[Treatment strategies for tumor-related pathological fractures of the extremities]

[3D printing/implants in traumatology]

The use of 3D printing offers numerous application possibilities in traumatology, including anatomic models, repositioning and drilling guides as well as patient-specific implants. The greatest challenge lies in the rapid availability as many procedures require an immediate intervention. Anatomic models support surgical planning by complementing visual impressions with tactile ones. Printed models not only help in the establishment of surgical strategies but also enhance patient clarification. Studies demonstrate that these models significantly reduce the operating time, duration of fluoroscopy and blood loss, particularly for joint fractures. Repositioning and drilling guides simplify complex procedures and improve outcomes; however, they require precise planning and critical evaluation by the surgeon. Intraoperative guides are helpful, for instance, in accurately placing screws, especially in difficult to access areas or in metaphyseal fractures lacking clear references. Individualized implants play a lesser role in acute care but are useful for posttraumatic defects or corrective osteotomy. In the conservative segment, such as customized splints, 3D printing is being tested but with mixed results. Key requirements for 3D printing in traumatology include high-resolution computed tomography (CT), precise data processing and swift production. Regulatory hurdles and lack of reimbursement currently limit the widespread use. An optimized collaboration between technology and medicine, along with standardized processes, are essential for effectively integrating this technology into practice.

Surgical treatments of metastatic bone disease of the hip joint: a scoping review protocol

INTRODUCTION

Metastatic disease of the hip causes severe pain and is a serious threat to the patient's motor function. Surgery is required, but the actual efficacy is unclear, and there are many concerns for both patients and doctors. The purpose of this protocol is to conduct a scoping review for helping decisions of the intended audience.

METHODS AND ANALYSIS

This scoping review will be conducted according to the framework proposed by Arksey and O'Malley and reported in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols Extension for Scoping Reviews criteria. To answer our research questions, we will search Chinese and English databases using appropriate search terms, comb through clinical studies on surgical procedures for metastatic bone disease of the hip and incorporate visual charts and graphs to provide a comprehensive analysis and evaluation of the literature according to the criteria for basic characteristics, interventions and outcome indicators.

ETHICS AND DISSEMINATION

Since the data are publicly available, no ethical approval or participant consent is required. The results of the review will be published in an open-access peer-reviewed journal and presented at national and international conferences.

[Pathological fractures of the extremities]

The diagnostics and treatment of pathological fractures of the extremities differ from the approach for conventional fractures. Metastases from breast, bronchial, renal cell and prostate cancer are the predominant cause. Typically, patients present at over 50 years old present after an inadequate trauma. They often report symptoms or swelling in the affected region that already existed before the fracture. An underlying malignant disease is sometimes already known; however, occasionally this is manifested in the form of a fracture. The femur is affected in 74% of cases, followed by the humerus and the tibia. Important indications for the presence of a pathological fracture can even be obtained from conventional radiographs. The diagnostics are supplemented with further modalities depending on the treatment goal. Surgical treatment is the first choice as the fractures do not heal using conservative measures. In this context, a prognosis-stratified approach is recommended.

Conventional Manufacturing by Pouring Versus Additive Manufacturing Technology of β-Tricalcium Phosphate Bone Substitute Implants

The aim of the study was to compare conventional sintering with additive manufacturing techniques for β-TCP bioceramics, focusing on mechanical properties and biocompatibility. A "critical" bone defect requires surgical intervention beyond simple stabilization. Autologous bone grafting is the gold standard treatment for such defects, but it has its limitations. Alloplastic bone grafting with synthetic materials is becoming increasingly popular. The use of bone graft substitutes has increased significantly, and current research has focused on optimizing these substitutes, whereas this study compares two existing manufacturing techniques and the resulting β-TCP implants. The 3D printed β-TCP hybrid structure implant was fabricated from two components, a column structure and a freeze foam, which were sintered together. The conventionally fabricated ceramics were fabricated by casting. Both scaffolds were characterized for porosity, mechanical properties, and biocompatibility. The hybrid structure had an overall porosity of 74.4 ± 0.5%. The microporous β-TCP implants had a porosity of 43.5 ± 2.4%, while the macroporous β-TCP implants had a porosity of 61.81%. Mechanical testing revealed that the hybrid structure had a compressive strength of 10.4 ± 6 MPa, which was significantly lower than the microporous β-TCP implants with 32.9 ± 8.7 MPa. Biocompatibility evaluations showed a steady increase in cell proliferation over time for all the β-TCP implants, with minimal cytotoxicity. This study provides a valuable insight into the potential of additive manufacturing for β-TCP bioceramics in the treatment of bone defects.

[Update on 3D printing in the surgery of musculoskeletal tumors]

The importance of 3D printing applications in the surgery of musculoskeletal tumors has increased in recent years. Even prior to the era of 3D printing, computer-assisted techniques, such as navigation, have proved their utility. Due to the variable appearance of bone tumors, there is a need for individual solutions. The 3D printing can be used for the development of anatomical demonstration models, the construction of patient-specific instruments and custom-made implants. For these three applications, different regulatory hurdles exist. Especially for the resection of pelvic tumors, 3D printing technologies seem to provide advantages due to the complicated anatomy and the proximity to relevant neurovascular structures. With the introduction of titanium printing, construction of individualized implants that fit exactly into the defect became feasible.