Background: Very frequent and common paediatric orthopaedic emergency is fracture of shaft of femur. Traction and casting were the standard common practice for all femoral shaft fractures in paediatric group. Titanium Elastic Nailing System (TENS) is, now a days, a common practice for treating these fractures. In last twenty years, this fixation showed rapid union and early mobilization and have gained a general popularity. Objective: To evaluate clinical and radiological outcome of titanium elastic nailing system for displaced femoral shaft fractures in paediatric patients. Methods: This retrospective study was conducted in Orthopaedic Centre, CMH (Combined Military Hospital) Dhaka from January 2020 to December 2022. A total of 52 cases (34 boys, 18 girls), aged 6-14 years were fixed with TENS. Two nails of proper and equal diameter were used for each case. Plaster was used postoperatively upto soft tissue healing and stitch off (2 weeks postoperatively). Outcomes were assessed on the basis of Flynn et al scoring system. Results: The results of the 52 cases were included in our study. Each fracture achieved complete healing at a mean of 9.1 (Range: 8-10) weeks. 44 fractures needed closed reduction and 8 needed open reduction. Nail entry site skin irritation was recorded as minor complication in 9 patients. 78.85% got excellent result and 21.15% got satisfactory result. Conclusion: TENS has been increasingly popularized as a treatment option for paediatric shaft femur fracture over the last twenty years. It permits early mobilization and ambulation. Higher satisfaction with shorter hospital stay can be achieved with TENS. It also provides translational, angular and rotational stability to the fracture. Length can be well-achieved as well. JAFMC Bangladesh, Vol 21, No 1 (June) 2025:19-23

Which augmentation is more efficient for ankle lateral ligament repair: A biomecanical study.

The septocolumellar suture technique has shown consistent efficacy in achieving precise nasal tip aesthetics for over 20 years. This study aims to evaluate the long-term outcomes of primary endonasal rhinoplasty.Retrospectively analyze 1,096 consecutive patients who underwent primary endonasal rhinoplasty using the septocolumellar suture technique between March 2005 and March 2025. The procedure anchors the medial crura to the caudal septum at variable distances from the anterior nasal spine, allowing control of tip projection and rotation. Objective and photographic analyses assessed the nasal tip parameters, including projection, rotation, shape, deviation, alar width, and flare. Statistical significance was set at p < 0.001.Long-term stability of nasal tip projection and rotation was maintained in 96% of the patients at a minimum 12-month follow-up. All the evaluated parameters demonstrated statistically significant improvement (p < 0.001). The revision and complication rates were 3.2 and <1%, respectively.The septocolumellar suture technique is a reliable and minimally invasive method for nasal tip refinement in rhinoplasty. It ensures stable aesthetic outcomes while preserving nasal support and functional integrity. This technique effectively enhances tip projection in mestizo patients using intrinsic anatomy and can be applied in both open and closed approaches.

This study aimed to examine the biomechanical properties of full-length S2 alar-iliac screws combined with posterior iliac transfixion screws for the treatment of unilateral unstable sacral fractures, thereby providing a theoretical foundation for clinical application. A 3-dimensional finite element analysis was applied to simulate Tile C1-C3 pelvic injuries, characterized by a unilateral sacral fracture in Denis Zone II combined with fractures of the superior and inferior pubic rami. Three posterior pelvic ring fixation techniques were evaluated: (1) standard S1 screws with S2 alar-iliac screws, (2) full-length S2 screws, and (3) full-length S2 screws combined with posterior iliac transfixion screws. Vertical and rotational stability of the posterior pelvic ring under simulated standing conditions were quantified and compared. Peak stress, vertical displacement of the sacral surface, posterior rotation angle displacement of the sacrum, and stress distribution across the pelvis were recorded and analyzed for each fixation technique. The fixation stability achieved by full-length S2 alar-iliac screws combined with posterior iliac transfixion screws was comparable to that of standard S1 screws with S2 alar-iliac screws. Both techniques demonstrated significantly less vertical displacement and posterior rotational angle of the sacrum compared with single S2 alar-iliac screws (P<0.05). In addition, these methods produced lower peak stress and a more uniform stress distribution. Full-length S2 alar-iliac screws combined with posterior iliac transfixion screws demonstrated a favorable load-sharing capacity and a reduced risk of implant fatigue. These findings indicate that this fixation method may represent an effective alternative to standard S1 screws with S2 alar-iliac screws for the treatment of unilateral unstable sacral fractures.

Effect of Capsular Tension Ring on Rotational Stability of Loop-Haptic Intraocular Lens in Highly Myopic Patients.

Innervation pattern of the anterolateral ligament (ALL) of the knee: Indication of an active role in proprioception and autonomic modulation.

Anterior cruciate ligament reconstruction with lateral extra-articular tenodesis: national utilization patterns and 2-year postoperative outcomes.

Research on the cage rotational stability of high-speed precision special ball bearing based on the visual trajectory capture method

Current cheerleading skill assessment predominantly relies on coaches' subjective evaluations, lacking quantifiable biomechanical benchmarks. Although electromyography and ground reaction forces provide critical neuromuscular and kinetic insights, their computational integration for automated motion quality assessment remains underdeveloped in aesthetic sports. This study systematically investigates the Tour à la Seconde through explainable machine learning, establishing an interpretable human-AI collaboration framework to bridge empirical coaching knowledge with data-driven biomechanical diagnostics. Twenty-eight elite athletes (18-22 years, 3+ years training) performed standardized Tour à la Seconde while synchronized 14-lead EMG (2000Hz) and triaxial force plate data were captured. Biomechanical feature engineering encompassed: Neuromuscular dynamics: RMS amplitudes, inter-muscular coherence. Kinetic signatures: Vertical force phasing (Fz_peak), medio-lateral impulse (Fy_impulse), dynamic stability index. A hierarchical modeling approach employing PyCaret's automated ML optimized 12 classifiers via leave-athlete-out cross-validation. SHAP value decomposition elucidated biomechanical determinants of expert-rated performance (binary classification threshold: coach score ≥7/10). The XGBoost model achieved superior generalizability (86% cross-validation accuracy vs. LightGBM's 82%, logistic regression's 76%), with three biomechanical drivers identified: Rotational stability control: Fz_peak timing (SHAP=0.41) correlating with centrifugal force management. Ankle proprioception: Gastrocnemius activation intensity (0.33) reflecting plantarflexion precision. Neuromuscular synergy: Inter-muscular coordination (0.28), indicating kinetic chain efficiency. Notably, while decision trees showed complete training accuracy (100%), 21% test accuracy drop revealed critical overfitting risks. The model's strong congruence with expert evaluations (κ=0.72, 95%CI:0.65-0.79) validates its potential as a coach-assistive tool, particularly through real-time visualization of weight transfer dynamics and muscle activation sequencing. This work establishes a novel computational paradigm for aesthetic sports biomechanics, decoding cheerleading rotational skills through explainable multimodal learning. The framework's technical viability for real-time deployment—evidenced by latency-optimized feature engineering (&lt; 50ms processing time)— AI-enhanced athletic training systems. Future research directions include inertial sensor fusion for 3D kinematic validation and cross-domain adaptation to gymnastics and dance.

Biomechanical evaluation of anterolateral ligament anatomical variants in anterior cruciate ligament-injured and reconstructed knee joints.

IntroductionThe biomechanical effects of transverse and longitudinal capsulotomy on hip joint stability in arthroscopy have not been thoroughly investigated. This study used fresh-frozen cadavers to evaluate whether rotational stability and traction resistance differ between these two capsulotomy orientations.MethodsTwelve hips from six fresh-frozen cadavers with intact femurs and pelvises were tested under three conditions: intact, post-capsulotomy, and post-repair. Two capsulotomy patterns were created: a 4 cm transverse capsulotomy assuming inter-portal capsulotomy and a longitudinal capsulotomy. Six hips underwent a transverse capsulotomy, and six underwent a longitudinal capsulotomy. The pelvis was fixed using a wooden plate, and an intramedullary nail was inserted into the femur. To assess rotational stability, internal and external torques of 5 Nm were applied at hip extension angles of 15° and 0°, and at hip flexion angles of 15°, 30°, 45°, and 60°. To evaluate traction resistance, a 200 N axial traction force was applied at flexion angles of 0°, 30°, 45°, and 60°.ResultsExternal rotation laxity increased significantly at all flexion angles following transverse capsulotomy, and only at 0° after longitudinal capsulotomy. The change in external rotation laxity was significantly greater in transverse capsulotomy at 15° of hip extension and 0° than longitudinal capsulotomies in post-capsulotomy compared to intact conditions. Internal rotation laxity did not significantly increase after the both types of capsulotomies and following capsular repair. Separation distance under traction force increased significantly after both types of capsulotomies. The separation distance with post-capsulotomy and post-repair at 0° flexion, and with post-repair at 30° flexion was significantly greater in the transverse group, but no significant differences observed in other positions or conditions.ConclusionsThis cadaveric study demonstrated that vertical (longitudinal) capsulotomy results in less external rotation and traction laxity - particularly at 15° extension and 0° flexion - than horizontal (transverse) capsulotomy. These differences were partially retained even after capsular repair. While standard repair improves overall joint stability, surgeons should note that the longitudinal incision tends to be more stable at lower levels of hip flexion.

BackgroundShelf acetabuloplasty is a surgical option for developmental dysplasia of the hip (DDH), gaining attention as a less invasive alternative to periacetabular osteotomy. While favorable clinical outcomes have been reported, the biomechanical effect of shelf acetabuloplasty remains unclear due to limited cadaveric evidence. The purpose of this study was to evaluate the stabilizing effect of shelf acetabuloplasty in a dysplastic hip model using cadaveric specimens.MethodsTen fresh-frozen cadaveric hips were dissected to the capsule and mounted to a six-degrees-of-freedom robotic system. Each specimen underwent biomechanical testing in four conditions: 1) Intact, 2) Capsular repair, 3) Hip dysplasia model, and 4) Shelf acetabuloplasty. To simulate dysplasia, the acetabular rim was resected to achieve a lateral center-edge angle (LCEA) of 15–20°, and the labrum was detached and re-fixed. Shelf acetabuloplasty involved placing a tricortical iliac crest bone graft (5×30×35 mm) into a slot above the capsule to restore LCEA to 35–40°. Robotic tests included 5-Nm abduction, internal rotation (IR) at 75° flexion, flexion, and 88-N lateral drawer. Primary outcomes were rotational range of motion and lateral translation. Statistical analysis was performed using ANOVA and Tukey’s method.ResultsCapsular repair showed no significant differences from the intact state. The dysplastic state showed significantly increased abduction (+2.3°, p=0.003) and IR at 75° flexion (+0.9°, p=0.017) compared to intact, indicating instability. Shelf acetabuloplasty restored both abduction and IR to levels not significantly different from intact, but reduced hip flexion (-1.7°, p=0.003). Lateral translation was unchanged across all conditions.ConclusionShelf acetabuloplasty biomechanically restored hip stability in abduction and internal rotation to levels comparable to the native hip. These findings add to the limited cadaveric evidence supporting the stabilizing effect of shelf acetabuloplasty in the setting of DDH.

Effect of posterior inclination and facet joint orientation on the annulus fibrosus stiffness and rotational stability of the thoracolumbar spine.

Abstract Effects of reversed magnetic shear on the plasma rotation stabilization of resistive wall modes in tokamaks are investigated using the AEGIS code. MHD equilibria in toroidal configuration from circular cross-sections to realistic CFETR-like scenarios with various magnetic shear profiles are considered. Two critical aspects of the n =1 RWM are examined: the influence of toroidal rotation on the RWM-unstable β N range and the toroidal rotation frequency thresholds required for complete stabilization. It is found that strongly reversed magnetic shear consistently broadens the RWM-unstable β N range in both circular and CFETR equilibria when toroidal rotation is included. Furthermore, reversed magnetic shear significantly reduces the rotational stabilization, resulting in narrower wall-stabilization window width and notably higher toroidal rotation frequency thresholds required for complete RWM suppression compared to the cases with positive shear only. These results clearly demonstrate that the reversed magnetic shear in the advanced tokamak configuration imposes more stringent requirements for the effective toroidal rotation stabilization of the n =1 RWM.

To compare the long-term rotational stability of septal extension grafts (SEGs) fixed with polypropylene (PP) versus polydioxanone (PDO) sutures in rhinoplasty and to evaluate the impact of skin thickness on surgical outcomes. A retrospective analysis was conducted on 308 patients who underwent rhinoplasty with SEG placement between January 2022 and June 2024. Patients were grouped according to the suture material used for caudal septal fixation (PP vs. PDO) and stratified by skin thickness (thin, medium, thick). Tip Rotation Angle (TRA) was measured from standardized lateral photographs at preoperative, 1-month, and 1-year postoperative time points. All measurements were performed by a blinded observer using the ImageMeter application. Rotation loss and revision rates were compared across groups. TRA increased from a preoperative mean of 92.65° to 101.6° at 1 month postoperatively, then stabilized at 100.23° at 1 year. Mean rotation loss was significantly higher in the PDO group (2.16° ± 2.98°) compared to the PP group (0.67° ± 1.02°) (p < 0.01). Subgroup analysis revealed no significant difference in thin-skinned patients, but significantly greater rotation loss with PDO in medium- and thick-skinned patients (p < 0.01). Revision surgery due to rotation-related complications was required in 5.2% of patients, with a majority (81.2%) occurring in thick-skinned individuals from the PDO group. No adverse suture-related reactions were observed. Polypropylene provides superior long-term rotational stability in SEG fixation compared to polydioxanone, particularly in patients with medium or thick nasal skin. Suture selection should be individualized based on patient skin type to optimize outcomes..

Syndesmosis injury healing remains poorly understood, despite its high prevalence in ankle fractures. Unstable syndesmosis is commonly addressed with either syndesmosis screw (SS) or suture button (SB) fixation, and up to 20% of operated ankle fractures may require some form of syndesmosis fixation. However, in biomechanical studies no repair technique fully restores the preinjury rotational stability or the anatomical alignment of the tibiofibular joint. In a study of 39 patients with operatively treated supination external-rotation type 4 and pronation external-rotation type 4 ankle fractures and fixation of an unstable syndesmosis, weightbearing cone beam computed tomography with rotational stress was performed on both ankles at a mean follow-up of 7.8 (range, 6.2-10.3) years to evaluate tibiofibular syndesmosis dimensions and fibular rotation. Sagittal translation of the fibula (ST), anterior width (AW) and posterior width (PW) of the syndesmosis, tibiofibular clear space (TFCS), and fibular rotation (RO) were measured in neutral position and in maximal internal and external rotation. Mean change in measurements between maximal rotations were calculated to represent range of motion of the fibula under rotational stress.ResultsTwenty-six patients had screw fixation (SS) and 13 had suture button (SB) fixation of the syndesmosis. Eight SSs had been removed and 3 were broken. No SBs had been removed. The mean Olerud-Molander Ankle Score was 84.7 (SD 20.3). Fibular rotation demonstrated a mean difference of 2.7 degrees (95% CI, 1.3-4.1; P < .05) compared with the patient's non-injured ankle. Other measurements showed no significant differences; however, we lacked statistical power to detect significant changes in ST, AW, PW, and TFCS.ConclusionExcess fibular rotation persists after healing of ankle fractures with fixed unstable syndesmosis. However, clinical relevance remains unclear and should be explored with larger patient groups.

Rotational instability is a key factor in fixation failure of extracapsular hip fractures. The U-Blade (RC) lag screw was designed to improve rotational stability. This study aimed to compare mechanical complication rates between Gamma3 and Gamma3 RC nails in elderly patients with rotationally unstable extracapsular fractures. We conducted a prospective, single-center randomized controlled trial including 316 patients aged ≥ 65 years with rotationally unstable extracapsular fractures. Patients were randomized to treatment with a Gamma3 nail (n = 169) or a Gamma3 RC nail (n = 147). Mechanical complications were classified as major (rotation and migration of the implant, cut-out, non-union) or minor (back-out, cervicodiaphyseal angle change, excessive sliding). The overall rate of major complications was 2.9 per 10,000 person-days, being the most frequent the cut out (2.2%), with no significant difference between Gamma3 and Gamma3 RC groups (RR = 1.0; 95% CI: 0.4-2.7). TAD > 25mm increased the risk of major complications (RT = 3.7; 95% CI: 1.2-11.2), as did superior screw placement (Cleveland zones 1-3: RT = 7.5; 95% CI: 2.7-20.8) and postoperative diastasis (RT = 4.7; 95% CI: 1.4-16.2). Similarly, implant type was not significantly associated with minor complications that were observed in 85 patients (26.9%), most frequently back-out (14.6%). The U-Blade (RC) lag screw did not reduce mechanical complication rates compared with the standard Gamma3. Radiographic parameters, particularly TAD, reduction quality, screw position, and postoperative diastasis, were the main predictors of fixation failure.

Restoring medial knee stability: A cadaveric comparison of three posteromedial reconstruction techniques.

The practical possibility of self-synchronization of two pairs of unbalanced vibration exciters with multiple rotation frequencies is considered. The problem is solved using the integral criterion of stability of synchronous movements. Formulas for synchronizing moments are obtained; conditions for the existence and stability of synchronous modes of motion of exciters. Equations are given for determining the phase shift angles in possible synchronous modes of motion of vibration exciters. Practical recommendations are formulated regarding increasing the stability of multiple-synchronous rotation of vibration exciters. Theoretical results are consistent with the results of computer modeling

Outcomes of collared uncemented stems in total hip arthroplasty for primary osteoarthritis: A Swiss National joint registry analysis.