Internal fixation using fully threaded cannulated compression screws for fresh femoral neck fractures in adults.

OBJECTIVES: Internal fixation with multiple cannulated compression screws is an optional treatment for femoral neck fracture. Recently, fully threaded cannulated compression screws (FTCCS) have been introduced to fix fresh femoral neck fractures (FNF). The purpose of this study was to investigate the effectiveness of FTCCS. PATIENTS AND METHODS: Patients with FNF fixed by multiple FTCCS from February 1st, 2014 to August 31st, 2017 were included in this study. They were followed for at least 12 months postoperatively. Nonunion, osteonecrosis of the femoral head (ONFH), fixation failure, reoperation, and femoral neck shortening (FNS) were used to evaluate the outcomes. Risk factors including age, sex, fracture side, fracture displacement, fracture stability, fixation configuration, and screw numbers were analyzed. RESULTS: A total of 113 patients including 67 males and 46 females with an average age of 48.4 ± 13.4 years were included. The mean duration of follow-up was 27.1 months (range: 12-51 months). The incidence of nonunion, ONFH, fixation failure, and reoperation was 15.9%, 22.1%, 8.8%, and 24.8%, respectively. The rates of nonunion and reoperation were significantly higher in displaced fractures and unstable fractures. And patients with an unstable fracture had a higher risk of internal fixation failure. The median length of FNS was 2.9 mm (interquartile range: 0.9-6.5 mm, range: 0-17.5 mm). Age was a significant risk factor for FNS. CONCLUSIONS: The screw fixation method with FTCCS provided encouraging clinical results which may be a rational choice for the treatment of fresh FNF. Displaced fractures and unstable fractures were attributed to the higher incidence of complications. TRIAL REGISTRATION: ChiCTR, ChiCTR1800017200. Registered 17 July 2018-Retrospectively registered, http: www.chictr.org.cn/showprojen.aspx?proj=29182 .

Gadolinium-doped mesoporous calcium silicate/chitosan scaffolds enhanced bone regeneration ability.

Chitosan (CTS) and mesoporous calcium silicate (MCS) have been developed for bone defect healing; however, their bone regeneration capacity still does not satisfy the patients with bone diseases. Gadolinium (Gd) is accumulated in human bones, and plays a beneficial role in regulating cell performance and bone regeneration. We firstly constructed Gd-doped MCS/CTS (Gd-MCS/CTS) scaffolds by a lyophilization technology. The interconnected arrangement of CTS films lead to forming macropores by using ice crystals as templates during the lyophilization procedure, and the Gd-MCS nanoparticles dispersed uniformly on the macropore walls. The biocompatible chemical components and hierarchical pores facilitated the attachment and spreading of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Interestingly, the Gd dopants in the scaffolds effectively activated the Wnt/ß-catenin signaling pathway, resulting in excellent cell proliferation and osteogenic differentiation capacities. The osteogenic-related genes such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and collagen type1 (COL-1) were remarkably up-regulated by Gd-MCS scaffolds as compared with MCS scaffolds, and their expression levels increased in a positive correlation with Gd doping amounts. Moreover, in vivo rat cranial defect tests further confirmed that Gd-MCS/CTS scaffolds significantly stimulated collagen deposition and new bone formation. The exciting finding suggested the beneficial effects of Gd3+ ions on osteogenic differentiation and new bone regeneration, and Gd-MCS/CTS scaffolds can be employed as a novel platform for bone defect healing.

La-Doped mesoporous calcium silicate/chitosan scaffolds for bone tissue engineering.

Trace rare earth elements such as lanthanum (La) regulated effectively bone tissue performances; however, the underlying mechanism remains unknown. In order to accelerate bone defects especially in patients with osteoporosis or other metabolic diseases, we firstly constructed lanthanum-doped mesoporous calcium silicate/chitosan (La-MCS/CTS) scaffolds by freeze-drying technology. During the freeze-drying procedure, three-dimensional macropores were produced within the La-MCS/CTS scaffolds by using ice crystals as templates, and the La-MCS nanoparticles were distributed on the macropore walls. The hierarchically porous structures and biocompatible components contributed to the adhesion, spreading and proliferation of rat bone marrow-derived mesenchymal stem cells (rBMSCs), and accelerated the in-growth of new bone tissues. Particularly, the La3+ ions in the bone scaffolds remarkably induced the osteogenic differentiation of rBMSCs via the activation of the TGF signal pathway. A critical-sized calvarial-defect rat model further revealed that the La-MCS/CTS scaffolds significantly promoted new bone regeneration as compared with pure MCS/CTS scaffolds. In conclusion, the La-MCS/CTS scaffold showed the prominent ability in osteogenesis and bone regeneration, which showed its application potential for bone defect therapy.