Systematic Reviews
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Jun 18, 2016; 7(6): 392-400
Published online Jun 18, 2016. doi: 10.5312/wjo.v7.i6.392
Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review
Jesse Dashe, Robert L Parisien, Antonio Cusano, Emily J Curry, Asheesh Bedi, Xinning Li
Jesse Dashe, Robert L Parisien, Antonio Cusano, Emily J Curry, Xinning Li, Depatment of Orthopaedic Surgery, Boston University School of Medicine - Boston Medical Center, Boston, MA 02118, United States
Asheesh Bedi, Depatment of Orthopaedic Surgery, University of Michigan School of Medicine, Ann Arbor, MI 48105, United States
Author contributions: Dashe J, Parisien RL, Cusano A and Curry EJ were in charge of manuscript write up and assisted with performing the systematic review; Dashe J, Parisien RL, Cusano A, Curry EJ, Bedi A and Li X all reviewed and approved the final version of this manuscript before submission; Bedi A and Li X designed the research study and performed critical review and edits of the manuscript.
Conflict-of-interest statement: All authors report no conflicts of interest regarding this manuscript.
Data sharing statement: All data for this manuscript is available by contacting the corresponding author at
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Xinning Li, MD, Department of Orthopaedic Surgery, Boston University School of Medicine - Boston Medical Center, 850 Harrison Avenue - Dowling 2 North, Boston, MA 02118, United States.
Telephone: +1-508-8163939 Fax: +1-617-4145226
Received: July 18, 2015
Peer-review started: July 23, 2015
First decision: October 17, 2015
Revised: January 23, 2016
Accepted: March 24, 2016
Article in press: March 25, 2016
Published online: June 18, 2016

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 PubMed, 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 irradiated with less than 2.2 Mrad appears to be a reasonable alternative to autograft for patients above 25 years of age.

Keywords: Anterior cruciate ligament reconstruction, Graft choice, Allograft, Gamma irradiation, Anterior cruciate ligament graft failure rate

Core tip: The dose of gamma irradiation is directly correlated with increased failure rate of allograft in both in vitro and in vivo studies. Optimal gamma irradiation dose is less than 2.2 Mrad and should be performed in the setting of a low temperature.