The application of three-dimensional printed porous titanium implants (TIs) is compromised in patients suffering from diabetes mellitus (DM), which disturbs the normal process of implant osseointegration, resulting in fixation failure. It was possibly because of reactive oxygen species (ROS) overproduction at the bone−implant interface. A silk fibroin-based hydroxyapatite (SF/HA) hybrid material emerged as a novel biological material for accelerating new bone formation. We proposed that the SF/HA hybrid coated titanium implant (SHT) could mitigate DM-mediated impaired osseointegration, which had never been reported previously. To test this assumption and further elucidate the mechanisms, primary rabbit osteoblasts were seeded on TIs or SHTs and cultured with normal serum, diabetic serum (DS), DS + N-acetyl-L-cysteine (NAC) (a potent ROS inhibitor), and DS + LY294002 (a specific PI3K/Akt inhibitor) for osteoblast behavior examinations. An animal study was performed on diabetic rabbits implanted with the two kinds of implants for osseointegration tests. DM-mediated ROS overproduction caused osteoblastic biological dysfunctions and apoptotic injury, associated with suppression of PI3K/Akt signaling in osteoblasts cultured on a TI substrate. Of note, the SHT substrate significantly suppressed ROS overproduction under diabetic conditions, improved osteoblast functional recovery including ameliorative osteoblast adhesion and morphology, improved cellular proliferation and differentiation, and abrogated apoptosis, which exhibited the same effect as NAC administration on the TI. The in vitro results were further corroborated in vivo by enhanced osteogenesis and osseointegration of SHTs in diabetic rabbits. Moreover, the aforesaid promotive effects afforded by the SF/HA coating were totally abolished with administration of LY294002 for blocking PI3K/Akt signaling. The above results collectively demonstrated that the SF/HA hybrid coating significantly ameliorated DM-mediated impaired osseointegration of the TI via reactivation of the ROSmediated PI3K/Akt signaling pathway. The hybrid coating elicited a novel surface biofunctionalization strategy to attain favorable clinical performance of TI in diabetics.
Objective Inferior pole fractures of patella are notorious fractures where it is difficult to obtain rigid internal fixation by conventional methods. The objective of the study was to introduce the Hand Plating System (HPS), which was a novel surgical technique for inferior pole fractures of patella, and to report the radiological and clinical outcomes following the application of the surgical technique. Methods The study was designed as a retrospective cohort study. Between July 2017 and December 2018, 30 patients who were diagnosed with inferior pole fracture of the patella without additional orthopaedic injuries were enrolled in this case series. After X‐ray and 3D‐CT examinations, all patients underwent open reduction and internal fixation by HPS with or without supplementary cannulated screw and lag screw stabilization. The bony union time, final range of motion (ROM), Bostman score, visual analog scale (VAS), and complications were measured as the clinical outcomes under a minimum of 12 months of follow‐up. Results All of the operations went well with the mean operative time of 76.2 ± 15.3 min. Bony union achieved in all the cases at an average of 9.5 ± 1.4 weeks after surgery. There was no loss of reduction, fixative failure, or surgical implant removal during follow‐up. The average range of motion 1 year postoperatively was 0°–123.3°. The mean Bostman Score at the last follow‐up was 26.8 ± 2.1 with the satisfactory rate of 100%. The pain feeling during walking as measured by VAS averaged at 0.9 ± 1.3. No complications developed except for one case of poor incision healing, which healed eventually after surgical debridement. Conclusions HPS was demonstrated as a secure fixation and as a kind of tension band for inferior pole fractures of the patella. Satisfactory recovery of knee function and low complication rate, including no need for hardware removal, could be expected.
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