To explore the surgical technique and effectiveness of limited bone and soft tissue surgery combined with Ilizarov technique in the treatment of adolescents severe cerebral palsy with flattened valgus foot and lower leg external rotation deformity. A retrospective analysis was conducted on 12 patients with severe cerebral palsy with flattened valgus foot and external rotation deformity of the lower leg, totaling 16 feet, admitted between January 2022 and January 2025. There were 5 males with 7 feet and 7 females with 9 feet, the age ranged from 12 to 18 years, with an average of 15 years. There were 10 cases on the left foot, 6 cases on the right foot, and 4 cases on both feet. The preoperative external rotation angle of the lower leg ranged from 20° to 35°, with an average of 26°. The preoperative visual analogue scale (VAS) score was 4.9±0.9, the American Orthopaedic Foot & Ankle Society (AOFAS) score was 68.7±12.0, the calcaneal tilt angle was (12.69±1.78)°, and the hindfoot angle was (18.69±3.55)°. Patients with bilateral lower leg deformities underwent surgery in two phases, with an interval of 3-6 months between surgeries. Select soft tissue surgery (Achilles tendon elongation, release or transposition of joint capsule and ligaments) and bone surgery (joint fusion, calcaneal osteotomy, medial wedge osteotomy, etc.) combined with tibiofibular internal rotation osteotomy and Ilizarov external fixation were selected according to the patient's condition. At 1 week after operation, the external fixators of the lower leg and ankle were slowly adjusted, and the deformities that were not completely solved in the three-dimensional correction operation were corrected. Postoperative pain relief and functional recovery were evaluated by VAS and AOFAS scores, and the improvement of foot deformity was evaluated by calcaneal tilt angle and hindfoot angle on radiographic data, and the postoperative effctiveness was evaluated according to the International Clubfoot Study Group (ICFSG). At 2 weeks after operation, the foot deformity of the patient was basically adjusted. All patients were followed up 6-36 months, with an average of 18 months. The incisions healed by first intention without nerve injury, infection, or other complications. At last follow-up, the patients recovered satisfactorily, the osteotomy sites healed, and the external rotation of the lower leg was corrected. The VAS score was 1.2±0.1 and AOFAS score was 86.7±6.8, which were significantly different from those before operation ( P<0.05). The calcaneal tilt angle was (18.38±1.15)° and the hindfoot angle was (10.06±2.93)°, which were significantly different from those before operation ( P<0.05). According to the ICFSG scoring standard, 13 feet were excellent and 3 feet were good, and the excellent and good rate was 100%. The combination of bone and soft tissue limited surgery and Ilizarov technique is a safe, minimally invasive, and effective method for treating severe cerebral palsy in adolescents with flattened valgus foot and external rotation deformity of the lower leg. It conforms to biological principles and follows the concept of natural bone reconstruction.

Synchronous measures of head kinematics and in vivo brain deformation during rapid head rotation are needed to advance understanding of traumatic brain injury (TBI) mechanics and enhance computational modeling as a tool for injury risk assessment and prevention. The aims of this study were to produce repeatable rapid rotation of the in vivo sheep head, to assess the viability of the sonomicrometry method for measuring multipoint brain displacement, and to quantify the in vivo brain deformation response to rapid rotation. In three anaesthetized adult sheep, arrays of sonomicrometry transceivers were implanted into the brain and rigidly attached to the inner skull surface. Repeatable, rapid, sagittal plane head rotation (nominally about the second cervical vertebra) was induced with a non-impact head rotation apparatus. Computed tomography imaging was performed to assess relative motion between transceivers and brain tissue. Three-dimensional brain displacement, strain, and head kinematics were assessed for repeatability. The location of up to 13 (mean = 11) brain transceivers were tracked in each of 11 rapid head rotation tests. Peak head angular acceleration and velocity were up to 38.56 krad/s2 and 30.43rad/s, respectively, and average duration of head motion was 241.9 ± 23.1ms. Pre-to-post-test transceiver displacement in brain tissue was less than the spatial resolution of the measurement system, and brain displacements measured during rapid head rotation had excellent repeatability (CORA score 0.99). Brain displacements and strains up to 2.47mm and 18%, respectively, were observed. The brain exhibited decaying sinusoidal rotational deformation in the sagittal plane with oscillating tension-compression waves. Sonomicrometry was reliably applied in vivo and provided repeatable measurements of brain deformation in a non-survival large animal model of rapid head rotation.

Plastic Deformation of the Pediatric Forearm: Recognition, Radiographic Measurement, and Management.

Abstract Malunion of a distal radius fracture may lead to persistent pain and functional limitation. Traditionally, the indication for corrective osteotomy is based on two-dimensional radiographic criteria. However, a subset of patients with radiographically subtle malunions—defined as cases in which all radiographic parameters fall within the acceptable limits outlined by current guidelines—may still experience significant symptoms that impair activities of daily living or occupational performance. Notably, rotational deformities are typically not evaluated, despite their potential clinical relevance. The objective of this retrospective cohort study was to evaluate the clinical outcomes of corrective osteotomy using a three-dimensional-printed patient-specific implant in patients with a minimal malunion of the distal radius. Surgical outcomes were assessed using patient-reported outcome measures, including the Patient-Rated Wrist/Hand Evaluation (PRWHE), as well as clinical evaluation of distal radioulnar joint (DRUJ) stability. Fourteen patients were included. The PRWHE improved from 72 (interquartile range [IQR]: 56, 81) to 35 (IQR: 8, 57), p = 0.004, after a follow-up of 11 months (IQR: 10, 13). Preoperatively, 12 patients had DRUJ instability. Postoperatively, only one patient exhibited asymptomatic DRUJ instability. No postoperative complications were observed. Patients with subtle malunions of the distal radius may benefit from corrective osteotomy. Standard guideline parameters may not be sufficient to identify all patients who could benefit from surgical intervention. Moreover, DRUJ instability following a distal radius fracture should be considered a manifestation of malunion until proven otherwise. IV.

Abstract A special type of Stewart mechanism, the orthogonal mechanism, is declared to have special advantage in performance. However, the current study of orthogonal mechanism lacks a systematic analysis that accounts for the advantage. Towards this goal, this paper studies multi-dimensional performance evolution and evaluation from traditional Stewart to 3-3 orthogonal parallel mechanisms. Six evaluation indicators named Good Displacement and Orientation Velocity Workspace (GDVW, GOVW), Good Force and Torque Payload Workspace (GFPW, GTPW), and Good Translation and Rotation Stiffness Workspace (GTSW, GRSW) are established to comprehensively evaluate the performance. This method can intuitively reveal the evolution trends of different performances, including motion/force transmission capacity, displacement and orientation velocity isotropy, force and torque payload isotropy, and translation and rotation deformation stiffness isotropy, within the different parameter spaces, which can provide guidance on the design of high-performance mechanism. Results indicate that the performance of orthogonal mechanism is better than traditional Stewart mechanisms in motion/force transmission capacity, velocity and torque payload. Finally, the orthogonal mechanism is designed and adopted for application to validate the effectiveness.

The influence of greater femoral anteversion on outcomes after medial patellofemoral ligament (MPFL) reconstruction is increasingly recognized, leading to the more frequent use of combined derotational femoral osteotomy. However, the indications for this additional invasive procedure remain poorly defined, particularly in patients without severe patellar maltracking. To evaluate the clinical outcomes of isolated MPFL reconstruction in patients with recurrent patellar dislocations (RPDs), increased femoral anteversion (>30°), and an absent or mild J-sign. Cohort study; Level of evidence, 3. A retrospective cohort study was conducted on 52 consecutive patients (mean age, 19.1 ± 5.9 years) with RPDs, femoral anteversion >30°, and an absent/mild J-sign who underwent isolated MPFL reconstruction between 2018 and 2022. Rotational deformities of the lower extremities, including femoral anteversion, tibiofemoral rotation, and tibial external torsion, were assessed using computed tomography. Clinical and radiological outcomes were assessed preoperatively and at a minimum 2-year follow-up. Additionally, outcomes were compared between patients with and without severe trochlear dysplasia (Dejour type B or D) to evaluate its potential confounding effect. This study evaluated the outcomes of isolated MPFL reconstruction in 52 patients with RPDs, high femoral anteversion (mean, 35.2°± 6.5°), and an absent/mild J-sign. At a mean follow-up of 2.4 ± 1.1 years, no redislocations occurred. Functional scores improved significantly from preoperatively to postoperatively: Tegner (from 3 to 5; P = .021), Kujala (from 58 ± 9 to 88 ± 9; P < .001), and Lysholm (from 62 ± 7 to 90 ± 11; P < .001). Subgroup analysis demonstrated comparable functional outcomes (all P > .05) but significantly greater patellar tilt (18°± 5° vs 13°± 4°, respectively; P < .001) in patients with severe trochlear dysplasia (n = 17) compared to those without severe trochlear dysplasia (n = 35). Isolated MPFL reconstruction provided excellent short-term stability and functional outcomes for patients with RPDs, increased femoral anteversion (>30°), and an absent/mild J-sign. Crucially, the presence of severe trochlear dysplasia did not compromise functional results.

Accuracy of vertebral rotation assessment using biplanar imaging technology in adolescent idiopathic scoliosis.

Flexion-type supracondylar humerus fractures are rare, highly unstable, and often associated with technical challenges. Current literature is limited to small series, and no standardized diagnostic-therapeutic guidelines have been established. This retrospective study includes 47 patients with Gartland type II or III flexion-type supracondylar fractures surgically treated between September 2012 and October 2023. Demographic, clinical, radiographic, and functional data were collected to evaluate outcomes after closed or open reduction with percutaneous pinning. Univariate and multivariate model testing were used to analyze associations between fracture severity, surgical timing, rotational or translational deformities, and the need for open reduction and functional outcomes. No major complications occurred. In the multivariate analysis, translational deformity emerged as the sole independent predictor of open reduction (P=0.017). While the Gartland classification and rotational deformities correlated with the need for open surgery in univariate analysis, they were not significant in the final model. Surgical delay beyond 48 hours was not associated with open reduction (P=0.751) or inferior functional outcomes (P=0.327). Regarding functional results, although translational or rotational components were associated with higher QuickDASH scores in the univariate analysis (P=0.036), this significance was not confirmed in the multivariate model. The requirement for open reduction itself was not associated with worse functional outcomes (P=0.173). Translational deformity is the most significant predictor of the need for open reduction. However, complex fracture patterns do not independently result in inferior functional outcomes when appropriately managed. Our results suggest that open reduction is a safe option that does not negatively impact long-term function. It should be considered a valid alternative for unstable flexion-type fractures whenever closed reduction fails to restore anatomy. Level IV.

Vertical atlantoaxial distraction (AAD) represents a rare and severe form of craniocervical injury caused by high-energy trauma. It involves vertical separation of the atlas and axis due to complete rupture of the ligamentous stabilizers and poses an immediate risk of neurological or vascular compromise. A 33-year-old male sustained multiple injuries following a suicidal jump from 10 meters, including a Type III vertical AAD with 6 mm distraction between the C1 and C2 lateral masses. Imaging revealed complete rupture of the alar, apical, and posterior longitudinal ligaments, bilateral facet joint capsule disruption, and a Gehweiler Type I anterior arch fracture of C1. A traumatic dural tear with suspected CSF leak was also identified. Initial anterior stabilization was performed with mini-fragment screws, followed by delayed posterior C1/C2 fusion via transarticular screws one week later due to clinical instability. Intraoperative correction of a 10° C1-C2 rotational deformity was achieved, and dural repair was completed using TachoSil and muscle graft. The patient remained neurologically intact and had an uneventful recovery. Follow-up imaging at one year demonstrated stable alignment of the construct without signs of hardware loosening, failure, or new neurological findings. At the 6-year follow-up, the patient remained neurologically intact with preserved cervical rotation up to 50° Conclusion: This case highlights the diagnostic complexity and management challenges associated with vertical AAD. A classification-based surgical strategy supported by high-resolution imaging and intraoperative navigation led to successful stabilization and excellent neurological outcome.

Myofibril arrangement is critical to cardiac muscle function in health and disease. Historically, analysis of the impact of myofibril organisation on force and cell contraction has relied on the assumption of uniaxial arrays. However, improvements in imaging indicate that myofibrils form complex networks, though how these networks modulate force has yet to be explored. Here, morphological analysis of sheep left-ventricular cardiomyocytes is utilised to inform a non-linear finite element model of cell contraction. Analysis of deep learning segmentations of z-discs demonstrate that myofibrils are oriented about the contraction axis (mean ) but deviate locally by up to (standard deviation ). Simulations produce unique deformations for geometries informed by myofibril orientations, displaying internal rotation and off-axis deformations. Moreover, anisotropy generates shear stresses distinct from the uniaxial case, demonstrating spatial relationships that balance shear across the cell and a correlation between shear stress and z-disc orientation. These findings highlight the impact of myofibril networks on forces during cell contraction.

Presence of lesser trochanter fragments is a risk factor for malrotation in subtrochanteric femoral fractures: A multicenter, retrospective, observational study.

Randomized prospective study on the treatment of extra-articular fractures of the distal tibia with intramedullary locked nails with or without simultaneous fibula fixation.

Spatial characteristics of metacarpal fractures: A quantitative 3D CT study of fall-related versus nonfall-related injuries.

To address the urgent demand for high-performance and durable rotational blades in turbomachinery, e.g., aero-engine turbine blades operating under harsh environments and complex pulse loads, this study proposes a novel rotational sandwich plate model with a pre-set angle for investigating the dynamic responses of rotational composite turbine blades with graphene coating layers under pulse loads to capture both structural stagger angle effects and layered reinforcement mechanisms. A unique three-level discretization method of Chebyshev-Ritz-Galerkin is established to overcome the solving difficulty of partial differential governing equations (PDGEs), efficiently transforming them into numerically solvable ordinary differential governing equations (ODGEs), a key innovation that addresses the convergence challenge of traditional finite element methods (FEM) under high-speed rotation and large deformation and that ensures high computational efficiency and accuracy. Based on the first-order shear deformation theory and Hamilton principle, the model comprehensively integrates rotational centrifugal effects, material anisotropy of graphene-reinforced composites, and geometric nonlinearity. Three typical pulse loads, that is, step load, sinusoidal load, air blast load are considered to mimic real-world extreme working conditions, e.g., bird strikes, gusts, ice impacts. The modified Halpin-Tsai micromechanical model is adopted to accurately characterize the effective material properties of graphene-reinforced composites coating layers, while a systematic parametric study is conducted to reveal the effects of blade aspect ratio, graphene platelet (GPL) geometry length-to-thickness ratio, GPL weight fraction, rotational speed, damping, and excitation parameters on dynamic responses with a special focus on the synergistic effect of GPL weight fraction and rotational speed. Meanwhile, the integration of multi-physical field loads and graphene reinforcement to fill the gap in dynamic modeling of graphene-reinforced composites-based rotational blades under pulse loads. This work provides a robust theoretical framework and quantitative design guidelines for optimizing rotational composite turbine blades with graphene coating layers with superior vibration suppression, impact resistance, and fatigue performance, advancing the engineering application of advanced composite materials in high-speed turbomachinery.

Tibial torsion significantly influences knee biomechanics, yet its interaction with ACL reconstruction history in elite alpine skiers remains under-investigated. In this cross-sectional observational study, we analyzed 20 elite alpine skiers (7 ACL-reconstructed, 13 non-injured) using a markerless motion capture system during dynamic tasks (Squat, Single-Leg Squat, Lunge). Static tibial torsion was assessed via the Transmalleolar Axis and Thigh–Foot Angle. The results revealed a critical divergence in biomechanical strategies based on tibial alignment (p &lt; 0.05). Skiers with rotational deformity adopted a pattern we describe as a “Stiffness Strategy”, characterized by suppressed knee valgus and hip rotation, but relied on excessive ankle dorsiflexion (39.5°)—a compensatory mechanism that may become limited when constrained by rigid ski boots. In contrast, ACL-reconstructed skiers with normal alignment exhibited what we term an “Instability Strategy”, showing dynamic valgus collapse and persistent asymmetry. These findings suggest that “one-size-fits-all” rehabilitation may be insufficient. We propose that injury prevention protocols may benefit from incorporating anatomical screening, focusing on decoupling mobility for skiers with tibial torsion and enhancing dynamic stability for those with normal alignment.

This study proposes a tension-spring-based unidirectional rotational stiffness mechanism (TS-URM) and its implementation in a Unidirectional Series Elastic Actuator (USEA). Unlike conventional bidirectional rotary SEAs, the proposed design is structurally optimized for unidirectional torque transmission, improving deformation utilization efficiency in pulling-type applications. An analytical model was derived to establish the geometric relationship between spring elongation and rotational deformation, enabling explicit formulation of the torque–angle relationship. The influence of the installation angle on stiffness linearity was systematically analyzed, and a multilayer spring configuration was optimized to achieve a target rotational stiffness of approximately 42 Nm/rad. A preload adjustment mechanism was incorporated to eliminate nonlinear behavior in the initial operating region. Experimental results validated the analytical model and demonstrated stable unidirectional force control up to 130 N with steady-state errors within 1 N. The proposed mechanism provides predictable stiffness characteristics and an efficient structural solution for compact USEA systems.

Supracondylar correction outside the joint block is performed to achieve asymmetrical cubital axis in the frontal plane and abalanced range of motion in the sagittal plane without interfering with joint congruence. Supracondylar correction is performed mainly in the frontal plane. Asimultaneous correction in the sagittal plane is effortlessly possible as well. The condylar prominence can be balanced through additional medial translation. Dome osteotomy is not suitable for patients aged under 10years. It is not the first-choice method for correction of rotational deformity. Moreover, dome osteotomy alone is insufficient for correction of deformities with joint incongruence. The distal humerus is exposed through aposterior triceps-splitting approach. Aseries of drillings in the curve of adome were made using a2-mm K‑wire. Gear-formed osteotomy was further completed with a4-mm osteotome, so that the distal fragment could be gradually rotated. After the required correction had been achieved, the osteotomy was temporarily fixed with a2-mm K-wire. Final fixation was achieved with a3.5-mm locking compression tibia plate. Free range of motion and full weightbearing are possible immediately after surgery. However, weightbearing exceeding the weight of the arm and propping up the arm are prohibited in the first 6weeks. Radiologic examinations are performed after 6weeks and 3months. Sports are prohibited during the first 3months. Further clinical follow-ups are continued annually until bone maturity is attained. The correction that was aimed for was achieved in all concluded cases. None of the complications mentioned in the literature occurred in our cases. Moreover, elbow function and stability were significantly improved. Although dome osteotomy is technically demanding, standardized surgical execution contributes to excellent reproducible results.

Our study aimed to analyze the relationship between distal metatarsal articular angle (DMAA) and first metatarsal (M1) pronation by measuring the DMAA and first metatarsal rotation angle (MRA) of patients with unilateral hallux valgus (HV) and discussed its significance in the surgery for HV treatment. We performed a retrospective self-controlled study including patients with unilateral HV from January 2015 to December 2018 in our hospital. The affected and contralateral normal feet were divided into HV and normal groups. The hallux valgus angle (HVA), DMAA, the first and second intermetatarsal angle (IMA), first metatarsal rotation angle (MRA), Hardy score in weight-bearing anteroposterior radiographs of the foot, and Yildirim score in tangential radiographs of the sesamoid were measured in the two groups. Statistical analysis was conducted to investigate the difference in all radiographic parameters between the two groups and the correlation between DMAA, Hardy score, and Yildirim score. A total of 20 unilateral HV patients, including 1 man and 19 women (average age 53.35 ± 13.90, range 25–73), were enrolled in this study. The average HVA, DMAA, IMA, Hardy score, and Yildirim score in the HV group (n = 20) were 40.04 ± 8.96°, 29.40 ± 9.73°, 13.34 ± 2.73°, 5.5 ± 0.97, and 2.35 ± 0.65, respectively. The average HVA, DMAA, IMA, Hardy score, and Yildirim score in the normal group (n = 20) were 16.06 ± 2.70°, 16.13 ± 7.77°, 10.02 ± 2.14°, 3.4 ± 1.02, and 0.85 ± 0.73, respectively. There was a significant difference in DMAA between the two groups (P < 0.001). A significant positive correlation was observed between MRA and DMAA (r = 0.617, P = 0.004). However, no significant correlations were found between MRA and the Hardy score (r = 0.028, P = 0.908) or Yildirim score (r = 0.285, P = 0.223). M1 rotation is significantly correlated with DMAA in HV deformity, underscoring the importance of assessing rotational alignment in preoperative planning. Intraoperative correction of rotational deformity may be essential in cases of an inadequately corrected DMAA.

This study proposes a novel bio-inspired round auxetic metamaterial with tunable mechanical performance, designed for advanced protective applications. Inspired by the overlapping and rotational deformation mechanisms of fish scales, the structure exhibits pronounced negative Poisson’s ratio behavior, high stiffness, and enhanced energy absorption under compressive loading. Specimens were fabricated using digital light processing (DLP) and investigated through quasi-static compression experiments and validated Abaqus finite element simulations. A parametric study was conducted to evaluate the influence of unit-cell curvature radius and thickness on the mechanical response, including stiffness, buckling behavior, Poisson’s ratio, and energy absorption capacity. The numerical model showed excellent agreement with experimental results, with deviations below 5% in load–displacement response and buckling force. Results indicate that increasing the curvature radius enhances stiffness and buckling resistance by up to 6% while reducing Poisson’s ratio by nearly 50%. In contrast, increasing the unit-cell thickness by only 0.2[Formula: see text]mm leads to a substantial improvement in mechanical performance, raising the buckling force by approximately 70% and stiffness by about 45%, identifying thickness as the dominant design parameter. The combination of strong auxetic behavior, tunable stiffness, and high energy dissipation highlights the proposed metamaterial as a promising candidate for protective components such as blow hammer systems requiring controlled load transfer and mechanical durability.

Exercise prescription for Duchenne muscular dystrophy (DMD) is complicated by the susceptibility of unstable skeletal muscle to contraction-induced damage. Although evidence suggests that isometric contractions can confer molecular and physiological benefits to DMD muscle, their impact on viscoelastic properties has not been assessed invivo. Given that DMD is characterized by muscular instability due to the absence of dystrophin, we employed "myomechanical profiling"-a custom apparatus compatible with an MCR702e rheometer-to evaluate stiffness, compressibility, and elasticity of the tibialis anterior muscle of male mice following a bout of submaximal isometric fatiguing exercise. Fatigue was standardized to a 50% reduction in strength. Immediately after exercise, both dystrophin-positive (wildtype) and dystrophin-deficient (mdx) muscles exhibited reduced compressibility. Storage and loss moduli, reflecting stiffness and energy dissipation during rotational deformation, increased markedly in fatigued wildtype muscle but remained unchanged in mdx muscle. Conversely, elasticity was unaffected in wildtype muscle but shifted mdx muscle toward a more viscous state. These findings indicate that compressibility, stiffness, and energy storage capacity are not disproportionately affected in dystrophin-deficient muscle compared to wildtype muscle following fatiguing contractions. Thus, metabolically fatiguing, non-lengthening contractions appear not to compromise viscoelastic properties in dystrophin-deficient muscle, supporting their potential clinical use without exacerbating muscle instability.