High-dose electron beam sterilization of soft-tissue grafts maintains significantly improved biomechanical properties compared to standard gamma treatment

• Published in: Cell and tissue banking 2015-06, Vol.16 (2), p.219-226
• Main Authors: Hoburg, A., Keshlaf, S., Schmidt, T., Smith, M., Gohs, U., Perka, C., Pruss, A., Scheffler, S.
• Format: Article
• Language: English
• Subjects: Anterior Cruciate Ligament - surgery; Anterior Cruciate Ligament Reconstruction - methods; Biomechanics; Biomedical and Life Sciences; Biomedicine; Bone-Patellar Tendon-Bone Grafting; Cell Biology; Comparative studies; Electrons; Gamma Rays; Humans; Life Sciences; Ligaments; Original Paper; Patellar Ligament - radiation effects; Skin & tissue grafts; Sterilization; Sterilization - methods; Transplant Surgery; Transplantation, Homologous - methods
• ISSN: 1389-9333; 1573-6814
• DOI: 10.1007/s10561-014-9461-x

Allografts have gained increasing popularity in anterior cruciate ligament (ACL) reconstruction. However, one of the major concerns regarding allografts is the possibility of disease transmission. Electron beam (Ebeam) and Gamma radiation have been proven to be successful in sterilization of medical products. In soft tissue sterilization high dosages of gamma irradiation have been shown to be detrimental to biomechanical properties of grafts. Therefore, it was the objective of this study to compare the biomechanical properties of human bone-patellar tendon-bone (BPTB) grafts after ebeam with standard gamma irradiation at medium (25 kGy) and high doses (34 kGy). We hypothesized that the biomechanical properties of Ebeam irradiated grafts would be superior to gamma irradiated grafts. Paired 10 mm-wide human BPTB grafts were harvested from 20 donors split into four groups following irradiation with either gamma or Ebeam (each n = 10): (A) Ebeam 25 kGy, (B) Gamma 25 kGy, (C) Ebeam 34 kGy (D) Gamma 34 kGy and ten non-irradiated BPTB grafts were used as controls. All grafts underwent biomechanical testing which included preconditioning (ten cycles, 0–20 N); cyclic loading (200 cycles, 20–200 N) and a load-to-failure (LTF) test. Stiffness of non-irradiated controls (199.6 ± 59.1 N/mm) and Ebeam sterilized grafts did not significantly differ (152.0 ± 37.0 N/mm; 192.8 ± 58.0 N/mm), while Gamma-irradiated grafts had significantly lower stiffness than controls at both irradiation dosages (25 kGy: 126.1 ± 45.4 N/mm; 34 kGy: 170.6 ± 58.2 N/mm) ( p