Angle Correction Research Articles

Debridement and bone graft fusion via the lateral extracavitary approach combined with lateral and posterior screw-rod fixation in the treatment of thoracic spinal tuberculosis: A retrospective study of 38 cases

ObjectivesThoracic spinal tuberculosis (TB) is still common, and surgical treatment can rapidly relieve pain, correct deformity, reduce bone loss and prevent further damage to neurological function. We have practiced an efficient and safe surgical method. MethodsFrom January 2013 to April 2021, 38 patients with thoracic spinal TB were included in our study. Debridement and bone grafting were performed via the lateral extracavitary approach, combined with two different fixation methods. Data from these cases were analyzed retrospectively. ResultsFor all cases, the C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) of all the patients decreased to normal levels at the last follow-up. The average visual analog scale (VAS) score was 7.5 ± 1.6 preoperatively and 0.6 ± 0.8 at the last follow-up, showing a significant reduction. The average angle of kyphosis correction was 6.3 ± 4.7°, and the loss of correction was 1.4 ± 1.6°. Neurological function was significantly improved in all cases according to the American Spinal Injury Association (ASIA) classification. Solid fusion was observed in all cases at the last follow-up. ConclusionsDebridement and bone graft fusion via the lateral extracavitary approach combined with two fixation methods can be very effective in the treatment of thoracic spinal TB.

Optimizing range of motion in reverse shoulder arthroplasty.

Optimal glenoid positioning in reverse shoulder arthroplasty (RSA) is crucial to provide impingement-free range of motion (ROM). Lateralization and inclination correction are not yet systematically used. Using planning software, we simulated the most used glenoid implant positions. The primary goal was to determine the configuration that delivers the best theoretical impingement-free ROM. With the use of a 3D planning software (Blueprint) for RSA, 41 shoulders in 41 consecutive patients (17 males and 24 females; means age 73 years (SD 7)) undergoing RSA were planned. For the same anteroposterior positioning and retroversion of the glenoid implant, four different glenoid baseplate configurations were used on each shoulder to compare ROM: 1) no correction of the RSA angle and no lateralization (C-L-); 2) correction of the RSA angle with medialization by inferior reaming (C+M+); 3) correction of the RSA angle without lateralization by superior compensation (C+L-); and 4) correction of the RSA angle and additional lateralization (C+L+). The same humeral inlay implant and positioning were used on the humeral side for the four different glenoid configurations with a 3 mm symmetric 135° inclined polyethylene liner. The configuration with lateralization and correction of the RSA angle (C+L+) led to better ROM in flexion, extension, adduction, and external rotation (p ≤ 0.001). Only internal rotation was not significantly different between groups (p = 0.388). The configuration where correction of the inclination was done by medialization (C+M+) led to the worst ROM in adduction, extension, abduction, flexion, and external rotation of the shoulder. Our software study shows that, when using a 135° inlay reversed humeral implant, correcting glenoid inclination (RSA angle 0°) and lateralizing the glenoid component by using an angled bony or metallic augment of 8 to 10 mm provides optimal impingement-free ROM.

Impact of teardrop angle correction on functional outcomes in die punch fractures of the distal radius: retrospective study

Background: Anatomic reduction of die punch fractures of the distal radius is crucial to optimize functional outcomes. The teardrop angle, formed by the volar cortex and articular surface, reflects distal radius alignment and articular congruity. This study evaluated the relationship between teardrop angle correction and clinical/functional results following surgical fixation of these injuries. Methods: This retrospective study included patients undergoing open reduction and internal fixation for die punch distal radius fractures between 2015-2020. Patients were divided into two groups based on teardrop angle correction: group 1 (≤10°) and group 2 (>10°). Disabilities of the arm, shoulder and hand (DASH) scores, patient-rated wrist evaluation (PRWE) scores, range of motion, and grip strength were assessed at final follow-up (minimum 12 months). Multivariate analysis identified predictors of functional outcomes. Results: 60 patients were included (32 in group 1, 28 in group 2). Groups were similar in baseline demographics and injury characteristics. Group 2 (>10° correction) had significantly better outcomes including lower DASH scores (14.5 versus 24.6, p=0.003), lower PRWE scores (21.6 versus 36.8, p=0.002), greater grip strength (84.6% versus 71.2%, p=0.005), increased flexion (62.5° versus 52.7°, p=0.004), and extension range of motion (55.8° versus 43.5°, p<0.001). On multivariate analysis, greater teardrop angle correction was an independent predictor of improved DASH and PRWE scores. Conclusions: Obtaining >10° of teardrop angle correction during surgical fixation of die punch distal radius fractures correlated with superior functional outcome scores, grip strength, and mobility compared to ≤10° of correction. These findings emphasize the importance of restoring distal radius anatomy and articular congruity in this injury pattern. Precise intraoperative correction of the teardrop angle deformity should be a key goal.

Derotational distal femoral osteotomy yields better outcomes in patellar subluxation with proximal femoral torsion compared with distal femoral torsion: A retrospective comparative study.

Controversy exists regarding the origin of femoral torsion, and specific treatment rules regarding the optimal position of femoral osteotomy in patients with recurrent patellar subluxation and excessive femoral torsion are scarce. To establish a novel classification system for such patients, and to compare clinical and radiological outcomes after distal derotational femoral osteotomy (DDFO) between femoral torsion at proximal (neck and shaft) and distal levels. Between January 2014 and June 2019, patients who underwent DDFO were retrospectively reviewed. The segmental torsion analysis was performed to establish a novel classification system, and classify included patients into two groups: 35 patients in proximal torsion group and 38 patients in distal torsion group. These patients were followed-up for at least 3years. Clinical evaluations included functional outcomes, physical examinations, quality of life, activity level, satisfaction, and complications. Radiological outcomes included patellofemoral osteoarthritis, congruence, and alignment. Type I was defined as the proximal torsion. Type II was defined as the distal torsion. Proximal torsion group had lower postoperative femoral torsion (12.6 ± 2.6° vs. 14.8 ± 3.6°; P = .004) and higher surgical correction angle (21.6 ± 5.0° vs. 19.1 ± 3.0°; P = .009). All clinical and radiological outcomes improved significantly in both groups, but proximal torsion group had significantly higher quality of life (EQ-5D-5L: 0.96 ± 0.06 vs. 0.91 ± 0.07; P = .003. 92.0 ± 6.0 vs. 88.7 ± 5.8; P = .021) and Tegner activity score (5.2 ± 1.5 vs. 4.5 ± 1.4; P = .040), and fewer patellofemoral osteoarthritis (8.6% vs. 26.3%; P = .048). Two patients in the distal torsion group had subjective patellar instability. The percentage of patients with anterior knee pain was higher in the distal torsion group. A novel classification system for patients with recurrent patellar subluxation and excessive femoral torsion based on segmental femoral torsion analysis was established. DDFO was more appropriate for patients with proximal torsion, yielding higher surgical correction angle, and better clinical and radiological outcomes. Cohort study; Level of evidence, 3.

Clinical effect analysis of vertebroplasty with high viscosity and standard bone cement for Kummell disease.

This study aims to observe and compare the effects of high-viscosity bone cement versus standard bone cement on the postoperative outcomes of percutaneous vertebroplasty (PVP) in patients with Kummell disease. A retrospective analysis was conducted on 135 patients with Kummell disease who underwent PVP between January 2019 and May 2023. Patients were divided into 2 groups: the high-viscosity group (group H, 63 cases) received high-viscosity bone cement during surgery, while the standard group (group S, 72 cases) received standard bone cement. Surgery duration, bone cement volume, bone cement leakage rate, as well as preoperative and postoperative evaluations using the Visual Analogue Scale (VAS) for pain, Oswestry Disability Index (ODI), anterior vertebral height, and kyphotic Cobb angle were recorded and compared between the 2 groups. In the group H, significant improvements were observed in VAS scores, ODI, anterior vertebral height, and Cobb angle at 24 hours, 3 months, and 1 year postoperatively compared to preoperative values (P < .01). In the group S, VAS scores and ODI showed significant improvement at 24 hours, 3 months, and 1 year postoperatively (P < .01), but there were no significant differences in anterior vertebral height or Cobb angle compared to preoperative values (P > .05). Comparatively, the group H demonstrated superior outcomes in terms of bone cement volume, leakage rate, recovery of anterior vertebral height, and Cobb angle correction at 24 hours, 3 months, and 1 year postoperatively (P < .05). However, there were no significant differences between the 2 groups in terms of surgery duration, VAS scores, and ODI at the same time points (P > .05). PVP is an effective treatment for Kummell disease, providing significant pain relief and improved spinal function. The use of high-viscosity bone cement allows for greater volume infusion, better restoration of vertebral height, and correction of deformities, while also reducing the risk of cement leakage.

Comparison of Surgical Outcomes Following Percutaneous Pedicle Screw Fixation and Traditional Open Pedicle Screw Fixation for Thoracolumbar Fractures Without Neurological Deficit.

Traumatic thoracolumbar fractures are frequently encountered in blunt trauma patients. The Open pedicle screw fixation has been proven to be effective in stabilizing fractures, deformity correction, early mobilization and improving long term quality of life of patients with thoracolumbar fracture. Percutaneous pedicle screw fixation is a minimally invasive approach that minimizes the tissue injury, enhances early recovery and facilitates rehabilitation program. To compare the surgical outcomes of percutaneous versus open pedicle screw fixation for thoracolumbar fractures without neurological deficit. Single center, Prospective, Comparative study Methods: A total of 34 patients with thoracolumbar fractures with intact neurology were treated with either percutaneous or open pedicle screw fixation between February 1st 2023 to March 1st 2024 at the National trauma center , Kathmandu. There were 17 patients in each group. The perioperative clinical and radiological parameters were collected using a preformed pro forma. Postoperatively follow-up was conducted at post op day 1, during discharge and 3 months. The clinical and radiological outcomes of percutaneous and open pedicle screw fixation were analyzed and compared. This study included 24(70.6%) males and 10(29.4%) females. The mean age was 40.73 ±15.44 years. There was a statistically significant difference between percutaneous and open pedicle screw with regard to intraoperative blood loss, fluoroscopy time, operative duration, deambulation day and overall hospital stay (p<0.05). Overall, there was a statistically significant improvement in overall pain perception at discharge and three month follow up in both groups. The kyphosis correction in percutaneous group was similar to open pedicle screw fixation technique (mean cobbs angle correction of 4.7 degree). The percutaneous approach has several advantages over the open pedicle screw fixation with regard to less intraoperative blood loss, less postoperative pain, early deambulation, no was a statistically complications and shorter hospital stay Keywords: Open pedicle screw; percutaneous pedicle screw fixation; thoracolumbar fracture.

Australian radiographers’ digital era practice in selecting the image receptor angle for female body habitus for the mediolateral oblique view of the breast

IntroductionCorrect alignment of the image receptor (IR) in mammography for the mediolateral oblique (MLO) view of the breast is fundamental to enable the maximum inclusion of breast tissue. This study aims to assess Australian radiographers' knowledge and digital era practice in selecting the IR angle for female body habitus in the MLO view of the breast. MethodsAn online survey was distributed to all members of the Australian Society of Medical Imaging and Radiation Therapy (ASMIRT) through their electronic newsletter and via direct email to radiographers holding the Certificate of Mammographic Practice (CMP). Descriptive analysis was undertaken, and a Pearson's chi-squared test of independence was used to compare associations between academic qualification and IR selection data. A value of p < 0.05 was deemed statistically significant. ResultsA total of 107 valid surveys were returned; 67.3 % reported using the posterior lateral margin to select the IR angle. For linear body habitus, 44.9 % reported using 50°; for all other body habitus, participants most commonly used 45° (59.1 %); 85.1 % used a range of angles between 40 and 55°; 16.8 % recognised the link between correct IR angle selection and breast tissue inclusion. ConclusionThe range of angles used in practice has reduced in the digital era; the frequency of the use of 45° across all body habitus may reflect tube angle movement automation. Few radiographers recognised the important link between correct selection of IR angle and breast tissue inclusion on the image. Implications for practiceUnderstanding of the link between IR angle selection and image quality enhances current practice in the digital era to maximise the inclusion of breast tissue and minimise the potential of missed breast cancer.

On erosion wear of flat specimens incorporating roughness angle correction

Particle erosion-induced damage to structural walls constitutes a critical concern in aerospace and petrochemical engineering. Over time, this phenomenon leads to surface roughening, thereby altering particle impingement dynamics, a facet often overlooked in current simulation methodologies. This study proposes a novel numerical approach for investigating erosion characteristics of flat specimens, integrating a corrective model for roughness angle to enhance accuracy in predicting erosion profiles. Experimental validation confirms the superior performance of the proposed correction method, achieving a remarkable enhancement of approximately 60.27% in accurately predicting maximum erosion depth compared to conventional techniques. Notably, the corrected erosion depth exhibits a nonlinear relationship with erosion duration, closely mirroring experimental observations. In regions characterized by intensified erosion rates, the present method discloses a notable decrease of approximately 1.8° in forecasted particle impact angles with advancing erosion stages, thereby achieving closer adherence to empirical trends. The refined simulation method effectively rectifies historical overestimations, offering a robust framework for future studies in erosion prediction and mitigation strategies.

Outcome of Short Segment Fixation for Degenerative Scoliosis in Osteoporotic Patients Using Augmented Pedicle Screws; Prospective Case Series Study

Abstract Background When a patient’s general condition is taken into account, long-segment fusion may not necessarily be the best approach for degenerative scoliosis management. Often, a patient’s symptoms may be alleviated by short segment decompression and fusion surgery that is limited to the upper and lower vertebral boundaries of the scoliotic region. In osteoporotic patients studies reported good functional outcomes and very low revision rates with polymethylmethacrylate augmented screws. Aim of the Work This study aims to evaluate the clinical and radiological outcomes of short segment fixation for degenerative scoliosis in osteoporotic patients using augmented screws. Patients and Methods This is a prospective Case series study carried out at Ain Shams University hospitals which included 23 patients resistant back pain and lower limb claudication pain not relieved by medical treatment or physical therapy for at least 6 months. All cases managed with Posterior decompression and short segment fixation using pedicle screws augmented with cement (PMMA). Results As regards the VAS for leg pain, it showed improvement from 7.18 (± 0.07) to 1.91 (± 0.14). The VAS for back pain also improved from preoperatively 8.17 (± 0.11) to postoperatively 2.52 (± 0.24). As regards the ODI score, there was a significant decrease in the ODI scores from pre-surgery 68.09 (± 1.13) to 12 months post-surgery 25.57 (± 2.02). The Cobb angle decreased dramatically from pre-operative 15.9 (± 0.57) to post- operative, and then increased slightly but remained stable at 6 and 12 months with mean value at last follow up 4.85 (± 0.45). We did not have nonunion cases but only 3 delayed union cases at 6 months and was full united at 12 months that assessed by continuity of osseous bridging between transverse processes in plain X rays and CT scan. compared to similar published literatures This study technique has average blood loss, operation time and hospital stay and decrease the need for revision surgery but with increased hazards of high intraoperative radiation exposure. Conclusion Short segment fixation using augmented screws showed a very good clinical outcome in management of degenerative scoliosis with osteoporosis as regards VAS for back pain, VAS for leg pain and ODI score. According to radiological parameters it showed a good result in cobb angle correction, fusion rate, screws and construct stability after 1 year follow up, less pedicle screw loosening and less rate of revision surgery.

Prediction of angular correction following first metatarsal-phalangeal joint arthrodesis

The literature has established that the first metatarsal-phalangeal joint arthrodesis procedure will provide some correction of the first intermetatarsal and hallux valgus angles. But while this has previously primarily been investigated as a simple association (i.e. comparison of pre-operative to post-operative values), the objective of this investigation was to consider angular change as a continuous variable and to specifically correlate it with pre-operative values. Radiographs from 100 consecutive first metatarsal-phalangeal joint arthrodeses meeting selection criteria were evaluated. A negative Pearson correlation coefficient was observed between the pre-operative first intermetatarsal angle and intraoperative change in the first intermetatarsal angle (Pearson -0.547; p<0.001). In other words, with progressively increased levels of pre-operative intermetatarsal angle deformity, one should expect greater intermetatarsal angle correction. The relationship is described by the equation Y = 2.82 – 0.38X indicating that for every one degree of pre-operative intermetatarsal deformity over approximately 7 degrees, 0.38 degrees of post-operative correction might be expected. A negative Pearson correlation was observed between the pre-operative hallux valgus angle and the intraoperative change in the first hallux valgus angle (Pearson -0.806; p<0.001). In other words, with progressively increased levels of pre-operative hallux valgus angle deformity, one should expect greater hallux valgus correction. The relationship is described by the equation Y = 5.5 – 0.63X indicating that for every one degree of pre-operative hallux valgus angle deformity over approximately 9 degrees, 0.63 degrees of hallux valgus angle post-operative correction might be expected. Results of this investigation demonstrate a statistical correlation between pre-operative radiographic deformity and intermetatarsal angle and hallux valgus angle post-operative correction, and might provide foot and ankle surgeons with a degree pre-operative prediction of expected angular correction following the procedure. Level of Evidence3

Spine to pelvis “T-Construct” using magnetic controlled growing rods in non-walkers neuromuscular early-onset scoliosis: a preliminary study

BackgroundsMagnetic controlled growing rods (MCGRs) have been proven to be effective in controlling early onset neuromuscular scoliosis but no study has evaluated the combination with a sacro-bi-iliac construct. The aim of our study is to report surgical management of early onset non-walkers neuromuscular scoliosis correction using MCGRs associated with a sacro-bi-iliac “T-construct” and its mid-term outcomes. Our hypothesis was that this set-up provided well correction of the pelvic obliquity and that this correction was maintained over time. MethodsA retrospective single-center study was conducted including all consecutive neuromuscular early onset scoliosis who underwent spinopelvic fixation using “T-construct” with two MCGRS. Four millimeters lengthening was performed every 4 months during outpatient clinics sessions. All children had a low-dose biplanar stereoradiography in EOS-Chair at pre/postoperative phase, each outpatient clinic appointment and last follow-up. ResultsEighteen patients were included and 17 analyzed at the last follow-up. The mean age at surgery was 9.5 (range from 5 to 12 years), the mean follow-up was 4,7 years (range from 2.5 to 6.6 years) and 8 patients had a Risser stage above four. The global complication rate was 35% (N = 6/17 patients) including three medical and three mechanical complications related to “T-construct”, while the reoperation rate was 18% (N = 2 patients for wound debridement and one for iterative pelvic fixation). Cobb angle and pelvic obliquity were significantly improved by surgery (mean correction was 33.2 ° (55%) and 11 ° (77%) respectively; p < 0.001). At the last follow-up, we noted a loss of frontal Cobb angle correction (p < 0.01) whereas we did not observe any significant loss of pelvic obliquity (p > 0.9). ConclusionsAlthough the global complication rate was 35% (half of which are mechanical complications), the treatment combining pelvic T-construct and MCGRs provides satisfactory correction of pelvic obliquity correction, good maintenance in the medium term and may be a procedure to consider for the surgical treatment of early onset neuromuscular scoliosis. Level of evidenceIV; Retrospective cohort prognostic study

Adjusted planning based on the joint line convergence angle improves correction accuracy in the standing position after opening wedge high tibial osteotomy

BackgroundPostoperative change of the joint line convergence angle (JLCA) is known to be a factor affecting correction error in opening wedge high tibial osteotomy (OWHTO). The purpose of this study was to assess whether preoperative planning that considers change of the JLCA can achieve accurate correction in the standing position after OWHTO.MethodsOWHTO was performed for 109 knees with osteoarthritis of the knee. The amount of angular correction was planned aiming to achieve mechanical valgus of 5° in 55 knees (conventional planning), and it was adjusted in 54 knees (adjusted planning) according to the preoperative JLCA as follows: not changed with JLCA ≤ 3°; decreased 1° with JLCA 4–6°; decreased 2° with JLCA 7–8°; and decreased 3° with JLCA ≥ 9°. The hip-knee-ankle (HKA) angle, JLCA, and medial proximal tibial angle (MPTA) were measured on standing long-leg radiographs. Correction error ≤ 2º was defined as the acceptable range, and correction error > 2º was defined as an outlier.ResultsThe conventional planning group had a significantly greater postoperative HKA angle than the adjusted planning group (6.1º and 4.9º, respectively). The mean JLCA decreased from 4.8º to 2.6º in the conventional planning group and from 4.6º to 2.7º in the adjusted planning group. The conventional planning group had significantly greater postoperative MPTA than the adjusted planning group (96.2º and 94.7º, respectively). The rate of outliers with correction error > 2º was significantly lower in the adjusted planning group (9%) than in the conventional planning group (24%). The rate of the MPTA > 95º was significantly lower in the adjusted planning group (30%) than in the conventional planning group (69%).ConclusionsThis study demonstrated that preoperative planning with adjustment of the correction angle according to the preoperative JLCA improved correction accuracy in the standing position after OWHTO.

Acquired angle error correction based on variation of an angle detection signal intensity in rotary encoders

Abstract Rotary encoders are used in various machines to measure the angular position of a rotating axis. Therefore, rotary encoders are required not only to be highly accurate, but also usable in various environments. When using a rotary encoder on a machine, angle errors occur due to eccentricity between the encoder and the machine, the deformation of the scale, and the shaft runout of a rotation axis. Various methods have been adopted to reduce such angle errors. However, these methods have problems such as the large size and high cost of the rotary encoder, the necessity of additional devices for measuring, and increasing installation labor, so the environment in which they can be implemented is limited. In this study, we have proposed a method to correct the angle errors based on variation of an angle detection signal intensity in the sensor head. This method can correct the errors on machine without using multiple sensor heads or separate devices. The angle error estimated by this method is compared with that measured by the external equipment of a reference encoder. While the maximum angle error was 28.36” without correction, the residual error with correction can be reduced to 1.75” or less. From this result, the proposed method can improve the measurement accuracy of the rotary encoder already installed on the machine. Therefore, this method is an effective means for achieving both high rotational accuracy on machines and ease of correcting an error in rotary encoders to the machines.

Three-Dimensional Analysis of the First Metacarpal Axes in Healthy Individuals and Early-Stage Thumb Carpometacarpal Osteoarthritis Patients-Potential Implication on First Metacarpal Corrective Osteotomy.

Background: Numerous anatomical features of the first carpometacarpal (CMC I) joint have been investigated as potential predispositions for CMC I osteoarthritis (OA). Even though load transmission through the CMC I joint-and, therefore, the development of osteoarthritis-is believed to be influenced by the geometry of the first metacarpal (MC I) bone, there is no common definition of the MC I axes. Methods: CT scans of twenty healthy volunteers and pre- and postoperative CT scans of six patients with CMC I OA undergoing Wilson osteotomy were analyzed. We proposed a calculation method based on anatomical landmarks for the proximal joint surface axis (PA) angle and the definition of an anatomical (AA) and a mechanical (MA) longitudinal axis. We hypothesized that for an MC I extension osteotomy to be effective, the AA and MA need to be aligned surgically. Results: To align AA and MA, an average correction angle of 22.60° (SD 2.53°) at 1 cm and 26.73° (SD 2.55°) at 1.5 cm distal to the CMC I joint line is required. Conclusions: The hereby proposed method for patient-specific calculation of the correction can be used to improve the surgical technique.

Clinical effect of posterior-only approach debridement, intervertebral fusion, and internal fixation for upper thoracic tuberculosis.

This study aimed to evaluate the effectiveness and feasibility of the posterior-only approach for debridement, interbody fusion, and internal fixation in treating upper thoracic tuberculosis. This study retrospectively analysed the clinical and radiographic data of 8 patients diagnosed with upper thoracic tuberculosis. All patients underwent posterior approach debridement, interbody fusion, and internal fixation. We conducted pre- and postoperative assessments of the visual analog scale (VAS), Oswestry disability index (ODI) scores, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), ASIA score, and kyphotic Cobb angle. Back pain and lower limb weakness were the most common presenting symptoms. The mean duration of surgery, amount of blood loss, and volume of postoperative drainage were 262.5 ± 43.3 min, 625.0 ± 333.8 mL, and 285.0 ± 118.1 mL, respectively. Patients were followed up for 36 to 48 months. Three months after surgery, there was a significant improvement in VAS and ODI scores, which further improved until the final follow-up. A statistically significant difference was observed between the preoperative and postoperative periods (P < .05). At the final follow-up, lower extremity function had fully returned to normal in all 5 paralyzed patients. The ESR and CRP returned to normal, 18.1 ± 7.3 mm/h and 9.95 ± 5.41 mg/L, respectively, within 3 months postoperatively. There were statistical differences between the preoperative and postoperative periods (P < .05). The average kyphotic correction rate was (71.5 ± 7.3)%, and the average loss of correction angle was (3.5 ± 1.4)°. Intervertebral bone fusion was achieved by all patients within 15 months (mean 8.3 ± 3.2 months) postoperatively. The posterior-only approach seems an effective, safe, and reliable treatment method for upper thoracic tuberculosis, with favourable clinical and radiological outcomes. Level IV, Therapeutic study.

Exploring the catastrophic regime: thermodynamics and disintegration in head-on planetary collisions

ABSTRACT Head-on giant impacts (collisions between planet-sized bodies) are frequently used to study the planet formation process as they present an extreme configuration where the two colliding bodies are greatly disturbed. With limited computing resources, focusing on these extreme impacts eases the burden of exploring a large parameter space. Results from head-on impacts are often then extended to study oblique impacts with angle corrections or used as initial conditions for other calculations, for example, the evolution of ejected debris. In this study, we conduct a detailed investigation of the thermodynamic and energy budget evolution of high-energy head-on giant impacts, entering the catastrophic impacts regime, for target masses between 0.001 and 12 M$_{{\oplus }}$. We demonstrate the complex interplay of gravitational forces, shock dynamics, and thermodynamic processing in head-on impacts at high energy. Our study illustrates that frequent interactions of core material with the liquid side of the vapour curve could have cumulative effects on the post-collision remnants, leading to fragmentary disintegration occurring at lower impact energy. This results in the mass of the largest remnant diverging significantly from previously developed scaling laws. These findings suggest two key considerations: (1) head-on planetary collisions for different target masses do not behave similarly, so caution is needed when applying scaling laws across a broad parameter space; and (2) an accurate model of the liquid-vapour phase boundary is essential for modelling giant impacts. Our findings highlight the need for careful consideration of impact configurations in planetary formation studies, as head-on impacts involve a complex interplay between thermodynamic processing, shocks, gravitational forces, and other factors.

Data-Aided Maximum Likelihood Joint Angle and Delay Estimator Over Orthogonal Frequency Division Multiplex Single-Input Multiple-Output Channels Based on New Gray Wolf Optimization Embedding Importance Sampling.

In this paper, we propose a new data-aided (DA) joint angle and delay (JADE) maximum likelihood (ML) estimator. The latter consists of a substantially modified and, hence, significantly improved gray wolf optimization (GWO) technique by fully integrating and embedding within it the powerful importance sampling (IS) concept. This new approach, referred to hereafter as GWOEIS (for "GWO embedding IS"), guarantees global optimality, and offers higher resolution capabilities over orthogonal frequency division multiplex (OFDM) (i.e., multi-carrier and multi-path) single-input multiple-output (SIMO) channels. The traditional GWO randomly initializes the wolfs' positions (angles and delays) and, hence, requires larger packs and longer hunting (iterations) to catch the prey, i.e., find the correct angles of arrival (AoAs) and time delays (TDs), thereby affecting its search efficiency, whereas GWOEIS ensures faster convergence by providing reliable initial estimates based on a simplified importance function. More importantly, and beyond simple initialization of GWO with IS (coined as IS-GWO hereafter), we modify and dynamically update the conventional simple expression for the convergence factor of the GWO algorithm that entirely drives its hunting and tracking mechanisms by accounting for new cumulative distribution functions (CDFs) derived from the IS technique. Simulations unequivocally confirm these significant benefits in terms of increased accuracy and speed Moreover, GWOEIS reaches the Cramér-Rao lower bound (CRLB), even at low SNR levels.

Improving GNSS-IR Sea Surface Height Accuracy Based on a New Ionospheric Stratified Elevation Angle Correction Model

Approximately 71% of the Earth’s surface is covered by vast oceans. With the exacerbation of global climate change, high-precision monitoring of sea surface height variations is of vital importance for constructing global ocean gravity fields and preventing natural disasters in the marine system. Global Navigation Satellite System Interferometry Reflectometry (GNSS-IR) sea surface altimetry is a method of inferring sea surface height based on the signal-to-noise ratio of satellite signals. It enables the retrieval of sea surface height variations with high precision. However, navigation satellite signals are influenced by the ionosphere during propagation, leading to deviations in the measured values of satellite elevation angles from their true values, which significantly affects the accuracy of GNSS-IR sea surface altimetry. Based on this, the contents of this paper are as follows: Firstly, a new ionospheric stratified elevation angle correction model (ISEACM) was developed by integrating the International Reference Ionosphere Model (IRI) and ray tracing methods. This model aims to improve the accuracy of GNSS-IR sea surface altimetry by correcting the ionospheric refraction effects on satellite elevation angles. Secondly, four GNSS stations (TAR0, PTLD, GOM1, and TPW2) were selected globally, and the corrected sea surface height values obtained using ISEACM were compared with observed values from tide gauge stations. The calculated average Root Mean Square Error (RMSE) and Pearson Correlation Coefficient (PCC) were 0.20 m and 0.83, respectively, indicating the effectiveness of ISEACM in sea surface height retrieval. Thirdly, a comparative analysis was conducted between sea surface height retrieval before and after correction using ISEACM. The optimal RMSE and PCC values with tide gauge station observations were 0.15 m and 0.90, respectively, representing a 20.00% improvement in RMSE and a 4.00% improvement in correlation coefficient compared to traditional GNSS-IR retrieval heights. These experimental results demonstrate that correction with ISEACM can effectively enhance the precision of GNSS-IR sea surface altimetry, which is crucial for accurate sea surface height measurements.

Double-Level Torsional Osteotomy in Severe Torsional Malalignment: A Surgical Technique

Background: Torsional malalignment of the femur and/or tibia is associated with patellar maltracking, and torsional osteotomies have shown to improve clinical symptoms. In patients with severe torsional malalignment, a double-level torsional osteotomy may be necessary. Indications: Symptomatic torsional malalignment leading to patellofemoral maltracking associated with anterior knee pain and/or patellofemoral instability. Technique Description: A double-level torsional osteotomy correcting both increased internal femoral torsion and increased external tibial torsion, is described. Meticulous preoperative deformity analysis and planning of the osteotomy is mandatory. An arthroscopy of the knee is performed first to evaluate the patellofemoral joint and patellar tracking. Tibial torsional correction is performed by a lateral approach. A biplanar osteotomy is performed, and the amount of torsional correction is controlled by 2 Schanz screws. Osteosynthesis can be done via a bended 5-hole DC-Plate or an angle-stable plate. The femoral osteotomy is performed by a medial approach. A uniplanar osteotomy is performed perpendicular to the mechanical axis of the femur. The amount of torsional correction is controlled by 2 Schanz screws. Osteosynthesis is achieved by an angle-stable plate. Results: Double-level torsional osteotomy has been shown to be an effective treatment for patients with patellar dislocation or subluxation associated with severe torsional malalignment. In a series of 18 patients, double-level osteotomy led to improved patellofemoral stability, decreased pain, and increases subjective outcome scores. Discussion/Conclusion: In patients with patellofemoral problems caused by a combined increased tibial external torsion and increased femoral internal torsion, a double-level torsional osteotomy is able to correct torsional angles to normal. Available clinical data on this procedure are promising. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Medial opening wedge high tibial osteotomy performs similarly irrespective of body mass index.

This study investigates the effect of the body mass index (BMI) on the early (2 years) to midterm (5 years) results of medial opening wedge high tibial osteotomy (MOWHTO). A prospectively maintained single-centre database of 1138 knee osteotomies, between 2002 and2022, was retrospectively reviewed. Adult patients who underwent MOWHTO for symptomatic unicompartmental medial knee osteoarthritis (OA), with varus knee malalignment, having failed conservative management, were included. Patients were categorized into threegroups according to their BMI as per the classification from the National Institute for Health and Care Excellence (NICE): the healthy weight (HW) group (BMI of 18.5-24.9 kg/m2), the overweight (OW) (BMI of 25-29.9 kg/m2), and the obesity (OB) group (BMI ≥ 30 kg/m2). Multiple patient-reported outcome measures (n = 6) were recorded preoperatively and at 2 and 5 years postoperatively. Deformity analysis was undertaken preoperatively and postoperatively. The relative risk (RR) of the complications between the HW, OWand OB groups was calculated. The rate of conversion to arthroplasty, and 5and 10 years survivorship were recorded, as well as the hazard ratio (HR) of BMI on survivorship. A total of 574 cases were included in the study: the HW group (n = 96), the OW group (n = 233)and the OB group (n = 245), with a mean BMI of 23 ± 1.5 kg/m2, 27.4 ± 1.4 kg/m2 and 34.4 ± 3.8 kg/m2, respectively. The mean follow-up was 13.3 years (4.8-20.3). The mean mechanical tibiofemoral angle corrections were in the HW group: 7.1 ± 3°, OW group: 6.6 ± 3.5°and OB group: 7.1 ± 3.8°, with no intergroup significant difference (p = n.s.). Clinically, despite lower preoperative scores in the OW and OB groups, no difference was observed postoperatively amongst the three groups. The overall complication rate was 12.5% in the HW group, 6.8% in the OW group, and 9.8% in the OB group. There was no significant difference in the RR of complications between the HW and OW groups (RR = 0.6, 95% confidence interval [CI] = 0.3-1.3)(p = 0.2), and the HW and OB groups (RR = 0.8; 95% CI = 0.3-2.2)(p = 0.7). There was no overall significant difference in survival outcomes based on the BMI between the threegroups (p = 0.4). The HR of conversion to arthroplasty between the HW and OW groups was 1.4 [95% CI = 0.6-3.5](p = 0.5)and between the HW and OB groups was 1.8 [95% CI = 0.8-4.4] (p = 0.2). BMI has no significant effect on either the radiological corrections, clinical outcomes, complicationsor survivorship of MOWHTO at short- to medium-term follow-up. No specific cutoff point for BMI can be recommended as a contraindication to MOWHTO. Level IV, Retrospective cohort study.