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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.

Background: Retear of a repaired rotator cuff tendon is a major issue for shoulder surgeons. It is possible that diabetes mellitus (DM) is associated with a greater risk of tendon retear after arthroscopic rotator cuff repair. Purpose: To determine whether patients with DM have a higher tendon retear risk after arthroscopic rotator cuff repair. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the Web of Science, PubMed, and Embase databases. Inclusion criteria were articles written in the English language that included patients undergoing arthroscopic rotator cuff repair surgeries, reported the numbers of patients with and those without DM, and reported the number of rotator cuff retears. Data relevant to this study were extracted and statistically analyzed. Random-effects models were used to generate pooled odds ratio estimates and CIs. Results: A total of 160 studies were identified from the initial search, and 5 of them met the inclusion criteria. A total of 1065 patients (207 patients with DM and 858 patients without DM) were included. The pooled results showed that the patients in the DM group had a significantly higher tendon retear risk than did those in the non-DM group (relative risk, 2.25; 95% CI, 1.14-4.45; P = .02). Conclusion: Patients with DM have a 2.25 times higher risk of tendon retear after arthroscopic rotator cuff repair compared with patients without DM.

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.