Does Annulus Fibrosus Lamellar Adhesion Testing Require Preconditioning?

This technical brief examined whether mechanical preconditioning is necessary before conducting 180° peel tests of the interlamellar matrix (ILM) in the annulus fibrosus. Eighty-eight multilayer annular samples from porcine cervical discs were divided into four groups: no preconditioning, or ten cycles of 15% strain applied at 0.01 mm/s, 0.1 mm/s, or 1 mm/s. Following preconditioning (or lack thereof), all samples underwent a 180° peel test to quantify ILM adhesive stiffness and strength. Preconditioning at the slowest strain rate (0.01 mm/s) produced significantly lower stiffness compared to samples tested without preconditioning, suggesting that excessively slow cyclic loading may negatively affect tissue integrity. No other preconditioning conditions affected strength or stiffness outcomes. The findings indicate that preconditioning does not provide a mechanical advantage in peel testing of annular lamellae and may be unnecessary in standard ILM adhesion protocols.