At present, bone nonunion and delayed union are still difficult problems in orthopaedics. Since the discovery of bone morphogenetic protein (BMP), it has been widely used in various studies due to its powerful role in promoting osteogenesis and chondrogenesis. Current results show that BMPs can promote healing of bone defects and reduce the occurrence of complications. However, the mechanism of BMP in vivo still needs to be explored, and application of BMP alone to a bone defect site cannot achieve good therapeutic effects. It is particularly important to modify implants to carry BMP to achieve slow and sustained release effects by taking advantage of the nature of the implant. This review aims to explain the mechanism of BMP action in vivo, its biological function, and how BMP can be applied to orthopaedic implants to effectively stimulate bone healing in the long term. Notably, implantation of a system that allows sustained release of BMP can provide an effective method to treat bone nonunion and delayed bone healing in the clinic.

Objective: A systematic review and meta-analysis were used to directly evaluate the direct anterior approach (DAA) and the posterior approach (PA) for early efficacy and safety of total hip arthroplasty (THA). Methods: Control-led trials assessing DAA and PA for the efficacy and safety of THA were searched in the database. Articles were reviewed according to predetermined inclusion and exclusion criteria; the quality of the methodology included in a given study was strictly assessed before data extraction. Moreover, meta-analysis was performed for outcomes that can be combined; otherwise, descriptive analysis was performed. Results: There were 20 articles included, with a total of 7377 patients. Among these, 3728 and 3649 cases were in the DAA and PA groups, respectively. There was no difference between the DAA and PA groups at postoperative week 2 in the number of patients using the assistive ambulatory device or in time needed to completely discontinue all assistive ambulatory devices. Descriptive analysis found that DAA was slightly better than PA regarding early functional recovery and activity after surgery, as well as postoperative pain relief. Hospitalisation stay in the DAA group was shorter than in the PA group, in which the patients had a shorter operative time. Radiographic outcomes showed that there was little difference in prosthetic position between the DAA and PA groups. The proportions of intraoperative fractures and postoperative lateral cutaneous nerve of the thigh (LCNT) neuropraxia were significantly higher in the DAA group than in patients who underwent PA. Conclusion: Compared with PA, DAA presents superior early recovery following THA.

Tumor resection and treatment of trauma-related regional large bone defects have major challenges in the field of orthopedics. Scaffolds that treat bone defects are the focus of bone tissue engineering. 3D printing porous titanium alloy scaffolds, prepared via electron beam melting technology, possess customized structure and strength. The addition of a growth factor coating to the scaffold introduces a specific form of biological activation. Vascular endothelial growth factor (VEGF) is key to angiogenesis and osteogenesis in vivo. We designed a porous titanium alloy scaffold/thermosensitive collagen hydrogel system, equipped with VEGF, to promote local osseointegration and angiogenesis. We also verified the VEGF release via thermosensitive collagen and proliferation and induction of the human umbilical vein endothelial cells (HUVECs) via the composite system in vitro. In vivo, using microscopic computed tomography (Micro-CT), histology, and immunohistochemistry analysis, we confirmed that the composite scaffold aids in angiogenesis-mediated bone regeneration, and promotes significantly more bone integration. We also discovered that the composite scaffold has excellent biocompatibility, provides bioactive VEGF for angiogenesis and osteointegration, and provides an important theoretical basis for the restoration of local blood supply and strengthening of bone integration.

Osteonecrosis of the femoral head (ONFH) is a potentially disabling orthopedic condition that requires total hip arthroplasty in most late-stage cases. However, mechanisms underlying the development of ONFH remain unknown, and the therapeutic strategies remain limited. Growth factors play a crucial role in different physiological processes, including cell proliferation, invasion, metabolism, apoptosis, and stem cell differentiation. Recent studies have reported that polymorphisms of growth factor-related genes are involved in the pathogenesis of ONFH. Tissue and genetic engineering are attractive strategies for treating early-stage ONFH. In this review, we summarized dysregulated growth factor-related genes and their role in the occurrence and development of ONFH. In addition, we discussed their potential clinical applications in tissue and genetic engineering for the treatment of ONFH.