3D printing and its applications in orthopaedic trauma: A technological marvel

Impact of introducing 3D printing-assisted surgery into clinical practice for traumatic pelvic and acetabular fractures

Background

Given the novelty of three-dimensional (3D) printing-assisted fracture surgery in orthopaedics, surgeon familiarity is limited and learning curve is high. As such, it is unclear how the introduction of 3D printing into clinical practice for pelvic and acetabular fracture surgery would impact perioperative outcomes. The aim of this study was to determine the impact of introducing 3D printing-assisted surgery on perioperative outcomes for traumatic pelvic and acetabular fractures.

Methods

We retrospectively identified consecutive patients who underwent surgical fixation of traumatic pelvic and acetabular fractures from 2018 to 2022 at a single tertiary hospital. The patients included in the study were divided into two groups: (1) 3D printing-assisted surgery and (2) conventional surgery. Baseline demographics and perioperative outcomes of total surgical duration, estimated blood loss, blood transfusion, number fluoroscopy images, fluoroscopy duration and postoperative disposition were recorded and compared between the two groups.

Results

In total, 26 patients were included in the present study, with 3D printing-assisted surgery being used in 34.6 % (n = 9) of cases. There were no significant differences in baseline demographics or fracture type between the 3D printing group and conventional group. As compared to patients who underwent conventional surgery, those that underwent 3D printing-assisted surgery had, on average, shorter surgical duration (299.8 ± 88.2 vs 309.1 ± 143.1 min), lesser estimated blood loss (706.3 ± 330.0 vs 800.0 ± 584.2 ml), lower transfusion rates (50.0 % vs 52.9 %), lower number of intraoperative fluoroscopy images (62.8 ± 74.5 vs 71.6 ± 47.9 images) and shorter fluoroscopy duration (235.0 ± 79.2 vs 242.3 ± 83.5 min), although statistical significance was not achieved. None of the patients in the present study developed surgical complications postoperatively.

Conclusion

The introduction of 3D printing-assisted surgery in clinical practice for pelvic and acetabular fractures is a safe and viable adjunct in pelvic and acetabular surgery, achieving comparable perioperative outcomes in the initial phase.

3D PRINTING IN COMPLEX TIBIAL FRACTURE CLASSIFICATION & PLANNING

Objective

Tibial plateau fractures are common intra-articular fractures that pose classification and treatment challenges for orthopedic surgeons.

Objective

This study examines the value of 3D printing for classifying and planning surgery for complex tibial plateau fractures.

Methods

We reviewed 54 complex tibial plateau fractures treated at our hospital from January 2017 to January 2019. Patients underwent preoperative spiral CT scans, with DICOM data processed using Mimics software. 3D printing technology created accurate 1:1 scale models of the fractures. These models helped subdivide the fractures into seven types based on the tibial plateau's geometric planes. Surgical approaches and simulated operations, including fracture reduction and plate placement, were planned using these models.

Results

The 3D models accurately depicted the direction and extent of fracture displacement and plateau collapse. They facilitated the preoperative planning, allowing for precise reconstruction strategies and matching intraoperative details with the pre-printed models. Post-surgery, the anatomical structure of the tibial plateau was significantly improved in all 54 cases.

Conclusion

3D printing effectively aids in the classification and preoperative planning of complex tibial plateau fractures, enhancing surgical outcomes and anatomical restoration. Level of Evidence IV, Prospective Study.

Is still effective massive allograft reconstruction in parosteal osteosarcoma of the distal femur? Review of the literature and advantages of newer technologies

PURPOSE

Parosteal Osteosarcoma is a well-differentiated, low-grade bone sarcoma. It most commonly occurs in the third decade of life, usually in the distal femur. This study aims to perform a literature review about the types of reconstructions reported and to analyze the results of an updated technique of resection using custom-made 3D-printed cutting guides.

METHODS

We perform a systematic literature review about parosteal osteosarcoma, evaluating treatments, margins, local recurrence, complications, and functional results when available. We also report a case treated in our Center with a revisited technique introducing custom-made 3D-printed cutting guides.

RESULTS

We analyzed 12 studies with a total of 151 patients. The distal femur was the most frequently reported site (81.5%). After distal femur resection, reconstruction was performed with graft in most cases (48%), followed by prosthetic reconstruction (40%). Margins were wide in 85.5% of cases. The total incidence of local recurrence was 11%. Functional results were excellent in all cases, with a mean MSTS score of 86%. In our case, with the help of the jigs, the surgical technique was relatively easy, graft fusion excellent and fast, margins wide, and functional results excellent.

CONCLUSIONS

In the literature, the most commonly used type of reconstruction after resection is biological with graft. Indeed, despite the increasing number of prosthetic reconstructions, the historical diaphysometaphyseal hemiresection and graft is still indicated in parosteal osteosarcoma of the distal femur. New technologies, such as the jigs we used, allow significant advantages during the procedure: reduce the resection and graft preparation time, allow a better match between components, and help to obtain safer margins, sparing as much bone as possible.

Clinical Workflow Algorithm for Preoperative Planning, Reduction and Stabilization of Complex Acetabular Fractures with the Support of Three-Dimensional Technologies

Background: Treatment of pelvic injuries poses serious problems for surgeons due to the difficulties of the associated injuries. The objective of this research is to create a clinical workflow that integrates three-dimensional technologies in preoperative planning and performing surgery for the reduction and stabilization of associated acetabular fractures. Methods: The research methodology consisted of integrating the stages of virtual preoperative planning, physical preoperative planning, and performing the surgical intervention in a newly developed clinical workflow. The proposed model was validated in practice in a pilot surgical intervention. Results: On a complex pelvic injury case of a patient with an associated both-column acetabular fracture (AO/OTA-62C1g), we presented the results obtained in the six stages of the clinical workflow: acquisition of three-dimensional (3D) images, creation of the virtual model of the pelvis, creation of the physical model of the pelvis, preoperative physical simulation, orthopedic surgery, and imaging validation of the intervention. The life-size 3D model was fabricated based on computed tomography imagistics. To create the virtual model, the images were imported into Invesalius (version 3.1.1, CTI, Brazil), after which they were processed with MeshLab (version 2023.12, ISTI-CNR, Italy) and FreeCAD (version 0.21.2, LGPL, FSF, Boston, MA, USA). The physical model was printed in 21 h and 37 min using Ultimaker Cura software (version 5.7.2), on an Ultimaker 2+ printing machine through a Fused Deposition Modeling process. Using the physical model, osteosynthesis plate dimensions and fixation screw trajectories were tested to reduce the risk of neurovascular injury, after which they were adjusted and resterilized, which enhanced preoperative decision-making. Conclusions: The life-size physical model improved anatomical appreciation and preoperative planning, enabling accurate surgical simulation. The tools created demonstrated remarkable accuracy and cost-effectiveness that support the advancement and efficiency of clinical practice.

Functional outcome of 2-D- and 3-D-guided corrective forearm osteotomies: a systematic review

We performed a systematic review to compare conventional (2-D) versus 3-D-guided corrective osteotomies regarding intraoperative results, patient-reported outcome measures, range of motion, incidence of complications and pain score. PubMed (MEDLINE), Embase and Cochrane CENTRAL were searched, and 53 articles were included, reporting 1257 patients undergoing forearm corrective osteotomies between 2010 and 2022. 3-D-guided surgery resulted in a greater improvement in median Disabilities of the Arm, Shoulder and Hand (DASH) score (28, SD 7 vs. 35, SD 5) and fewer complications (12% vs. 6%). Pain scores and range of motion were similar between 3-D-guided and conventional surgery. 3-D-guided corrective osteotomy surgery appears to improve patient-reported outcomes and reduce complications compared to conventional methods. However, due to the limited number of comparative studies and the heterogeneity of the studies, a large randomized controlled trial is needed to draw definitive conclusions.Level of evidence: III.

Cylindrical depth image based customized helical bone plate design

Commercial straight metal plates have been generally used to fix fractured bones, but recently, the need for customized and helical metal plates has emerged. Customized metal plates are designed to fit the shape of the fracture area that is a 3D curved surface, making it more difficult than designing on a 2D plane. Helical plates are researched due to their advantage in avoiding blood vessel damage compared to commercially available straight metal plates. In this paper, we propose a novel algorithm to design a customized helical metal plate for the femur using cylindrical depth images and Boolean operations. We also present the results of 3D printing a metal plate designed using the proposed algorithm, and the shape matching is verified by calculating the minimum distance between the surface of the printed plate and the surface of the femur.

Impact of 3D printing on Orthopedic Surgery in India: Has the Technology Really Arrived!

Surgical innovations have driven advancements in patient care, leading to improved surgical results and decreased patient morbidity. The integration of new technical advancements in orthopedic surgery is linked to the clinical advantages, ethical challenges, financial factors, and its broader influence on the global health-care sector [1]. 3D printing in orthopedic surgery is a developing technique that is rapidly gaining recognition and positively impacting patient results. The widespread influence and usefulness of 3D printing in orthopedics have been confirmed through reports detailing its application in complex trauma, complex hip revision surgeries, and various other areas such as complex spine deformity for pedicle screw trajectory guides, 3D printed implants, and bio-scaffolds [2-5]. The amount of scientific literature on the use of 3D printing in orthopedics has significantly increased in the past decade, both internationally and in India [6]. However, it has this quickly rising trend in the field of orthopedic surgery “really arrived in India.”

Three-dimensional printed models for surgery planning of post-traumatic stiff elbow: Current concepts

The post-traumatic stiff elbow is a challenge for the surgeon, requiring expertise for the treatment choice and accurate planning. Stiffness can result from traumatic injury involving the periarticular soft tissues and the joint articular surfaces. In this article, we want to assess the impact of three-dimensional (3D) printed models in selecting the appropriate surgical strategy for this pathology. Six cases of increasing complexity regarding post-traumatic stiff elbow were submitted to four expert elbow surgeons who had the possibility to evaluate videos and reports of clinical examination, plain radiograms and CT with 3D reconstruction for each case. After a first treatment proposition given by the experts for each patient, a three-dimensional printed model of each elbow based on the CT was provided to the surgeons, asking them to evaluate again all the cases having the possibility to assess also the 3D models. In the four most complex cases all surgeons found more beneficial the use of three-dimensional representation for treatment planning and rate the risk of complications than the sole CT imaging with 3D reconstruction and many of them changed surgical strategy after analysing the model. 3D printing technology is a useful tool in surgery planning for treating complex cases of post traumatic elbow stiffness, especially in the presence of joint deformity. LEVEL OF EVIDENCE: IV.

3D-printed Multifunctional Guide Plate for Fenestration and Screws Drill in Proximal Femoral Benign Tumor

The accurate fenestration, screw implantation and assisting stabilizing-plate placement in surgery of benign tumors in the proximal femur needs be defined easily. The aim of this study was to investigate the value of 3D printed multifunctional guides plate (3D-MGP) based on computer aided design. Between January 2020 and June 2022, 17 patients (nine females and eight males) with benign proximal femoral tumor had lesion curettage and allograft combined with internal plate fixation using 3D-MGP. In this study, the patients had CT scans and a technician reconstructed the 3D images of tumor and the femur, a doctor designed the location and margin of the fenestration and screws, and integrated different functions into MGP for benign proximal femoral lesions, which assisted in precise localization, fenestration and screw drilling. Musculoskeletal Tumor Society (MSTS) scoring was used to evaluate lower extremity function. Bone healing and the screws location was assessed with the radiographs. All patients underwent successful surgery with complete resection of the tumor and internal fixation with using the 3D-MGP. The mean follow-up was 16.4 months. The operative time was 126.47 ± 18.44 min, intraoperative bleeding was 198.23 ± 67.94 mL, intraoperative fluoroscopy was 6.47 ± 0.62, postoperative drainage was 223.82 ± 119.51 mL, and MSTS score was 27.29 ± 1.31 points. There were no unplanned fenestration and improper screw fixation. The 3D-MGP enabled personalized and accurate location of tumor, fenestration, screw placement and assisted stabilizing-plate placement for the treatment of benign tumor of the proximal femur. This technique has the potential to shorten operative times, decrease intraoperative bleeding, and reduce radiation exposure to patients.

Flatfoot arch correction with generic 3D-printed orthoses at different body weight percentages

BACKGROUND

Flatfoot can be associated with foot pathologies and treated conservatively with foot orthoses to correct arch collapse and alleviate painful symptoms. Recently, 3D printing has become more popular and is widely used for medical device manufacturing, such as orthoses. This study aims at quantifying the effect of generic 3D-printed foot orthoses on flatfoot arch correction under different static loading conditions.

METHODS

Participants with normal and flatfeet were recruited for this cross-sectional study. Clinical evaluation included arch height, foot posture index, and Beighton flexibility score. Surface imaging was performed in different loading conditions: 1) 0% when sitting, 2) 50% when standing on both feet, and 3) 125% when standing on one foot with a weighted vest. For flatfoot participants, three configurations were tested: without an orthosis, with a soft generic 3D printed orthosis, and with a rigid 3D printed orthosis. Arch heights and medial arch angles were calculated and compared for the different loading conditions and with or without orthoses. The differences between groups, with and without orthoses, were analyzed with Kruskal-Wallis tests, and a p < 0.05 was considered significant.

RESULTS

A total of 10 normal feet and 10 flatfeet were analyzed. The 3D printed orthosis significantly increased arch height in all loading conditions, compared to flatfeet without orthosis. Wearing an orthosis reduced the medial arch angle, although not significantly. Our technique was found to have good to excellent intra and interclass correlation coefficients.

CONCLUSIONS

Generic 3D printed orthoses corrected arch collapse in static loading conditions, including 125% body weight to simulate functional tasks like walking. Our protocol was found to be reliable and easier to implement in a clinical setting compared to previously reported methods.

LEVEL OF EVIDENCE

II.

3D bioprinting: a review and potential applications for Mohs micrographic surgery

Mohs Micrographic Surgery (MMS) is effective for treating common cutaneous malignancies, but complex repairs may often present challenges for reconstruction. This paper explores the potential of three-dimensional (3D) bioprinting in MMS, offering superior outcomes compared to traditional methods. 3D printing technologies show promise in advancing skin regeneration and refining surgical techniques in dermatologic surgery. A PubMed search was conducted using the following keywords: "Three-dimensional bioprinting" OR "3-D printing" AND "Mohs" OR "Mohs surgery" OR "Surgery." Peer-reviewed English articles discussing medical applications of 3D bioprinting were included, while non-peer-reviewed and non-English articles were excluded. Patients using 3D MMS models had lower anxiety scores (3.00 to 1.7, p < 0.0001) and higher knowledge assessment scores (5.59 or 93.25% correct responses), indicating better understanding of their procedure. Surgical residents using 3D models demonstrated improved proficiency in flap reconstructions (p = 0.002) and knowledge assessment (p = 0.001). Additionally, 3D printing offers personalized patient care through tailored surgical guides and anatomical models, reducing intraoperative time while enhancing surgical. Concurrently, efforts in tissue engineering and regenerative medicine are being explored as potential alternatives to address organ donor shortages, eliminating autografting needs. However, challenges like limited training and technological constraints persist. Integrating optical coherence tomography with 3D bioprinting may expedite grafting, but challenges remain in pre-printing grafts for complex cases. Regulatory and ethical considerations are paramount for patient safety, and further research is needed to understand long-term effects and cost-effectiveness. While promising, significant advancements are necessary for full utilization in MMS.

3D Printing for the Development of Palatal Defect Prosthetics

Background

Three-dimensional (3D) printing has emerged as a promising new technology for the development of surgical prosthetics. Research in orthopedic surgery has demonstrated that using 3D printed customized prosthetics results in more precise implant placements and better patient outcomes. However, there has been little research on implementing customized 3D printed prosthetics in otolaryngology. The program sought to determine whether computed tomography (CT) serves as feasible templates to construct 3D printed palatal obturator prosthetics for defects in patients who have been treated for head and neck cancers.

Observations

A retrospective review of patients with palatal defects was conducted and identified 1 patient with high quality CTs compatible with 3D modeling. CTs of the patient's craniofacial anatomy were used to develop a 3D model and a Formlabs 3B+ printer printed the palatal prosthetic. We successfully developed and produced an individualized prosthetic using CTs from a veteran with head and neck deformities caused by cancer treatment who was previously treated at the Veterans Affairs Palo Alto Health Care System. This project was successful in printing patient-specific implants using CT reproductions of the patient's craniofacial anatomy, particularly of the palate. The program was a proof of concept and the implant we created was not used on the patient.

Conclusions

Customized 3D printed implants may allow otolaryngologists to enhance the performance and efficiency of surgeries and better rehabilitate and reconstruct craniofacial deformities to restore appearance and function to patients. Additional research will strive to enhance the therapeutic potential of these prosthetics to serve as low-cost, patient-specific implants.

Ex vivo comparison of pin placement with patient-specific drill guides or freehand technique in canine cadaveric spines

OBJECTIVE

To compare vertebral implant placement in the canine thoracolumbar spine between 3D-printed patient-specific drill guides (3DPG) and the conventional freehand technique (FH).

STUDY DESIGN

Ex vivo study.

ANIMALS

Cadaveric canine spines (n = 24).

METHODS

Implant trajectories were established for the left and right sides of the T10 through L6 vertebrae based on computed tomography (CT) imaging. Customized drill guides were created for each vertebra of interest. Each cadaver was randomly assigned to one of six veterinarians with varying levels of experience placing vertebral implants. Vertebrae were randomly assigned a surgical order and technique (3DPG or FH) for both sides. Postoperative CT images were acquired. A single, blinded observer assessed pin placement using a modified Zdichavsky classification.

RESULTS

A total of 480 implants were placed in 240 vertebrae. Three sites were excluded from the analysis; therefore, a total of 238 implants were evaluated using the FH technique and 239 implants using 3DPG. When evaluating implant placement, 152/239 (63.6%) of 3DPG implants were considered to have an acceptable placement in comparison with 115/248 (48.32%) with FH. Overall, pin placement using 3DPG was more likely to provide acceptable pin placement (p < .001) in comparison with the FH technique for surgeons at all levels of experience.

CONCLUSION

The use of 3DPG was shown to be better than the conventional freehand technique regarding acceptable placement of implants in the thoracolumbar spine of canine cadavers.

CLINICAL SIGNIFICANCE

Utilizing 3DPG can be considered better than the traditional FH technique when placing implants in the canine thoracolumbar spine.

3D surgical planning including patient-specific drilling guides for tibial plateau fractures

Aims

Proper preoperative planning benefits fracture reduction, fixation, and stability in tibial plateau fracture surgery. We developed and clinically implemented a novel workflow for 3D surgical planning including patient-specific drilling guides in tibial plateau fracture surgery.

Methods

A prospective feasibility study was performed in which consecutive tibial plateau fracture patients were treated with 3D surgical planning, including patient-specific drilling guides applied to standard off-the-shelf plates. A postoperative CT scan was obtained to assess whether the screw directions, screw lengths, and plate position were performed according the preoperative planning. Quality of the fracture reduction was assessed by measuring residual intra-articular incongruence (maximum gap and step-off) and compared to a historical matched control group.

Results

A total of 15 patients were treated with 3D surgical planning in which 83 screws were placed by using drilling guides. The median deviation of the achieved screw trajectory from the planned trajectory was 3.4° (interquartile range (IQR) 2.5 to 5.4) and the difference in entry points (i.e. plate position) was 3.0 mm (IQR 2.0 to 5.5) compared to the 3D preoperative planning. The length of 72 screws (86.7%) were according to the planning. Compared to the historical cohort, 3D-guided surgery showed an improved surgical reduction in terms of median gap (3.1 vs 4.7 mm; p = 0.126) and step-off (2.9 vs 4.0 mm; p = 0.026).

Conclusion

The use of 3D surgical planning including drilling guides was feasible, and facilitated accurate screw directions, screw lengths, and plate positioning. Moreover, the personalized approach improved fracture reduction as compared to a historical cohort.

Optimizing 3D-printed workpieces for radiotherapy application: modelling the CT number and print time

This study aims to analyze the influence of specific printing parameters, including infilling, print speed, and layer height, on the CT numbers and printing time of 3D-printed workpieces fabricated from Polylactic Acid (PLA). The primary objective is to optimize these parameters to attain desired CT numbers and print time for radiotherapy applications. To achieve this objective, we employed the Taguchi experimental design and regression analysis methodologies. A series of experiments were conducted to systematically assess the effects of varying infilling, print speed, and layer height values on the CT numbers and printing time of the PLA workpieces. The resulting data were then used to create mathematical models for predicting optimal parameter settings. Our investigations revealed that specific adjustments to infilling and layer height significantly influence the CT numbers and printing time of 3D-printed workpieces. By leveraging the developed mathematical models, precise predictions can be made to optimize independent parameters for the desired CT numbers and printing times, enhancing the efficacy of 3D-printed workpieces for radiotherapy applications. This research contributes to the advancement of 3D-printed workpieces utilized in radiotherapy, offering a pathway to enhance the accuracy and efficiency of treatment delivery. The optimization of printing parameters outlined in this study provides a valuable tool for clinicians and researchers in the field, ultimately benefiting patients undergoing radiotherapy treatments.

Three-dimensional printed exoskeletons and orthoses for the upper limb-A systematic review

This systematic review aims to assess and summarize the current landscape in exoskeletons and orthotic solutions developed for upper limb medical assistance, which are partly or fully produced using 3-dimensional printing technologies and contain at least the elbow or the shoulder joints. The initial search was conducted on Web of Science, PubMed, and IEEEXplore, resulting in 92 papers, which were reduced to 72 after removal of duplicates. From the application of the inclusion and exclusion criteria and selection questionnaire, 33 papers were included in the review, being divided according to the analyzed joints. The analysis of the selected papers allowed for the identification of different solutions that vary in terms of their target application, actuation type, 3-dimensional printing techniques, and material selection, among others. The results show that there has been far more research on the elbow joint than on the shoulder joint, which can be explained by the relative complexity of the latter. Moreover, the findings of this study also indicate that there is still a gap between the research conducted on these devices and their practical use in real-world conditions. Based on current trends, it is anticipated that the future of 3-dimensional printed exoskeletons will revolve around the use of flexible and high-performance materials, coupled with actuated devices. These advances have the potential to replace the conventional fabrication methods of exoskeletons with technologies based on additive manufacturing.

Advanced Preoperative Planning Techniques in the Management of Complex Proximal Humerus Fractures

This review evaluates the current literature on the recent advances of preoperative planning in the management of complex proximal humerus fractures (PHF). PHFs can pose a considerable challenge for orthopaedic surgeons due to their diversity in presentation and complexity. Poor preoperative planning can lead to prolonged operations, increased blood loss, higher risk of complications, and increased stress on the surgical team. Recent advances have seen the evolution of preoperative planning from conventional methods to computer-assisted virtual surgical technology (CAVST) and three-dimensional (3D) printing, which have been highlighted as transformative tools for improving preoperative planning and postoperative outcomes. CAVST allows the creation of 3D renderings of patient-specific anatomy, clearly demonstrating fracture patterns and facilitating detailed planning for arthroplasty or surgical fixation. The early studies show promising outcomes however the literature calls for more high-quality randomised controlled trials. Using 3D printing for high-fidelity simulation involving patient-specific physical models offers an immersive experience for surgical planning. Preoperative planning with 3D printing reduces operative time, blood loss and use of fluoroscopy. The technology's potential to produce customisable surgical implants further improves its versatility. There is a need for a cost analysis for the use of these technologies within the orthopaedic field, particularly considering the high expense of 3D printing materials and extended hospital stays until the printed models are available. CAVST and 3D printing also show promising applications within high-fidelity simulation surgical training, with CAVST offering possibilities in virtual reality and haptic-enhanced simulations and 3D printing providing physical models for trainee surgeons to hone their skills. Moving forward, a reduction in the cost of 3D printing and the advancement of CAVST using artificial intelligence would lead to future improvement. In conclusion, preoperative planning supported by these innovative technologies will play a pivotal role in improving surgical outcomes and training for complex PHF cases.

Personalized additive manufacturing of devices for the management of enteroatmospheric fistulas

Additive manufacturing techniques allow the customized design of medical devices according to the patient's requirements. Enteroatmospheric fistula is a pathology that benefits from this personalization due to its extensive clinical variability since the size and morphology of the wound differ extensively among patients. Standard prosthetics do not achieve proper isolation of the wound, leading to a higher risk of infections. Currently, no effective personalized technique to isolate it has been described. In this work, we present the workflow for the design and manufacture of customized devices adapted to the fistula characteristics as it evolves and changes during the treatment with Negative Pressure Wound Therapy (NPWT). For each case, a device was designed with dimensions and morphology depending on each patient's requirements using white light scanning, CAD design, and additive manufacturing. The design and manufacture of the devices were performed in 230.50 min (184.00-304.75). After the placement of the device, the wound was successfully isolated from the intestinal content for 48-72 h. The therapy was applied for 27.71 ± 13.74 days, and the device was redesigned to adapt to the wound when geometrical evolutionary changes occur during the therapy. It was observed a decrease in weekly cures from 23.63 ± 10.54 to 2.69 ± 0.65 (p = 0.001). The fistulose size was reduced longitudinal and transversally by 3.25 ± 2.56 cm and 6.06 ± 3.14 cm, respectively. The wound depth also decreased by 1.94 ± 1.08 cm. In conclusion, customization through additive manufacturing is feasible and offers promising results in the generation of personalized devices for the treatment of enteroatmospheric fistula.

Use of 3D Printing Technology in Fracture Management: A Review and Case Series

SUMMARY

Three-dimensional (3D) offers exciting opportunities in medicine, particularly in orthopaedics. The boundaries of 3D printing are continuously being re-established and have paved the way for further innovations, including 3D bioprinting, custom printing refined methods, 4D bioprinting, and 5D printing potential. The quality of these applications have been steadily improving, increasing their widespread use among clinicians. This article provides a review of the current literature with a brief introduction to the process of additive manufacturing, 3D printing, and its applications in fracture care. We illustrate this technology with a case series of 3D printing used for correction of complex fractures/nonunion. Factors limiting the use of this technology, including cost, and potential solutions are discussed. Finally, we discuss 4D bioprinting and 5D printing and their potential role in fracture surgery.

Preoperative Virtual Reduction Planning Algorithm of Fractured Pelvis Based on Adaptive Templates

OBJECTIVE

The minimally invasive treatment of pelvic fractures is one of the most challenging trauma orthopedics surgeries, where preoperative planning is crucial for the performance and outcome of the surgery. However, planning the ideal position of fragments currently relies heavily on the experience of the surgeon.

METHODS

A pelvic fracture virtual reduction algorithm for target position is provided based on statistical shape models (SSM). First, according to sexual dimorphism, pelvic SSM based on point cloud curvature down-sampling are constructed as adaptive templates. Then, an optimization algorithm is designed to iteratively adjust the target pose of the fragments and the adaptive matching of the templates. Finally, the feasibility of the method is verified by simulating fractures and clinical data.

RESULTS

The pelvis has complex shape characteristics, which can be analyzed by SSM to clearly understand the pattern of change. Experiments showed that the SSM-based pelvic fracture reduction method had translation and rotation errors of 2.20±1.09 mm and 3.16±1.26° in simulated cases, and 2.78±0.95 mm and 3.10±0.53° in clinical cases, which has higher accuracy than methods based on mean shape models, and wider applicability than methods based on pelvic symmetry.

CONCLUSION

The pelvic digital model created by SSM has good generalization properties, and the SSM-based virtual reduction algorithm can effectively reconstruct the target position of the fractured pelvis in preoperative planning.

SIGNIFICANCE

The proposed reduction method has the characteristics of high precision and wide application range, which provides a powerful tool for the surgeon's virtual preoperative planning.

Orthopaedic Advances: Use of Three-Dimensional Metallic Implants for Reconstruction of Critical Bone Defects After Trauma

Multiple successful strategies exist for the management of critical-sized bone defects. Depending on the location and etiology of an osseous defect, there are nuances that must be considered by the treating surgeon. The induced membrane technique and various modifications of the Ilizarov method (bone transport by distraction osteogenesis) have been the most common methods for biologic reconstruction. Despite the versatility and high union rates reported, they may not be practical for every patient. The rapid expansion of three-dimensional printing of medical devices has led to an increase in their use within orthopaedic surgery, specifically in the definitive treatment of critical bone defects. This article proposes indications and contraindications for implementation of this technology and reviews the available clinical evidence on the use of custom nonresorbable implants for the treatment of traumatic bone loss. Clinical cases are presented to illustrate the scenarios in which this approach is viable.

Use of patient-specific guides and 3D model in scapula osteotomy for symptomatic malunion

BACKGROUND

Scapular osteotomy for malunion can lead to resolution of pain and functional improvement in scapula fracture sequelae. Understanding three-dimensional bone morphology and analysing post-traumatic deformity is the main step of planning and the key to success of the procedure. 3D models and patient-specific guides are a growing technology to enhance accuracy of planning and to assist during surgery.

CASE PRESENTATION

We report the case of a 50 years old male, complaining of pain and limited function after a malunited scapular body fracture. Clinical assessment showed a severe impairment of shoulder function with active and passive forward flexion limited to 80°, absent external rotation, and internal rotation limited to the buttock. X-rays and CT scan showed an excessive lateral border offset of 53 mm and complete displacement of the glenoid segment anteriorly and medially to the scapular body, with impingement between the lateral most prominent scapular bone spur and humeral shaft. Glenopolar angle was 19°, scapular body angulation on the sagittal plane was 12°. Corrective osteotomy was planned on a virtual interactive rendering and on 3D printed models. Patient-specific guides were developed to perform a body-spine osteotomy with removal of a bone wedge, and a glenoid-spine osteotomy; a patient-specific wedge spacer was used to hold the reduction during plate fixation. Follow-up up to 12 months after surgery demonstrated improvement in scapula anatomy, shoulder girdle function, and patient-reported outcomes.

CONCLUSIONS

For the first time in scapula malunion surgery, patient-specific osteotomy guides were succesfully used during surgery to perform osteotomies and to assist in reduction maneuvers.

Biodegradable Magnesium Alloys for Personalised Temporary Implants

The objective of this experimental work was to examine and characterise the route for obtaining demonstrative temporary biodegradable personalised implants from the Mg alloy Mg-10Zn-0.5Zr-0.8Ca (wt.%). This studied Mg alloy was obtained in its powder state using the mechanical alloying method, with shape and size characteristics suitable for ensuing 3D additive manufacturing using the SLM (selective laser melting) procedure. The SLM procedure was applied to various processing parameters. All obtained samples were characterised microstructurally (using XRD-X-ray diffraction, and SEM-scanning electron microscopy); mechanically, by applying a compression test; and, finally, from a corrosion resistance viewpoint. Using the optimal test processing parameters, a few demonstrative temporary implants of small dimensions were made via the SLM method. Our conclusion is that mechanical alloying combined with SLM processing has good potential to manage 3D additive manufacturing for personalised temporary biodegradable implants of magnesium alloys. The compression tests show results closer to those of human bones compared to other potential metallic alloys. The applied corrosion test shows result comparable with that of the commercial magnesium alloy ZK60.

3-D Printed Fracture Models Improve Resident Performance and Clinical Outcomes in Operative Fracture Management

OBJECTIVE

To determine if preoperative examination of patient additive manufactured (AM) fracture models can be used to improve resident operative competency and patient outcomes.

DESIGN

Prospective cohort study. Seventeen matched pairs of fracture fixation surgeries (for a total of 34 surgeries) were performed. Residents first performed a set of baseline surgeries (n = 17) without AM fracture models. The residents then performed a second set of surgeries randomly assigned to include an AM model (n = 11) or to omit it (n = 6). Following each surgery, the attending surgeon evaluated the resident using an Ottawa Surgical Competency Operating Room Evaluation (O-Score). The authors also recorded clinical outcomes including operative time, blood loss, fluoroscopy duration, and patient reported outcome measurement information system (PROMIS) scores of pain and function at 6 months.

SETTING

Single-center academic level one trauma center.

PARTICIPANTS

Twelve orthopaedic residents, between postgraduate year (PGY) 2 and 5, participated in this study.

RESULTS

Residents significantly improved their O-Scores between the first and second surgery when they trained with AM models for the second surgery (p = 0.004, 2.43 ± 0.79 versus 3.73 ± 0.64). Similar improvements were not observed in the control group (p = 0.916, 2.69 ± 0.69 versus 2.77 ± 0.36). AM model training also significantly improved clinical outcomes, including surgery time (p = 0.006), fluoroscopy exposure time (p = 0.002), and patient reported functional outcomes (p = 0.0006).

CONCLUSIONS

Conclusions: Training with AM fracture models improves the performance of orthopaedic surgery residents during fracture surgery.

Experimental and numerical investigation of 3D-Printed bone plates under four-point bending load utilizing machine learning techniques

The fused deposition modeling (FDM) technique is widely used to produce components for various applications and has the potential to revolutionize orthopedic research through the production of custom-fit and readily available biomedical implants. The properties of FDM-produced implants are significantly influenced by processing parameters, with layer thickness being a crucial parameter. This study investigated the effect of layer thickness on the flexural properties of Polylactic Acid (PLA) bone plate implants produced by the FDM technique. Experimental results showed that the flexural strength is inversely proportional to the layer thickness due to the variation of voids in the specimens. A 3D finite element (FE) model was developed using Abaqus/Explicit software by incorporating the Gurson-Tvergaard (GT) porous plasticity model to predict the elastoplastic and damage behavior of specimens with different layer thicknesses. The characterization of the elastoplastic and GT parameters was done using a tensile test and by the calibration of a machine learning algorithm. It was shown that the FE model was able to predict the flexural behavior of 3D-printed solid plates with a maximum error of 6.13% in the maximum load. The optimal layer height was found to be 0.1 mm, providing both high flexural strength and adequate bending stiffness.

Clinical effects of 3D printing-assisted posterolateral incision in the treatment of ankle fractures involving the posterior malleolus

Objective

To explore the clinical outcomes of a 3D printing-assisted posterolateral approach for the treatment of ankle fractures involving the posterior malleolus.

Methods

A total of 51 patients with ankle fractures involving the posterior malleolus admitted to our hospital from January 2018 to December 2019 were selected. The patients were divided into 3D printing group (28 cases) and control group (23 cases). 3D printing was performed for ankle fractures, followed by printing of a solid model and simulation of the operation on the 3D model. The operation was then performed according to the preoperative plan, including open reduction and internal fixation via the posterolateral approach with the patient in the prone position. Routine x-ray and CT examinations of the ankle joint were performed, and ankle function was evaluated using the American Foot and Ankle Surgery Association (AOFAS) ankle-hindfoot score.

Results

All patients underwent x-ray and CT examinations. All fractures healed clinically, without loss of reduction or failure of internal fixation. Good clinical effects were achieved in both groups of patients. The operation time, intraoperative blood loss and intraoperative fluoroscopy frequency in the 3D printing group were significantly less than those in the control group (p < 0.05). There was no significant difference between the two groups in the anatomical reduction rate of fractures or the incidence of surgical complications (p > 0.05).

Conclusion

The 3D printing-assisted posterolateral approach is effective in the treatment of ankle fractures involving the posterior malleolus. The approach can be well planned before the operation, is simple to perform, yields good fracture reduction and fixation, and has good prospects for clinical application.

Challenges of Integrating New Technologies for Orthopedic Doctors to Face up to Difficulties during the Pandemic Era

In the field of orthopedics, competitive progress is growing faster because new technologies used to facilitate the work of physicians are continuously developing. Based on the issues generated in the pandemic era in this field, a research study was developed to identify the intention of orthopedic doctors to integrate new medical technologies. The survey was based on a questionnaire that was used for data collection. The quantitative study registered a sample of 145 orthopedic doctors. The data analysis was performed based on the IBM SPSS program. A multiple linear regression model was applied, which analyzed how the independent variables can influence the dependent variables. After analyzing the data, it was observed that the intention of orthopedic doctors to use new medical technologies is influenced by the advantages and disadvantages perceived by them, the perceived risks, the quality of the medical technologies, the experience of physicians in their use, and their receptivity to other digital tools. The obtained results are highly important both for hospital managers and authorities, illustrating the main factors that influence doctors to use emergent technologies in their clinical work.

Short-term results and complications of the operative treatment of the distal radius fracture AO2R3 C type, planned by using 3D-printed models. Prospective randomized control study

PURPOSE

3D-printed models rapidly evolving in orthopaedic. Studies show that 3D-printed models used for preoperative planning improve a better understanding of fracture morphology and reduce operative time, blood loss and frequency of fluoroscopy, but there are no studies that investigated possible advantages in the outcomes and complications for the treatment of distal radius fracture (DRF). Our study aims to evaluate short-term functional results and complications between two groups treated DRF using 3D-printed models for preoperative planning and without. We hypothesize that the addition of 3D-printed models would improve functional outcomes and reduce complication rates.

METHODS

66 randomized cases of DRF AO/OTA C type were enrolled and divided into "Control group" (n = 33) and "3D-printed model group" (n = 33). Personalized 3D-printed models were created. The primary outcomes were: Patient-Rated Wrist Evaluation questionnaire, Quick Disabilities of the Arm, Shoulder and Hand Score questionnaire, and complications. The secondary outcomes were: measurement of the range of motions, grip strength, radiological evaluation, and the visual analogue scale. Assessments were measured at 6 weeks, 3 months, and 6 months intervals.

RESULTS

We found that the integration of the 3D-printed model in preoperative planning decreased complication incidence significantly - from 30.3% in the "Control group" to 6.1% in the "3D-printed model group", p = .022. But we did not find a difference in functional and radiological outcomes.

CONCLUSION

The 3D-printed models for preoperative planning surgically treating DRF AO/OTA C type can help minimize the complication rate, however, they can't improve functional outcomes in the short-term results.

LEVEL OF EVIDENCE

Level I randomized controlled study.

Effectiveness in Sterilization of Objects Produced by 3D Printing with Polylactic Acid Material: Comparison Between Autoclave and Ethylene Oxide Methods

Objective  Due to the popularity of 3D technology, surgeons can create specific surgical guides and sterilize them in their institutions. The aim of the present study is to compare the efficacy of the autoclave and ethylene oxide (EO) sterilization methods for objects produced by 3D printing with polylactic acid (PLA) material. Methods Forty cubic-shaped objects were printed with PLA material. Twenty were solid and 20 were hollow (printed with little internal filling). Twenty objects (10 solid and 10 hollow) were sterilized in autoclave, forming Group 1. The others (10 solid and 10 hollow) were sterilized in EO, composing Group 2. After sterilization, they were stored and referred to culture. Hollow objects of both groups were broken during sowing, communicating the dead space with the culture medium. The results obtained were statistically analyzed (Fisher exact test and residue analysis). Results  In group 1 (autoclave), there was bacterial growth in 50% of solid objects and in 30% of hollow objects. In group 2 (EO), growth occurred in 20% of hollow objects, with no bacterial growth in solid objects (100% of negative samples). The bacteria isolated in the positive cases was non-coagulase-producing Staphylococcus Gram positive. Conclusions  Sterilization by both autoclave and EO was not effective for hollow printed objects. Solid objects sterilized by autoclave did not demonstrate 100% of negative samples and were not safe in the present assay. Complete absence of contamination occurred only with solid objects sterilized by EO, which is the combination recommended by the authors.

Evaluation of a Medical Grade Thermoplastic Polyurethane for the Manufacture of an Implantable Medical Device: The Impact of FDM 3D-Printing and Gamma Sterilization

Three-dimensional printing (3DP) of thermoplastic polyurethane (TPU) is gaining interest in the medical industry thanks to the combination of tunable properties that TPU exhibits and the possibilities that 3DP processes offer concerning precision, time, and cost of fabrication. We investigated the implementation of a medical grade TPU by fused deposition modelling (FDM) for the manufacturing of an implantable medical device from the raw pellets to the gamma (γ) sterilized 3DP constructs. To the authors' knowledge, there is no such guide/study implicating TPU, FDM 3D-printing and gamma sterilization. Thermal properties analyzed by differential scanning calorimetry (DSC) and molecular weights measured by size exclusion chromatography (SEC) were used as monitoring indicators through the fabrication process. After gamma sterilization, surface chemistry was assessed by water contact angle (WCA) measurement and infrared spectroscopy (ATR-FTIR). Mechanical properties were investigated by tensile testing. Biocompatibility was assessed by means of cytotoxicity (ISO 10993-5) and hemocompatibility assays (ISO 10993-4). Results showed that TPU underwent degradation through the fabrication process as both the number-averaged (Mn) and weight-averaged (Mw) molecular weights decreased (7% Mn loss, 30% Mw loss, p < 0.05). After gamma sterilization, Mw increased by 8% (p < 0.05) indicating that crosslinking may have occurred. However, tensile properties were not impacted by irradiation. Cytotoxicity (ISO 10993-5) and hemocompatibility (ISO 10993-4) assessments after sterilization showed vitality of cells (132% ± 3%, p < 0.05) and no red blood cell lysis. We concluded that gamma sterilization does not highly impact TPU regarding our application. Our study demonstrates the processability of TPU by FDM followed by gamma sterilization and can be used as a guide for the preliminary evaluation of a polymeric raw material in the manufacturing of a blood contacting implantable medical device.

The Possibilities of Personalized 3D Printed Implants-A Case Series Study

Background and Objectives: Following the most recent software and 3D printing developments, the use of personalized 3D printed orthopedic implants for treatment of complicated surgical cases has gained more popularity. Today, orthopedic problems that cannot be solved with standard implants may be effectively addressed using personalized prostheses. The aim of this study is to present the designing, modeling and production stages of four different personalized 3D printed prostheses and their application in clinical cases of patients who underwent treatment in various anatomical locations with a precisely specified indication for implantation. Materials and Methods: Based on computed tomography scanning, personalized 3D printed prostheses were designed, produced and used in four patients within a period of three to five days after injury or admission. Results: Early term follow-ups demonstrated good to excellent results. Conclusions: Personalized 3D printed prostheses offer an opportunity for a treatment of choice and provide good anatomical and functional results, shortened surgical time, less complications, and high satisfaction in patients with appropriate indications. The method should be considered primarily for patients with large bone defects, or such indicated for resection. Personalized 3D printed prostheses have the potential to become more common and beneficial in the future.

Treatment of an Infected Tibial Shaft Non-Union Using a Novel 3D-Printed Titanium Mesh Cage: A Case Report

Treating large bone defects resulting from trauma, tumors, or infection can be challenging, as current methods such as external fixation with bone transport, bone grafting, or amputation often come with high costs, high failure rates, high requirements for follow-up, and potential complications. In this case report, we present the successful treatment of a complicated, infected tibial shaft non-union by using a personalized three-dimensional (3D)-printed titanium mesh cage. This case adds to the existing body of literature by demonstrating successful integration of bone into a titanium implant and a demonstration of immediate postoperative weight bearing in the setting of suboptimal operative and psychosocial conditions. Futhermore, this report highlights the flexibility of 3D-printing technology and its ability to allow for continued limb salvage, even after a planned bone transport procedure has been interrupted. The use of 3D-printed implants customized to the patient's specific needs offers a promising new avenue for treating complex tibial pathologies, and the technology's versatility and ability to be tailored to individual patients makes it a promising tool for addressing a wide range of bone defects.

Combining Virtual Surgical Planning and Patient-Specific 3D-Printing as a Solution to Complex Spinal Revision Surgery

With the advent of three-dimensional printing, rapid growth in the field and application in spinal and orthopedic surgery has been seen. This technology is now being applied in creating patient-specific implants, as it offers benefits over the generic alternative, with growing literature supporting this. This report details a unique application of virtual surgical planning and manufacture of a personalized implant in a case of cervical disc replacement failure with severe osteolysis and resultant hypermobility. Where this degree of degenerative bone loss would often necessitate a vertebrectomy to be performed, this case highlights the considerable customizability of 3D-printed patient-specific implants to contour to the bony defects, allowing for a smaller and safer operation, with the achievement of stability as early as 3 months after the procedure, by the presence of osseointegration. With increasing developments in virtual planning technology and 3D printing ability, the future of complex spinal revision surgery may adopt these technologies as it affords the patient a faster, safer, and less invasive and destructive procedure.

Application of 3D modeling in a personalized approach to bone osteosynthesis (A literature review)

Three-dimensional printing opens up many opportunities for use in traumatology and orthopedics, because it takes into account personal characteristics of the patients. Modern methods of high-resolution medical imaging can process data to create threedimensional images for printing physical objects. Today, three-dimensional printers are able to create a model of any complexity of shape and geometry. The article provides a review of the literature about three-dimensional digital modeling in shaping implants for osteosynthesis. Data search was carried out on the Scopus, Web of Scince, Pubmed, RSCI databases for the period 2012–2022. The effectiveness of three-dimensional printing for preoperative modeling of bone plates has been confirmed: implants perfectly corresponds with the unique anatomy of the patient, since the template for it is based on the materials of computed tomography. Individual templates can be useful when the geometry of patients' bones goes beyond the standard, and when improved results of surgery are expected due to better matching of implants to the anatomical needs of patients. 

Management of Complex Acetabular Fractures by Using 3D Printed Models

Background and Objectives: Using 3D printed models in orthopaedics and traumatology contributes to a better understanding of injury patterns regarding surgical approaches, reduction techniques, and fracture fixation methods. The aim of this study is to evaluate the effectiveness of a novel technique implementing 3D printed models to facilitate the optimal preoperative planning of the surgical treatment of complex acetabular fractures. Materials and Methods: Patients with complex acetabular fractures were assigned to two groups: (1) conventional group (n = 12) and (2) 3D printed group (n = 10). Both groups included participants with either a posterior column plus posterior wall fracture, a transverse plus posterior wall fracture, or a both-column acetabular fracture. Datasets from CT scanning were segmented and converted to STL format, with separated bones and fragments for 3D printing in different colors. Comparison between the two groups was performed in terms of quality of fracture reduction (good: equal to, or less than 2 mm displacement, and fair: larger than 2 mm displacement), functional assessment, operative time, blood loss, and number of intraoperative x-rays. Results: A significant decrease in operative time, blood loss, and number of intraoperative x-rays was registered in the 3D printed group versus the conventional one (p < 0.01), with 80% of the patients in the former having good fracture reduction and 20% having fair reduction. In contrast, 50% of the patients in the conventional group had good reduction and 50% had fair reduction. The functional score at 18-month follow-up was better for patients in the 3D printed group. Conclusions: The 3D printing technique can be considered a highly efficient and patient-specific approach for management of complex acetabular fractures, helping to restore patient′s individual anatomy after surgery.

3D printing in fracture treatment : Current practice and best practice consensus

The use of 3D printing in orthopedic trauma is supported by clinical evidence. Existing computed tomography (CT) data are exploited for better stereotactic identification of morphological features of the fracture and enhanced surgical planning. Due to complex logistic, technical and resource constraints, deployment of 3D printing is not straightforward from the hospital management perspective. As a result not all trauma surgeons are able to confidently integrate 3D printing into the daily practice. We carried out an expert panel survey on six trauma units which utilized 3D printing routinely. The most frequent indications are acetabular and articular fractures and malalignments. Infrastructure and manpower structure varied between units. The installation of industrial grade machines and dedicated software as well as the use of trained personnel can enhance the capacity and reliability of fracture treatment. Setting up interdisciplinary jointly used 3d printing departments with sound financial and management structures may improve sustainability. The sometimes substantial logistic and technical barriers which impede the rapid delivery of 3D printed models are discussed.

Sources, Selection, and Microenvironmental Preconditioning of Cells for Urethral Tissue Engineering

Urethral stricture is a common urinary tract disorder in men that can be caused by iatrogenic causes, trauma, inflammation, or infection and often requires reconstructive surgery. The current therapeutic approach for complex urethral strictures usually involves reconstruction with autologous tissue from the oral mucosa. With the goal of overcoming the lack of sufficient autologous tissue and donor site morbidity, research over the past two decades has focused on cell-based tissue-engineered substitutes. While the main focus has been on autologous cells from the penile tissue, bladder, and oral cavity, stem cells from sources such as adipose tissue and urine are competing candidates for future urethral regeneration due to their ease of collection, high proliferative capacity, maturation potential, and paracrine function. This review addresses the sources, advantages, and limitations of cells for tissue engineering in the urethra and discusses recent approaches to improve cell survival, growth, and differentiation by mimicking the mechanical and biophysical properties of the extracellular environment.

Innovations in orthopaedic trauma: Top advancements of the past two decades and predictions for the next two

The first Trauma and Orthopaedic unit dates back to 1780, originally dedicated to the treatment of children's deformities. The specialty has subsequently become multifaceted, with a plethora of subspecialty areas of which orthopaedic trauma is the most commonly practiced. Recently there has been a significant demand for an evidence base with more than 130,000 of the 162,000 publications in the last century occurring within the past 20 years. This narrative review will summarise some of the more landmark changes within orthopaedic trauma that have been made within the past 20 years, whilst also attempting to predict where the specialty will continue to develop as we move forward.

Modified Masquelet Technique Assisting 3D Printed Elbow Prosthesis for Open Elbow Fracture with Severe Bone Defect: A Case Report and Technique Note

BACKGROUND

Internal fixation for severe open articular bone defects is sometimes ineffective or dangerous. In the emergency stage, radical debridement and infection prevention are demanded to provide a good tissue base and the space-occupying effect to provide enough necessary space to avoid soft-tissue contraction for the reconstruction. In addition, the 3D printing technology makes individual limb reconstruction a reality.

CASE PRESENTATION

Here, we present a 31-year-old patient with an open fracture and severe bone defect of his left elbow caused by traffic accident, classified as Gustilo-Anderson IIIB. We adopted aggressive debridement and insertion of polymethyl methacrylate (PMMA) to prevent the infection and temporarily construct the bone defect in the emergency stage. Secondly, the total elbow arthroplasty was performed using a unique three-dimensional (3D) printed prosthesis to reconstruct the elbow joint. During the follow-up, the elbow movement function was satisfactory.

CONCLUSIONS

The modified Masquelet technique assisting 3D printing of personalized elbow joint makes the satisfactory functional reconstruction for open high-energy injuries come true. It could be promoted for the similar surgery of other open joints fractures with severe bone defects.

Fracture-Related Infection in Bicolumnar Acetabular Fracture: A Case Report

Case: A 51-year-old man was affected by a fracture-related infection after a bicolumnar acetabular fracture. A significant alteration of the anatomy was present; thus, a 3D-printed model was useful for planning. A two-stage treatment was planned: in the first stage, implant removal with irrigation and debridement was performed, while in the second stage, a new osteosynthesis and implant of a THA were planned. During the second stage, the patient suffered a cardiogenic shock, so a third surgical procedure was necessary to implant THA. Targeted antibiotic therapy was administered eight weeks after the first stage, with the resolution of the infection. Conclusions: The infection was resolved following the recent guidelines and treating it like a periprosthetic infection with a two-stage revision. A collaboration between specialists in orthopaedics and infectious disease, respectively, and using multidisciplinary approach, were mandatory.

Application of 3D printed models in the surgical treatment of spinal deformity

OBJECTIVE

To test if preoperative planning with 3 dimensional (3D)-printed spine models can increase the effectiveness and safety of spinal deformity surgery.

METHODS

A total of 53 patients who were treated in our center for spinal deformities from January 2010 to January 2018 were included in the current study. They were divided into two groups based on whether 3D-printed models were used in the surgical planning. A total of 28 patients who were treated with 3D-printed models were assigned to the experimental group, and 25 patients who were treated with conventional methods were assigned to the control group. Duration of surgery, intraoperative hemorrhage, incidence of surgery related complications, Oswestry disability index (ODI), visual analogue scale (VAS), and Cobb's angle were compared between the two groups before and after surgery.

RESULTS

There were significant differences in the duration of surgery, intraoperative hemorrhage and intraoperative x-ray exposure between the two groups (P<0.01). Cobb's angle was smaller in the experimental group than in the control group when measured three days and a year after surgery (P<0.01). Although there was no significant difference between the experimental and control groups (P>0.05), Oswestry disability index and VAS pain scores were lower a month and a year after the surgery than before the surgery (P<0.01).

CONCLUSION

Surgical planning using 3D-printed spine models can decrease the operation time, intraoperative hemorrhage, and x-ray exposure, and help achieve satisfactory structural restoration in patients with severe spinal deformity.

Three-Dimensional Printing and Fracture Mapping in Pelvic and Acetabular Fractures: A Systematic Review and Meta-Analysis

Three-dimensional printing and fracture mapping technology is gaining popularity for preoperative planning of fractures. The aim of this meta-analysis is to further understand for the effects of 3D printing and fracture mapping on intraoperative parameters, postoperative complications, and functional recovery on pelvic and acetabular fractures. The PubMed, Embase, Cochrane and Web of Science databases were systematically searched for articles according to established criteria. A total of 17 studies were included in this study, of which 3 were RCTs, with a total of 889 patients, including 458 patients treated by traditional open reduction and internal fixation methods and 431 patients treated using 3D printing strategies. It was revealed that three-dimensional printing and fracture mapping reduced intraoperative surgical duration (RoM 0.74; 95% CI; 0.66–0.83; I² = 93%), and blood loss (RoM 0.71; 95% CI; 0.63–0.81; I² = 71%). as compared to traditional surgical approaches. In addition, there was significantly lower exposure to intraoperative imaging (RoM 0.36; 95% CI; 0.17–0.76; I² = 99%), significantly lower postoperative complications (OR 0.42; 95% CI; 0.22–0.78; I² = 9%) and significantly higher excellent/good reduction (OR 1.53; 95% CI; 1.08–2.17; I² = 0%) in the three-dimensional printing and fracture mapping group. Further stratification results with only prospective studies showed similar trends. Three-dimensional printing and fracture mapping technology has potential in enhancing treatment of complex fractures by improving surgical related factors and functional outcomes and therefore could be considered as a viable tool for future clinical applications.

A Two-Step Approach for 3D-Guided Patient-Specific Corrective Limb Osteotomies

Background: Corrective osteotomy surgery for long bone anomalies can be very challenging since deformation of the bone is often present in three dimensions. We developed a two-step approach for 3D-planned corrective osteotomies which consists of a cutting and reposition guide in combination with a conventional osteosynthesis plate. This study aimed to assess accuracy of the achieved corrections using this two-step technique. Methods: All patients (≥12 years) treated for post-traumatic malunion with a two-step 3D-planned corrective osteotomy within our center in 2021 were prospectively included. Three-dimensional virtual models of the planned outcome and the clinically achieved outcome were obtained and aligned. Postoperative evaluation of the accuracy of performed corrections was assessed by measuring the preoperative and postoperative alignment error in terms of angulation, rotation and translation. Results: A total of 10 patients were included. All corrective osteotomies were performed according to the predetermined surgical plan without any complications. The preoperative deformities ranged from 7.1 to 27.5° in terms of angulation and 5.3 to 26.1° in terms of rotation. The achieved alignment deviated on average 2.1 ± 1.0 and 3.4 ± 1.6 degrees from the planning for the angulation and rotation, respectively. Conclusions: A two-step approach for 3D-guided patient-specific corrective limb osteotomies is reliable, feasible and accurate.

Improved Accuracy of Coronal Alignment Can Be Attained Using 3D-Printed Patient-Specific Instrumentation for Knee Osteotomies: A Systematic Review of Level III and IV Studies

PURPOSE

To evaluate the accuracy and precision of postoperative coronal plane alignment using 3D-printed patient-specific instrumentation (PSI) in the setting of proximal tibial or distal femoral osteotomies.

METHODS

A systematic review evaluating the accuracy of 3D-printed PSI for coronal plane alignment correcting knee osteotomies was performed. The primary outcomes were accuracy of coronal plane limb alignment correction and number of correction outliers. Secondary variables were duration of surgery, number of intraoperative fluoroscopic images, complications, cost, and clinical outcomes (as applicable).

RESULTS

Ninety-three studies were identified, and 14 were included in the final analysis. Overall, mean postoperative deviation from target correction ranged from 0.3° to 1° for all studies using hip-knee angle measurements and 2.3% to 4.9% for all studies using weight-bearing line measurements. The incidence of correction outliers was assessed in 8 total studies and ranged from 0 to 25% (total n = 10 knees) of patients corrected with 3D-printed PSI. Osteotomies performed with 3D-printed cutting guides or wedges demonstrated significantly shorter operative times (P < .05) and fewer intraoperative fluoroscopic images (P < .05) than control groups in four case control studies.

CONCLUSION

Patients undergoing distal femoral osteotomy or proximal tibial osteotomy procedures with 3D-printed patient-specific cutting guides and wedges had highly accurate coronal plane alignment with a low rate of outliers. Patients treated with 3D printed PSI also demonstrated significantly shorter operative times and decreased intraoperative fluoroscopy when compared to conventional techniques.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III-IV studies.

Artificial Intelligence-Empowered 3D and 4D Printing Technologies toward Smarter Biomedical Materials and Approaches

In the last decades, 3D printing has played a crucial role as an innovative technology for tissue and organ fabrication, patient-specific orthoses, drug delivery, and surgical planning. However, biomedical materials used for 3D printing are usually static and unable to dynamically respond or transform within the internal environment of the body. These materials are fabricated ex situ, which involves first printing on a planar substrate and then deploying it to the target surface, thus resulting in a possible mismatch between the printed part and the target surfaces. The emergence of 4D printing addresses some of these drawbacks, opening an attractive path for the biomedical sector. By preprogramming smart materials, 4D printing is able to manufacture structures that dynamically respond to external stimuli. Despite these potentials, 4D printed dynamic materials are still in their infancy of development. The rise of artificial intelligence (AI) could push these technologies forward enlarging their applicability, boosting the design space of smart materials by selecting promising ones with desired architectures, properties, and functions, reducing the time to manufacturing, and allowing the in situ printing directly on target surfaces achieving high-fidelity of human body micro-structures. In this review, an overview of 4D printing as a fascinating tool for designing advanced smart materials is provided. Then will be discussed the recent progress in AI-empowered 3D and 4D printing with open-loop and closed-loop methods, in particular regarding shape-morphing 4D-responsive materials, printing on moving targets, and surgical robots for in situ printing. Lastly, an outlook on 5D printing is given as an advanced future technique, in which AI will assume the role of the fifth dimension to empower the effectiveness of 3D and 4D printing for developing intelligent systems in the biomedical sector and beyond.

Rapid Personalised Virtual Planning and On-Demand Surgery for Acute Spinal Trauma Using 3D-Printing, Biomodelling and Patient-Specific Implant Manufacture

Three-dimensional printing is a rapidly growing field, with extensive application to orthopaedics and spinal surgery. Three-dimensional-printed (3DP) patient-specific implants (PSIs) offer multiple potential benefits over generic alternatives, with their use increasingly being described in the spinal literature. This report details a unique, emergency case of a traumatic spinal injury in a 31-year-old male, acquired rurally and treated with a 3DP PSI in a tertiary unit. With increasing design automation and process improvements, rapid, on-demand virtual surgical planning (VSP) and 3DP PSIs may present the future of orthopaedics and trauma care, enabling faster, safer, and more cost-effective patient-specific procedures.

Does 3D-assisted surgery of tibial plateau fractures improve surgical and patient outcome? A systematic review of 1074 patients

PURPOSE

The aim of this systematic review was to provide an overview of current applications of 3D technologies in surgical management of tibial plateau fractures and to assess whether 3D-assisted surgery results in improved clinical outcome as compared to surgery based on conventional imaging modalities.

METHODS

A literature search was performed in Pubmed and Embase for articles reporting on the use of 3D techniques in operative management of tibial plateau fractures. This systematic review was performed in concordance with the PRISMA-guidelines. Methodological quality and risk of bias was assessed according to the guidelines of the McMaster Critical Appraisal. Differences in terms of operation time, blood loss, fluoroscopy frequency, intra-operative revision rates and patient-reported outcomes between 3D-assisted and conventional surgery were assessed. Data were pooled using the inverse variance weighting method in RevMan.

RESULTS

Twenty articles evaluating 948 patients treated with 3D-assisted surgery and 126 patients with conventional surgery were included. Five different concepts of 3D-assisted surgery were identified: '3D virtual visualization', '3D printed hand-held fracture models', 'Pre-contouring of osteosynthesis plates', '3D printed surgical guides', and 'Intra-operative 3D imaging'. 3D-assisted surgery resulted in reduced operation time (104.7 vs. 126.4 min; P < 0.01), less blood loss (241 ml vs. 306 ml; P < 0.01), decreased frequency of fluoroscopy (5.8 vs. 9.1 times; P < 0.01). No differences in functional outcome was found (Hospital for Special Surgery Knee-Rating Scale: 88.6 vs. 82.8; P = 0.23).

CONCLUSIONS

Five concepts of 3D-assisted surgical management of tibial plateau fractures emerged over the last decade. These include 3D virtual fracture visualization, 3D-printed hand-held fracture models for surgical planning, 3D-printed models for pre-contouring of osteosynthesis plates, 3D-printed surgical guides, and intra-operative 3D imaging. 3D-assisted surgery may have a positive effect on operation time, blood loss, and fluoroscopy frequency.