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Objective:To retrospectively analyze the clinical effects and complications of alcohol inactivation, irradiation inactivation, and liquid nitrogen inactivation in the treatment of femur osteosarcoma in children, in an attempt to provide a theoretical basis for clinical selection of in vitro inactivation methods of tumor bone segment. Methods:The clinical data of 93 children with femur osteosarcoma admitted to the Department of Bone and Soft Tissue, the Affi-liate Cancer Hospital of Zhengzhou University from January 2008 to December 2017 were retrospectively analyzed, and 40 children, including 21 males and 19 females, aged 8-18 (13.65±2.87) years, who were treated with in vitro inactivation and replantation of autogenous tumor bone segment, were screened.Among these children, there was alcohol inactivation in 15 cases, irradiation inactivation in 12 cases, and liquid nitrogen inactivation in 13 cases.A comparison was drawn on these 3 inactivation methods with respect to bone healing time, bone healing rate, tumor recurrence rate, infection rate, fracture or fixation failure rate, and revision rate. Results:All those 40 children were subject to valid medical followed-up, with the alcohol inactivation group for (102.60±16.55) months, the irradiation inactivation group for (59.33±6.39) months, and the liquid nitrogen inactivation for (36.85±6.49) months.The difference in follow-up time of 3 groups was statistically significant ( P<0.05). Compared with other 2 groups, the index of bone healing time, bone healing rate, infection rate and revision rate in the alcohol inactivation group were unfavorable, which showed a significant difference (all P<0.05); However, there was no significant difference in the recurrence rate, fracture rate or fixation failure rate compared with other 2 groups (all P>0.05); There was no significant difference in all above indexes between the irradiation group and the liquid nitrogen group (all P>0.05). Conclusions:Three in vitro inactivation methods for the treatment of tumor bone segment are safe and reliable.The alcohol inactivated bone has a long healing time and more complications.Both irradiation inactivation and liquid nitrogen inactivation are clinical options, but irradiation inactivation requires professional equipment, which may limit the clinical application.
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BACKGROUND:Titanium alloy, a commonly used bone biomaterial, holds good biocompatibility and proper mechanical properties, but without osteointegration ability. Surface bioactive coating of titanium alloy can overcome such problems. OBJECTIVE:To review the application progress of surface bioactive coating on titanium alloys, and to explore the mechanism underlying its osteogenic induction. METHODS:PubMed and CNKI databases were searched for literatures concerning surface bioactive coating on titanium alloys published from January 2000 to March 2016, using the keywords oftitanium, titanium alloys, coating, surface modification, bonein English and Chinese, respectively. Through preliminary analysis, 42 eligible articles were selected. RESULTS AND CONCLUSION:The surface modification method has undergone the transition from surface roughening, oxidation, acidification treatment to the most widely used biomimetic coating technology. The surface biomimetic coatings of titanium alloys mainly include hydroxyapatite, bioactive glass, zeolite, which have been developed from a single coating to the composite coatings and gradient coatings. What's more, the bioactive factor or/and metal ions in the coating can improve the osteointegration of surface coating. Surface modification for titanium alloys is a complex process, during which, both the osteogenesis ability and the bonding strength between the coating and its substrate cannot be ignored. Improving the fabrication method of existing coatings and exploring new materials of biomimetic coatings are critical to achieve a high-quality surface coating modification.
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BACKGROUND:Surface modification of titanium surface to improve its biological activity is the research hotspot. Strontium-doped coating is considered to be an effective approach to promote the implant osseointegration. OBJECTIVE:To introduce the research progress of strontium-modified biomedical titanium al oys.METHODS:Articles related to the medical titanium al oys modified with strontium published from January 2000 to April 2016 were retrieved from CNKI and PubMed databases. The keywords were“titanium (Ti), strontium (Sr), bone, osteogenic”in Chinese and English, respectively. RESULTS AND CONCLUSION:Titanium al oys have been widely used in bone implantation because of their good biocompatibility and similar elasticity modulus with human bones. However, pure titanium al oys have poor bioactivity which leads to weak bone-implant contact. Surface modification is a good approach to enhance implant osseointegration. Sr-doped surface treatment can promote new bone formation and osseointegration. Most of the studies about Sr-doped modification are ongoing at the extracorporeal and animal experiment stage;therefore, further investigation is required to seek rapid, stable, available, safe and effective methods.
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BACKGROUND: Porosity has been proven to improve the stability of orthopedic implants, and the architecture of pores is considered as a significant factor to improve the osseointegration of implants. OBJECTIVE: To introduce the research advance in porous architecture. METHODS: WOS database was searched for the articles addressing the porous structure of the implants published from January 2000 to April 2016 using the keywords of scaffold, pore size, porosity, osteogenesis. The literatures were screened according to the inclusion and exclusion criteria.RESULTS AND CONCLUSION: (1) The stability of traditional implants cannot meet the requirements in some specific circumstances, while the implants with porosity can improve the stability due to its osteogenesis ability. (2) Porous structure is a hotspot, and the osseointegration of porous implants in vivo is explored through series of in vitro and in vivo experiments. (3) It has been shown that higher porosity, proper pore size, microporous morphology and microstructure of the pore wall may contribute to the growth and differentiation of bone tissue under enough mechanical support. (4) However, most studies on the porous implants are still on the in vivo and animal experimental stage, and its promoting effects on the osteogenesis and bone in-growth are needed to be investigated in depth.