Irradiation at 11 kGy conserves the biomechanical properties of fascia lata better than irradiation at 25 kGy.

The objective of this study was to determine the biomechanical properties of the fascia lata and the effects of three preservation methods: freezing, cryopreservation with dimethylsulfoxide solution and lyophilization; and to compare the effects of low-dose (11 kGy) and normal-dose (25 kGy) gamma-ray sterilization versus no irradiation. 248 samples from 14 fasciae latae were collected. Freezing samples were frozen at -80 °C. Cryopreservation with dimethylsulfoxide solution samples were frozen with 10 cl dimethylsulfoxide solution at -80 °C. Lyophilization samples were frozen at -22 °C and lyophilized. Each preservation group were then randomly divided into 3 irradiation groups. The cryopreservation with dimethylsulfoxide solution samples had significantly worse results in all 3 irradiation conditions. Young's modulus was lower for the freezing samples (p < 0.001) and lyophilization samples groups (p < 0.001). Tear deformation was lower for the freezing samples (p = 0.001) and lyophilization samples groups (p = 0.003), as was stress at break (p < 0.001 and p < 0.001). Taking all preservation methods together, samples irradiated at 25 kGy had worse results than the 0 kGy and 11 kGy groups in terms of Young's modulus (p = 0.007 and p = 0.13) and of stress at break (p = 0.006 and p = 0.06). The biomechanical properties of fascia lata allografts were significantly worse under dimethylsulfoxide cryopreservation. The deleterious effects of irradiation were dose-dependent.