Endoscopic-Assisted Forehead Augmentation with Polyetheretherketone (PEEK) Patient-Specific Implant (PSI) for Aesthetic Considerations.

BACKGROUND: Forehead augmentation have become popular aesthetic procedures among Asians in recent years. However, the use of polyetheretherketone (PEEK) patient-specific implant (PSI) in the facial contouring surgery for aesthetic considerations is not well documented in the existing studies. The purpose of this study was to develop a novel method for forehead augmentation and assess the clinical outcomes and complications in patients who underwent forehead augmentation with PEEK PSI assisted by endoscopy. METHODS: The PEEK PSIs were fabricated using the virtual surgical planning (VSP) and the computer-aided manufacturing (CAM) for each patient, preoperatively. The implant pockets were dissected in the subperiosteal plane, and PEEK PSIs were placed in their designed position and fixed assisting by endoscopy via small incision within the hairline. All patients were asked to complete the FACE-Q questionnaire before and 6 months after the operation. Pre- and postoperative demographics, photographs, and other clinical data of patients were collected and analyzed. RESULTS: 11 patients underwent forehead augmentation were enrolled in this study. All procedures were completed successfully with the help of endoscope. The average patient age was 30.63 ± 2.54 years. The mean thickness and size of PEEK PSI were 4.44 ± 1.77 mm and 38.43 ± 22.66 cm2, respectively. The mean operative time was 83.00 ± 29.44 min, and the mean postoperative follow-up period was 11.00 ± 6.50 months. No implant exposure, extrusion or removal were reported. The FACE-Q scores of patients in satisfaction with the forehead increased from 47.64 ± 7.15 to 78.81 ± 6.35. CONCLUSIONS: PEEK PSIs can be prefabricated to achieve accurate remodeling of the frontal contour with good esthetic outcomes. The endoscope provides direct and magnified vision, which allow easy access to the supraorbital rim and lateral edge of the eyebrow arch and confirming the position of the implants without damaging nerves and vessels. Endoscopic-assisted forehead augmentation with PEEK PSI is safe and effective. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of contents or the online Instructions to Authors www.springer.com/00266 .

Clinical and patient-reported outcome after patient-specific 3D printer-assisted cranioplasty.

Various cranioplasty techniques exist for the reconstruction of cranial bone defects. Patient-specific implants can be produced in-house using a recently developed 3D printer-assisted cranioplasty technique. However, the resulting cosmetic outcomes from the patient's perspective are underreported. With our case series, we aim to present the clinical outcome, morbidity rate, patient-reported cosmetic results, and cost-effectiveness of patient-specific3D printer-assisted cranioplasty technique. This is a consecutive retrospective case series of adult patients undergoing cranioplasty using the patient-specific 3D printer-assisted technique. As primary endpoint, the functional outcome based on modified Rankin scale (mRS) at discharge and follow-up was assessed. A prospective telephone survey was conducted to collect and provide patient-reported outcomes. Thirty-one patients underwent patient-specific 3D printer-assisted cranioplasty, mostly to reconstruct frontotemporoparietal (61.3%) and frontotemporal defects with orbital involvement (19.4%). Good functional outcome (mRS ≤ 2) at discharge and during the last follow-up was achieved in 54.8% (n = 17) and 58.1% (n = 18) patients. Overall, the rate of clinically relevant surgery-related complications was 35.5% (n = 11). Postoperative epidural hematoma/collection (16.1%) and infections (12.9%) were the most frequent complications. Permanent morbidity occurred in one patient (3.2%) with postoperative acute ipsilateral vision loss after frontotemporal cranioplasty with orbital involvement. No surgery-related mortality occurred. The mean patient-reported cosmetic satisfaction score was 7.8 ± 1.5, with 80% of patients reporting satisfying or very satisfying cosmetic results. No significant differences were seen between the different defect localization regarding the cosmetic outcome. The mean manufacturing costs of a patient-specific 3D printer-assisted implant ranged from 748 to 1129 USD. Based on our case series, patient-specific 3D printer-assisted cranioplasty is cost-effective and leads to satisfying cosmetic results, especially in large defects and/or defects with complex geometry.

Probing real-world Central European population midfacial skeleton symmetry for maxillofacial surgery.

OBJECTIVES: Symmetry is essential for computer-aided surgical (CAS) procedures in oral and maxillofacial surgery (OMFS). A critical step for successful CAS is mirroring the unaffected side to create a template for the virtual reconstruction of the injured anatomical structure. The aim was to identify specific anatomical landmarks of the midfacial skeleton, to evaluate the symmetry in a group of the real-world Central European population, and to use these landmarks to assess midfacial symmetry in CT scans. MATERIAL AND METHODS: The retrospective cross-sectional study defined landmarks of the midface's bony contour using viscerocranial CT data. The distances of the skeletal landmarks (e.g., the frontozygomatic suture and temporozygomatic suture) of the left and right sides from the midline were measured and statistically compared. Midfacial symmetry for reference points was defined as a difference within 0 mm and their mean difference plus one standard deviation. RESULTS: We examined a total of 101 CT scans. 75% of our population shows symmetrical proportions of the midface. The means of the differences for the left and right sides ranged from 0.8 to 1.3 mm, averaging 1.1 ± 0.2 mm for all skeletal landmarks. The standard deviations ranged from 0.6 to 1.4 mm, with a computed mean of 0.9 ± 0.3 mm. CONCLUSION: We established a methodology to assess the symmetry of the bony midface. If the determined differences were equal to or lower than 2.5 mm in the mentioned midfacial skeletal landmarks, then the symmetry of the bony midface was considered present, and symmetry-based methods for CAS procedures are applicable. CLINICAL RELEVANCE: Many CAS procedures require facial symmetry. We provide an easy-to-apply method to probe for symmetry of the midface. The method may be used for population-based research, to check for proper reduction of fractures after reposition or to screen for symmetry prior to CAS planning.

Three-Dimensionally Planned and Printed Patient-Tailored Plates for Corrective Osteotomies of the Distal Radius and Forearm.

PURPOSE: We evaluated the 1-year postoperative clinical and patient-reported outcomes in patients who had a 3-dimensional planned corrective osteotomy of their distal radius, radial shaft, or ulnar shaft using a printed, anatomical, patient-tailored plate to determine the feasibility and effectiveness of this methodology. METHODS: Simulations in computer-assisted preoperative planning of corrective osteotomies resulted in 3-dimensionally printed surgical guides, surgical models, and anatomically customized plates for application at the distal radius and forearm. Patients with malunions of the distal radius or forearm who underwent fixation with the custom-made plates were documented in our registry. Grip strength and range of motion assessments were made before surgery (baseline), as well as at 6 weeks and 3 and 12 months. Additionally, patients rated their wrist-related pain and disability using the Patient-Rated Wrist Evaluation. RESULTS: Fifteen patients underwent corrective surgery, and the 1-year follow-up data of 14 patients with a median age of 56 years (interquartile range, 24-64 years) were available for analysis. The median baseline Patient-Rated Wrist Evaluation score improved from 47 to 7 after 1 year. The flexion-extension arc of motion of the wrist increased from 90° at baseline to 130° at 1 year and the pronation-supination arc of motion of the wrist increased from 135° to 160° in the same time period. Differences in radiological measurements for palmar and radial inclinations, as well as for ulnar variance between the affected and contralateral wrists, were reduced with the osteotomy. In 1 case, the plate was removed 11 months after the osteotomy. No severe adverse events were reported. CONCLUSIONS: Three-dimensionally planned and printed patient-tailored plates offer a reliable method for correcting even complex malunions of the distal radius and forearm. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

One size may not fit all: patient-specific computational optimization of locking plates for improved proximal humerus fracture fixation.

BACKGROUND: Optimal treatment options for proximal humerus fractures (PHFs) are still debated because of persisting high fixation failure rates experienced with locking plates. Optimization of the implants and development of patient-specific designs may help improve the primary fixation stability of PHFs and reduce the rate of mechanical failures. Optimizing the screw orientations in locking plates has shown promising results; however, the potential benefit of subject-specific designs has not been explored yet. The purpose of this study was to evaluate by means of finite element (FE) analyses whether subject-specific optimization of the screw orientations in a fixed-angle locking plate can reduce the predicted cutout failure risk in unstable 3-part fractures. METHODS: FE models of 19 low-density proximal humeri were generated from high-resolution computed tomographic images using a previously developed and validated computational osteosynthesis framework. The specimens were virtually osteotomized to simulate unstable malreduced 3-part fractures and fixed with the PHILOS plates using 6 proximal locking screws. The average principal compressive strain in cylindrical bone regions around the screw tips-a biomechanically validated surrogate for the risk of cyclic screw cutout failure-was defined as the main outcome measure. The angles of the 6 proximal locking screws were optimized via parametric analysis for each humerus individually, resulting in subject-specific screw orientations (SSO). The average peri-implant strains of the SSO were statistically compared with the previously reported cohort-specific (CSO) and original PHILOS screw orientations (PSO) for females vs. males. RESULTS: The optimized SSO significantly reduced the peri-screw bone strain vs. CSO (6.8% ± 4.0%, P = .006) and PSO (25.24% ± 7.93%, P < .001), indicating lower cutout risk for subject-specific configurations. The benefits of SSO vs. PSO were significantly higher for women than men. CONCLUSION: The findings of this study suggest that subject-specific optimization of the locking screw orientations could lead to lower cutout risk and improved PHF fixation. These computer simulation results require biomechanical and clinical corroboration. Further studies are needed to evaluate whether the potential benefit in stability could justify the increased efforts related to implementation of individualized implants. Nevertheless, computational exploration of the biomechanical factors influencing the outcome of fracture fixations could help better understand the fixation failures and reduce their incidence.

A prospective study on outcome of patient-specific cones in revision knee arthroplasty.

BACKGROUND: Cones are known to be good substitutes for metaphyseal and diaphyseal bone loss during revision total knee arthroplasty (RTKA). Often the off-the-shelf cones do not fit to the individual patient's anatomy. New 3D-printing additive technologies allow to develop patient-specific cones. The aim of this prospective study was to describe their outcome. METHODS: From 2017 until 2020, 35 patient-specific titanium cones (15 femoral and 20 tibial) were implanted during 31 RTKAs (45% varus-valgus constrained implants and 55% rotating hinges). Clinical outcome was evaluated using KSS, WOMAC and FJS-12 scoring systems at 12 and 24 months. No patients were lost for follow-up. RESULTS: In all cases, there were no technical difficulties in adapting the cones to both the host bone and the revision implant. By the time of performing data analysis (January 2021), none of the 31 patients needed revision surgery for any reason. At 12 months of follow-up, the mean values of scores for knee function improved significantly from baseline (p < 0.01): KSS-103.00 (min 100-max 111, SD 5.35), WOMAC-16.5 (min 9-max 24, SD 6.45), FJS-12-61.60 (min 52-max 76, SD 9.20). At 24 months, the trend towards improvement of functional results continued but did not reached statistical significance comparing to 12 months: KSS was 105.92 (min 95-max 155, SD 16.18), WOMAC-14.07 (min 0-max 42, SD 12.42), FJS-12-83.78 (min 65-max 97, SD 09.64). Radiographic signs of osteointegration were detected within the first 6 month after surgery in all cases. Loosening of femoral or tibial components as well as peri-prosthetic infection was not observed in any of the patients during the follow-up. CONCLUSION: The original additive technology for designing and producing patient-specific metaphyseal and diaphyseal cones with different porosity zones for extensive femoral and tibial bone defects in RTKA is precise and clinically effective solution, at least in the short term. It could be a valid alternative to "off-the-shelf" cones or sleeves as well as structural allografts and even mega-prosthesis, but a longer follow-up period is required to assess its medium- and long-term reliability.

TOTAL MANDIBULAR DEFECT RECONSTRUCTION BY TOTAL TITANIUM PATIENT-SPECIFIC IMPLANT: CLINICAL EFFICACY AND LONG TERM FOLLOW UP. CLINICAL CASE.

The aim of this clinical case in demonstrating the possibility of replacing total defect of the mandible with a patient specific implant and the result of long-term follow up. Literature data on the replacement of total mandibular defects are extremely limited and they are presented by only several clinical cases where various surgical approaches were used. In the available literature, there are two approaches to solving this problem, including the replacement of the jaw with vascularised bone grafts, of which the fibula flap is the most promising, and the implantation of endoprostheses of the jaws, of which patient-specific anatomical endoprostheses made using additive technologies are the most advanced. The concept of using patient-specific endoprostheses of the whole mandible is considered revolutionary because it has a number of significant benefits, including the greatest accuracy in restoring the anatomical shape of the mandible. One of the unresolved problems associated with the installation of total mandibular endoprostheses is the prosthetic rehabilitation of patients using fixed structures. The analysis of the presented case can be a good tool for the clinician and bioengineer while making the final decision on the treatment method and modality in patients who need an identical option for the repair of a mandibular defect. Based on CT data, we can conclude that the employed approach, methodology of design and manufacture of patient-specific titanium mandibular endoprosthesis for the total defect demonstrated the sufficient efficacy, which suggest the need for further systematic studies to address this issue.

Computational analysis of customized cruciate retaining total knee arthroplasty restoration of native knee joint biomechanics.

The purpose of this study was to verify if customized prosthesis better preserves the native knee joint kinematics and provides lower contact stress on the polyethylene (PE) insert owing to the wider bone preservation than that of standard off-the-shelf prosthesis in posterior cruciate-retaining type total knee arthroplasty (TKA). Validated finite element (FE) models for were developed to evaluate the knee joint kinematics and contact stress on the PE insert after TKA with customized and standard off-the-shelf (OTS) prostheses as well as in normal healthy knee through FE analysis under dynamic loading conditions. The contact stresses on the customized prosthesis decreased by 18% and 8% under gait cycle loading conditions, and 24% and 9% under deep-knee-bend loading conditions, in the medial and lateral sides of the PE insert, respectively, compared with the standard OTS prosthesis. The anterior-posterior translation and internal-external (IE) rotation in customized TKA were more similar to native knee joint behaviors compared with standard OTS TKA under gait loading conditions. The difference from normal knee kinematics was lower for femoral rollback and IE rotation in customized TKA than in standard OTS TKA in the deep-knee-bend condition. In general, customized prostheses achieve kinematics that are close to those of the native healthy knee joint and have better contact stresses than standard OTS prostheses in gait and deep-knee-bend loading conditions.

Tibiofemoral conformity variation offers changed kinematics and wear performance of customized posterior-stabilized total knee arthroplasty.

PURPOSE: Posterior-stabilized (PS)-total knee arthroplasty (TKA) can be applied in any of several variations in terms of the tibiofemoral conformity and post-cam mechanism. However, previous studies have not evaluated the effect of the condylar surface radii (tibiofemoral conformity) on wear in a customized PS-TKA. The present study involved evaluating the wear performance with respect to three different conformities of the tibiofemoral articular surface in a customized PS-TKA by means of a computational simulation. METHODS: An adaptive computational simulation method was developed that conduct wear simulation for tibial insert to predict kinematics, weight loss due to wear, and wear contours to results. Wear predictions using computational simulation were performed for 5 million gait cycles with force-controlled inputs. Customized PS-TKA designs were developed and categorized as conventional conformity (CPS-TKA), medial pivot conformity (MPS-TKA), and anatomical conformity (APS-TKA). The post-cam design in the customized PS-TKA is identical. We compared the kinematics, contact mechanics, and wear performance. RESULTS: The findings revealed that APS-TKA exhibited the highest internal tibial rotation relative to other TKA designs. Additionally, the higher contact area led to there being less contact stress although it did not directly affect the wear performance. Specifically, MPS-TKA exhibited the lowest volumetric wear. CONCLUSIONS: The results of the present study showed that tibiofemoral articular surface conformity should be considered carefully in customized PS-TKA design. Different wear performances were observed with respect to different tibiofemoral conformities. Even though APS-TKA exhibited an inferior wear performance compared to MPS-TKA, it proved to be better in terms of kinematics so its functionality may be improved through the optimization of the tibiofemoral articular surface conformity. Additionally, it should be carefully designed since any changes may affect the post-cam mechanism.

[Reconstructive orbital surgery]. / Rekonstruktive Orbitachirurgie.

BACKGROUND: In complex orbital reconstructions ideal positioning of the bony buttress and surrounding soft tissue is a prerequisite for an aesthetic and functional result. The use of computer-assisted surgery can support the surgeon before and during the reconstruction procedure and facilitate quality control processes. This is illustrated using three clinical examples. MATERIAL AND METHODS: The areas of interest (bony defect areas, surrounding tissues) are segmented in a 3D image series. In most cases, the contralateral non-affected side can serve as the reference in virtual reconstruction. The virtual model obtained can now be used for the manufacturing of patient specific models and implants, as well as for intraoperative navigation or direct quality control with the use of intraoperative cone beam computed tomography (CBCT). RESULTS: For the reconstruction of primary and secondary traumatic defects as well as for congenital malformations or neoplastic diseases, the presented workflow can be used. Preoperative virtual visualization, patient specific reconstruction and direct quality control using intraoperative CBCT ensure that the preoperatively planned result can be achieved. Together with the interplay of hard and soft tissue the best possible results can be achieved. CONCLUSION: Computer-assisted surgery has been continuously further developed over the last two decades and is currently used in the clinical routine. Patient specific implants in combination with the use of direct intraoperative quality control facilitate the reconstruction of complex orbital injuries and defects and enable the ideal reconstruction from both aesthetic and functional aspects.

Digital import of orbital implants to enhance navigation in reconstruction of the deep orbit.

Stereotactic navigation has become established in orbital surgery. It can assist in exploration and reconstruction by preventing plate positioning errors and ensuring adequate restoration of deep orbital anatomy. Pre-formed and custom-made implants have become increasingly popular with reliable outcomes in complex orbital reconstructions, but may require adjustment at the time of surgery. Planning for reconstruction can be improved by import of digital models of implants into the navigation system. This technique allows on-table confirmation of successful orbital reconstruction.

Feasibility of augmented reality combine patient-specific implants (PSI) applied to navigation in mandibular genioplasty: A phantom experiment.

PURPOSE: Genitoplasty is becoming more and more common, and it is important to improve the accuracy of the procedure and simplify the procedure. This experiment explores the feasibility of using augmented reality (AR) technology combined with PSI titanium plates for navigational assistance in genioplasty performed on models, aiming to study the precision of such surgical interventions. METHODS: Twelve genioplasty procedures were designed and implemented on 3D-printed resin mandibular models by the same surgeon using three different approaches: AR+3DT group (AR+PSI) , 3DT group (patient-specific titanium plate) , and a traditional free-hand group(FH group). Postoperative models were assessed using CBCT to evaluate surgical accuracy. RESULTS: In terms of osteotomy accuracy, the AR group demonstrated a surgical error of 0.9440±0.5441 mm, significantly lower than the control group, which had an error of 1.685±0.8907 mm (P < 0.0001). In experiments positioning the distal segment of the chin, the overall centroid shift in the AR group was 0.3661±0.1360 mm, significantly less than the 2.304±0.9629 mm in the 3DT group and 1.562±0.9799 mm in the FH group (P < 0.0001). Regarding angular error, the AR+3DT group showed 2.825±1.373°, significantly <8.283±3.640° in the 3DT group and 7.234±5.241° in the FH group. CONCLUSION: AR navigation technology combined with PSI titanium plates demonstrates higher surgical accuracy compared to traditional methods and shows feasibility for use. Further validation through clinical trials is necessary.

Cleft lip and palate outcomes: Multidisciplinary approach for comprehensive management.

In patients with cleft lip and palate the most common associated dental problem is lateral incisor agenesis, often associated with lack of support and definition of the nasal tip. In many cases, adhesions deriving from surgical procedures and skeletal discrepancy make orthognathic surgery and rhinoseptoplasty unavoidable. In the present case report a dental rehabilitation with canine substitution and prosthetic-implant treatment in a posterior area is described. The use, during rhinoseptoplasty, of a customized titanium prosthesis, which provides projection for the tip of the nose, is also introduced. The patient was administered two questionnaires in order to assess the psychological aspects related to the cleft outcomes and the influence that the treatment conveyed.

A 3-Dimensional finite element analysis of patient-specific implant (with strut abutments) interface on stress concentration on the implant and surrounding bone in bilateral maxillary deformities.

Purpose: To determine the efficacy and longevity of patient-specific implants (PSIs) with strut abutment design to rehabilitate bilateral maxillectomy defect. Materials and Methods: Finite Element Analysis was performed on a PSI with strut abutments to repair a patient's bilateral maxillectomy defect due to COVID associated mucormycosis. Results: The von Mises stress recorded was maximum in the zygomaticomaxillary buttress region, and displacement values were noted to be highest in the posterior-most strut, although both parameters were within acceptable limits, which is favorable. Conclusion: The authors draw the conclusion that a PSI with strut abutments is a workable therapeutic modality for patients with these kinds of abnormalities based on this information.

Surgical management of a temporal meningoencephalocele with a patient-specific combined craniofossa prosthesis: illustrative case.

BACKGROUND: Meningoencephaloceles can originate through any defect in the cranial bones, including the skull base. They can be completely asymptomatic or present with typical symptoms such as headaches, seizures, or meningitis. OBSERVATIONS: The authors present the case of a 54-year-old female who presented with right-sided ear and temporomandibular joint (TMJ) pain. Computed tomography showed a large lytic lesion of the squamous part of the temporal bone with cortical bone destruction, extending to the mandibular fossa. Magnetic resonance imaging demonstrated a temporal bone meningoencephalocele. The patient underwent resection, dural repair, and multilayer reconstruction with a patient-specific three-dimensional-printed titanium combined craniofossa prosthesis. LESSONS: To the authors' knowledge, this is the first case report of TMJ pain associated with a temporal meningoencephalocele. The exact location and extension of the lesion determine the surgical approach and need for reconstruction in temporal bone meningoencephaloceles. In cases of destruction of the mandibular fossa, a patient-specific combined craniofossa prosthesis is recommended to reconstruct the bone defect. https://thejns.org/doi/10.3171/CASE24132.

Three-dimensional measurements of symmetry for the mandibular ramus.

BACKGROUND: The study examines a sample of patients presenting for viscerocranial computer tomography that does not display any apparent signs of asymmetry, assesses the three-dimensional congruency of the mandibular ramus, and focuses on differences in age and gender. METHODS: This cross-sectional cohort study screened viscerocranial CT data of patients without deformation or developmental anomalies. Segmentations were obtained from the left and right sides and superimposed according to the best-fit alignment. Comparisons were made to evaluate three-dimensional congruency and compared between subgroups according to age and gender. RESULTS: Two hundred and sixty-eight patients were screened, and one hundred patients met the inclusion criteria. There were no statistical differences between the left and right sides of the mandibular ramus. Also, there were no differences between the subgroups. The overall root mean square was 0.75 ± 0.15 mm, and the mean absolute distance from the mean was 0.54 ± 0.10 mm. CONCLUSION: The mean difference was less than one millimetre, far below the two-millimetre distance described in the literature that defines relative symmetry. Our study population displays a high degree of three-dimensional congruency. Our findings help to understand that there is sufficient three-dimensional congruency of the mandibular ramus, thus contributing to facilitating CAD-CAM-based procedures based on symmetry for this specific anatomic structure.

Accuracy and Sterilizability of In-House Printed Patient-Specific Aortic Model for Surgeon-Modified Stent Grafts-A Workflow Description for Emergency Aortic Endovascular Procedures.

Introduction: The use of 3D-printed aortic models for the creation of surgeon-modified endoprostheses represents a promising avenue in aortic surgery. By focusing on the potential impact of sterilization on model integrity and geometry, this report sheds light on the suitability of these models for creating customized endoprostheses. The study presented here aimed to investigate the safety and viability of 3D-printed aortic models in the context of sterilization processes and subsequent remodeling. Methods: The study involved the fabrication of 3D-printed aortic models using patient-specific imaging data and established additive manufacturing techniques. Five identical aortic models of the same patient were printed. Two models were subjected to sterilization and two to disinfection using commonly employed methods, and one model remained untreated. The models were checked by in-house quality control for deformation (heat map analyses) after the sterilization and disinfection processes. Three models (sterilized, disinfected, and untreated) were sent for ex-house (Lufthansa Technik, AG, Materials Technologies and Central Laboratory Services, Hamburg, Germany) evaluation and subsequent quantification of possible structural changes using advanced imaging and measurement technologies (macroscopic and SEM/EDX examinations). After sterilization and disinfection, each aortic model underwent sterility checks. Results: Based on macroscopic and SEM/EDX examinations, distinct evidence of material alterations attributed to a treatment process, such as a cleaning procedure, was not identified on the three implants. Comparative material analyses conducted via the EDX technique yield consistent results for all three implants. Disinfected and sterilized models tested negative for common pathogens. Conclusions: The evaluation of 3D-printed aortic models' safety after sterilization as well as their suitability for surgeon-modified endoprostheses is a critical step toward their clinical integration. By comprehensively assessing changes in model integrity and geometry after sterilization, this research has contributed to the broader understanding of the use of 3D-printed models for tailor-made endovascular solutions. As medical technologies continue to evolve, research endeavors such as this one can serve as a foundation for harnessing the full potential of 3D printing to advance patient-centered care in aortic surgery.

Reconstruction of the orbitozygomatic framework: State of the art and perspectives.

The reconstruction of the whole orbitozygomatic framework (OZF) is complex and can be encountered in cases of congenital midface deformity, after tumor ablative surgery and in severe facial trauma. Nowadays, surgeon has a wide range of available techniques that have continually grown over the past years, optimizing the surgical management and the aesthetical outcomes. Among them, the autologous bone graft (ABG) remains one of the most suitable options : ABG is easy to harvest and has optimal biological properties for bone healing. It can be tailored to the patient anatomy thanks to the recent advances in computer-assisted surgery. However, substantial drawbacks remain such as the early resorption of the non-vascularized graft, the need of a donor site and its potential morbidity. Alloplastic reconstruction is another option that can resolve both the resorption issue and the donor site morbidity. Moreover, the 3D-printing technologies also allows the manufacturing of patient specific implants. However, alloplastic materials have a variable success, especially due to the high risk of infection or exposure. Consequently, regenerative medicine is a promising field that aims to find a procedure without the disadvantages of ABG or alloplastic based reconstructions, but displaying similar or even higher success rate. Indeed, recent tissue engineering strategies have demonstrated encouraging results for bone regeneration using natural or synthetic biomaterials, patient cells and synthetic bioactive substances. The objective of this review is to present the etiologies of OZF defect, the available reconstruction procedures as well as the current state of the research.

Cranio-Maxillo-Facial Reconstruction with Polyetheretherketone Patient-Specific Implants: Aesthetic and Functional Outcomes.

BACKGROUND: Reconstructing cranio-maxillo-facial defects presents significant challenges. This study evaluates the results of polyetheretherketone patient-specific implants (PEEK PSIs) in primary and secondary cranio-maxillo-facial reconstructions, with a focus on aesthetic and functional outcomes and long-term complications. METHODS: From October 2009 to February 2023, 45 patients underwent cranio-maxillo-facial reconstructions with PSIs. Patients aged 18 years or older, with a minimum follow-up period of 12 months, were included. The morpho-functional outcome was evaluated through a modified Katsuragy Scale, the Visual Analogue Scale (VAS) for pain, and four FACE-Q|Aesthetics© scales. RESULTS: In total, 44 PSIs were placed in 37 patients (51.3% males; mean age 45.1 years). The main cause of the defect was the resection of a tumor (55.4%). Mean follow-up was 78.6 months. Clinical evaluations showed an improvement in the postoperative period both in patient's and surgeon's scores (p: 0.01 and p: 0.002, respectively). Subgroup analysis confirmed a significant improvement in patients undergoing cranioplasty (p = 0.02) and mandible reconstruction (p = 0.03). No cases of prosthesis dislocation, rupture, or long-term infection were recorded. CONCLUSIONS: PEEK PSIs offer significant advantages in craniofacial reconstructions. Despite challenges in predicting soft tissue adaptation, overall patient satisfaction was high with no long-term complications. Future improvements should focus on predicting and enhancing soft tissue adaptations.

PSI: Planner-specific, physician-specific, or patient-specific implant for orbital reconstruction?

This study aimed to identify and quantify the variations in PSI designs intended for an identical patient. Records from 10 patients with an orbital fracture involving two walls, for which a primary orbital reconstruction was indicated, were retrospectively included. Clinical engineers from two centers independently generated proposal designs for all patients. Following web meeting(s) with the surgeon from the same institute, the PSI designs were finalized by the engineer. A cross-over of the engineer with the surgeon of the other center created two new design teams. In total, 20 proposal and 40 final PSI designs were produced. A three-dimensional comparison between different PSI designs for the same patient was performed by computing a difference score. Initially, the design proposals of the two engineers showed a median difference score of 37%, which was significantly reduced to a median difference score of 26% for the final designs with different engineers. The median difference score of 22% between surgeons demonstrated that both parties introduced notable user variations to the final designs. Evidence supporting the advantages of an experienced design team was found, with significantly fewer modifications, fewer meetings, and less time required to complete the design (up to 40% time reduction). The findings of the study underline the dependency of PSI design on the surgeon and engineer, and support the need for a more evidence-based protocol for PSI design.