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OBJECTIVE Anterior cervical discectomy and fusion (ACDF) has long been regarded as a gold standard in the treatment of cervical myelopathy. Subsequently, cervical artificial disc replacement (c-ADR) was developed and provides the advantage of motion preservation at the level of the intervertebral disc surgical site, which may also reduce stress at adjacent levels. The goal of this study was to compare clinical and functional outcomes in patients undergoing ACDF with those in patients undergoing c-ADR for cervical spondylotic myelopathy (CSM). METHODS A systematic literature review and meta-analysis were performed using the Embase, PubMed, and Cochrane Central Register of Controlled Trials databases from database inception to November 21, 2021. The authors compared Neck Disability Index (NDI), SF-36, and Japanese Orthopaedic Association (JOA) scores; complication rates; and reoperation rates for these two surgical procedures in CSM patients. The Mantel-Haenszel method and variance-weighted means were used to analyze outcomes after identifying articles that met study inclusion criteria. RESULTS More surgical time was consumed in the c-ADR surgery (p = 0.04). Shorter hospital stays were noted in patients who had undergone c-ADR (p = 0.04). Patients who had undergone c-ADR tended to have better NDI scores (p = 0.02) and SF-36 scores (p = 0.001). Comparable outcomes in terms of JOA scores (p = 0.24) and neurological success rate (p = 0.12) were noted after the surgery. There was no significant between-group difference in the overall complication rates (c-ADR: 18% vs ACDF: 25%, p = 0.17). However, patients in the ACDF group had a higher reoperation rate than patients in the c-ADR group (4.6% vs 1.5%, p = 0.02). CONCLUSIONS At the midterm follow-up after treatment of CSM, better functional outcomes as reflected by NDI and SF-36 scores were noted in the c-ADR group than those in the ACDF group. c-ADR had the advantage of retaining range of motion at the level of the intervertebral disc surgical site without causing more complications. A large sample size with long-term follow-up studies may be required to confirm these findings in the future.

Two-stage exchange arthroplasty is a feasible treatment for chronic PJI (periprosthetic joint infection) of total hip arthroplasty (THA). However, there are large numbers of patients who are unable to ultimately receive reimplantation after resection arthroplasty owing to uncontrolled infection and multiple comorbidities. The purpose of the current study was to identify patient-related risk factors and reasons for being unable to undergo revision THA. Individuals undergoing resection arthroplasty for chronic PJI treatment from 2013 to 2020 at our institution were retrospectively reviewed. A variety of patient comorbidities, laboratory data, isolated pathogens, and follow-up status were collected for analysis. A total of 84 patients (46 men and 38 women) with a 2.7 ± 2.1-year follow-up were analyzed. Thirty-eight (45.2%) patients eventually underwent revision THA, while the other 46 (54.8%) did not receive reimplantation during follow-up. The patients without receiving reimplantation had higher Charlson comorbidity index (CCI) score (3.1 ± 2.9 versus 1.2 ± 1.5; p = 0.001). Lower cumulative incidence of receiving reimplantation was observed in patients with chronic kidney disease (log-rank test, p = 0.019), anemia (p = 0.011), presence of initial fever (p = 0.030), and oxacillin-resistant strain infection (p = 0.030). The most common reasons for not receiving reimplantation were uncontrolled infection, unstable medical conditions, and death. The patients without reimplantation had a relatively higher mortality rate (log-rank test, p = 0.002). Chronic hip PJI with poor medical conditions or oxacillin-resistant strain infection decreased the chance of undergoing revision surgery. These patients had unfavourable outcomes and a higher mortality rate after resection arthroplasty.

Kyphoplasty with the SpineJack system was able to restore vertebral height and stabilize the vertebra with an injection of bone cement. The goal of this study was to seek a reliable assessing method during the surgery in determining the minimum amount of bone cement required for the SpineJack system to restore vertebral height and stabilize the vertebra. We defined the “double cross sign” as bone cement that expanded vertically along the bilateral SpineJack system, and spread across the midline of the vertebral body as viewed in the anteroposterior (AP) view of the radiographic image. Sixty-five patients aged 74.5 ± 8.5 years with vertebral compression fracture were included in the study. Patients with a positive double cross sign had better ODI score than those without the double cross sign (20.0 ± 6.9 vs. 32.3 ± 8.2; p < 0.001). Postoperative regional kyphotic and local kyphotic angle were significantly better in the positive double cross sign group (11 ± 8.8 degrees vs. 5.3 ± 3.2 degrees; p = 0.001/11.7 ± 6.2 degrees vs. 6.6 ± 4.1 degrees; p = 0.001, respectively). The more stable construct was built once the double cross sign was achieved during surgery. In this study, a convenient and intuitive method in identifying the minimum but sufficient quantity of injected cement during the SpineJack procedure was developed.

Background: Vertebral compression fractures, resulting in significant pain and disability, commonly occur in elderly osteoporotic patients. However, the current literature lacks long-term follow-up information related to image parameters and bone formation following vertebroplasty. Purpose: To evaluate new bone formation after vertebroplasty and the long-term effect of vertebroplasty. Methods: A total of 157 patients with new osteoporotic compression fractures who underwent vertebroplasty were retrospectively analyzed. The image parameters, including wedge angles, compression ratios, global alignment, and new bone formation, were recorded before and after vertebroplasty up to three years postoperatively. Results: The wedge angle improved and was maintained for 12 months. The compression ratios also improved but gradually deteriorated during the follow-up period. New bone formation was found in 40% of the patients at 36 months, and the multivariate analysis showed that this might have been related to the correction of the anterior compression ratio. Conclusions: Vertebroplasty significantly restored the wedge angles and compression ratios up to one year postoperatively, and new bone formation was noted on plain radiographs, which increased over time. Last, the restoration of vertebral parameters may contribute to new bone formation.

Background: Although arthroscopic screw fixation and suture fixation are mainstream interventions for displaced anterior cruciate ligament avulsion fractures of the tibia, the differences in clinical outcomes between them remain inconclusive. Purpose: To conduct a meta-analysis comparing the clinical and functional outcomes between arthroscopic screw fixation and suture fixation for tibial avulsion fractures. Study Design: Systematic review; Level of evidence, 3. Methods: A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and using the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases. Inclusion criteria were English-language articles that compared functional outcomes after screw fixation versus suture fixation for tibial avulsion fractures and had at least 1-year follow-up. Relevant data were extracted and analyzed statistically using the Mantel-Haenszel method and variance-weighted means. Random-effects models were used to generate pooled relative risk (RR) estimates with confidence intervals (CIs). Results: Of 1395 articles initially identified, we included 5 studies with 184 patients (91 patients with screw fixations and 93 patients with suture fixations). The pooled results indicated similar postoperative outcomes for screw fixation and suture fixation: Lysholm score (mean difference [MD], −0.32 [95% CI, −6.08 to 5.44]; P = .91), proportion of International Knee Documentation Committee score grade A (74% vs 74%; RR, 0.63 [95% CI, 0.10-3.95]; P = .63), Tegner score (MD, 0.10 [95% CI: −1.73 to 1.92]; P = .92), and Lachman test results (stable knee joint, 82% vs 82%; RR, 0.99; 95% CI: 0.85-1.16; P = .90). Patients in the screw fixation group had a significantly higher overall subsequent surgery rate (46% vs 19%; RR, 2.33; 95% CI,1.51-3.60; P = .0001) and implant removal rate (44% vs 3%; RR, 8.52; 95% CI, 3.58-20.29; P < .00001) compared with those in the suture fixation group. Nonimplant-related subsequent surgery rates were similar for the 2 groups. Conclusion: The findings indicated a higher risk of subsequent surgery (RR, 2.33) and implant removal (RR, 8.52) after screw fixation when compared with suture fixation for tibial avulsion fractures. However, there were no significant differences in clinical outcome scores between the 2 techniques.

Extracorporeal shockwave therapy (ESWT) has become a common practice for treating knee osteoarthritis (OA). However, the effectiveness and safety of this treatment are still questionable. This meta-analysis is aimed at determining the degree of pain reduction and functional outcome after ESWT for knee OA. We systematically searched MEDLINE, EMBASE, and other online databases. The articles comparing the outcomes between ESWT and controls were included in the analysis. Nine studies with 705 patients were included. The pooled data revealed significantly lower pain scores in the ESWT groups than in the control groups within two weeks of treatment and six months after treatment (visual analogue scale, − 1.59, p = 0.0003, 95% confidence interval (CI) − 2.45 to − 0.72 at 2 weeks; − 1.12, p = 0.005, 95% CI − 1.89 to − 0.34 at 6 months). The ESWT group also had better functional outcomes four to six weeks post treatment (Western Ontario and McMaster Universities Osteoarthritis Index, − 11.96, p = 0.003, 95% CI − 19.76 to − 4.15). No rebound pain was noted for up to 12 months. Using ESWT to treat knee OA may reduce pain and improve functional outcomes. The effect may last six months to one year. More prospective studies are needed to investigate the settings for ESWT to optimize treatment results.

Background Poor functional outcome can result from humeral greater tuberosity (GT) fracture if not treated appropriately. A two-screw construct is commonly used for the surgical treatment of such injury. However, loss of reduction is still a major concern after surgery. To improve the biomechanical strength of screw fixation in GT fractures, we made a simple modification of the two-screw construct by adding a cerclage wire to the two-screw construct. The purpose of this biomechanical study was to analyze the effect of this modification for the fixation of GT fractures. Materials and methods Sixteen fresh-frozen human cadaveric shoulders were used in this study. The fracture models were arbitrarily assigned to one of two fixation methods. Group A (n = 8) was fixed with two threaded cancellous screws with washers. In group B (n = 8), all screws were set using methods identical to group A, with the addition of a cerclage wire. Horizontal traction was applied via a stainless steel cable fixed directly to the myotendinous junction of the supraspinatus muscle. Displacement of the fracture fixation under a pulling force of 100 N/200 N and loading force to construct failure were measured. Results The mean displacements under 100 N and 200 N traction force were both significantly decreased in group B than in group A. (100 N: 1.06 ± 0.12 mm vs. 2.26 ± 0.24 mm, p p p = 0.01), Conclusions The current biomechanical cadaveric study demonstrated that the two-screw fixation construct augmented with a cerclage wire has higher mechanical performance than the conventional two-screw configuration for the fixation of humeral GT fractures. Trial registration Retrospectively registered.

A meta-analysis to investigate the difference in fracture risk between individuals with and without HIV infection was performed. People living with HIV had lower bone mineral density (BMD) and greater risks of overall fractures and fragility fractures. Reducing fragility and maintaining skeletal strength for PLWH are urgently needed for this population. The introduction of effective antiretroviral therapy increased the life expectancy of people living with HIV (PLWH). This population now faces problems related to aging such as decreased bone mineral density (BMD) and increased fracture risk. Some antiretroviral therapies may also negatively impact bone health. We performed a meta-analysis to investigate the difference in the fracture risk between individuals with and without HIV infection. We compared BMD, risk of fragility fracture, and risk of all fracture between the two groups. This study included 35 articles with 106,994 PLWH and 228,794,335 controls. PLWH had lower lumbar spine and hip BMD than controls. PLWH had a higher prevalence of all fracture events (4.08% versus 0.44%) and fragility fractures (2.66% versus 2.19%). The relative risks of all and fragility fractures of PLWH were 1.91 (95% confidence interval (CI), 1.46–2.49; p < 0.001) and 1.68 (95% CI: 1.40–2.01; p < 0.001). PLWH also had more vertebral fractures (1.26% versus 0.37%; RR, 1.97; 95% CI: 1.22–3.2; p < 0.05), hip fractures (1.38% versus 0.81%; RR, 1.88; 95% CI: 0.99–3.57; p = 0.05), and wrist fractures (1.38% versus 1.29%; RR, 1.67; 95% CI: 1.13–2.45; p < 0.05) than healthy controls. The pooled incidence of fractures was 1.72 per 100 person-years in PLWH and 1.29 in healthy controls. PLWH had lower BMD and greater risks of all fractures and fragility fractures. Reducing fragility and maintaining skeletal strength for PLWH are urgently needed for this population.

A meta-analysis to investigate the difference in fracture risk between individuals with and without HIV infection was performed. People living with HIV had lower bone mineral density (BMD) and greater risks of overall fractures and fragility fractures. Reducing fragility and maintaining skeletal strength for PLWH are urgently needed for this population.The introduction of effective antiretroviral therapy increased the life expectancy of people living with HIV (PLWH). This population now faces problems related to aging such as decreased bone mineral density (BMD) and increased fracture risk. Some antiretroviral therapies may also negatively impact bone health. We performed a meta-analysis to investigate the difference in the fracture risk between individuals with and without HIV infection.We compared BMD, risk of fragility fracture, and risk of all fracture between the two groups. This study included 35 articles with 106,994 PLWH and 228,794,335 controls.PLWH had lower lumbar spine and hip BMD than controls. PLWH had a higher prevalence of all fracture events (4.08% versus 0.44%) and fragility fractures (2.66% versus 2.19%). The relative risks of all and fragility fractures of PLWH were 1.91 (95% confidence interval (CI), 1.46-2.49; p0.001) and 1.68 (95% CI: 1.40-2.01; p0.001). PLWH also had more vertebral fractures (1.26% versus 0.37%; RR, 1.97; 95% CI: 1.22-3.2; p0.05), hip fractures (1.38% versus 0.81%; RR, 1.88; 95% CI: 0.99-3.57; p = 0.05), and wrist fractures (1.38% versus 1.29%; RR, 1.67; 95% CI: 1.13-2.45; p0.05) than healthy controls. The pooled incidence of fractures was 1.72 per 100 person-years in PLWH and 1.29 in healthy controls.PLWH had lower BMD and greater risks of all fractures and fragility fractures. Reducing fragility and maintaining skeletal strength for PLWH are urgently needed for this population.

Aims Cigarette smoking has a negative impact on the skeletal system, causes a decrease in bone mass in both young and old patients, and is considered a risk factor for the development of osteoporosis. In addition, it disturbs the bone healing process and prolongs the healing time after fractures. The mechanisms by which cigarette smoking impairs fracture healing are not fully understood. There are few studies reporting the effects of cigarette smoking on new blood vessel formation during the early stage of fracture healing. We tested the hypothesis that cigarette smoke inhalation may suppress angiogenesis and delay fracture healing. Methods We established a custom-made chamber with airflow for rats to inhale cigarette smoke continuously, and tested our hypothesis using a femoral osteotomy model, radiograph and microCT imaging, and various biomechanical and biological tests. Results In the smoking group, Western blot analysis and immunohistochemical staining revealed less expression of vascular endothelial growth factor (VEGF) and von Willebrand factor (vWF). The smoking group also had a lower microvessel density than the control group. Image and biochemical analysis also demonstrated delayed bone healing. Conclusion Cigarette smoke inhalation was associated with decreased expression of angiogenic markers in the early bone healing phase and with impaired bone healing. Cite this article: Bone Joint Res. 2020;9(3):99–107.

Vegetation covers in urban parks are very useful for providing a cool microclimate which mitigates urban heat islands (UHIs). The objectives of this investigation are to therefore conduct on-site measurements and computational fluid dynamic simulations to evaluate the cooling efficacy from vegetation planted in a public park in Taipei, which is a subtropical city in Taiwan. The thermo-flow characteristics are predicted and compared with the measured air velocity and temperature data by using ultrasonic anemometers and an infrared camera to validate the computer modeling, including the sophisticated configurations of trees. Computations are also conducted to resolve the physiological equivalent temperature (PET) profiles for assessing the thermal comfort state at the pedestrian level of the outdoor environment. To investigate the impacts of park renewal on the urban microclimate, three pavilions and supplementary green areas are added to the simulation, and the results reveal that there is a better cooling effect in the park with a higher green coverage ratio (GCR). Moreover, the simulations find that the increased tree coverage ratio can more than compensate for loss of coverage of grasses, resulting in an overall decrease in average temperature. The relationship between thermal comfortable area and green coverage ratio tends to be nonlinear in nature. However, it would be more convenient for applications to adopt the linear regression analysis for determining the correlation between the GCR and PET for the percentage of areas that are comfortable (Cf). It shows that Cf = 0.96 × GCR + 5.08, with a reasonable R2 value of 0.91, for GCR ranged from 54.5 to 71.6%, indicating that there is a significant reduced UHI effect with increases in the GCR. In addition, the correlation implies that a completely thermally comfortable condition will prevail in the park if it has full green coverage. This correlation thus serves as an important guideline for urban planners and managers when designing and managing public urban spaces, such as parks.

Energy-efficient task scheduling is a fundamental issue in many application domains, such as energy conservation for mobile devices and the operation of green computing data centers. Modern processors support dynamic voltage and frequency scaling (DVFS) on a per-core basis, i.e., the CPU can adjust the voltage or frequency of each core. As a result, the core in a processor may have different computing power and energy consumption. To conserve energy in multi-core platforms, we propose task scheduling algorithms that leverage per-core DVFS and achieve a balance between performance and energy consumption. We consider two task execution modes: the batch mode, which runs jobs in batches; and the online mode in which jobs with different time constraints, arrival times, and computation workloads co-exist in the system.For tasks executed in the batch mode, we propose an algorithm that finds the optimal scheduling policy; and for the online mode, we present a heuristic algorithm that determines the execution order and processing speed of tasks in an online fashion. The heuristic ensures that the total cost is minimal for every time interval during a task's execution. Furthermore, we analyze and derive algorithms with low time complexity for each mode. We propose task scheduling algorithms that leverage per-core DVFS on multi-cores.Solve task-to-core, execution order, and the core frequency of task simultaneously.For batch mode, our algorithm finds the optimal scheduling plan.For online mode, our heuristic achieves a balance between performance and energy.

A majority of patients with diabetes have trigger digits. Initial management of symptomatic trigger digits commonly involves corticosteroid injection. However, varying outcomes have been reported for patients with diabetes who receive corticosteroid injections. The authors conducted a meta-analysis to evaluate the effect of diabetes on outcome after corticosteroid injection for trigger digit. PubMed and other Internet databases were searched for the period 1977 to 2015. Five articles, involving 381 diabetic digits and 449 non-diabetic digits, were included in the meta-analysis. The authors found treatment failure rates of 78% for patients with insulin-dependent diabetes, 47% for patients with non–insulin-dependent diabetes, and 49% for patients without diabetes when a single injection of corticosteroid was administered for trigger digit. After 3 injections, the failure rates were 57%, 39%, and 30%, respectively. The pooled data showed that patients with insulin-dependent diabetes and patients with non–insulin-dependent diabetes had worse prognoses after corticosteroid injection for trigger digit than patients without diabetes. Furthermore, the patients with insulin-dependent diabetes had a trend toward multiple digit involvement and much worse treatment outcomes than the patients with non–insulin-dependent diabetes. The authors conclude that more aggressive treatment, such as surgical intervention, should be considered for those patients expected to have high failure rates after injection. [ Orthopedics. 2018; 41(1):e8–e14.]

The goal of this investigation is to conduct the CFD analysis in conjunction with the wind comfort level standard to predict the pedestrian wind comfort level around the Dreams, Angel Life and Future pavilions in the Xinsheng Park of the Taipei International Flora Exposition. The computerized airflow simulations were carried out to predict the detailed flowfield for determining the comfort level of outdoor wind environment for three pavilions in the Xinsheng Park. In order to generate the suitable environments of natural ventilation for visitors, the calculated results can be used to appraise the sufficiency of natural ventilation for the open space around the building cluster.

Virtualization has recently become popular in the embedded-systems area. In order to apply virtualization techniques on embedded-systems, we need a hypervisor that provides a software virtualization environment. A hypervisor scheduler assigns virtual cores in a virtual machine to physical cores. Since traditional load-balanced scheduling strategy is not aware of the asymmetry of cores, its deployment to an asymmetric platform may cause performance degradation or energy waste. In this paper, we propose an energy-efficient, asymmetry-aware scheduler for hypervisor on asymmetric multi-core platform. The goal is to generate an energy-efficient scheduling plan with performance guarantee.

Energy-efficient task scheduling is a fundamental issue in many application domains, such as energy conservation for mobile devices and the operation of green computing data centers. Modern processors support dynamic voltage and frequency scaling (DVFS) on a per-core basis, i.e., the CPU can adjust the voltage or frequency of each core. As a result, the core in a processor may have different computing power and energy consumption. To conserve energy in multi-core platforms, we propose task scheduling algorithms that leverage per-core DVFS and achieve a balance between performance and energy consumption. We consider two task execution modes: the batch mode, which runs jobs in batches, and the online mode in which jobs with different time constraints, arrival times, and computation workloads co-exist in the system. For tasks executed in the batch mode, we propose an algorithm that finds the optimal scheduling policy, and for the online mode, we present a heuristic algorithm that determines the execution order and processing speed of tasks in an online fashion. The heuristic ensures that the total cost is minimal for every time interval during a task's execution.