No abstract

Background: Complicated acetabular fractures comprise the most challenging field for orthopedists. The purpose of this study was to develop three-dimensional printed patient-specific (3DPPS) Ti-6Al-4 V plates to treat complicated acetabular fractures involving quadrilateral plate (QLP) disruption and to evaluate their efficacy. Methods: Fifty patients with acetabular fractures involving QLP disruption were selected between January 2016 and June 2017. Patients were divided into a control group (Group A, 35 patients) and an experimental group (Group B, 15 patients), and were treated by the conventional method of shaping reconstruction plates or with 3DPPS Ti-6AL-4 V plates, respectively. The efficacy of Ti-6AL-4 V plates was evaluated by blood loss, operative time, reduction quality, postoperative residual displacement, and complications. Results: The operative time and blood loss in Group B were reduced compared to Group A, and the difference was statistically significant (P < 0.05). There was no significant difference in reduction quality between the two groups (P > 0.05). Reduction quality in Group B was anatomic in 10 (66.7%), satisfactory in four (26.7%), and poor in one (6.7%). In Group A, they were anatomic in 18 (51.4%), satisfactory in 13 (37.1%), and poor in four (11.4%). Residual displacement in Group B was less than that in Group A, and the difference was statistically significant (P < 0.05). In Group B, one case exhibited loosening of the pubic screw postoperatively. In Group A, there was one case of wound infection, one of deep vein thrombosis (DVT) in the ipsilateral lower limb, one case of traumatic arthritis and two obturator nerve injuries.

Heart disease is the main cause of death worldwide. Because death of the myocardium is irreversible, it remains a significant clinical challenge to rescue myocardial deficiency. Cardiac tissue engineering (CTE) is a promising strategy for repairing heart defects and offers platforms for studying cardiac tissue. Numerous achievements have been made in CTE in the past decades based on various advanced engineering approaches. 3D bioprinting has attracted much attention due to its ability to integrate multiple cells within printed scaffolds with complex 3D structures, and many advancements in bioprinted CTE have been reported recently. Herein, we review the recent progress in 3D bioprinting for CTE. After a brief overview of CTE with conventional methods, the current 3D printing strategies are discussed. Bioink formulations based on various biomaterials are introduced, and strategies utilizing composite bioinks are further discussed. Moreover, several applications including heart patches, tissue-engineered cardiac muscle, and other bionic structures created via 3D bioprinting are summarized. Finally, we discuss several crucial challenges and present our perspective on 3D bioprinting techniques in the field of CTE.

This study was aimed to improve the surgical accuracy of plating and screwing for complicated tibial plateau fracture assisted by 3D implants library and 3D-printed navigational template. Clinical cases were performed whereby complicated tibial plateau fractures were imaged using computed tomography and reconstructed into 3D fracture prototypes. The preoperative planning of anatomic matching plate with appropriate screw trajectories was performed with the help of the library of 3D models of implants. According to the optimal planning, patient-specific navigational templates produced by 3D printer were used to accurately guide the real surgical implantation. The fixation outcomes in term of the deviations of screw placement between preoperative and postoperative screw trajectories were measured and compared, including the screw lengths, entry point locations and screw directions. With virtual preoperative planning, we have achieved optimal and accurate fixation outcomes in the real clinical surgeries. The deviations of screw length was 1.57 ± 5.77 mm, P > 0.05. The displacements of the entry points in the x-, y-, and z-axis were 0.23 ± 0.62, 0.83 ± 1.91, and 0.46 ± 0.67 mm, respectively, P > 0.05. The deviations of projection angle in the coronal (x-y) and transverse (x-z) planes were 6.34 ± 3.42° and 4.68 ± 3.94°, respectively, P > 0.05. There was no significant difference in the deviations of screw length, entry point and projection angle between the ideal and real screw trajectories. The ideal and accurate preoperative planning of plating and screwing can be achieved in the real surgery assisted by the 3D models library of implants and the patient-specific navigational template. This technology improves the accuracy and efficiency of personalized internal fixation surgery and we have proved this in our clinical applications.

Antiadhesive hydrogels have been developed for preventing the formation of postoperative adhesions. However, it is challenging to design an injectable hydrogel with superior tissue retention properties that can be easily administered during minimally invasive surgical procedures to prevent the development of postsurgical adhesions. In this study, an injectable asymmetric‐adhesive hydrogel is fabricated using photocurable catechol‐grafted hyaluronic acid (HAD) for use during minimally invasive procedures to prevent the development of postoperative adhesions. The hydrogel exhibits superior tissue retention properties and favorably inhibits postoperative adhesion formation. This is the first time that an injectable hydrogel is designed via photocrosslinking to control asymmetric‐adhesive capability. The results show that laparoscopically delivered HAD precursor acts as a wet adhesive on the injured cecum, while its outward‐facing side is nonadherent after photocrosslinking. Intriguingly, the HAD acts as a physical barrier and polyanion trap to neutralize scavenger receptors, thereby inhibiting collagen deposition and uncontrolled recruitment of GATA6+ cavity macrophages. Furthermore, the HAD significantly downregulates the expression of fibrosis‐related and proinflammatory cytokines and promotes macrophage polarization. These results demonstrate that injection of the hydrogel can be readily integrated into laparoscopic surgery. Moreover, the HAD may be suitable for preventing adhesion formation after minimally invasive surgical procedures.