Angle Correction Research Articles

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.

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% CI 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 evidenceⅢ; Retrospective 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

BackgroundTo 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.MethodsPreoperative 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.ResultsWe 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.ConclusionsIt 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.

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 (&gt;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 (&gt;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&lt;0.001). On multivariate analysis, greater teardrop angle correction was an independent predictor of improved DASH and PRWE scores. Conclusions: Obtaining &gt;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.

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.

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.

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.

Does the coronal deformity angular ratio affect bracing outcome in adolescent idiopathic scoliosis?

To examine if coronal deformity angular ratio (C-DAR) serves as a predictor for progression to surgical magnitude in patients with Adolescent Idiopathic Scoliosis (AIS) treated with thoracolumbar sacral orthosis (TLSO). Patients with AIS, prescribed a full-time TLSO, Cobb angle 20-40°, Risser 0-2, who wore the brace ≥ 12.9 h and reached skeletal maturity/surgery were included retrospectively. C-DAR was defined as the Cobb angle divided by the number of vertebrae in the curve, yielding a larger value in short curves. The association between C-DAR and the risk of progression to surgical magnitude (> 45°) was assessed. Secondly, we evaluated the association between pre-treatment Cobb angle and in-brace correction on the risk of progression to > 45°. We included 165 patients with a mean Cobb angle of 30 ± 6°. Of these, 46/165 (28%) progressed ≥ 6° and 26/165 (16%) reached surgical magnitude at the end of treatment. C-DAR was a significant predictor for risk of progression to surgical magnitude with an OR of 1.9 (CI 1.2-2.9) per unit increase in C-DAR. A threshold value of 5.15 was established and demonstrated an OR 5.9 (CI 2.1-17.9) for curve progression to a surgical magnitude. Likewise, pre-treatment Cobb angle showed a significant OR 1.3(CI 1.2-1.4) per degree increase in Cobb, whereas in-brace % correction showed OR 0.96 (CI 0.93-0.98). C-DAR is an independent predictor for progression to a surgical magnitude in AIS patients treated with bracing. Patients with a higher C-DAR should be counseled to help set realistic expectations regarding the likelihood of curve progression despite compliance with brace wear.

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.