Orthopedic Plate Research Articles

Anesthesia Management of a Child with Severe Pectus Excavatum Complicated with Heart Compression Displacement

We report the anesthesia management of a severe pectus excavatum with cardiac compression displacement under thoracoscopic correction with general anesthesia. Preoperative chest computed tomography showed that the lower end of the sternum was significantly depressed, and the distance between the depressed sternum and the spine was less than 2cm. The heart was obviously compressed and shifted to the left thoracic cavity. During the intraoperative reversal of the orthopedic plate, the blood flow velocity of the tricuspid valve increased to 87.9cm/s and showed a single peak. The transesophageal echocardiography indicated mild tricuspid valve regurgitant flow, and the blood pressure dropped rapidly. After the surgeon was informed of the situation, the orthopedic plate was quickly turned to the convex side up, and the locally depressed anterior chest wall was lifted up. Satisfactory correction of chest wall malformations.

Impact of Patient Body Posture on RF-Induced Energy Absorption by Orthopedic Plates

This study investigates variations in radiofrequency- (RF-) induced energy absorption by orthopedic plates within the human body during 1.5T and 3T magnetic resonance imaging (MRI) scans, considering diverse postures. Using the poseable Duke model, we developed typical postures (O-posture, X-posture, Y-posture, and Z-posture) and placed anatomically correct representations of various orthopedic plates within these postures. Numerical simulations were conducted to evaluate electromagnetic fields and RF-induced energy absorption in these postures near orthopedic plates during MRI scans. Comparing RF-induced energy absorption (peak spatial averaged SAR over 1 g, pSAR1g) in postured models to the original posture reveals substantial variations. The pSAR1g differences for X-posture, Y-posture, and Z-posture reach 48%, 134%, and 32% at 1.5T, and 36%, 83%, and 101% at 3T, respectively. Changing posture can lead to higher or lower pSAR1g. These findings underscore the impact of patient posture on RF-induced energy absorption in orthopedic plates on the ulna bone. The study recommends considering representative body postures in future evaluations for MR conditional labeling of passive implants. Until then, maintaining a neutral posture during MR scans is advised to mitigate unforeseen RF-induced heating risks.

Fatigue crack growth simulation by extended finite element method: A review of case studies

AbstractNumerical simulation of fatigue crack growth (FCG) is presented, based on the application of the extended finite element method (XFEM). Couple of case studies are presented, as a review of recent experience of the Belgrade school of XFEM simulations, established at the Faculty of Mechanical Engineering. Case studies comprised Charpy specimen with initial crack at the notch tip, oil rig pipe with an axial surface crack, pressure vessels with a crack at the welded joint with connecting pipe, turbine shaft with a crack at the transition radius, optimization of a wing spar in respect to FCG, the effect of mesh size on fatigue life estimation of a stringer panel, fatigue life estimation of wing‐to‐fuselage connecting lug, geometry effect on fatigue life of orthopedic plates and fatigue life of hip implant. Based on these case studies, XFEM is discussed in respect to its accuracy and efficiency. It is concluded that XFEM is a versatile tool for simulation of FCG, providing an excellent option for precise and reliable fatigue life of a cracked component.

Preliminary Results of Rib Osteosynthesis at the Teaching Hospital Sylvanus Olympio in Lomé

Introduction: Flaps and rib fractures can be life-threatening due to disruption of hematosis. In certain “many” situations, it is important to quickly restore parietal rigidity by costal osteosynthesis. The objective of our work is to report the surgical results of a first Togolese series of rib osteosynthesis performed in the context of chest trauma.Patients and methods: We proceed by a retrospective study on a series of patients treated for severe blunt chest trauma and who underwent osteosynthesis from 2020 to 2022. Epidemiological and clinical data, in particular the radiological lesion assessment clinic, the therapeutic measures as well as the immediate operative follow-up were collected.Results: six patients with blunt chest trauma. They were four men and two women whose mean age was 44.4 years. Five patients were admitted for polytrauma and one patient for a serious thoracic trauma. All were admitted to intensive care unit on day 0 of the trauma. The radioclinical assessment had noted staged fractures of ribs and/or thoracic flap with an average of six affected ribs. All the patients presented pleural effusions and benefited from pleural drainage on their admission to intensive care, often after a chest X-ray or after carrying out a chest CT scan or a whole-body CT scan. The indication for rib osteosynthesis was retained on the clinical criteria, in particular the existence of a pleural effusion, the instability of the wall and the impact on hematosis, by the drop in peripheral oxygen saturation (Sp02). Despite oxygen therapy above 6 l/min for more than 4 days, and according to the results of the chest CT scan and the evolution of the patient after the implementation of the means of resuscitation. The osteosynthesis material used was “third tube” orthopedic plates molded intraoperatively in three patients, pelvic plates in one patient. The average number of plates used was 4.5 and that of Vis was 18. Two patients underwent osteosynthesis by Judet staple.Conclusion: rib osteosynthesis contributes to a regression of symptoms, in particular chest pain, to reduce the duration of hospitalization, morbidity and mortality, and then improves the functional respiratory prognosis in the short and long term. Despite our reduced technical platform, the results are generally good, reducing the hospital stay in intensive care. This encourages the practice of surgical management of multiple rib fractures associated or not with a rib flap.

Biomechanical comparison of titanium alloy additively manufactured and conventionally manufactured plate-screw constructs

ABSTRACTAimTo biomechanically compare the bending stiffness, strength, and cyclic fatigue of titanium additively manufactured (AM) and conventionally manufactured (CM) limited contact plates (LCP) of equivalent dimensions using plate-screw constructs.MethodsTwenty-four 1.5/2.0-mm plate constructs (CM: n = 12; AM: n = 12) were placed under 4-point bending conditions. Data were collected during quasi-static single cycle to failure and cyclic fatigue testing until implants plastically deformed or failed. Bending stiffness, bending structural stiffness, and bending strength were determined from load–displacement curves. Fatigue life was determined as number of cycles to failure. Median test variables for each method were compared using the Wilcoxon rank sum test within each group. Fatigue data was also analysed by the Kaplan–Meier estimator of survival function.ResultsThere was no evidence for a difference in bending stiffness and bending structural stiffness between AM and CM constructs. However, AM constructs exhibited greater bending strength (median 3.07 (min 3.0, max 3.4) Nm) under quasi-static 4-point bending than the CM constructs (median 2.57 (min 2.5, max 2.6) Nm, p = 0.006). Number of cycles to failure under dynamic 4-point bending was higher for the CM constructs (median 164,272 (min 73,557, max 250,000) cycles) than the AM constructs (median 18,704 (min 14,427, max 33,228) cycles; p = 0.02). Survival analysis showed that 50% of AM plates failed by 18,842 cycles, while 50% CM plates failed by 78,543 cycles.Conclusion and clinical relevanceAdditively manufactured titanium implants, printed to replicate a conventional titanium orthopaedic plate, were more prone to failure in a shorter fatigue period despite being stronger in single cycle to failure. Patient-specific implants made using this process may be brittle and therefore not comparable to CM orthopaedic implants. Careful selection of their use on a case/patient-specific basis is recommended.

3D printed patient-specific fixation plates for the treatment of slipped capital femoral epiphysis: Topology optimization vs. conventional design

Orthopedic plates are commonly used after osteotomies for temporary fixation of bones. Patient-specific plates have recently emerged as a promising fixation device. However, it is unclear how various strategies used for the design of such plates perform in comparison with each other. Here, we compare the biomechanical performance of 3D printed patient-specific bone plates designed using conventional computer-aided design (CAD) techniques with those designed with the help of topology optimization (TO) algorithms, focusing on cases involving slipped capital femoral epiphysis (SCFE). We established a biomechanical testing protocol to experimentally assess the performance of the designed plates while measuring the full-field strain using digital image correlation. We also created an experimentally validated finite element model to analyze the performance of the plates under physiologically relevant loading conditions. The results indicated that the TO construct exhibited higher ultimate load and biomechanical performance as compared to the CAD construct, suggesting that TO is a viable approach for the design of such patient-specific bone plates. The TO plate also distributed stress more evenly over the screws, likely resulting in more durable constructs and improved anatomical conformity while reducing the risk of screw and plate failure during cyclic loading. Although differences existed between finite element analysis and experimental testing, this study demonstrated that finite element modelling can be used as a reliable method for evaluating and optimizing plates for SCFE patients. In addition to enhancing the mechanical performance of patient-specific fixation plates, the utilization of TO in plate design may also improve the surgical outcome and decrease the recovery time by reducing the plate and incision sizes.

Thermomechanical properties of coated PLA-3D-printed orthopedic plate with PCL/Akermanite nano-fibers: Experimental procedure and AI optimization

Nowadays, 3D printing has become a popular method among surgeons due to its merits in orthopedic treatments. In this method, polymeric biomaterials are deposited in a layer-by-layer manner to fabricate 3D objects that can be used as orthopedic implants and plates; however, 3D-printed implants or plates may lack properties required to bond with host tissue. Coating surface of plates with nano-fibers is an appropriate way to modify plates to overcome this challenge. In this study, first, an orthopedic plate was 3D printed with Polylactic acid (PLA) and coated with polycaprolactone (PCL)/Akermanite (AKT) nano-fibers. The composition included 8 wt% of PCL and 3 wt% of nAKT, while diameter of the PCL/AKT nano-fibers was approximately 253 nm ± 33 nm. Thermomechanical properties such as pressure, three-point bending flexural, and thermal conductivity of coated and non-coated specimens were examined and compared. In the next step, the bioactivity of the coated samples was evaluated following a 28-day immersion in simulated body fluid (SBF). Further, scanning electron microscope (SEM) images were taken to assess morphology of nanofibers and apatite formation on samples. By adding PCL to PLA, the maximum pressure force is enhanced by 16.83%. Further by adding nAKT to PLA + PCL sample, the maximum pressure force is enhanced by 4.72%. Further, by adding PCL to PLA, the maximum bending flexural force is enhanced by 21.06%. Further by adding nAKT to PLA + PCL sample, the maximum bending flexural force is enhanced by 21.39%. The results of this study are used to improve modeling of the orthopedic plates.

Quantification of Thread Engagement in Screw-Plate Interface of Polyaxial Locking System Using X-ray Computed Tomography.

This study demonstrates a new method for quantifying thread engagement in mechanical connections and verifies its applicability using biomedical implants under push-out tests. The focus is on orthopedic plate implants employed for bone fracture fixation, which, by design, allow off-axis screw insertion to accommodate different contact conditions. Thread engagement is crucial in determining connection strength and stability. In medical practice, off-axis screw placement is usually necessary due to bone geometries and implant plate rigidity. To address this, the study proposes a quantification method using non-destructive testing with X-ray micro-computed tomography and automated image processing, although tuning the image processing parameters is vital for accurate and reliable results. This enables detailed 3D models of screw-plate interfaces for precise thread engagement measurement. The results show that thread engagement decreases with both, increased off-axis insertion angles and higher torque during insertion. Correlation analysis reveals a strong relationship (R2 > 0.6) between average thread engagement and push-out strength, underscoring the importance of proper screw placement for stable fixation.

Ulnar fracture deriving from metastasis of a primary hepatoblastoma in a Thoroughbred weanling

SummaryAn 8‐month‐old Thoroughbred filly presented for surgical repair of a fracture of the right olecranon. Fixation of the fracture with an orthopaedic plate and screws was attempted, with complications of intraoperative haemorrhage and poor bone viability. The filly was euthanised 5 days after the repair, following a post‐operative secondary fracture. Primary hepatoblastoma of the liver with secondary metastasis of the right humerus, radius and ulna were diagnosed at necropsy. A history of ‘un‐thriftiness’ was later described by the farm manager.

Automated and data-driven plate computation for presurgical cleft lip and palate treatment

PurposePresurgical orthopedic plates are widely used for the treatment of cleft lip and palate, which is the most common craniofacial birth defect. For the traditional plate fabrication, an impression is taken under airway-endangering conditions, which recent digital alternatives overcome via intraoral scanners. However, these alternatives demand proficiency in 3D modeling software in addition to the generally required clinical knowledge of plate design.MethodsWe address these limitations with a data-driven and fully automated digital pipeline, endowed with a graphical user interface. The pipeline adopts a deep learning model to landmark raw intraoral scans of arbitrary mesh topology and orientation, which guides the nonrigid surface registration subsequently employed to segment the scans. The plates that are individually fit to these segmented scans are 3D-printable and offer optional customization.ResultsWith the distance to the alveolar ridges closely centered around the targeted 0.1 mm, our pipeline computes tightly fitting plates in less than 3 min. The plates were approved in 12 out of 12 cases by two cleft care professionals in a printed-model-based evaluation. Moreover, since the pipeline was implemented in clinical routine in two hospitals, 19 patients have been undergoing treatment utilizing our automated designs.ConclusionThe results demonstrate that our automated pipeline meets the high precision requirements of the medical setting employed in cleft lip and palate care while substantially reducing the design time and required clinical expertise, which could facilitate access to this presurgical treatment, especially in low-income countries.

Physical Analysis of Failed Orthopaedic Plates Used in Long Bone Fractures

Physical Analysis of Failed Orthopaedic Plates Used in Long Bone Fractures

A Point-of-Care Digital Workflow for 3D Printed Passive Presurgical Orthopedic Plates in Cleft Care.

Cleft lip and palate are one of the most common congenital craniofacial malformations. As an initial treatment, presurgical orthopedics is considered standard treatment at many cleft centers. Digital impressions are becoming feasible in cleft care. Computer-aided design (CAD) and three-dimensional (3D) printing are manufacturing standards in dentistry. The assimilation of these technologies has the potential to alter the traditional workflow for the fabrication of customized presurgical orthopedic plates. We present a digital workflow comprising three steps: 3D digital image acquisition with an intraoral scanner, open-source CAD modeling, and point-of-care 3D printing for the fabrication of personalized passive presurgical plates for newborns with cleft lip and palate. The digital workflow resulted in patient-related benefits, such as no risk of airway obstruction with quicker data acquisition (range 1–2.5 min). Throughput time was higher in the digital workflow 260–350 min compared to 135 min in the conventional workflow. The manual and personal intervention time was reduced from 135 min to 60 min. We show a clinically useful digital workflow for presurgical plates in cleft treatment. Once care providers overcome procurement costs, digital impressions, and point-of-care 3D printing will simplify these workflows and have the potential to become standard for cleft care.

Prefabricated Trays Stock for Impression of Cleft lip and Palate Orthopedic Appliances: A Three-Dimensional Computational Analysis of Maxillary Jaws.

This study aimed to propose digitally designed impression trays, for newborns with cleft lip and palate (CLP) defects, using the computer-assisted design and manufacturing (CAD/CAM) technique, based on measurements of width, length, and height made on processed and scanned plaster models. Thus, we will describe the different software and concepts that can be used for the design of these impression trays. A total of 59 plaster casts of newborn patients with CLP were collected and then scanned. After that, digital dental casts were three-dimensional (3D) evaluated, using precise anatomical landmarks. The Maxillofacial Prosthodontics Team at the Dental consultation and treatment center in Rabat, Morocco. The study involved plaster casts of newborns with CLP, who had undergone presurgical neonatal treatment in the Maxillofacial Prosthodontics service in Rabat, Morocco. None. 3D evaluation of 59 scanned plaster casts of newborn patients with CLP. This work allowed us to obtain digital impression trays for each anatomical variation of orofacial clefts. These trays will limit the problems linked to conventional techniques for making neonatal orthopedic plates. We also emphasized the importance of a multidisciplinary approach involving several professionals in Morocco from various fields and specialties. This original technique is advantageous for the practitioner as well as for the patients and their parents. It allows for precise recording, better adaptation, time-saving, and parental comfort.

Design and Analysis of Interpretation for Orthopedic Plate with Titanium Alloy

Abstract: The bone is considered as a linear-elastic, isotropic, and homogeneous materials. Trauma is a major cause of death and disability in both developed and developing nations. The mainly consider interpretation of accident after healing orthopaedic surgery plate replacement material design, evaluation, machining and optimization can be consider in this project. In this project setup is simply replacement method for three models of healing plate of single hole, four holes and six holes plate design in Solid Works. Evaluation process used in 3D finite element methods for a fractured bone with three models of titanium alloy plates is analysed using ANSYS workbench.

A Clinical Study on the Use of Supracondylar Plate in the Treatment of Distal Femoral Fractures in Dogs

Background: The current study was undertaken to evaluate the clinical efficacy of supracondylar plate for repair of distal femoral fractures in dog. The distal extremity of femur is the greatest weight bearing area, supracondylar plate is an orthopaedic plate system that is pre-contoured to the complex shape of the lateral surface of the canine distal femur. Methods: The study was conducted on six dogs presented with femur fracture to the Department of Surgery and Radiology, CVSc., Hyderabad over a period of 6 months (2020-21). Diagnosis based on the clinical signs, orthopaedic examination and radiography. Three fractures in right hind limb and three in the left limb. In dogs weighing less than 10 kg (N=3) were stabilized using 2.7 mm supracondylar plate while in dogs weighing more than 10 kg (N=3), 3.5 mm supracondylar plates were used. Right supracondylar plates of 2.7 mm were used in one dog while left supracondylar plates of 2.7 mm were used in two dogs. Similarly, right supracondylar plates of 3.5 mm were used in two dogs and left supracondylar plate of 3.5 mm in one dog. All the three right were 8 H while two left were 8 H and one was 6 holed. All the dogs showed partial weight bearing from 1st post-operative day. Lameness grading on pre-operatively showed grade V. Post-operatively, five dogs progressed to grade I lameness on 60th post-operative day and one dog to grade III lameness by the end of 60th post-operative day and later progressed to grade I by 120th post-operative day. The mean lameness pre-operatively and on 1st day, 15th day, 30th day, 60th day post- operatively were found to be 5.00±0.00, 4.00±0.00, 2.00±0.25, 1.66±0.33, 1.3±0.30 and 1.00±0.00 respectively. Radiographs obtained on the 60th post-operative day revealed dense callus of reduced size; fracture line barely visible with corticomedullary remodelling. The radiographs obtained on the 90th post-operative day clearly shows complete formation of bone with distinct cortex and medulla. Primary bone healing with minimal callus formation was recorded in case 5. Result: The supracondylar plate was successfully used in the treatment of distal femur fractures in dogs. Its configuration permitted early return to function of dogs affected with distal femur fractures.

Fatigue life assessment of orthopedic plates made of Ti6Al4V

This study is aimed to analyse fatigue life of orthopedic plates due to cracks initiated in the stress concentration areas. Material used for this analysis was typical orthopedic alloy, Ti-6Al-4V, strong but not very ductile, meaning also sensivite to cracking, as indicated by its mechanical properties, such as tensile strength, impact toughness and fracture toughness, as well as by high fatigue crack rate, all of them tested and analysed here. Extended finite element method (XFEM) in ANSYS software was used for simulating the fatigue crack growth in 5 orthopedic plates with different geometries. Results for crack length and stress intensity factor vs. number of cycles are given, indicating plate D as the best option regarding residual life. Crack paths are analysed in all 5 plates to explain such a behaviour, indicating benefits of initial crack growth into length, followed by growth into depth. Also, the effect of geometry of plates is considered to explain differences in life predictions for 5 different plates.

A Finite Element Investigation on the Design of Mechanically Compatible Functionally Graded Orthopaedic Plate for Diaphyseal Tibia Transverse Fracture

The bidirectional stiffness grading of orthopaedic plate has been investigated for internal fixation of transverse fracture in tibia bone. Highly porous cellular materials made of two types of cubic unit cells were designed. Their effective mechanical properties (elastic moduli and yield strengths) were computationally evaluated using finite element analysis. The Gibson-Ashby model was derived for elastic moduli and yield strengths of the cellular geometries. The modified cellular structure provided the desired minimum stiffness within the selected strut sizes. The developed structures were mapped to seven zones of the orthopaedic plate assigning the bidirectional stiffness grading (longitudinal direction). The effect of functional grading on mechanical stimulation through three stages of healing was studied. The results indicated less stress shielding and improvement in uniformity of distribution of equivalent stress around the newly formed bone. Thus, a functionally designed plate will offer a way to dynamically load the healing tissues by encouraging the patient for a regular walk and exercise. Hence, the generated mechanical signal will significantly help mechanically stimulated bone formation and remodeling in the fractured zone.

Numerical simulation of fatigue crack paths in orthopedic plates

This study is aimed to explain the behaviour of different orthopedic plate designs, under uniaxial bending, with cracks initiated in the stress concentration areas. Extended finite element method (XFEM) in ANSYS software was used for simulating the fatigue crack growth in 5 orthopedic plates with different geometries. Results for crack length vs, plate geometry indicated plate D as the best option regarding residual life. Crack paths are analysed in all 5 plates to explain such a behaviour, indicating benefits of initial crack growth into length, followed by growth into depth.

Measuring Orthopedic Plate Strain to Track Bone Healing Using a Fluidic Sensor Read via Plain Radiography.

We describe a fluidic X-ray visualized strain indicator under applied load (X-VISUAL) to quantify orthopedic plate strain and inform rehabilitative care. The sensor comprises a polymeric device with a fluidic reservoir filled with a radio-dense fluid (cesium acetate) and an adjoining capillary wherein the liquid level is measured. A stainless-steel lever attaches to the plate and presses upon the acrylic bulb with a displacement proportional to plate bending strain. The sensor was attached to a plate in a Sawbones composite tibia mimic and a human cadaveric tibia. An osteotomy model (5 mm gap) was used to simulate an unstable fracture, and allograft repair to simulate a stiffer healed fracture. The cadaveric and Sawbones tibia were cyclically loaded five times (0-400 N) using a mechanical test stand, and fluid displacement was measured from plain radiographs. The sensor displayed reversible and repeatable behavior with a slope of 0.096 mm/kg and fluid level noise of 50-80 micrometer (equivalent to 5-10 N). The allograft-repaired composite fracture was 13 times stiffer than the unstable fracture. An analysis of prior external fracture fixation studies and fatigue curves for internal plates indicates that the threshold for safe weight bearing should be 1/5th-1/10th of the initial bending for an unstable fracture. The precision of our device (<2% body weight) should thus be sufficient to track fracture healing from unstable through safe weight bearing. The X-VISUAL fluidic sensor enables orthopedic plate strain quantification to monitor facture healing via X-ray imaging.

The application of local rotating flap and latissimus dorsi flap in thoracic deformity correction.

Wound healing problem is one of the main complications after correction of chest wall deformity. Orthopedic flap tissue repair technique has a clear significance in non-healing wound and defect wound and provides a new choice for poor wound healing after orthopedic surgery of chest wall deformity. To investigate, the application value of modified local rotary flap and latissimus dorsi myocutcutaneous flap in the treatment of poor wound healing after orthodontic treatment of chest wall deformity. A retrospective analysis was performed on patients who admitted to our department from August 2012 to November 2019 due to non-healing incision after surgery for thoracic deformity. Skin flap was selected according to the size of the wound surface, and the effect of skin flap repair was observed. The clinical data of the included patients were recorded, and the preoperative and postoperative wound conditions were evaluated. This study included 13 patients with chest wall deformity who received plastic surgery tissue using flap technique for wound repair, 11 cases used modified local rotation skin flap, and 2 cases used modified latissimus dorsi myocutaneous flap. The mean age of the 13 patients was 18.54±4.14years old, the mean body mass index (BMI) was 17.02±2.16kg/m2 , and the mean preoperative nonunion time of the incision was 64.77±93.01days. Five patients had positive bacteria culture on the wound surface, including 3 cases of Staphylococcus aureus, 1 case of Pseudomonas aeruginosa, and 1 case of Staphylococcus epidermidis. All the 13 patients achieved primary grade A healing. The modified local rotary flap and latissimus dorsi musculocutaneous flap have a significant effect on the postoperative correction of chest wall deformity, which can ensure wound healing while retaining the orthopedic plate to the maximum extent to ensure the effect of the correction.