Abstract
Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks. Accelerated EB, in contrast to more often used gamma photons, is a form of ionizing radiation that is characterized by lower penetration, however it is more effective in producing ionisation and to reach the same level of sterility, the exposition time of irradiated product is shorter. There are several factors, including dose and temperature of irradiation, processing conditions, as well as source of irradiation that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect e-beam irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors, aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as e-beam irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress–strain curves examined by univariate analysis are described. Based on multivariate analysis, including all groups, it was found that temperature of e-beam irradiation and defatting had no consistent significant effect on evaluated mechanical parameters of compact bone rings. In contrast, irradiation with both doses significantly decreased the ultimate strain and its derivative toughness, while not affecting the ultimate stress (bone strength). As no deterioration of mechanical properties was observed in the elastic region, the reduction of the energy absorption capacity of irradiated bone rings apparently resulted from changes generated by irradiation within the plastic strain region.
Highlights
Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks
This study evaluated the effect of accelerated electrons beam irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature on mechanical properties of non-defatted or defatted compact bone grafts
Most of experimental data regarding the effect of irradiation on biological, physical and biochemical properties of bone allografts refers to gamma irradiation (Anderson et al 1992; Godette et al 1996; Salehpour et al 1995; Stevenson 1999)
Summary
Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks (Dziedzic-Goclawska et al 2005). Several studies have been carried out to introduce beam of accelerated electrons for sterilisation of particular tissue grafts, e.g. patellar tendon, using conventional—one step (Kaminski et al 2009; Hoburg et al 2010), or newly proposed fractionated method of radiation-sterilisation (Hoburg et al 2011). In both types of experiments evaluated irradiation doses exceeded 30 kGy, the dose which is very often acknowledged to impair allograft biomechanical properties (Pelker et al 1993; Cornu et al 2000). There are limited data regarding the effect of accelerated EB irradiation on biomechanical properties of banked bone allografts, especially compact bone (Hemigou et al 1993; Dziedzic-Goclawska et al 2005)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
