Three-dimensional printed implant for reconstruction of pelvic bone after removal of giant chondrosarcoma: a case report

Evaluation of finite element modeling methods for predicting compression screw failure in a custom pelvic implant

Introduction: Three-dimensional (3D)-printed custom pelvic implants have become a clinically viable option for patients undergoing pelvic cancer surgery with resection of the hip joint. However, increased clinical utilization has also necessitated improved implant durability, especially with regard to the compression screws used to secure the implant to remaining pelvic bone. This study evaluated six different finite element (FE) screw modeling methods for predicting compression screw pullout and fatigue failure in a custom pelvic implant secured to bone using nine compression screws. Methods: Three modeling methods (tied constraints (TIE), bolt load with constant force (BL-CF), and bolt load with constant length (BL-CL)) generated screw axial forces using functionality built into Abaqus FE software; while the remaining three modeling methods (isotropic pseudo-thermal field (ISO), orthotropic pseudo-thermal field (ORT), and equal-and-opposite force field (FOR)) generated screw axial forces using iterative physics-based relationships that can be implemented in any FE software. The ability of all six modeling methods to match specified screw pretension forces and predict screw pullout and fatigue failure was evaluated using an FE model of a custom pelvic implant with total hip replacement. The applied hip contact forces in the FE model were estimated at two locations in a gait cycle. For each of the nine screws in the custom implant FE model, likelihood of screw pullout failure was predicted using maximum screw axial force, while likelihood of screw fatigue failure was predicted using maximum von Mises stress. Results: The three iterative physics-based modeling methods and the non-iterative Abaqus BL-CL method produced nearly identical predictions for likelihood of screw pullout and fatigue failure, while the other two built-in Abaqus modeling methods yielded vastly different predictions. However, the Abaqus BL-CL method required the least computation time, largely because an iterative process was not needed to induce specified screw pretension forces. Of the three iterative methods, FOR required the fewest iterations and thus the least computation time. Discussion: These findings suggest that the BL-CL screw modeling method is the best option when Abaqus is used for predicting screw pullout and fatigue failure in custom pelvis prostheses, while the iterative physics-based FOR method is the best option if FE software other than Abaqus is used.

Global research development of chondrosarcoma from 2003 to 2022: a bibliometric analysis

Background

Chondrosarcomas are common primary malignant bone tumors; however, comprehensive bibliometric analysis in this field has not yet been conducted. Therefore, this study aimed to explore the research hotspots and trends in the field of chondrosarcoma through bibliometric analysis to help researchers understand the current status and direction of research in the field.

Methods

Articles and reviews related to chondrosarcoma published between 2003 and 2022 were retrieved from the Web of Science. Countries, institutions, authors, journals, references, and keywords in this field were visualized and analyzed using CtieSpace and VOSviewer software.

Results

Between 2003 and 2022, 4,149 relevant articles were found. The number of articles published on chondrosarcoma has increased significantly annually, mainly from 569 institutions in China and the United States, and 81 in other countries. In total, 904 authors participated in the publication of studies related to chondrosarcomas. Over the past 20 years, articles on chondrosarcoma have been published in 958 academic journals, with Skeletal Radiology having the highest number of publications. Furthermore, keywords such as "gene expression," "radiotherapy," "experience," and "apoptosis" have been popular in recent years.

Conclusion

Over the past 20 years, the global trend in chondrosarcoma research has primarily been clinical research, with basic research as a supplement. In the future, communication and exchange between countries and institutions should be strengthened. Further, the future main research hotspots in the field of chondrosarcoma include mutated genes and signaling pathways, precision surgical treatment, proton therapy, radiation therapy, chemotherapy, immunotherapy, and other aspects.

A systematic review of follow-up results of additively manufactured customized implants for the pelvic area

INTRODUCTION

While 3D printing of bone models for preoperative planning or customized surgical templating has been successfully implemented, the use of patient-specific additively manufactured (AM) implants is a newer application not yet well established. To fully evaluate the advantages and shortcomings of such implants, their follow-up results need to be evaluated.

AREA COVERED

This systematic review provides a survey of the reported follow-ups on AM implants used for oncologic reconstruction, total hip arthroplasty both primary and revision, acetabular fracture, and sacrum defects.

EXPERT OPINION

The review shows that Titanium alloy (Ti4AL6V) is the most common type of material system used due to its excellent biomechanical properties. Electron beam melting (EBM) is the predominant AM process for manufacturing implants. In almost all cases, porosity at the contact surface is implemented through the design of lattice or porous structures to enhance osseointegration. The follow-up evaluations show promising results, with only a small number of patients suffering from aseptic loosening, wear, or malalignment. The longest reported follow-up length was 120 months for acetabular cages and 96 months for acetabular cups. The AM implants have proven to serve as an excellent option to restore premorbid skeletal anatomy of the pelvis.

Computational evaluation of psoas muscle influence on walking function following internal hemipelvectomy with reconstruction

An emerging option for internal hemipelvectomy surgery is custom prosthesis reconstruction. This option typically recapitulates the resected pelvic bony anatomy with the goal of maximizing post-surgery walking function while minimizing recovery time. However, the current custom prosthesis design process does not account for the patient's post-surgery prosthesis and bone loading patterns, nor can it predict how different surgical or rehabilitation decisions (e.g., retention or removal of the psoas muscle, strengthening the psoas) will affect prosthesis durability and post-surgery walking function. These factors may contribute to the high observed failure rate for custom pelvic prostheses, discouraging orthopedic oncologists from pursuing this valuable treatment option. One possibility for addressing this problem is to simulate the complex interaction between surgical and rehabilitation decisions, post-surgery walking function, and custom pelvic prosthesis design using patient-specific neuromusculoskeletal models. As a first step toward developing this capability, this study used a personalized neuromusculoskeletal model and direct collocation optimal control to predict the impact of ipsilateral psoas muscle strength on walking function following internal hemipelvectomy with custom prosthesis reconstruction. The influence of the psoas muscle was targeted since retention of this important muscle can be surgically demanding for certain tumors, requiring additional time in the operating room. The post-surgery walking predictions emulated the most common surgical scenario encountered at MD Anderson Cancer Center in Houston. Simulated post-surgery psoas strengths included 0% (removed), 50% (weakened), 100% (maintained), and 150% (strengthened) of the pre-surgery value. However, only the 100% and 150% cases successfully converged to a complete gait cycle. When post-surgery psoas strength was maintained, clinical gait features were predicted, including increased stance width, decreased stride length, and increased lumbar bending towards the operated side. Furthermore, when post-surgery psoas strength was increased, stance width and stride length returned to pre-surgery values. These results suggest that retention and strengthening of the psoas muscle on the operated side may be important for maximizing post-surgery walking function. If future studies can validate this computational approach using post-surgery experimental walking data, the approach may eventually influence surgical, rehabilitation, and custom prosthesis design decisions to meet the unique clinical needs of pelvic sarcoma patients.

3D printing applications in spine surgery: an evidence-based assessment toward personalized patient care

PURPOSE

Spine surgery entails a wide spectrum of complicated pathologies. Over the years, numerous assistive tools have been introduced to the modern neurosurgeon's armamentarium including neuronavigation and visualization technologies. In this review, we aimed to summarize the available data on 3D printing applications in spine surgery as well as an assessment of the future implications of 3D printing.

METHODS

We performed a comprehensive review of the literature on 3D printing applications in spine surgery.

RESULTS

Over the past decade, 3D printing and additive manufacturing applications, which allow for increased precision and customizability, have gained significant traction, particularly spine surgery. 3D printing applications in spine surgery were initially limited to preoperative visualization, as 3D printing had been primarily used to produce preoperative models of patient-specific deformities or spinal tumors. More recently, 3D printing has been used intraoperatively in the form of 3D customizable implants and personalized screw guides.

CONCLUSIONS

Despite promising preliminary results, the applications of 3D printing are so recent that the available data regarding these new technologies in spine surgery remains scarce, especially data related to long-term outcomes.

Bilateral asymmetry of bone density adjacent to pelvic sarcomas: A retrospective study using computed tomography

Limb-salvaging hemipelvectomy surgeries involving allograft or custom prosthesis reconstruction require high quality remaining pelvic bone for adequate device fixation. Modeling studies of custom pelvis prosthesis designs typically mirror contralateral pelvic bone material properties to the ipsilateral pelvis. However, the extent of bone material property and geometric symmetry, and thus the appropriateness of mirroring, remains unknown and should be considered when designing or analyzing the performance of pelvic prostheses. This study investigates preoperative differences between ipsilateral and contralateral pelvic bone for patients with a pelvic sarcoma. Computed tomography (CT) data were obtained retrospectively from eight patients with a pelvic sarcoma. Subject-specific computational models of the pelvic bones were constructed from the CT data. Bilateral asymmetry of bone material properties and cross-sectional areas between the ipsilateral and contralateral hemipelvis were quantified at points adjacent to the pelvic sarcoma. Large bilateral asymmetry (>20%) in trabecular but not cortical bone density was observed within 20 mm of the tumor location. Differences in trabecular bone density typically declined with increased distance from the tumor. The greatest bilateral difference in cross-sectional area occurred within 10 mm of the tumor boundary for three patients and within 40 mm from the tumor site for four patients. Our results suggest that pelvic sarcomas can cause significant bilateral asymmetries in trabecular bone density for patients with a pelvic sarcoma. These differences should be taken into account when designing custom implants for this patient population.

Chondrosarcoma of the proximal radius treated by wide resection and reconstructed by 3D printed implant: A case report and description of surgical technique

Introduction

Chondrosarcoma is the second most common primary malignancy of bone that can occur in multiple locations in the skeleton. It has been rarely reported in the proximal radius. While surgical resection is the primary treatment modality for individuals with localized disease, reconstruction can be challenging in the elbow joint due to its complex anatomy. 3D printing technology can be used in such complex cases to restore the normal anatomy after resection.

Case presentation

We present a case of mesenchymal chondrosarcoma in a 33-year-old male occurring in the proximal radius, restricting his elbow motion. That was resected and reconstructed using 3D modeling. Restoring a functional range of motion without instability.

Discussion

Many surgical options for chondrosarcoma presented over the years including en bloc resection, resection with or without reconstruction, or amputation. Usage of 3D modeling in the orthopedic surgery field is relatively new and it can be used in pre-operative planning and shortens surgical time. 3D printing in our case helped in obtaining a full range of motion (flexion, extension, pronation, and supination) for the patient.

Conclusion

It's important to reconstruct elbow joint support structure and function after resection of such a large malignant tumor in young patients. We used 3D printed implant to maintain a functional limb and it was an excellent alternative treatment.

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Chondrosarcoma occurring in the proximal radius is very rare. Up to our knowledge, this is the second case report.

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We report a case of proximal radius chondrosarcoma managed by reconstruction with Three-Dimension printed implant.

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3D printing in the field of orthopedic surgery is relatively new and has upscaled medical management.

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A description of a surgical technique to reconstruct proximal radius and maintaining full range of motion of the elbow.

Limb-salvage surgery using personalized 3D-printed porous tantalum prosthesis for distal radial osteosarcoma: A case report

RATIONALE

Three-dimensional (3D) printing has been widely utilized for treating the tumors of bone and soft tissue. We herewith report a unique case of distal radial osteosarcoma who was treated with a 3D printed porous tantalum prosthesis.Patient concerns: A 58-year-old Chinese male patient presented to our clinic complaining about a 6-month history of a progressive pain at his right hand, associated with a growing lump 2 months later.

DIAGNOSIS

Osteosarcoma of distal radius confirmed by percutaneous biopsy and tumor biopsy.

INTERVENTIONS

A limb-salvage surgery was performed with a 3D printed porous tantalum prosthesis, combined with the postoperative chemotherapy for 4 cycles.

OUTCOMES

At 2-year follow-up, complete pain relief and satisfactory functional recovery of his right wrist were observed.

LESSONS

Personalized 3D printed prosthesis is an effective and feasible method for treating the osteosarcoma and reconstruction of complex bone defects.

Partial replacement of pelvis with the hip joint in osteosarcoma treatment: A case report

Introduction

and importance: Pelvic osteosarcoma is quite rare and is a challenging task for orthopedic surgeons. This aim of this study is to present the first case report using customized 3D-printed prosthesis in Vietnam.

Case presentation

57-year-old male was diagnosed with pelvic osteosarcoma. After neoadjuvant chemotherapy, we did limb-salvage surgery after partial pelvic resection. He had to undergo another surgery due to an infection complication that exposed part of the prosthesis. At 6 months follow-up, the patient's overall status was stable. VAS score when moving is 2/10. He can walk with one crutch. Patient is still being followed up and treated.

Clinincal discussion

Management of pelvic osteosarcoma remains a challenging task for orthopedic surgeons. Advancements in customized 3D-printed prosthesis have been applied in treatment of pelvic osteosarcoma. Despite the complications, the results are promising. We believe that this is a new and innovative route in surgery of pelvic osteosarcoma.

Conclusion

Using customized 3D-printed prosthesis is a good way for management of pelvic osteosarcoma.

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Osteosarcoma of pelvis is not common, account for 4–10% of all bone cancer.

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Pelvis connect the lower limb with body by hip joint and support the intraabdominal organ.

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It is very difficult to preserve the pelvis after wide resection.

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Custom made 3D printed implant give us a chance to restore the pelvis anatomically and functionally.