Search Results (307)

Background: Congenital talipes equinovarus (clubfoot) affects 1–2 per 1000 newborns worldwide. The Ponseti method, based on staged manipulations and casting, is the gold standard for correction. However, the biomechanical processes underlying these corrections remain poorly understood, as infants rarely undergo imaging. Computational modeling may offer a non-invasive approach to studying correction pathways and exploring novel applications, such as customized casts. Methods: We developed a proof-of-concept framework using iterative finite element analysis (iFEA) to approximate the surface-level geometric corrections targeted in Ponseti treatment. A 3D surface model of a training clubfoot foot was scanned, meshed, and deformed stepwise under applied computational loads. The model was assumed to be homogeneous and hyperelastic, and correction was quantified using Cavus, Adductus, Varus, Equinus, and Derotation angles. We also introduced a secondary adult leg 3D surface model to assess whether model simplification influences correction outcomes, by comparing a homogeneous soft tissue model with a non-homogeneous model incorporating bone structure. Results: In the training model, iFEA generated progressive deformations consistent with Ponseti correction, with mean angular deviations of ±3.2°. In the adult leg model, homogeneous and non-homogeneous versions produced comparable correction geometries, differing by <2° in outcomes. The homogeneous model required less computation, supporting its use for feasibility testing. Applied loads were computational drivers, not physiological forces. Conclusions: This feasibility study shows that iFEA can reproduce surface-level geometric changes consistent with Ponseti correction, independent of model homogeneity. While not replicating clinical biomechanics, this framework lays the groundwork for future work that incorporates clinician-applied forces, pediatric tissue properties, and patient-specific geometries, with potential applications in customized 3D-printed casts. Full article

When mechanically excavating deep-buried large-section metro stations, stringent deformation control requirements for the surrounding rock must be adhered to. Calculations indicate that horizontal convergence in certain areas of the station exceeds acceptable limits, necessitating adjustments to construction parameters to comply with these requirements. This study, based on a project for the Chongqing Metro Line 18, establishes a three-dimensional numerical analysis model for an underground excavation station by utilizing the characteristics of the stratum-structure model. A comprehensive 3D numerical simulation was conducted to evaluate the deformation characteristics of the stratum and surrounding rock resulting from excavation, and to determine optimal excavation parameters based on deformation control. The key findings are as follows: (1) Under the original excavation design parameters, the horizontal convergence displacement at the arch foot met specification requirements and was smaller than that at the sidewall. However, the horizontal convergence displacement at the sidewall exceeded the 20 mm limit specified by the relevant codes, failing to satisfy deformation control standards. (2) The deformation of the surrounding rock increased with factors such as the distance between the excavation face and the initial support, as well as the length of the excavation step. While the spacing between adjacent pilot tunnels had a relatively minor impact on overall station deformation, the number of pilot tunnels, in conjunction with other parameters, proved beneficial for controlling surrounding rock deformation. (3) Among the parameters examined, the distance between the excavation face and the initial support, along with the excavation step length, exerted the greatest influence on deformation. Based on deformation control criteria, the optimal excavation parameters were determined as follows: the distance between the excavation face and the initial support should not exceed 6 m; the excavation step length is set to 1.5 m; the number of pilot tunnels is established at 11; and the spacing between adjacent pilot tunnels is set at 10.5 m. (4) Field monitoring data closely corresponded with the effects observed from implementing the optimized parameters, thus validating the reliability of the optimization scheme. The results of this study provide a valuable reference for the excavation of metro stations under similar conditions in the future. Full article

Background: Cerebral palsy (CP) is a static, non-progressive brain pathology that affects mobility and musculoskeletal health. Objective: This review aims to describe the pediatric orthopedic management strategy at one specialty center with focus on optimal lifelong mobility function for ambulatory CP. Methods: Beginning in the 1990s, a protocol was developed to proactively monitor children with surgical or conservative interventions. After three decades, we undertook a prospective institutional review, board-approved 25–45-year-old adults callback study. Inclusion criteria were all children treated through childhood who could be located and were willing to return for a full evaluation. Results: Pediatric orthopedic interventions focused on regular surveillance with proactive treatment of progressive deformities. When function was impacted, we utilized multi-level orthopedic surgery guided by instrumented gait analysis. Childhood outcomes of this approach were evaluated through retrospective studies. Results show high correction rates were achieved for planovalgus foot deformity, knee flexion contracture, torsional malalignments, and stiff-knee gait. Our prospective adult callback study evaluated 136 adults with CP, gross motor function classification system levels I (21%), II (51%), III (22%), and IV (7%), with average ages of 16 ± 3 years (adolescent visit) compared with 29 ± 3 years (adult visit). Adults in the study had an average of 2.5 multi-level orthopedic surgery events and 10.4 surgical procedures. Compared with adults without disability, daily walking ability was lower in adults with CP. Adults with CP had limitations in physical function but no increased depression. A higher frequency of chronic pain compared with normal adults was present, but pain interference in daily life was not different. Adults demonstrated similar levels of education but higher rates of unemployment, caregiver needs, and utilization of Social Security disability insurance. Conclusions: The experience from our center suggests that consistent, proactive musculoskeletal management at regular intervals during childhood and adolescence may help maintain in gait and mobility function from adolescence to young adulthood in individuals with CP. Full article

Orthoses are a vital part of treating gait disorders, especially in children and adolescents with neurological and neuromuscular conditions. For proper walking, the supporting leg must be stable to allow the other leg to swing forward and take a step. Stability is also essential for motor development. This stability depends on the inclination of the tibia, which needs to be kept upright during mid-stance in both the sagittal and coronal planes. Controlling the load axis in all planes and the foot in the transverse plane helps maintain proper tibial control. More studies are now examining the effects different orthoses and designs. While much focus has been on the sagittal plane, there is much less information about how orthoses influence the coronal plane or foot control. As a result, there is limited guidance from the existing literature. Children who find it hard to express discomfort or negative effects may simply reject orthoses altogether. This paper explains how important proper tibia inclination and control on the load axis are in all planes and how they affect stability. The foot acts as a lever for the gastrosoleus muscle, which controls the tibia. In case of foot instability or deformity, the foot requires support that takes into account the changing load when walking. I also emphasize that these points are regularly considered when studies are reported. Full article

Background/Objectives: Commonly known as clubfoot, congenital talipes equinovarus (CTEV) is a structural deformity characterized by cavus, adductus, varus, and equinus (CAVE) positioning of the foot. Idiopathic clubfoot requires prompt treatment to achieve functional, pain-free, and aesthetically normal feet. The Ponseti method is a conservative treatment involving serial manipulation, casting, and Achilles tenotomy, which has demonstrated high success rates. The purpose of this study is to report 10 years of experience using the Ponseti method. Methods: A retrospective and follow-up analysis were conducted with 72 patients (118 feet) with idiopathic clubfoot were treated between 2011 and 2023 who met the minimum follow-up requirement of 12 months (mean follow-up: 54.15 months). The severity of deformities was assessed using the Pirani score. Data collection included demographic details, number of casts, tenotomy procedures, adherence to the Denis Browne brace protocol, and complications. Results: Initial correction of deformities was achieved in all 91 patients (100%). Outcomes were measured using the Ponseti functional scoring system. The average number of casts applied was 9.51 per patient. Percutaneous Achilles tenotomy was performed in 91.21% of cases. Relapse occurred in 22.2% of patients, which required additional treatments. The outcomes were excellent in 77.7% of cases, good in 13.88%, fair in 6.94%, and poor in 1.38%. Discussion: The Ponseti method is effective for idiopathic clubfoot treatment and achieves high rates of initial correction, favorable mid-term outcomes, and minimal complications. These results confirm its reliability and align with previously reported success rates. Full article

Osteochondroses of the foot represent a unique and less frequently discussed topic. This narrative review aims to provide a comprehensive overview of foot osteochondroses, highlighting their definition, pathophysiology, clinical features, diagnosis, and treatment. Historical sources, including early case reports, were included along with the current literature to picture the current knowledge on the subject. Anatomical mapping of pain locations and associated ossification centers was employed as a framework to present the various forms of foot osteochondroses. Multiple types of foot osteochondrosis were identified. The calcaneus, navicular and lesser metatarsal are among the more common involved bones. Most forms share a multifactorial etiology involving mechanical stress, vascular insufficiency, and delayed ossification. The pain is localized and common to all forms. Diagnosis relies on clinical assessment supported by radiographic and sometimes magnetic resonance imaging findings. During the acute phase, joint rest is essential. Despite the potential for spontaneous resolution, some cases can lead to structural deformities or persistent symptoms. Foot osteochondroses, although rare, require careful clinical evaluation due to their impact on pediatric patients. Increased awareness and standardized treatment approaches may improve early recognition and management, potentially reducing long-term sequelae. Full article

Taking the segmented utility tunnel crossing f5 ground fissures in Xi’an Xingfu forest belt as the research object, this paper investigates the acceleration response and the variation of displacement and stress of the segmented utility tunnel under the El-Centro seismic wave through 3D finite element simulation. The results show that under the orthogonal condition, the peak acceleration of foot wall soil is greater than that of hanging wall soil; conversely, under oblique loading, the hanging wall exhibits higher peak acceleration. In both loading conditions, the peak soil acceleration initially increases and then decreases with depth, while the amplification effect weakens as depth increases. Furthermore, the seismic response and deformation of the tunnel are more pronounced under oblique loading than under orthogonal loading. This study offers quantitative guidance for the seismic design of segmented utility tunnels crossing ground fissures. Full article

Background: Charcot–Marie–Tooth disease (CMT) is a genetically and phenotypically heterogeneous hereditary neuropathy. Axonal CMT type 2 (CMT2) subtypes often exhibit overlapping clinical features, which makes molecular genetic analysis essential for accurate diagnosis and subtype differentiation. Methods: This retrospective study included five pediatric patients who presented with gait disturbance, muscle weakness, and foot deformities and were subsequently diagnosed with axonal forms of CMT. Clinical data, electrophysiological studies, neuroimaging, and genetic analyses were evaluated. Whole exome sequencing (WES) was performed in three sporadic cases, while targeted CMT gene panel testing was used for two siblings. Variants were interpreted using ACMG guidelines, supported by public databases (ClinVar, HGMD, and VarSome), and confirmed by Sanger sequencing when available. Results: All had absent deep tendon reflexes and distal muscle weakness; three had intellectual disability. One patient was found to carry a novel homozygous frameshift variant (c.2568_2569del) in the IGHMBP2 gene, consistent with CMT2S. Other variants were identified in the NEFH (CMT2CC), DYNC1H1 (CMT2O), and MPV17 (CMT2EE) genes. Notably, a previously unreported co-occurrence of MPV17 mutation and congenital heart disease was observed in one case. Conclusions: This study expands the clinical and genetic spectrum of pediatric axonal CMT and highlights the role of early physical examination and molecular diagnostics in detecting rare variants. Identification of a novel IGHMBP2 variant and unique phenotypic associations provides new insights for future genotype–phenotype correlation studies. Full article

Background: Spring ligament (SL) injuries are primarily associated with progressive collapsing flatfoot deformity, but can also occur due to trauma. It remains unclear whether the morphological changes following trauma differ from those caused by chronic overload. The aim of this study was (1) to analyze whether a relationship exists between the injury pattern and foot deformity and (2) to evaluate whether there is a distinction between trauma-related and non-trauma-related injuries. Method: We prospectively enrolled 198 patients with a median age of 57 years (range, 13 to 86 years; female, 127 (64%); male, 71 (36%)) who had a clinically diagnosed, surgically confirmed, and classified SL injury. We used weight-bearing standard X-rays to assess foot deformity. The control group consisted of 30 patients (median age 51 years, range, 44–66; female, 21 (70.0%); male, 9 (30.0%)) with no foot deformities or prior foot surgeries. Results: A 41.9% incidence of trauma was identified as the cause of these injuries, accounting for 16 (20.8%) of isolated injuries to the SL, 30 (42.9%) of SL injury accompanied by a posterior tibial (PT) tendon avulsion, and 37 (72.5%) of SL injury alongside a bony avulsion at the navicular injuries. The odds of being post-traumatic decreased with each year of age by a factor of 0.97 (95% CI: 0.95–0.99). Conclusions: While all radiographic measurements for flatfoot deformity became pathological after an injury to the SL, they did not accurately predict the injury patterns of the SL and distal PT tendon. Generally, post-traumatic cases exhibited lower severity of foot deformity, suggesting that other structures beyond the SL may contribute to the development of flatfoot deformity. Full article

Hallux valgus is one of the common causes of forefoot pain in the field of foot and ankle surgery. This condition is characterized by valgus and pronation deformities of the first ray, leading to bunion pain, metatarsalgia, callus formation, and gait disturbances. Conventional open osteotomy of the first metatarsal and proximal phalanx of the first toe has been widely performed. Recently, with increasing reports of favorable radiologic and clinical outcomes of minimally invasive surgery, this technique has been performed by many surgeons. Despite the various surgical methods available, there is still no consensus on the optimal treatment of hallux valgus, and the advantages and disadvantages of open versus minimally invasive techniques remain a topic of debate. This narrative review aims to provide a comprehensive overview of the latest radiographic evaluation and surgical treatment for hallux valgus. Full article

Biopolymers, owing to their environmentally friendly and sustainable characteristics, have become a promising alternative for soil stabilization in geotechnical engineering. The application of protein-based biopolymers as binders for soil stabilization is less prevalent in geotechnical engineering compared to polysaccharide-based biopolymers. This study explores the potential of gelatin, a protein-based biopolymer derived from animal collagen, for stabilizing silty sand and improving its geotechnical properties. Gelatin was mixed into the soil at concentrations ranging from 0.25% to 2% of the dry weight of soil, and its effects on various soil characteristics were evaluated. The tests conducted include liquid limit, plastic limit, compaction behavior, and unconfined compressive strength (UCS); the addition of 1% gelatin led to an approximate 1.69 times increase in the strength of the unamended soil. After 28 days of curing, the UCS improved by approximately 5.03 times compared to the untreated soil, and the treated soil exhibited increased resistance to deformation under load. Microstructural analysis using scanning electron microscopy (SEM) revealed that gelatin facilitated the formation of a cohesive matrix, enhancing particle bonding and reducing void spaces within the soil. Carbon footprint analysis (CFA) conducted on an isolated footing stabilized with gelatin showed that the carbon emissions were reduced by 99.8% and 99% compared to traditional stabilizers such as lime and cement. Additionally, the interaction between the biopolymer and the fine-grained soil is distinctly evident in the FTIR and XRD analysis through hydrogen bonding and the formation of cementitious compounds. Full article

Background/Objectives: Subtalar arthroereisis (STA) is a widely used surgical procedure for symptomatic pediatric flexible flatfoot. However, implant migration remains a concern due to its potential impact on long-term correction and complications. This study evaluated the migration pattern of STA implants and assessed long-term clinical and radiographic outcomes. Methods: This retrospective cohort study included 47 feet from children aged 8–13 years who underwent STA with adjunctive soft tissue procedures between 2014 and 2018, following ≥6 months of failed conservative treatment, with a minimum follow-up of 5 years. Exclusion criteria included neuromuscular or rigid flatfoot. Weight-bearing radiographs assessed anteroposterior (AP) and lateral Meary’s angles, reflecting forefoot-to-hindfoot alignment, and calcaneal pitch, indicative of longitudinal arch height. Implant migration was recorded and clinical outcomes were measured by the American Orthopedic Foot and Ankle Society (AOFAS) score. Measurements were recorded preoperatively, immediately postoperatively, and at 1 month, 3 months, 6 months, 1 year, and 5 years. Results: Radiographic correction was significant and sustained at 5 years. The AP Meary’s angle improved from 13.09° to 5.26° at 1 month and 6.69° at 5 years (p < 0.001); lateral Meary’s angle from 9.77° to 4.06° and 4.88° (p < 0.001); and calcaneal pitch from 14.52° to 16.87° and 16.89° (p < 0.001), respectively. AOFAS scores increased from 67.52 to 90.86 at 1 month and 96.33 at 5 years (p < 0.001). Implant migration peaked within the first postoperative month (mean: 3.2 mm on ankle AP view; 3.0 mm on foot AP view) and stabilized thereafter. Four cases of complications included implant dislodgement, subsidence, and persistent sinus tarsi tenderness, which were successfully resolved after appropriate management. No recurrence of deformity was observed. Conclusions: STA implant migration is most pronounced during the first month, likely due to physiological settling as the foot adapts to altered biomechanics. With appropriate implant selection, technique, and follow-up, migration does not compromise long-term correction or outcomes. In general, symptomatic cases can often be managed conservatively prior to implant removal. Full article

Nowadays, Fused Filament Fabrication (FFF) 3D printing offers promising opportunities for the customized manufacturing of ankle–foot orthoses (AFOs) targeted towards rehabilitation purposes. Polypropylene (PP) represents an ideal candidate in orthotic applications due to its light weight and superior mechanical properties, offering an excellent balance between flexibility, chemical resistance, biocompatibility, and long-term durability. However, Additive Manufacturing (AM) of AFOs based on PP remains a major challenge due to its limited bed adhesion and high shrinkage, especially for making large parts such as AFOs. The primary innovation of the present study lies in the optimization of FFF 3D printing parameters for the fabrication of functional, patient-specific orthoses using PP, a material still underutilized in the AM of medical devices. Firstly, a thorough thermomechanical characterization was conducted, allowing the implementation of a (thermo-)elastic material model for the used PP filament. Thereafter, a Taguchi design of experiments (DOE) was established to study the influence of several printing parameters (extrusion temperature, printing speed, layer thickness, infill density, infill pattern, and part orientation) on the mechanical properties of 3D-printed specimens. Three-point bending tests were conducted to evaluate the strength and stiffness of the samples, while additional tensile tests were performed on the 3D-printed orthoses using a home-made innovative device to validate the optimal configurations. The results showed that the maximum flexural modulus of 3D-printed specimens was achieved when the printing speed was around 50 mm/s. The most significant parameter for mechanical performance and reduction in printing time was shown to be infill density, contributing 73.2% to maximum stress and 75.2% to Interlaminar Shear Strength (ILSS). Finally, the applicability of the finite element method (FEM) to simulate the FFF process-induced deflections, part distortion (warpage), and residual stresses in 3D-printed orthoses was investigated using a numerical simulation tool (Digimat-AM^®). The combination of Taguchi DOE with Digimat-AM for polypropylene AFOs highlighted that the 90° orientation appeared to be the most suitable configuration, as it minimizes deformation and von Mises stress, ensuring improved quality and robustness of the printed orthoses. The findings from this study contribute by providing a reliable method for printing PP parts with improved mechanical performance, thereby opening new opportunities for its use in medical-grade additive manufacturing. Full article

Background: Charcot-Marie-Tooth (CMT) disease is a hereditary motor and sensory neuropathy that affects foot morphology and gait patterns, potentially leading to abnormal plantar pressure distribution. This systematic review synthesizes the existing literature examining plantar pressure characteristics in CMT patients. Methods: A comprehensive search was conducted across PubMed, Scopus, and Web of Science databases. Risk of bias was assessed using the Newcastle–Ottawa Scale. Results: Six studies comprising 146 patients were included. Four studies employed dynamic baropodometry, and two used in-shoe pressure sensors to evaluate the main plantar pressure parameters. The findings were consistent across different populations and devices, with a characteristic plantar-pressure profile of marked midfoot off-loading with peripheral overload at the forefoot and rearfoot, often accompanied by a lateralized center-of-pressure path and a prolonged pressure–time exposure. These alterations reflect both structural deformities and impaired neuromuscular control. Interventional studies demonstrated a load redistribution of pressure after corrective surgery, though residual lateral overload often persists. Conclusions: Plantar pressure mapping seems to be a valuable tool to identify high-pressure zones of the foot in order to personalize orthotic treatment planning, to objectively monitor disease progression, and to evaluate therapeutic efficacy. Further longitudinal studies with standardized protocols are needed to confirm these results. Full article

Hallux valgus (HV) is described as a lateral deviation of the great toe at the first metatarsophalangeal joint (MTP), which is a very common foot deformity in the clinic. This deformity extends beyond localized foot mechanics to affect the entire lower extremity kinetic chain, potentially increasing dynamic instability during locomotion. This study aimed to characterize the kinematics of ankle and knee joints during walking in HV patients compared to controls. In total, 23 patients with bilateral HV and matched healthy controls were recruited. The 6-DOF kinematics data of ankles and knees were collected using a joint motion function analysis system while level walking at adaptive speed. HV patients demonstrated significant kinematic alterations in the ankle joint at IC, including decreased varus by 2.87° (p < 0.001), decreased internal rotation by 1.77° (p = 0.035), and decreased plantarflexion by 4.39° (p < 0.001) compared with healthy subjects. Concurrent compensatory changes in the knee joint included increased varus rotation by 1.41° (p = 0.023), reduced anterior translation by 0.84 mm (p < 0.001), and increased lateral translation by 0.26 mm (p = 0.036). HV patients showed increased ankle dorsiflexion of 3.61° (p = 0.06) and decreased ankle internal rotation of 2.69° (p = 0.043), with concurrent increased knee internal rotation of 2.59° (p = 0.009) at SPF. The ripple effect during walking in the HV population may elevate the risk of knee pathologies. These findings may inform both conservative management strategies and post-surgical rehabilitation regimens. Full article