Different sterilization and disinfection methods used for human tendons – a systematic review using mechanical properties to evaluate tendon allografts

Abstract

Background It is important to know the biomechanical properties of an allograft. This is because when looking to do a transplant of a tendon, the tendon must have very similar biomechanical properties to the original tendon. To use tendon allografts, it is critical to properly sterilize the tendon before implantation. In past decades, several sterilization procedures have been used. This study aimed to systematically evaluate the existing literature to compare the values of failure load/ultimate strength and Young’s modulus of elasticity of different sterilization methods on commonly used tendon allografts. Five major scientific literature databases (Web of Science, Science Direct, Scopus, PLOS ONE, Hindawi) and additional sources were used. Results Studies used had to show a particular sterilization method. Studies were identified to meet the following inclusion criteria: is a controlled laboratory study, gamma irradiation (dose reported), and other sterilization methods. Search for publications dated between 1991 and March 31st, 2020. The database search and additional sources resulted in 284 records. Two hundred thirty records eliminated during the screening for various reasons. The number of articles used in the final synthesis was 54. Conclusions Identified sterilization methods (gamma irradiation, ethylene oxid, supercritical carbon dioxide (SCCO2), BioCleanse, Electron Beam) are offered as a catalog of potential methods. As a result of the broadness of the present research, it provides an overview of sterilization methods and their effect on the mechanical properties (failure load and Young’s modulus of elasticity) of tendons. It does not stand for the state-of-the-art of any single process. Based on a systematic literature review, we recommend freezing and gamma irradiation or electron beam at 14.8–28.5 kGy. These methods are effective at keeping or improving the mechanical properties, while fully sterilizing the inside and the outside of the tendon. Other sterilization method (ethylene oxide, supercritical carbon dioxide (SCCO2), BioCleanse) deteriorated the mechanical properties. These methods are not recommended.

Optimal Graft Choice in Athletic Patients with Anterior Cruciate Ligament Injuries: Review and Clinical Insights

“… 3 , 22–25 Allograft has its main advantages of lack of donor site morbidity, better control over graft size, shorter operative time, and improved cosmesis. 3 , 26 , 27 Disadvantages include graft availability, cost, and, more significantly, infection risk and graft rejection. 3 , 26–28 Disease transmission remains a serious complication that has been largely eliminated with development of better donor screening and testing procedures and introduction of sterilization techniques.…”

“… 3 , 26 , 27 Disadvantages include graft availability, cost, and, more significantly, infection risk and graft rejection. 3 , 26–28 Disease transmission remains a serious complication that has been largely eliminated with development of better donor screening and testing procedures and introduction of sterilization techniques. 7 , 26 However, a major drawback of sterilization techniques is the effect it has on the biomechanical properties of the allograft.…”

“… 3 , 26–28 Disease transmission remains a serious complication that has been largely eliminated with development of better donor screening and testing procedures and introduction of sterilization techniques. 7 , 26 However, a major drawback of sterilization techniques is the effect it has on the biomechanical properties of the allograft. All allografts have slower rates of incorporation compared to autograft, alongside a much higher failure rate of up to 25% in the active population.…”

“…Gamma radiation can be used to address infection risk; however, it has a higher graft failure rate compared to autograft and fresh frozen allograft. 25 , 26 Furthermore, donor characteristics influence graft failure rates with increased risk of failure of grafts from female donors over 50 years old. 22 …”

“… 25 Doses greater than 2.5 kilogray (kGy) have been shown to decrease allograft tension and, therefore, result in greater post-operative laxity and predispose to failure. 25 Farago et al 26 reviewed articles over 29 years assessing the impact of various sterilization techniques on objective tendon mechanics (ie, failure load/ultimate strength and Young’s modulus of elasticity). Findings from the review support freezing followed by gamma radiation or electron beam at 14.8–28.5 kGy as the sterilization technique with the greatest biomechanical preservation.…”