Angle Correction Research Articles

Research on Phase Angle Correction Control Strategy for Grid-Forming Cluster in Distributed Energy Resources

The active power-phase angle droop control avoids the frequency deviation problem caused by taking the frequency as the droop variable. However, the active power output of distributed generations (DGs) can only be allocated by adjusting the droop coefficient, and the reference value of active power output cannot be set arbitrarily. In this paper, a phase angle correction module attached to the active power-phase angle droop control is proposed. This correction module is based on the real-time data of the voltage and phase angle of the node at the generation end and the transmission end of the grid, and directly changes the phase angle reference value of the active power-phase angle droop control output. The correction can make the phase angle reference value reach the phase angle value corresponding to the active power reference value without changing the actual characteristics of the droop control, so as to adjust the active power output of the converter to reach the active power reference value. Finally, the feasibility of the correction method in different cases is verified by Matlab 23.2.0.2365128 (R2023b)/Simulink simulation.

Surgical planning in HTO – alternative approaches to the Fujisawa gold-standard

Background Presurgical planning of the correction angle plays a decisive role in a high tibial osteotomy, affecting the loading situation in the knee affected by osteoarthritis. The planning approach by Fujisawa et al. aims to adjust the weight-bearing line to achieve an optimal knee joint load distribution. While this method is accessible, it may not fully consider the complexity of individual dynamic knee-loading profiles. This review aims to disclose existing alternative HTO planning methods that do not follow Fujisawa's standard. Methods PubMed, Web of Science and CENTRAL databases were screened, focusing on HTO research in combination with alternative planning approaches. Results Eight out of 828 studies were included, with seven simulation studies based on finite element analysis and multi-body dynamics. The planning approaches incorporated gradual degrees of realignment parameters (weight-bearing line shift, medial proximal tibial angle, hip-knee-ankle, knee joint line orientation), simulating their effect on knee kinematics, contact force/stress, Von Mises and shear stress. Two studies proposed implementing individual correction magnitudes derived from preoperatively predicted knee adduction moments. Conclusion Most planning methods depend on static alignment assessments, neglecting an adequate loading-depending profile. They are confined to their conceptual phases, making the associated planning methods unviable for current clinical use.

Angle Expansion Estimation and Correction Based on the Lindeberg–Feller Central Limit Theorem Under Multi-Pulse Integration

The radar monopulse angle measurement can obtain a target’s angle information within a single pulse, meaning that factors such as target motion and amplitude fluctuations, which vary over time, do not affect the angle measurement accuracy. However, in practical applications, when a target’s signal-to-noise ratio (SNR) is low, the single pulse signal is severely affected by noise, leading to a significant deterioration in angle measurement accuracy. Therefore, it is usually necessary to coherently integrate multiple pulses before estimating the angle. This paper constructs an angle expansion model for a multi-pulse angle measurement under coherent integration. The analysis reveals that even under noise-free conditions, after coherently integrating multiple pulses, the coupling of target amplitude fluctuations and motion state can still cause significant errors in the angle measurement. Subsequently, this paper conducts a detailed analysis of the impact of the amplitude fluctuations and target maneuvers on the random angle measurement error. It also derives approximate probability density functions of angle measurement errors under various fluctuation and motion scenarios based on the Lindeberg–Feller central limit theorem. In addition, based on the angle expansion model and the random error distribution, this paper proposes an angle correction algorithm based on multi-pulse integration and long-term estimation. Numerical experiments and radar data in the field verify the impact of target characteristics on the angle measurement under multi-pulse integration and the effectiveness of the angle correction algorithm.

Sloshing-induced evolution of self-cleaning performance and flow characteristics within a tank installed on an offshore aquaculture vessel

In this study, a six-degree-of-freedom (6-DOF) motion platform is utilized to simulate the transverse rolling motion of aquaculture tanks aboard deep-sea aquaculture vessels. It examines the effects of different inlet configurations (single and four-pipe inlet), rolling motions (amplitude Θ and period T), and inlet pipe jet angles α (the acute angle between the jet direction of the inlet pipe and the inclined wall to which it is connected) on the self-cleaning capabilities and flow field characteristics of the aquaculture tank. The findings indicate that the waste collection time in the tank is affected by the combined influences of rolling amplitude and period. In the single-pipe inlet configuration, waste collection time increases with the rolling period and initially increases, then decreases with the rolling amplitude. In the four-pipe inlet configuration, waste collection time increases with the rolling period and decreases with the rolling amplitude. Optimal waste collection performance is achieved at α = 45° in both configurations. Regarding flow field characteristics, variations in rolling period and amplitude significantly alter the flow field within the aquaculture tank. In both configurations, as the period decreases and the amplitude increases, the high-velocity regions and the central vortex area within the tank expand, and the average flow velocity of the water also rises. This corresponds to a reduction in waste collection time and an increase in the waste collection rate. In both configurations, the Flow field is most uniform at α = 45°, which corresponds to the highest waste collection capabilities among all jet angles. The results indicate that while decreasing the rolling period and increasing the amplitude can enhance the self-cleaning capabilities, they also lead to excessively rapid water flow velocities. In practical applications, it is important to select appropriate farming areas based on fish suitability and to choose the correct inlet jet angles for different numbers of inlets. The findings can provide theoretical support and a scientific basis for optimizing the flow characteristics and self-cleaning performance of aquaculture vessels under rolling motion and contribute positively to the advancement of deep-sea aquaculture technology.

Association between distal tibial rotation and clinical outcomes of medial open-wedge high tibial osteotomy

BackgroundThe purpose of this study was to evaluate the association between changes in knee joint geometry after medial open-wedge high tibial osteotomy (MOWHTO) and clinical outcomes. MethodsThis was a retrospective study of patients who underwent MOWHTO (101 knees) at our hospital between January 2015 and February 2022 and who were followed up for > 2 years. Radiological and functional outcomes were compared between those who were satisfied with surgery (satisfaction group) and patients who were dissatisfied with surgery (dissatisfaction group). Multiple regression analysis was performed to analyze factors affecting the radiological parameters that significantly differed between the two groups. ResultsThe average follow up period was 38.0 ± 15.4 months. There were no significant differences regarding demographic characteristics and preoperative radiological parameters between the satisfaction and dissatisfaction groups. There was a significant intergroup difference with respect to postoperative distal tibial rotation and change in distal tibial rotation (13.5 ± 4.8° and 9.5 ± 4.3°, respectively; P < 0.001). The difference in tibial rotation before and after surgery was 4.3 ± 2.3° and 1.7 ± 1.8° in the dissatisfaction and satisfaction groups (P < 0.001) Multiple regression analysis showed that the correction angle affected the distal tibial rotation in MOWHTO (R2 = 0.079, ß = 0.165, P = 0.038). ConclusionsIn MOWHTO, an increase in distal tibial rotation was associated with patient dissatisfaction. Because the increase in distal tibial rotation is associated with a large correction angle, excessive distal tibial rotation should be avoided when MOWHTO requires a large correction angle.

Risk factors for secondary vertebral compression fracture after percutaneous vertebral augmentation: a single-centre retrospective study

ObjectiveTo determine the incidence of secondary vertebral compression fracture (SVCF) after percutaneous vertebral augmentation (PVA) and its correlative risk factors, and to provide theoretical evidence for clinical practice.MethodsA retrospective analysis of 288 cases of PVA completed in our hospital from June 2020 to June 2023 was performed, and the patients were divided into the non-secondary vertebral compression fracture group (N-SVCF group) and the secondary vertebral compression fracture group (SVCF group) according to whether SVCF occurred during the postoperative follow-up review. Gender, age, body mass index (BMI), T value of bone mineral density (BMD-T), underlying diseases (hypertension, diabetes mellitus, coronary heart disease, chronic obstructive pulmonary disease), intravertebral vacuum cleft (IVC), amount of bone cement injected, classification of cement diffusion, anterior vertebral recovery ratio, local Cobb angle correction rate, leakage of bone cement into the intervertebral space, and fat infiltration rate (FIR) of paraspinal muscles were collected from the patients. The incidence and risk factors of SVCF after PVA were evaluated using univariate and multivariate logistic regression analysis, and the predictive value of the independent risk factors was evaluated using receiver operating characteristic curve (ROC) to determine the cut-off points at which they were meaningful for the development of SVCF.ResultsIn our study, the incidence of SVCF was 14.60% (42/288) in 288 patients who underwent PVA. Univariate analysis showed that age, BMI, fat infiltration rate of paraspinal muscles, cement leakage into the intervertebral space, unilateral/bilateral pedicle puncture approach and presence of IVC were statistically different between N-SVCF and SVCF (P < 0.05). Multifactorial regression analysis and ROC regression analysis revealed that the fat infiltration rate of the psoas major and erector spinae muscles, cement leakage into the intervertebral space, and IVC (P < 0.05) were risk factors for the incident of SVCF after PVA (P < 0.05). Psoas major (FIR) more than 5.490% and erector spinae (FIR) more than 52.413% had a high possibility of the occurrence of SVCF after PVA.ConclusionIn this study, logistic regression combined with ROC curve analysis indicated that FIR of psoas major and erector spinae, cement leakage in the intervertebral space, and IVC were risk factors for the occurrence of SVCF after PVA. Psoas major (FIR) more than 5.490% and erector spinae (FIR) more than 52.413% had a high possibility of the occurrence of SVCF after PVA.

Achieving Better Clinical Outcomes After Total Knee Arthroplasty in Knees with Valgus Deformity: The Role of Alignment Strategies.

Personalized alignment in total knee arthroplasty (TKA) has demonstrated good functional outcomes for knees with varus alignment. However, limited research has explicitly addressed optimal alignment strategies for valgus knees. The aims of the current study were to assess the impact of the postoperative knee alignment and of the degree of correction of knee alignment on functional outcomes and satisfaction in a population with preoperative valgus and to evaluate the complication and revision rates based on postoperative alignment. This retrospective study included primary posterior-stabilized TKA with a preoperative hip-knee-ankle (HKA) angle of ≥180°, with a minimum follow-up of 32 months. There were 460 knees included, divided into 3 groups: (1) preoperative neutral alignment (180° to 183°) (n = 162), (2) preoperative mild valgus (184° to 190°) (n = 204), and (3) preoperative severe valgus (>190°) (n = 94). A standardized surgical technique was employed with a goal of achieving neutral postoperative alignment. Data on radiographs, Knee Society Scores (KSS), range of motion, satisfaction, complications, and revisions were collected at the last follow-up. The mean follow-up was 74.3 ± 12.4 months. In the preoperative mild valgus group, 10.8% of patients had postoperative varus, 81.4% had postoperative neutral alignment, and 7.8% had postoperative valgus. In the preoperative severe valgus group, 4.3% had postoperative varus, 83.0% had postoperative neutral alignment, and 12.8% had postoperative valgus. In the preoperative mild valgus group, patients with postoperative neutral alignment had significantly higher satisfaction (p = 0.0004) and KSS function score (p = 0.031) than patients with postoperative valgus alignment. In the preoperative severe valgus group, patients with postoperative valgus alignment had significantly higher satisfaction (p = 0.035) and greater improvement of the KSS knee score (p = 0.014) than patients with postoperative neutral alignment. Functional outcomes were not impacted by the degree of HKA angle correction. There were significantly fewer complications (p = 0.022) and revisions (p = 0.007) in the preoperative mild valgus group when patients had a postoperative neutral alignment compared with a postoperative valgus alignment. For preoperative mild valgus, correction to neutral alignment achieved better outcomes and fewer complications than leaving residual valgus. For preoperative severe valgus, retaining residual valgus postoperatively ensured satisfactory functional outcomes without increased complications. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The best angle correction of basketball shooting based on the fusion of time series features and dual CNN

The best shooting angle correction of basketball based on intelligent image analysis is an important branch of the development of intelligent sports. However, the current method is limited by the variability of the shape base, ignoring dynamic features and visual information, and there are some problems in the process of feature extraction and correction of related actions. This paper proposes a method to correct the best shooting angle of basketball based on the fusion of time series characteristics and dual CNN. Segmenting the shooting video, taking the video frame as the input of the key node extraction network of the shooting action, obtaining the video frame with the sequence information of the bone points, extracting the continuous T-frame video stack from it, and inputting it into the spatial context feature extraction network in the shooting posture prediction model based on dual stream CNN (MobileNet V3 network with multi-channel attention mechanism fusion module), extract the space context features of shooting posture; The superimposed optical flow graph of continuous video frames containing sequence information of bone points is input into the time convolution network (combined with Bi-LSTM network of multi-channel attention mechanism fusion module), extract the skeleton temporal sequence features during the shooting movement, using the spatial context features and skeleton temporal sequence features extracted from the feature fusion module, and realizing the prediction of shooting posture through Softmax according to the fusion results, calculate the shooting release speed under this attitude, solve the shooting release angle, and complete the correction of the best shooting release angle by comparing with the set conditions. The experimental results show that this method can achieve the best shooting angle correction, and the training learning rate is 0.2 × 10–3, training loss is about 0.05; MPJPE and MPJVE indicators are the lowest, and Top-1 indicators are the highest; The shooting percentage is about 95 %.

Forearm bone mineral density as a predictor of adjacent vertebral refracture after percutaneous kyphoplasty in patients with osteoporotic vertebral compression fracture: a retrospective analysis

BackgroundThe incidence of adjacent vertebral body re-fracture after percutaneous kyphoplasty (PKP) is associated with a number of variables, of which decreased bone mineral density is one of the major risk factors. Forearm bone mineral density (BMD) measurements are gaining attention because of their convenience and validity, but there is a lack of systematic research on the specific relationship between forearm BMD and the risk of adjacent vertebral re-fracture after PKP.PurposeTo investigate the correlation between forearm BMD and the risk of adjacent vertebral re-fracture after PKP in osteoporotic vertebral compression fractures (OVCF) patients.MethodsRetrospective evaluation of 198 OVCF patients receiving PKP was conducted in this study. The patients were divided into two groups: the no-fracture group and the re-fracture group, according to whether or not they had undergone vertebral re-fracture. Obtain basic information about the patient's age, sex, body mass index, bone cement leakage, smoking history, diabetes history, and surgical segmentation. Using computed tomography, the mean Hounsfield unit (HU) values for the BMD of the L1 lumbar spine were determined. For the dual-energy X-ray BMD test, the distal one-third lengths of the patient's nondominant forearm's radius and ulna were chosen. Receiver operating characteristic curves were utilized to evaluate the predictive value of forearm BMD versus lumbar CT values for vertebral re-fracture, and univariate and multivariate logistic regression analyses were employed to identify characteristics related with vertebral re-fracture following PKP.ResultsRe-fracture rate after PKP was 17.2% at a minimum 12-month follow-up. Significant differences were seen between the refracture and non-fracture groups in terms of hypertension, Cobb angle correction, vertebral height recovery rate, intradiscal cement leakage, forearm bone density, and vertebral HU values. In multifactorial logistic regression analysis, forearm bone density (OR 0.821; 95% CI 0.728–0.937, p = 0.008) and HU values (OR 0.815; 95% CI 0.733–0.906, p = 0.005) were independent risk factors for vertebral re-fracture. The area under the curve (AUC) for forearm BMD values and HU values predicting adjacent vertebral re-fracture were 0.956 and 0.967, respectively.ConclusionsForearm BMD is an independent risk factor for re-fracture of adjacent vertebrae after PKP. In addition, forearm BMD, as a valid indicator of postoperative re-fracture after PKP in patients with OVCF, and the HU value of lumbar spine CT were both powerful tools for predicting re-fracture.

Study on the Liquid‐Holding Rate Law of Gas–Water–Foam Three‐Phase Flow in a Wavy Pipe

ABSTRACTAs a common method for liquid drainage in wave‐shaped pipelines, foam drainage has been used in gas‐gathering pipelines in various oil and gas fields. One of the common problems encountered in wave‐shaped foam drainage pipelines is the inaccurate prediction of the liquid retention rate. This issue makes it difficult to predict liquid accumulation points, which affects gas output efficiency, causes pipeline corrosion, and generates natural gas hydrates. To clarify the liquid‐holding rate law of wavy foam drainage pipelines is studied. In this study, through experiments to verify the accuracy of the numerical simulation method, we investigate the easiest liquid accumulation points and the liquid‐holding rate of wave‐shaped foam drainage pipelines, with factors such as inlet gas velocity, inlet liquid velocity, import and export differential pressure, undulation angle, and inlet temperature change rule. Among them, the error between the numerical simulation results and the experimental results is 4.68%. Finally, after considering the influence of the aforementioned factors on the liquid retention rate of wave‐shaped pipelines, a new liquid retention rate calculation model for wave‐shaped pipelines with foam drainage is established by introducing dimensionless numbers, such as gas‐phase velocity coefficient, liquid‐phase velocity coefficient, and angle correction coefficient. The method is compared with the results of previous research, and the error is within 15%. The model has a simple form and high calculation accuracy, providing a theoretical basis for pipeline inspectors to predict liquid accumulation conditions and reasonably adjust production schedules.

Decompression and reconstruction the spinal TB lesion of a single vertebra through thoracoscopy alone or combined with foraminal endoscopy

ObjectiveThis study aimed to compare the clinical efficacy of thoracoscopy combined with transforaminal endoscopy and thoracoscopy alone in the treatment of thoracic tuberculosis.MethodsPatients with thoracic tuberculosis who visited our hospital from February 2018 to October 2022 were retrospectively analyzed. The patients were divided into thoracoscopic combined transforaminal endoscopic surgery group (group A) and thoracoscopic surgery alone group (group B) according to the surgical methods. Surgery-related information, VAS score, ODI score, degree of spinal cord function improvement, fusion time, and progression of kyphotic deformity were compared.ResultsA total of 37 patients were included, 16 in group A and 21 in group B. Postoperative follow-up time was 10–48 months, with an average of 28.62 ± 10.53 months. All patients had significant improvement in chest and back pain and spinal cord function after the operation. There were statistical differences in operation time, intraoperative blood loss, incidence rate of complications, and JOA score at 1 week and 3 months after operation between the two groups (P<0.05). There was no significant difference in VAS, ODI score, kyphotic angle correction, kyphotic correction loss angle, postoperative drainage volume, and fusion time between the two groups (P>0.05). All patients had no recurrence of thoracic tuberculosis during follow-up.ConclusionThoracoscopy combined with transforaminal endoscopy produce equivalent long-term results with shorter operation time, less intraoperative blood loss, less complications and higher surgical safety comparing to thoracoscopy alone. And thoracoscopy combined with transforaminal endoscopy can fully decompress and facilitate the early recovery of spinal cord function.

Validity and reliability of the osteoporotic fracture treatment score (OF score) and outcomes across various treatments in osteoporosis vertebral compression fracture patients

BackgroundOsteoporotic vertebral compression fractures (OVF) are prevalent and substantially impact healthcare systems and patients’ quality of life. The osteoporotic fracture treatment score (OF score), developed by the German Society of Orthopedics and Trauma (DGOU), guides surgical decisions, but its reliability and validity are underexplored. This study assessed the OF score’s inter- and intraobserver reliability, validated its treatment recommendations, and investigated intermediate outcomes of different DGOU-recommended surgical strategies for OVF.MethodsA retrospective cohort study was conducted. Inter- and intraobserver reliability of the OF score and its subcomponents were analyzed using clinical and radiographic data. Validity was assessed by comparing the OF score’s recommended treatments with actual treatments received. Outcomes at the final follow-up were back pain visual analog scale, Oswestry Disability Index, EQ-VAS, EQ-5D-5 L, adjacent fracture incidence, local kyphotic angle, and reoperation rates. Patients with at least 1-year follow-up were included.ResultsA total of 157 patients (84.7% female; mean age 74.2 ± 10.5 years) were evaluated. The most frequent osteoporotic fracture (OF) types were OF4 (49.0%) and OF3 (40.8%). The OF score demonstrated good interobserver reliability (ICC = 0.77, 95% CI: 0.65–0.86) and intraobserver reliability (ICC = 0.83, 95% CI: 0.72–0.90). Kappa values for subcomponents ranged from 0.57 to 0.89. Excluding patients with indeterminate recommendations (OF score = 6), 82.9% received treatments concordant with OF score recommendations. Receiver operating characteristic curve analysis showed an area under the curve of 0.77 (95% CI: 0.67–0.86); an OF score cutoff > 6.5 predicted actual treatment with 87.9% sensitivity and 61.0% specificity. All surgical treatments showed comparable improvements in clinical outcomes. However, patients treated with stand-alone cement augmentation (CA) had less local kyphotic angle correction (P = 0.004) and greater postoperative kyphotic progression (P < 0.001) than those undergoing short-segment (SS-PI) or long-segment instrumentation (LS-PI). No significant differences in adjacent fractures or complications were observed.ConclusionsThe OF score is a reliable and valid system with good discriminative ability for surgical decision-making in OVF patients. CA, SS-PI, and LS-PI are viable options with comparable functional outcomes. However, in OF3 or OF4 fractures, caution is advised due to lesser kyphosis correction and greater kyphotic progression with CA compared to SS-PI or LS-PI, as recommended by the DGOU.

Clinical and Radiographic Results in Thoracic Hyperkyphosis Surgical Treatment Considering the Optimal Distal Fusion Area.

Introduction: The aim of this retrospective study was to evaluate the clinical and radiographic outcomes of patients who underwent posterior correction and fusion for thoracic hyperkyphosis, with a focus on determining the optimal distal fusion level. Methods: From 2006 to 2012, 26 patients with a median age of 16.8 years (range 14-25), diagnosed with either idiopathic hyperkyphosis or Scheuermann's kyphosis, underwent posterior fusion and Ponte osteotomies at two medical centers. Radiographic evaluations were performed preoperatively, immediately postoperatively, and at the final follow-up and included assessments of fusion extension, Cobb angle, sagittal balance, and the presence of junctional kyphosis or discopathy. Results: The median follow-up period was 12.3 years (range 11-17). Good clinical outcomes were observed in 24 patients, with no cases of hardware failure. The distal fusion area included the first lordotic vertebra in 17 patients, the sagittal stable vertebra in four patients, and both in five patients. Cobb angle correction was maintained at 50% at the final follow-up (p > 0.05). Significant sagittal balance correction was achieved in 87% of patients immediately postoperatively and was maintained at the final follow-up (p > 0.05). Junctional kyphosis occurred in two patients whose fusion area included only the first lordotic vertebra. Conclusions: Including at least the first lordotic vertebra in the fusion area is crucial for preventing junctional kyphosis. Extending the fusion to the stable vertebra can reduce the incidence of distal junctional kyphosis, especially in symptomatic young adult patients, potentially avoiding the need for revision surgery.

Three-Dimensional Printed Customized Scaffolds Covered with Decellularized Bone Extracellular Matrix for Open-Wedge High-Tibial Osteotomy.

Void fillers are required for osseous gaps generated after orthopedic procedures as medial open-wedge high-tibial osteotomy (MOWHTO) to provide sufficient structural support and a rapid osteosynthesis. We developed a novel three-dimensional (3D) printing-based platform technology using the customized 3D scaffolds covered with polycaprolactone (PCL)/β-tri-calcium phosphates (β-TCP)/bone decellularized extracellular matrix (dECM) for use as bone substitute scaffold, which can be effectively exploited to estimate the calculated correction angle with preoperative simulations. PCL/β-TCP/bone dECM scaffolds demonstrated significantly higher cell contain levels in cell seeding efficiency, excellent proliferation capacity, and promotion of early osteogenic differentiation compared with PCL/β-TCP scaffolds. The scaffolds promoted bone mineralization at the early time points of an in vivo study (8 weeks) and exhibited biodegradable properties (38% for 16 weeks). The correction angle measured after osteotomy using 3D printed scaffolds was estimated with high accuracy with low errors (10.3° ± 0.9°) and was not significantly different even in the presence of lateral cortical hinge fractures. The customized 3D scaffold enriched with PCL/β-TCP/bone dECM yielded excellent cell seeding efficiency, proliferation capacity, early osteogenic differentiation, and bone mineralization outcomes. It is expected to solve the disadvantages related to bone union in MOWHTO and to replace autografts in the future.

Gravitational Lensing Effects from Models of Loop Quantum Gravity with Rigorous Quantum Parameters

Many previous works have studied gravitational lensing effects from Loop Quantum Gravity. So far, gravitational lensing effects from Loop Quantum Gravity have only been studied by choosing large quantum parameters much larger than the Planck scale. However, by construction, the quantum parameters of the effective models of Loop Quantum Gravity are usually related to the Planck length and, thus, are extremely small. In this work, by strictly imposing the quantum parameters as initially constructed, we study the true quantum corrections of gravitational lensing effects by five effective black hole models of Loop Quantum Gravity. Our study reveals several interesting results, including the different scales of quantum corrections displayed by each model and the connection between the quantum correction of deflection angles and the quantum correction of the metric. Observables related to the gravitational lensing effect are also obtained for all models in the case of SgrA* and M87*.

Hemi-Percutaneous Epiphysiodesis Using Transphyseal Screws at Lateral Proximal Tibias After Epiphyseal Fusion of Distal Phalanges in the Hand Results in Undercorrection of Genu Varum.

Background and Objectives: To investigate postoperative courses after hemi-percutaneous epiphysiodesis using transphyseal screws (PETS) for genu varum. We especially focused on the degree of skeletal maturation that results in undercorrection. Materials and Methods: We identified patients with idiopathic genu varum treated with hemi-PETS at the proximal tibia and followed-up to the completion of skeletal maturation. The acceptable correction was defined as the (1) final deformity < varus 1.0° or (2) final correction angle obtained by surgery (f-CA) > mean value of preoperative deformity. Results: In our cohort of 29 patients and their 29 lower limbs (one side was randomly selected in bilateral cases), the mean hip-knee-ankle (HKA) alignment was varus 6.5 ± 1.3° at the time of hemi-PETS. The mean f-CA was 5.8 ± 2.0° with a rebound of 0.3 ± 1.0°. Ten patients showed the finding of partial or complete fusion of the epiphysis of distal phalanges in the hand at the time of hemi-PETS (the fusion group, FG). Their f-CA was 4.0 ± 1.9° (with preoperative deformity of 6.9 ± 1.4°), which was significantly smaller than that (6.7 ± 1.3°, p = 0.001) of remaining 19 patients (the open group, OG). The acceptable correction was obtained in all 19 patients of the OG. Otherwise, it was obtained in two patients in the FG (p < 0.001). The other two patients in the FG preoperatively showed a complete epiphyseal fusion of the distal phalanges in the hand, and their f-CA was 0.7 and 1.1°, respectively. Conclusions: The degree of skeletal maturation corresponding to epiphyseal fusion of distal phalanges in the hand results in undercorrection after the hemi-PETS performed at the proximal tibia for genu varum.

The influence in clinical results of lower limb length discrepancy following distal femoral osteotomy

BackgroundDistal femoral osteotomy (DFO) improves valgus limb alignment. However, it might affect lower limb length discrepancy (LLD) and influence functional scores. This study aims to evaluate functional scores and radiographic parameters associated with LLD after DFO. HypothesisIt was hypothesized that the presence of LLD after DFO affects functional scores and associated with femoral length. Patients and methodsA total of 50 patients who underwent DFO, including 24 closed wedge (CW) DFO and 26 open wedge (OW) DFO, were included. Patients were divided into three groups according to the presence of LLD after DFO: LLD-Absent group, LLD-CW group and LLD-OW group. Patient demographics, functional scores (Knee injury and Osteoarthritis Outcome Score (KOOS)), and radiographic parameters were evaluated and compared between the three groups. Multivariable logistic regression analysis was used to assess the radiographic parameter associated with the presence of post-operative LLD. ResultsThere were no significant differences between the three groups in demographic data, correction angles, complications including hinge fractures, time to osteotomy union, and functional scores. However, the return to sports (RTS) was significantly different between three groups. By further analysis between CWDFO and OWDFO, RTS in CWDFO was faster than those in OWDFO. There were significant differences in post-operative mLDFA and Δ femur length. Additionally, post-operative mLDFA was significantly associated with the presence of LLD (Odds ratio 0.11, 95% confidence interval 0.01 to 0.49, p = 0.03). ConclusionFunctional scores and postoperative outcomes following DFO are not affected by the presence of LLD. RTS is independent of LLD, but rather dependent on the surgical procedure and RTS in CWDFO was faster than those in OWDFO. Postoperative mLDFA is the radiographic parameter associated with the presence of LLD. These findings are clinically relevant and should be accounted for in preoperative planning of DFO. Level of evidence IIIRetrospective with comparative study

The lateral approach for total knee arthroplasty in valgus osteoarthritis provides similar clinical and radiological results compared with the medial approach.

In total knee arthroplasty (TKA), valgus deformities require special approaches to achieve precise mechanical axis correction and joint stability. This study aimed to determine whether the lateral approach without tibial tubercle osteotomy allows mechanical axis correction in valgus knee osteoarthritis (OA), which is at least as effective as the medial approach, while also assessing whether it provides clinically comparable results and complications. A total of 204 patients undergoing TKA for valgus knee OA were included in this retrospective comparative study, with 131 patients in the lateral approach group and 73 patients in the medial approach group. The surgical goal was to achieve stability with a neutral axis based on mechanical alignment. Detailed pre- and postoperative clinical and radiographic data were obtained, including measurements of the hip-knee-ankle angle (HKAA) and patella tilt angle. Functional status was determined based on the Oxford Knee Score (OKS). Age, body mass index, sex and preoperative HKAA were adjusted between both groups using propensity score matching (n = 45 per group). In the propensity score-matched cohort, the postoperative HKAA did not show differences when comparing the lateral and the medial approach at a mean follow-up of 19.7 months (p = 0.385). The achieved correction of the patella tilt angle was higher in the lateral approach group in the overall (p < 0.001) and matched cohort (p < 0.001). No differences were detected regarding the postoperative OKS and complications. However, wound healing disorders showed a tendency to be more prevalent in patients who underwent the lateral approach in the overall cohort (6.1%, n = 8 vs. 0.0%, n = 0, p = 0.053) but not in the propensity score-matched cohort (p = 0.494). This study demonstrated that for pronounced valgus OA, the lateral approach achieves favourable results in HKAA correction, patellar tilt and complications comparable to the medial approach. However, the risk of wound healing disorders appears higher with severe valgus deformity. Level III therapeutic study.

Effects of different hinge positions on tibial rotation in uniplanar medial opening wedge high tibial osteotomy with three-dimensional tibial models.

To investigate the effects of different hinge positions in the sagittal and axial planes on distal tibial rotation (DTR) during medial opening wedge high tibial osteotomy (MOWHTO) with three-dimensional tibial models. Preoperative CT data from 30 knee joints in 30 patients who underwent surgery for varus malalignment of knee were included. 1 standard hinge position (0°), 6 axial planes (±5°, ±10°, ±15°), and 6 sagittal planes (±5°, ±10°, ±15°) hinge positions were defined and virtual uniplanar osteotomy was performed. The correction angle of each model was generated using Fujisawa's point. Participants' baseline characteristics, radiologic parameters and DTR were measured. One-Way Repeated Measures ANOVA and single factor linear regression analysis were used to analyze the association between tibial rotation and hinge position in the sagittal and axial planes. We found a clear linear correlation between changes in hinge position in the sagittal plane and DTR. The changes in DTR were the smallest when the hinge position was at 5°, where internal or external rotation of the DTR may occur. When the front aspect of hinge axis rotated distally, DTR tended towards internal. Meanwhile, when the front aspect of hinge axis rotated proximally, DTR tended towards external. There were no correlations with every hinge axis position in the axial plane. It is sagittal but not axial hinge axis affects DTR in uniplanar MOWHTO with three-dimensional tibial models. In the sagittal plane, every change in hinge position was significantly linearly correlated with DTR. However, no linear correlations were observed between every hinge position change in the axial plane.

Immediate Correction of Idiopathic Scoliosis With Nighttime Braces Created by a Fully Automated Generative Design Algorithm: A Randomized Controlled Crossover Trial.

Single-center, double-blinded, prospective crossover randomized controlled trial. To clinically validate the efficacy of nighttime braces designed automatically by a generative design algorithm to treat idiopathic scoliosis (IS). The tested hypothesis was the clinical equivalence of immediate in-brace correction for the new automatically generated brace design versus a standard Providence-type brace. Documented efficacy of brace treatment varies between centers, and depends on the empirical expertise of the treating orthotist. Our group previously developed a fully automated generative brace design algorithm that leverages a patient-specific finite-element model (FEM) to optimize brace geometry and correction before its fabrication. Fifty-eight skeletally immature patients diagnosed with IS, aged between 10 and 16 years were recruited. All patients received both a nighttime brace automatically generated by the algorithm (test) and a Providence-type brace designed by an expert orthotist (control). Radiographs were taken for each patient with both braces in a randomized crossover approach to evaluate immediate in-brace correction. The targeted 55 patients (48 females, 7 males) completed the study. The immediate Cobb angle correction was 57% 19 (test) versus 58% 21 (control) for the main thoracic (MT) curve, whereas it was 89% 25 (test) versus 87% 28 (control) for the thoracolumbar/lumbar (TLL) spine. The immediate correction with the test brace was noninferior to that of the Control brace ( P 0.001). The order in which the braces were tested did not have a residual effect on the immediate correction. The fully automated generative brace design algorithm proves to be clinically relevant, allowing for immediate in-brace correction equivalent to that of braces designed by expert orthotists. Patient 2 years follow-up will continue. This method's integration could help design and rationalize the design of braces for the treatment of IS. Level 2.