Those study limitations are detailed here. The most significant issues with the first study (Rappe et al. 2007) include questionable follow-up methodology and a lack of information regarding the irradiation process used. The study followed up with *73% of irradiated graft patients compared with *93% of non-irradiated graft patients. It is unclear why a substantially fewer number of patients in the irradiated graft group returned for follow up care especially since they reportedly had significant graft failure (33%). Also, the method used to irradiate the grafts is unknown, e.g., the temperature of irradiation. The irradiation dose is given as 20-25 kGy and it is unknown if this is a true dose range and what the dose range of irradiation exposure actually was. In addition, other processing methods are unknown, including whether these grafts were also exposed to harsh solvents or cyclic pressures as performed by some banks, such that they may have been prone to damage from the higher irradiation dose used. Also, one surgeon reported twice the failure rate as the other in the study and the recipient age in relation to failures in both groups was not reported, making interpretation difficult. Finally, many tissue providers will routinely treat 'non-irradiated' or 'non-sterilized' grafts with 10-15 kGy doses of pre-processing irradiation for safety reasons so it remains unknown whether the control grafts were truly non-irradiated and also whether the irradiated grafts were double-dosed. There are also numerous concerns with the Sun et al. study (2009) . Only the target dosage is given (25 kGy) with unknown dose range. Also, these grafts were irradiated at room temperature and the grafts were not disinfected prior to irradiation (author, private communication). In addition, grafts were soaked in iodine prior to use. These graft treatments compromise any meaningful interpretation of the results. As significantly, the study has inconsistent results that possibly indicate an issue in either the surgery or measuring techniques. Unfortunately, the allograft patients exhibited a significant increase in duration of post-operative fever over autograft patients. The average duration of fever for an irradiated allograft patient was over 1 week (8.8 days) versus 4.7 days for the autograft patients. In the discussion, the authors state that this high fever rate ''was associated with…[different possibilities, or]…the real ability of tissue banks in our country [China] to process allografts''. The study also concludes that irradiated bone patellar-tendon bone (BPTB) allografts are clinically inferior to both nonirradiated BPTB allografts and BPTB autografts because of the laxity measurements with a KT-2000 arthrometer. The study reports only 31.3% of irradiated BPTB allografts had less than 3 mm of laxity while 85.3% of the non-irradiated and 87.8% of the autograft group had less than 3 mm of laxity. This is a surprising difference made even larger by the report of 34.4% of the irradiated group exhibiting more than 5 mm of laxity (defined as graft failure by the authors). These extreme percentages should indicate noteworthy irradiated graft patient dissatisfaction as well as significantly different results in other subjective and objective tests. In contrast, however, there were no significant differences in the overall IKDC scores between any of the three groups. Irrgang et al. (1998) noted that the IKDC was an especially rigorous evaluation tool because the lowest score received in any given area becomes the overall score instead of combining the averages like other evaluation systems. This makes the validity of the Sun et al. study even more uncertain since laxity measurement is a component of the overall IKDC score. It is unclear how there was no significant difference in the overall IKDC score among the 3 groups when the irradiated graft group had such extreme laxity measurements. Furthermore, the objective range of motion (ROM), vertical jump, and one-leg hop tests found no significant difference in any of the groups. There were also no significant differences among the 3 groups for mean Lysholm, Tegner, or Cincinatti knee scores. Moreover, there was not a significant difference in patients' satisfaction with their ability to participate in sports in any of the groups. One would expect significant differences in all or most of these tests and responses if 68.7% of irradiated allograft patients had greater than 3 mm laxity. The IKDC system is one of the best evaluation tools to measure ACL reconstruction results (Foster et al. 2010 ) and the results of this test and all the others should have been balanced against the arthrometer measurements. This balance is particularly important because there may be no correlation between laxity measurements and functional outcome (Mirzayan 2005) . Pollet et al. (2005) investigated this correlation in a prospective, clinical study of 29 ACL deficient patients with an average 33 month followup. After comparing anterior knee laxity, questionnaire based on IKDC score, sports activity rating scale (SARS), activities of daily living (ADL), and other tests, the study found ''no correlation between the joint laxity and the functional outcome score.'' This lack of correlation is actually supported by the Sun et al. (2009) study in which, according to the authors, almost 4 times as many irradiated allograft patients had graft failure based on laxity measurements but there was no statistical difference in patients' satisfaction in their postoperative sports activity or overall IKDC score. At the very least, the inconsistent results and non-standard tissue treatment methods should have given the authors pause before making the recommendation to completely discontinue use of irradiation to sterilize allografts. Prodromos et al. (2007) performed a meta-analysis on stability of autografts and allografts for ACL reconstruction. This included a sub-analysis of nonirradiated vs. irradiated grafts. They came to the following conclusion: ''The direct deleterious effects of graft radiation are an additional area of concern. The stability rate in the radiation-sterilized grafts in this study was strikingly low.'' However, the data used to draw this conclusion is heavily skewed by one particular study. In detail, to examine irradiated tendons, the authors included three studies, here called Noyes, Gorschewsky, and Rihn. They based conclusions on normal stability rate (which was 43% for irradiated vs. 63% for non-irradiated allograft) and abnormal stability rates (which was 31% for irradiated and 12% for non-irradiated allografts). This certainly appears negative for irradiated allografts. However, the irradiated group included in the Gorschewsky study included more grafts, and thus was more heavily weighted, than the other two studies combined and, most importantly, included a process method with steps containing acetone, sodium hydroxide, and hydrogen peroxide. These harsh chemicals can be quite damaging to soft tissues and no conclusion can be drawn from the fact that these grafts were also irradiated unless the proper controls were included (treatment with these chemicals without irradiation). If this single study is removed from the meta-analysis, then the comparisons become: normal stability rates of 62% for irradiated vs. 63% for non-irradiated allografts and abnormal stability rates of 15% for irradiated and 12% for non-irradiated allografts, respectively. Thus, the exclusion of the harsh chemically treated graft data set, yields results suggesting equivalent performance for irradiated vs. non-irradiated grafts. Further, note that this study that was, in fact positive regarding irradiation reported on tissue irradiated with 2.5 Mrad, which is even above commonly used levels of 13-18 kGy, further suggesting the utility of terminal sterilization via gamma irradiation.