Compared with non-degradable materials, biodegradable biomaterials play an increasingly important role in the repairing of severe bone defects, and have attracted extensive attention from researchers. In the treatment of bone defects, scaffolds made of biodegradable materials can provide a crawling bridge for new bone tissue in the gap and a platform for cells and growth factors to play a physiological role, which will eventually be degraded and absorbed in the body and be replaced by the new bone tissue. Traditional biodegradable materials include polymers, ceramics and metals, which have been used in bone defect repairing for many years. Although these materials have more or fewer shortcomings, they are still the cornerstone of our development of a new generation of degradable materials. With the rapid development of modern science and technology, in the twenty-first century, more and more kinds of new biodegradable materials emerge in endlessly, such as new intelligent micro-nano materials and cell-based products. At the same time, there are many new fabrication technologies of improving biodegradable materials, such as modular fabrication, 3D and 4D printing, interface reinforcement and nanotechnology. This review will introduce various kinds of biodegradable materials commonly used in bone defect repairing, especially the newly emerging materials and their fabrication technology in recent years, and look forward to the future research direction, hoping to provide researchers in the field with some inspiration and reference.

Aberrant activation of Wnt/β-catenin signaling drives proliferation of bone sarcoma cells

Femoral neck fracture is considered a difficult fracture to treat and often gives rise to unsatisfactory treatment results. Cannulated cancellous screws (CCS) or a sliding hip screw (SHS) are the mainstream internal fixations used for osteosynthesis of femoral neck fractures. There is a need to integrate existing data through a meta-analysis to investigate the safety and effectiveness of CCS and SHS in the treatment of femoral neck fractures. According to the Cochrane Handbook for Systematic Reviews of Interventions, we screened for the relevant studies by searching Google Scholar, the Cochrane Controlled Trials Register, the Cochrane Library, Web of Science, EMBASE, and PubMed. The PICOS criteria was used to make sure the included studies fulfilled the inclusion criteria. Pooled data showed that there were no significant differences between the SHS and CCS groups for the Harris Hip Score. Significant differences were found between the SHS and CCS groups in terms of union time, postoperative complications, blood loss, operation time, incision length and length of hospital stay. Although the SHS and CCS groups showed similar functional recovery in treatment of femoral neck fracture in terms of the Harris Hip Score, the SHS group showed fewer postoperative complications and faster union time for patients with femoral neck fractures. Therefore, compared with CCS, the use of SHS may be a more effective treatment of femoral neck fractures.

Continuous femoral nerve block (CFNB) is considered the preferred analgesia after TKA. However, it may weaken quadriceps muscle strength, subsequently increasing the risk of falling. Adductor canal block (ACB) is a new sensory block technique that effectively relieves postoperative pain while preserving quadriceps strength. Thias meta-analysis was conducted to determine whether ACB of CFNB provides better pain relief and functional recovery after TKA. The PubMed, Embase, Web of Science and Cochrane Library databases were comprehensively searched. Seven studies comparing ACB with CFNB in patients with TKA were enrolled in our meta-analysis. Review Manager 5.3 for Windows was used to analyse the extracted data. Compared with the CFNB group, the ACB exhibited a significant decrease in visual analogue scale (VAS) score at rest within 24 h (p < 0.00001), as well as significant decreases in the length of hospital stay (P < 0.0001) and post-operative nausea (P = 0.03). ACB patients also exhibited greater improvements in ambulation ability (P = 0.01) and ambulation distance (P < 0.00001). There were no significant differences in the VAS score at rest 8 and 48 h following surgery, nor in the ambulation VAS score and opioid consumption two days following surgery. Compared with CFNB, ACB provides equally effective analgesia after TKA. ACB results in fast pain relief and early ambulation while decreasing post-operative nausea. ACB thus has the potential to replace CFNB as the gold standard for pain management in TKA patients.