deuteron breakup process, which provides insights into the nuclear gluonic structure.

Search for the Chiral Magnetic Effect via Charge-Dependent Azimuthal Correlations Relative to Spectator and Participant Planes in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

The chiral magnetic effect (CME) refers to charge separation along a strong magnetic field due to imbalanced chirality of quarks in local parity and charge-parity violating domains in quantum chromodynamics. The experimental measurement of the charge separation is made difficult by the presence of a major background from elliptic azimuthal anisotropy. This background and the CME signal have different sensitivities to the spectator and participant planes, and could thus be determined by measurements with respect to these planes. We report such measurements in Au+Au collisions at a nucleon-nucleon center-of-mass energy of 200 GeV at the Relativistic Heavy-Ion Collider. It is found that the charge separation, with the flow background removed, is consistent with zero in peripheral (large impact parameter) collisions. Some indication of finite CME signals is seen in midcentral (intermediate impact parameter) collisions. Significant residual background effects may, however, still be present.

Expression pattern of CRYAB and CTGF genes in two pig breeds at different altitudes

ABSTRACT Tibetan pigs are characterized by significant phenotypic differences relative to lowland pigs. Our previous study demonstrated that the genes CRYAB and CTGF were differentially expressed in heart tissues between Tibetan (highland breed) and Yorkshire (lowland breed) pigs, indicating that they might participate in hypoxia adaptation. CRYAB (ɑB-crystallin) and CTGF (connective tissue growth factor) have also been reported to be associated with lung development. However, the expression patterns of CRYAB and CTGF in lung tissues at different altitudes and their genetic characterization are not well understood. In this study, qRT-PCR and western blot of lung tissue revealed higher CRYAB expression levels in highland and middle-highland Tibetan and Yorkshire pigs than in their lowland counterparts. With an increase in altitude, the expression level of CTGF increased in Tibetan pigs, whereas it decreased in Yorkshire pigs. Furthermore, two novel single-nucleotide polymorphism were identified in the 5′ flanking region of CRYAB (g.39644482C>T and g.39644132T>C) and CTGF (g.31671748A>G and g.31671773T>G). The polymorphism may partially contribute to the differences in expression levels between groups at the same altitude. These findings provide novel insights into the high-altitude hypoxia adaptations of Tibetan pigs.

Measurement of the Sixth-Order Cumulant of Net-Proton Multiplicity Distributions in Au+Au Collisions at sqrt[s_{NN}]=27, 54.4, and 200 GeV at RHIC

According to first-principle lattice QCD calculations, the transition from quark-gluon plasma to hadronic matter is a smooth crossover in the region μ_{B}≤T_{c}. In this range the ratio, C_{6}/C_{2}, of net-baryon distributions are predicted to be negative. In this Letter, we report the first measurement of the midrapidity net-proton C_{6}/C_{2} from 27, 54.4, and 200 GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). The dependence on collision centrality and kinematic acceptance in (p_{T}, y) are analyzed. While for 27 and 54.4 GeV collisions the C_{6}/C_{2} values are close to zero within uncertainties, it is observed that for 200 GeV collisions, the C_{6}/C_{2} ratio becomes progressively negative from peripheral to central collisions. Transport model calculations without critical dynamics predict mostly positive values except for the most central collisions within uncertainties. These observations seem to favor a smooth crossover in the high-energy nuclear collisions at top RHIC energy.

Observation of D_{s}^{±}/D^{0} Enhancement in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the first measurement of charm-strange meson D_{s}^{±} production at midrapidity in Au+Au collisions at sqrt[s_{NN}]=200  GeV from the STAR experiment. The yield ratio between strange (D_{s}^{±}) and nonstrange (D^{0}) open-charm mesons is presented and compared to model calculations. A significant enhancement, relative to a pythia simulation of p+p collisions, is observed in the D_{s}^{±}/D^{0} yield ratio in Au+Au collisions over a large range of collision centralities. Model calculations incorporating abundant strange-quark production in the quark-gluon plasma and coalescence hadronization qualitatively reproduce the data. The transverse-momentum integrated yield ratio of D_{s}^{±}/D^{0} at midrapidity is consistent with a prediction from a statistical hadronization model with the parameters constrained by the yields of light and strange hadrons measured at the same collision energy. These results suggest that the coalescence of charm quarks with strange quarks in the quark-gluon plasma plays an important role in D_{s}^{±}-meson production in heavy-ion collisions.

[Application of channel-assisted minimally invasive repair system in Myerson types and chronic Achilles tendon rupture]

Objective

To investigate the effectiveness of channel-assisted minimally invasive repair system (CAMIR) in treatment of the Myerson types Ⅰ and Ⅱchronic Achilles tendon rupture.

Methods

Between May 2016 and August 2017, 19 patients with Myerson types Ⅰ and Ⅱchronic Achilles tendon ruptures were treated with CAMIR. There were 14 males and 5 females, aged from 21 to 48 years, with an average age of 34.5 years. The disease duration was 5-9 weeks (mean, 7.5 weeks). The preoperative Thompson tests of affected ankles showed positive. There were 11 cases of Myerson type Ⅰwith the gaps of Achilles tendon defect of 1-2 cm (mean, 1.58 cm), and 8 cases of Myerson type Ⅱwith the gaps of Achilles tendon defect of 2.5-4.0 cm (mean, 3.16 cm). The ankle dorsiflexion and plantarflexion range of motion were measured before and after operation; the American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score was used to assess the patients' ankle joint function.

Results

No major blood vessels, nerves, and other tissue structures were damaged during the operation; 3 cases of Myerson type Ⅰ were converted to Myerson type Ⅱ according to the gaps of the defect after the scar tissue was removed during the operation. After operation, the depressed part of the Achilles tendon disappeared, the continuity of the tendon was restored, and the Thompson tests were negative. All 19 patients were followed up 12-25 months, with an average of 14 months. All incisions healed by first intention, and no infection and skin necrosis occurred; all the pre-injury activities and exercise were restored at 6 months after operation. During the follow-up period, no heel pain or re-rupture occurred. At last follow-up, except that there was no significant difference in ankle dorsiflexion range of motion of Myerson type Ⅰ patients ( t=2.118, P=0.071), the AOFAS ankle and hindfoot score, ankle plantarflexion range of motion of Myerson types Ⅰ and Ⅱ patients, and ankle dorsiflexion range of motion of Myerson type Ⅱ patients were significantly improved when compared with preoperative values ( P<0.05). According to AOFAS ankle and hindfoot function score, the ankle joint function of type Ⅰ patients was excellent in 7 cases and good in 1 case, and of type Ⅱ patients were excellent in 8 cases, good in 2 cases, and fair in 1 case.

Conclusion

CAMIR is safe and effective in the treatment of Myerson types Ⅰ and Ⅱ chronic Achilles tendon rupture with fewer complications and better functional recovery of ankle joint.

Measurement of e^{+}e^{-} Momentum and Angular Distributions from Linearly Polarized Photon Collisions

The Breit-Wheeler process which produces matter and antimatter from photon collisions is experimentally investigated through the observation of 6085 exclusive electron-positron pairs in ultraperipheral Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements reveal a large fourth-order angular modulation of cos4Δϕ=(16.8±2.5)% and smooth invariant mass distribution absent of vector mesons (ϕ, ω, and ρ) at the experimental limit of ≤0.2% of the observed yields. The differential cross section as a function of e^{+}e^{-} pair transverse momentum P_{⊥} peaks at low value with sqrt[⟨P_{⊥}^{2}⟩]=38.1±0.9  MeV and displays a significant centrality dependence. These features are consistent with QED calculations for the collision of linearly polarized photons quantized from the extremely strong electromagnetic fields generated by the highly charged Au nuclei at ultrarelativistic speed. The experimental results have implications for vacuum birefringence and for mapping the magnetic field which is important for emergent QCD phenomena.

Global Polarization of Ξ and Ω Hyperons in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

Global polarization of Ξ and Ω hyperons has been measured for the first time in Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements of the Ξ^{-} and Ξ[over ¯]^{+} hyperon polarization have been performed by two independent methods, via analysis of the angular distribution of the daughter particles in the parity violating weak decay Ξ→Λ+π, as well as by measuring the polarization of the daughter Λ hyperon, polarized via polarization transfer from its parent. The polarization, obtained by combining the results from the two methods and averaged over Ξ^{-} and Ξ[over ¯]^{+}, is measured to be ⟨P_{Ξ}⟩=0.47±0.10(stat)±0.23(syst)% for the collision centrality 20%-80%. The ⟨P_{Ξ}⟩ is found to be slightly larger than the inclusive Λ polarization and in reasonable agreement with a multiphase transport model. The ⟨P_{Ξ}⟩ is found to follow the centrality dependence of the vorticity predicted in the model, increasing toward more peripheral collisions. The global polarization of Ω, ⟨P_{Ω}⟩=1.11±0.87(stat)±1.97(syst)% was obtained by measuring the polarization of daughter Λ in the decay Ω→Λ+K, assuming the polarization transfer factor C_{ΩΛ}=1.

Achieve Closed Reduction of Irreducible, Unilateral Vertically Displaced Pelvic Ring Disruption with an Unlocking Closed Reduction Technique

OBJECTIVE

To be able to treat irreducible unilateral vertically displaced pelvic ring disruption (UVDPRD) using closed reduction, we introduced a technique named Unlocking Closed Reduction Technique (UCRT) and evaluated its effectiveness with improved pelvic closed reduction system (PCRS).

METHODS

A retrospective study was performed in our department. Between January 2014 and December 2017, 43 patients whose UVDPRD were not successfully reduced using transcondylar traction. Subsequently, they were treated with UCRT using improved PCRS. The study included 19 male and 24 female patients, with a mean age at the time of the operation of 46.2 years. During surgery, operation time and blood loss were recorded. Post-surgical reduction quality was evaluated using Matta scoring criteria and patient lower-extremity functional outcome was evaluated using Majeed functional scoring criteria.

RESULTS

When used with improved PCRS, UCRT achieved pelvic reduction in all 43 cases of irreducible UVDPRD with postoperative pelvic reduction quality rated excellent and good for 42/43 (97.6%) patients according to the Matta scoring criteria (Matta Score < 10 mm). While no post-surgical complications emerged as the direct result of UCRT in this cohort of patients, 8/37 patients who were treated with subcutaneous supra-acetabular pedicle screw internal fixation (INFIX) for anterior ring fixation developed lateral femoral cutaneous nerve injury but recovered 6 months postoperatively. No revision surgery was performed on any of the recruited patients. All patients' lower-extremity functionality was rated excellent with an average Majeed function score of 94.3 during the last follow-up at an average of 41.6 months postoperatively.

CONCLUSION

With excellent surgical and functional outcomes in patients with irreducible UVDPRD, improved PCRS-assisted UCRT proved to be a safe and effective method for the treatment of irreducible UVDPRD.

[Research progress on medial support augmentation of plate osteosynthesis for proximal humeral fractures]

Objective

To review the literature about the clinical application and research progress on medial support augmentation of plate osteosynthesis for proximal humeral fractures, and to provide reference for clinical treatment.

Methods

The literature concerning medial support augmentation of plate osteosynthesis for proximal humeral fractures in recent years was extensively reviewed, as well as the biomechanical benefit and clinical advantage were analyzed thoroughly.

Results

Medial support augmentation of plate osteosynthesis for proximal humeral fractures is very important, especially in osteoporotic and/or comminuted fractures. Many medial support augmentation methods have been proposed which can be divided into extramedullary support and intramedullary support. It can also be divided into autogenous bone support and allogenic bone support according to the material and source, divided into medial column support, calcar support, and humeral head support according to the support site, and divided into fibular shaft support, femoral head support, anatomic fibula support according to the shape of the augmented fixation. At present, clinical and biomechanical researches show that medial support augmentation is an effective treatment for proximal humeral fractures.

Conclusion

As an important treatment strategy for the treatment of proximal humeral fractures, the medial support augmentation of plate osteosynthesis gets the focus from the biomechanical studies and clinical treatment. However, there are still widespread controversies among orthopedic surgeons regarding the support mode, site, implant shape, and material of medial column support for augmentation of proximal humeral fractures. More high-quality clinical trials and biomechanical researches as well as multi-disciplinary integration, are needed to provide better strategy treatment for the treatment of proximal humeral fractures.

Nonmonotonic Energy Dependence of Net-Proton Number Fluctuations

Nonmonotonic variation with collision energy (sqrt[s_{NN}]) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of the system, is suggested as a signature for the quantum chromodynamics critical point. We report the first evidence of a nonmonotonic variation in the kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of sqrt[s_{NN}] with 3.1  σ significance for head-on (central) gold-on-gold (Au+Au) collisions measured solenoidal tracker at Relativistic Heavy Ion Collider. Data in noncentral Au+Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of sqrt[s_{NN}].

Lee Silverman Voice Treatment for dysarthria in patients with Parkinson's disease: a systematic review and meta-analysis

Approximately 89% of patients with Parkinson's disease (PD) suffer from dysarthria. Lee Silverman Voice Treatment (LSVT), a behavioral therapy, aims to improve speech and voice functions. The objective was to assess the effectiveness of LSVT compared with other/no speech interventions for dysarthria in patients with PD. Electronic databases, including PubMed, Embase and the Cochrane Library, were searched. The publication date of all included studies was before 6 March 2020. Only randomized controlled trials (RCTs) that evaluated the LSVT intervention compared with other/no speech intervention were considered. The data obtained from the included studies were described and the mean differences were calculated. Eight RCTs were included in this meta-analysis comparing LSVT with other/no speech interventions. In the comparison of LSVT versus no intervention, vocal intensity for sustained 'Ah' phonation, reading the 'Rainbow passage', monologue and describing a picture increased by 8.87, 4.34, 3.25 and 3.31 dB, respectively, after 1 month of therapy. Compared with the respiratory therapy group, the LSVT group also showed significant improvement in vocal intensity for sustained 'Ah' phonation, reading the 'Rainbow passage' and monologue immediately after treatment (13.39, 6.66 and 3.19 dB). Positive improvement still existed after 24 months. There was no difference in the therapeutic effect between face-to-face and online LSVT. The effectiveness of LSVT for dysarthria in patients with PD was verified in these trials. However, future RCTs with sufficient participants are essential to evaluate the effectiveness of LSVT for dysarthria.

[Intelligent monitoring system assisted pelvic fracture closed reduction for treating one case with complex pelvic fracture]

Objective

To introduce the experience of intelligent monitoring system assisted pelvic fracture closed reduction to treat complex pelvic fracture in a minimally invasive method.

Methods

A 30-year-old male patient with complex pelvic fracture caused by a falling injury was treated in December 2019. The pelvic fracture was diagnosed by X-ray film and CT three-dimensional reconstruction. The AO/Orthopaedic Trauma Association (AO/OTA) classification was 61-C3.3 type (H-shaped sacrum fracture with pubic symphysis separation). At 48 hours after injury, the vital signs were stable, and the operation was performed. The pelvic fracture was reduced with the help of pelvic reduction frame and skeletal traction, the intelligent monitoring system, and fixed with the channel screws.

Results

The intraoperative blood loss was 50 mL, the operation time was 180 minutes, and the fluoroscopy time was 45 seconds. The incision healed well after operation. The X-ray film of pelvis was taken on the next day after operation, and the fracture reduction was evaluated as anatomical reduction according to Matta standard; CT three-dimensional reconstruction showed that the fixation screws were all located in the cortex of bone, without penetrating the cortex of bone.

Conclusion

The intelligent monitoring system assisted pelvic fracture closed reduction is reliable in the minimally invasive treatment of complex pelvic fractures, which can achieve good results and reduce intraoperative fluoroscopy.

[Application of three-dimensional navigation template in adult cubitus varus osteotomy]

Objective

To investigate the effectiveness of three-dimensional (3D) navigation template in the adult cubitus varus osteotomy.

Methods

Between April 2013 and September 2015, 17 patients with cubitus varus were admitted. There were 6 males and 11 females, aged from 19 to 38 years, with an average age of 26.9 years. There were 10 cases of left elbow joints and 7 cases of right elbow joints. The disease duration was 9-30 years (mean, 18 years). Based on the preoperative X-ray film, the humerus-elbow-wrist (HEW) angle was (-13.2 ±3.3)°, the anteversion angle was (-10.5±2.3)°. The preoperative range of motion (ROM) of flexion was (127.3±7.3)° and ROM of extension was (-10.0±2.5)°. Based on the CT 3D reconstruction, the osteotomy navigation template was designed and printed by 3D printing technique. The cubitus varus osteotomy was assisted by 3D navigation template. The postoperative HEW angle, anteversion angle, and ROMs of the elbow joints of both sides were measured. The elbow function was evaluated based on the Oppenheim elbow function score at 1 year after operation.

Results

All cubitus varus osteotomies succeeded with the assist of 3D navigation template. All incisions healed by first intention. All patients were followed up 12-15 months (mean, 13 months). X-ray films showed that all osteotomies healed after 9-12 weeks (mean, 11 weeks). At 1 year after operation, the HEW angle was (9.7±1.9)°, the anteversion angle was (20.7±4.3)°, the ROM was (2.6±3.5)° in extension and (139.2±4.8)° in flexion of affected side. The HEW angle, anteversion angle, and ROMs significantly increased compared with preoperative values ( P<0.05). And there was no significant difference between affected and normal elbow joints ( P>0.05). The elbow functions were excellent in 13 cases and good in 4 cases based on the Oppenheim elbow function score at 1 year after operation. There was no complication such as the nerve injury or osteomyositis of elbow joint during follow-up.

Conclusion

The 3D navigation template can provide a personalized and precise osteotomy treatment for adult cubitus varus deformity and obtain a satisfactory effectiveness.

Comparison of a multidimensional cross locking plate versus a locking compression plate for the treatment of femoral shaft nonunion: Finite element analysis

The purpose of this study was to explore the advantages and disadvantages of a multi-dimensional cross locking plate (MDC-LP) compared with a locking compression plate (LCP) as the augmentation plate (AP) over an intramedullary nail (IMN) for the treatment of femoral shaft nonunion by using finite element analysis. A finite element model of the femur was developed to analyze the maximum stress, stress distribution, displacement of fixation and nonunion site under increasing axial and torsional loads. Some differences in the stress distribution and stress values on the fixations were observed in the five fixation models. The MDC-LP with eight screw fixation showed the lowest variety of nonunion site displacement under the increasing axial and torsional loads. Models of the MDC-LP were more stable with regard to the bending and torsional forces. The short MDC-LP with eight screw insertion as an augmentation plate over intramedullary nail shows biomechanical advantages compared to the LCP. The MDC-LP may be an appropriate and effective treatment option for femoral shaft nonunion.

First Measurement of Λ_{c} Baryon Production in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the first measurement of the charmed baryon Λ_{c}^{±} production at midrapidity (|y|<1) in Au+Au collisions at sqrt[s_{NN}]=200  GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider. The Λ_{c}/D^{0} [denoting (Λ_{c}^{+}+Λ_{c}^{-})/(D^{0}+D[over ¯]^{0})] yield ratio is measured to be 1.08±0.16  (stat)±0.26  (sys) in the 0%-20% most central Au+Au collisions for the transverse momentum (p_{T}) range 3<p_{T}<6  GeV/c. This is significantly larger than the pythia model calculations for p+p collisions. The measured Λ_{c}/D^{0} ratio, as a function of p_{T} and collision centrality, is comparable to the baryon-to-meson ratios for light and strange hadrons in Au+Au collisions. Model calculations including coalescence hadronization for charmed baryon and meson formation reproduce the features of our measured Λ_{c}/D^{0} ratio.

The Mortality After Release from Incarceration Consortium (MARIC): Protocol for a multi-national, individual participant data meta-analysis

INTRODUCTION

More than 30 million adults are released from incarceration globally each year. Many experience complex physical and mental health problems, and are at markedly increased risk of preventable mortality. Despite this, evidence regarding the global epidemiology of mortality following release from incarceration is insufficient to inform the development of targeted, evidence-based responses. Many previous studies have suffered from inadequate power and poor precision, and even large studies have limited capacity to disaggregate data by specific causes of death, sub-populations or time since release to answer questions of clinical and public health relevance.

OBJECTIVES

To comprehensively document the incidence, timing, causes and risk factors for mortality in adults released from prison.

METHODS

We created the Mortality After Release from Incarceration Consortium (MARIC), a multi-disciplinary collaboration representing 29 cohorts of adults who have experienced incarceration from 11 countries. Findings across cohorts will be analysed using a two-step, individual participant data meta-analysis methodology.

RESULTS

The combined sample includes 1,337,993 individuals (89% male), with 75,795 deaths recorded over 9,191,393 person-years of follow-up.

CONCLUSIONS

The consortium represents an important advancement in the field, bringing international attention to this problem. It will provide internationally relevant evidence to guide policymakers and clinicians in reducing preventable deaths in this marginalized population.

KEY WORDS

Mortality; incarceration; prison; release; individual participant data meta-analysis; consortium; cohort.

Treatment of femoral neck nonunion with a new fixation construct through the Watson-Jones approach

Objective

The aim of the study is to explore the clinical effect of a dynamic condylar screw (DCS) system, medial anatomical buttress plate (MABP), and autogenous iliac bone graft through the Watson-Jones approach in the treatment of femoral neck nonunion.

Methods

This prospective study included 15 patients (12 men and 3 women) with nonunion of femoral neck fracture, who were treated with the DCS and MABP with autogenous iliac bone graft through the Watson-Jones approach. The patients were followed up for an average of 16 months (range, 12–24 months).

Results

All patients achieved bone healing with an average fracture healing time of 3.4 months (2.8–4.6 months). The Harris score significantly increased from 30 ± 3.9 before the operation to 87.6 ± 7.9 at the last follow-up, and the visual analogue scale significantly decreased from 4 ± 1.3 before the operation to 1 ± 1.7 at the last follow-up. The average limb shortening was reduced from 1.8 cm (range, 0–3.1 cm) before the revision operation to 0.5 cm (range, 0.1–1.3 cm) after the last follow-up. The neck-shaft angle of the injured side was restored from an average of 118° (range, 108–139°) before the revision operation to an average of 132° (range, 127–144°) at the last follow-up. No collapse of the femoral head, wound infections, screw backout, screw or plate breakages, or nerve injury was found.

Conclusion

TheDCS and MABP with autogenous iliac bone graft through the Watson-Jones approach is an effective option for the treatment of femoral neck nonunion or delayed healing.

The translational potential of the article

This article shows that the application of DCS and MABP provides a rigid fixation at the fracture site to promote bone graft integration and bone union. This new kind of technique could be one option of Hip conservation procedures, just special for young patients with femoral neck nonunion.