Objective To observe the clinical effect of headless compression Screw (HCS)under arthroscope in the treat-ment of patella fracture.Methods Nineteen patients of patella transverse fractures were selected,all of them were treated with HCS fixation under arthroscope,reviewed and followed-up after surgery.Results X-ray examination after surgery of 3 -5 weeks found that the fracture lines blurred or disappeared,and the patella articular surface was smooth without displacement.The healing time of fracture was 8 weeks on average after operation;There was no statistical difference in the range of the knee joint in the af-fected side in (135.42±5.82)°and the contralateral side in (139.38±6.55)°(P >0.05);The knee Lysholm score of the last follow-up was 86-100 points[(93.7±4.14)points],which was significantly higher than the preoperative score of 65.7 (P <0.05);There was no fracture displacement in the period of followed-up,drop of internal fixator,fracture and other complications.Conclusion HCS fixation under arthroscope in treatment of patella fracture is effective.The joint function recovered quickly with less complica-tion.It could be one of the effective methods for the treatment of patella transverse fracture.

BACKGROUND:Previous research by the research team found that domestically produced porous tantalum is beneficial for early adhesion and proliferation of MG63 cells,and can be used as a scaffold material for bone tissue engineering. OBJECTIVE:To investigate the effect of domestic porous tantalum modified by osteogenic induction factor slow-release system on the adhesion,proliferation,and differentiation of MG63 cells. METHODS:Osteogenic induction factor slow-release system was constructed by adding 15%volume fraction of osteogenic factor solution to poly(lactic-co-glycolic-acid)gel.The passage 3 MG63 cells were inoculated on a porous tantalum surface(control group),porous tantalum surface coated with poly(lactic-co-glycolic-acid)copolymer gel(gel group),and porous tantalum surface coated with osteoblastic induction factor slow-release system(slow-release system group),and co-cultured for 5 days.The surface cytoskeleton of the material was observed by phalloidine staining.Cell proliferation was detected by flow cytometry.Western blot assay and RT-qPCR were used to detect the protein and mRNA expressions of type Ⅰ collagen,osteopontin,and RUNX-2 on the surface cells of the material. RESULTS AND CONCLUSION:(1)Phalloidine staining showed that MG63 cells adhered to and grew on the surface and inside of the three groups of porous tantalum,and the matrix secreted by the cells covered the surface of the material.(2)Flow cytometry showed that the cell proliferation in the slow-release system group was faster than that in the control group and the gel group(P<0.05).(3)Western blot assay and RT-qPCR showed that the protein and mRNA expressions of type Ⅰ collagen,osteopontin,and RUNX-2 in the slow-release system group were higher than those in the control group and gel group(P<0.05).(4)The results showed that the domestic porous tantalum modified by the osteogenic induction factor slow-release system was beneficial to the adhesion,proliferation,and differentiation of MG63 osteoblasts.