IMproving facial PRosthesis construction with contactlESs Scanning and Digital workflow (IMPRESSeD): study protocol for a feasibility crossover randomised controlled trial of digital versus conventional manufacture of facial prostheses in patients with orbital or nasal facial defects.

BACKGROUND: Facial prostheses can have a profound impact on patients' appearance, function and quality of life. There has been increasing interest in the digital manufacturing of facial prostheses which may offer many benefits to patients and healthcare services compared with conventional manufacturing processes. Most facial prosthesis research has adopted observational study designs with very few randomised controlled trials (RCTs) documented. There is a clear need for a well-designed RCT to compare the clinical and cost-effectiveness of digitally manufactured facial prostheses versus conventionally manufactured facial prostheses. This study protocol describes the planned conduct of a feasibility RCT which aims to address this knowledge gap and determine whether it is feasible to conduct a future definitive RCT. METHODS: The IMPRESSeD study is a multi-centre, 2-arm, crossover, feasibility RCT with early health technology assessment and qualitative research. Up to 30 participants with acquired orbital or nasal defects will be recruited from the Maxillofacial Prosthetic Departments of participating NHS hospitals. All trial participants will receive 2 new facial prostheses manufactured using digital and conventional manufacturing methods. The order of receiving the facial prostheses will be allocated centrally using minimisation. The 2 prostheses will be made in tandem and marked with a colour label to mask the manufacturing method to the participants. Participants will be reviewed 4 weeks following the delivery of the first prosthesis and 4 weeks following the delivery of the second prosthesis. Primary feasibility outcomes include eligibility, recruitment, conversion, and attrition rates. Data will also be collected on patient preference, quality of life and resource use from the healthcare perspective. A qualitative sub-study will evaluate patients' perception, lived experience and preference of the different manufacturing methods. DISCUSSION: There is uncertainty regarding the best method of manufacturing facial prostheses in terms of clinical effectiveness, cost-effectiveness and patient acceptability. There is a need for a well-designed RCT to compare digital and conventional manufacturing of facial prostheses to better inform clinical practice. The feasibility study will evaluate key parameters needed to design a definitive trial and will incorporate early health technology assessment and a qualitative sub-study to identify the potential benefits of further research. TRIAL REGISTRATION: ISRCTN ISRCTN10516986). Prospectively registered on 08 June 2021,  https://www.isrctn.com/ISRCTN10516986 .

The use of 3D printing technology in limb reconstruction. Inspirations and challenges.

The management of septic non-unions with associated bone necrosis is challenging, especially when the resulting bone defect after the debridement is extensile. Different techniques have been described in the literature for the treatment of these demanding cases, with the most prominent being free vascularized Fibular graft and bone transport with distraction osteogenesis principles. Recently, 3D printing technology has been increasingly utilized in many complex orthopaedic pathologies. However, the application of those advancements regarding septic non-unions with residual bone defect has not been previously studied. This study presents a novel 3D printing technique for the management of an infected critical bone deficit of the tibia. Queries, challenges and future perspectives concerning the recruiting of 3D printing technology in limb reconstruction are also being discussed. Clinical Evidence Level: IV.

Clinical evaluation of 3D-printed zirconia crowns fabricated by selective laser melting (SLM) for posterior teeth restorations: Short-term pilot study.

Background/purpose: Zirconia crowns (ZrC) without veneering porcelain have become an effective alternative in clinical practice. Monolithic zirconia restorations fabricated by the dry milling method do not have acceptable clinical properties. This study evaluated the periodontal qualities of three-dimensional printed ZrC using the modified United States Public Health Service (USPHS) criteria. Materials and methods: A total of 15 patients who required dental crowns were recruited, and all 15 teeth were restored with digital 3D-printed ZrC. All crowns were assessed at the time of crown placement and 2, 6, and 24 weeks post-placement. Clinical parameters, including plaque index, gingival index, probing depth, crown marginal integrity, and attrition of the antagonist's teeth, were evaluated and recorded. Results: According to the Modified California Dental Association quality evaluation system, 100% of the crowns received satisfactory grades. Despite the significant increase in plaque index and gingival index at two weeks post-ZrC placement, there was no deterioration in probing depth. Moreover, there was discard usage of ZrC on the antagonist's teeth at 24 weeks posttreatment. Of the 15 crowns, one tooth had to be extracted due to a vertical root fracture. Overall, the digital 3D-printed crowns showed no adverse effects on periodontal tissues after 24 weeks of follow-up. Conclusion: The 3D-printed ZrC showed no periodontal problems. It can serve as an alternative for patients, particularly those with high esthetic expectations.

Application of 3D printing navigation template in hip arthroplasty / 国际外科学杂志

Hip arthroplasty is a common surgical method with good clinical effect. However, there are many influencing factors, among which the position of prosthesis is the key factor determining the prognosis. At present, 3D printing technology is widely used in hip replacement, which has an important effect in improving the position of hip replacement prosthesis. This paper reviews the application of 3D printing guide plate in hip arthroplasty.

3D printing-assisted percutaneous balloon dilatation plasty for treatment of osteoporotic calcaneal fractures of Sanders type Ⅱ or Ⅲ in the elderly patients / 中华创伤骨科杂志

Objective:To compare the clinical efficacy between 3D printing-assisted percutaneous balloon dilatation calcaneal plasty (3D-PCP) and conventional open reduction and internal fixation (ORIF) via the extended lateral L-shaped approach in the treatment of osteoporotic calcaneal fractures of Sanders type Ⅱ or Ⅲ in the elderly patients.Methods:Retrospectively analyzed were the data of 36 elderly patients with osteoporotic calcaneal fracture of Sanders type Ⅱ or Ⅲ who had been surgically treated at Department of Orthopaedics, Yixing People's Hospital from June 2012 to June 2018. According to their treatment methods, the patients were divided into a 3D-PCP group [16 cases, 9 males and 7 females with an age of (73.0 ± 3.4) years] and an ORIF group [20 cases, 8 females and 12 females with an age of (71.4 ± 2.6) years]. The 2 groups were compared in terms of hospital stay, operation time, intraoperative fluoroscopy frequency, suture removal time, weight bearing time, fracture healing time, visual analogue scale (VAS) for the surgical site 2 days and one year after surgery, American Foot and Ankle Surgery Association (AOFAS) ankle-hindfoot score, calcaneal imaging parameters (B?hler angle, Gissane angle, and length, width and height of the calcaneus axis) at 2 days and one year after surgery, and postoperative complications.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P > 0.05). All patients were followed up for 14 to 18 months (mean, 15.6 months). Compared with the ORIF group, the 3D-PCP group had significantly shorter hospital stay, significantly shorter operation time, significantly earlier suture removal, significantly earlier weight-bearing, significantly lower VAS scores at 2 days after surgery, significantly higher AOFAS ankle-hindfoot scores at one month after surgery, but significantly more times of intraoperative fluoroscopy (all P < 0.05). In all patients, the VAS scores at 2 days after surgery were significantly lower than those before surgery, and those at one year after surgery significantly lower than those at 2 days after surgery ( P < 0.05). In all patients, the AOFAS ankle-hindfoot scores at one month after surgery were significantly higher than those before surgery ( P < 0.001). In the ORIF group, the AOFAS ankle-hindfoot scores at one year after surgery were significantly higher than those at one month after surgery ( P < 0.05), but in the 3D-PCP group there was no such a significant difference between one year and one month after surgery ( P > 0.05). There was no significant difference in VAS score, AOFAS score, fracture healing time or postoperative imaging parameters between the 2 groups at one year after surgery ( P > 0.05). There was no significant difference either in the incidence of complications between the 2 groups ( P > 0.05). Conclusion:In the treatment of osteoporotic calcaneal fractures of Sanders type Ⅱ or Ⅲ in the elderly patients, compared with conventional ORIF, 3D-PCP shows advantages of shorter operation time, minimal invasion, quicker incision healing, shorter hospital stay, earlier weight-bearing exercise, and better functional recovery but a disadvantage of increased times of intraoperative fluoroscopy.

Study on traces left on a mechanical lock picked by a 3D printed key in toolmarks examination.

The three-dimensional (3D) printed key is a key that can be manufactured from its virtual model by means of a 3D printer. This research focuses on the picking feasibilities and traces that can be observed and exploited from a forensic point of view after the picking of such type of keys. In this paper, 40 printed keys were manufactured using three different polymer materials (white resin, white nylon powder and black ABS). All the experiments were carried out under controlled conditions to allow the collections of data and traces produced by the picking. Of the 40 prints, only 38 picked the locks and the total picking ratio was 95 percent, meaning that a 3D printed key using polymer materials can be used to pick a lock. Elements of lock - pins and keyways - appeared to carry polymer materials (flakes or pieces) transferred from the prints during picking process. Additional, characteristic marks of a 3D printed key on the surface of pins was identical to those of an original key, but not similar to those of other picking tools. Indeed, this method could not create more marks on the bits of an original key while striations were left by the picking method using a duplicated key. Besides, FT-IR was a useful method of analyzing the type of polymer material used. When receiving original keys and a lock suspected to be picked in a crime scene, the toolmark examiners can quickly determine whether or not the lock was picked by a 3D printed key based on the examination results of these traces.

Facile Strategy on Hydrophilic Modification of Poly(ε-caprolactone) Scaffolds for Assisting Tissue-Engineered Meniscus Constructs In Vitro.

Poly(ε-caprolactone) (PCL) derived scaffolds have been extensively explored in the field of tissue-engineered meniscus (TEM) originating from their good biosafety and biomechanical properties. However, the poor intrinsic hydrophobicity severely hindered their wide applications for the scaffold-assisted tissue regeneration. Herein, we developed a simple strategy on surface modification of three-dimensional (3D) PCL scaffolds via a simply soaking treatment of sodium hydroxide (NaOH) solutions to increase the hydrophilicity and roughness of scaffolds' surfaces. We investigated the effect of hydrolysis degree mediated by NaOH solutions on mechanical properties of 3D scaffolds, considering the importance of scaffolds' resistance to internal force. We also investigated and analyzed the biological performances of mesenchymal stromal cells (MSCs) and meniscal fibrocartilage cells (MFCs) onto the scaffolds treated or untreated by NaOH solutions. The results indicated that hydrophilic modification could improve the proliferation and attachment of cells on the scaffolds. After careful screening process condition, structural fabrication, and performance optimization, these modified PCL scaffolds possessed roughened surfaces with inherent hierarchical pores, enhanced hydrophilicity and preferable biological performances, thus exhibiting the favorable advantages on the proliferation and adhesion of seeded cells for TEM. Therefore, this feasible hydrophilic modification method is not only beneficial to promote smarter biomedical scaffold materials but also show great application prospect in tissue engineering meniscus with tunable architectures and desired functionalities.

Double stenting with silicone and metallic stents for malignant airway stenosis.

For severe malignant airway stenosis, there are several types of commercially available airway stents, and each has its own advantages and disadvantages. We herein describe the safety and efficacy of combination stenting with silicone and metallic stents for patients with extended malignant airway stenosis. Seven patients with malignant airway stenosis were treated via combination stenting with a silicone stent and a metallic stent for extended airway stenosis from the central to peripheral airways. Five patients were diagnosed with advanced esophageal cancer, two of whom had tracheoesophageal fistulas. One patient had adenoid cystic carcinoma, and another had mediastinal tumor. There were no specific complications related to the double stenting. Combination stenting with silicone and metallic stents proved to be a safe option for patients with severe, extended, and complicated malignant airway stenosis.

The present status and future prospects of application of digital medical technology in general surgery in China / 中华外科杂志

It has been almost 10 years since digital medical technology has started to becommonly used in general surgery in China.Led by advances in three dimensional(3D) visualization technology, virtual reality, simulation surgery, and 3D printing, digital medical technology have played important roles in changing the current practice of general surgery in China to become more effective by improving diagnostic accuracy and a better choice of therapeutic procedure with a resultant increased surgical success rate and a decreased surgical risks.Furthermore, education of medical students and young doctors become better and easier.