Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction:A systematic review

AIM:To evaluate whether anterior cruciate ligament(ACL) allograft irradiation is effective for sterility without compromising graft integrity and increasing failure rate.METHODS:A literature search was conducted using Pub Med,Cochrane,and Google.The following search terms were used:"Gamma irradiation AND anterior cruciate ligament AND allograft" with a return of 30 items.Filters used included:English language,years 1990-2015.There were 6 hits that were not reviewed,as there were only abstracts available.Another 5 hits were discarded,as they did not pertain to the topic of interest.There were 9 more articles that were excluded:Three studies were performed on animals and 6 studies were meta-analyses.Therefore,a total of 10 articles were applicable to review.RESULTS:There is a delicate dosing crossover where gamma irradiation is both effective for sterility without catastrophically compromising the structural integrity of the graft.Of note,low dose irradiation is considered less than 2.0 Mrad,moderate dose is between 2.1-2.4 Mrad,and high dose is greater than or equal to 2.5 Mrad.Based upon the results of the literature search,the optimal threshold for sterilization was found to be sterilization at less than 2.2 Mrad of gamma irradiation with the important caveat of being performed at low temperatures.The graft selection process also must include thorough donor screening and testing as well as harvesting the tissue in a sterile fashion.Utilization of higher dose(≥ 2.5 Mrad) of irradiation causes greater allograft tissue laxity that results in greater graft failure rate clinically in patients after ACL reconstruction.CONCLUSION:Allograft ACL graft gamma irradiatedwith less than 2.2 Mrad appears to be a reasonable alternative to autograft for patients above 25 years of age.

Correlative Analysis of Yanbian’s Primary Forestry Industry and Sub-industries

By selecting three indicators(timber cultivating and planting,timber harvesting,forest products),this paper uses grey relational degree to analyze the correlation between Yanbian’s primary forestry industry and sub-industries. Results show that there is a decline in the relational degree of three indicators concerning Yanbian’s primary forestry industry,but the relational degree of timber harvesting is still high and the relational degree of forest products is slightly increased.

Relational Analysis of Yanbian's Primary Industry of Forestry and Forestry Industry

In this paper,we use grey relational analysis method to systematically analyze the relational degree between Yanbian's forestry industry and three industries of forestry,and conclude that Yanbian's primary industry of forestry shows a downward trend in the development of forestry industry,so it is necessary to transform the traditional primary industry of forestry for the better development.