OPTIMIZATION OF EXTRUDED COLLAGEN-FIBERS FOR ACL RECONSTRUCTION

Collagen fibers used in a scaffolding device for ligament reconstructi on must be thin, strong, and degradable. The purpose of this study was to determine the effects of fiber diameter (20, 50, or 90 mu m), cros slinking agent (uncrosslinked, dehydrothermal-cyanamide, or glutaralde hyde), and hydration on the initial mechanical properties, biocompatib ility, and subcutaneous degradation rates of fibers extruded from an a cidic dispersion of insoluble type I collagen. The wet tensile strengt h of extruded collagen fibers was significantly improved by decreasing the fiber diameter. Low-diameter, crosslinked fibers had wet tensile strengths ranging from 75-110 MPa. In contrast, high diameter fibers h ad wet strength values of about 30MPa. The degradation rate of the imp lanted fibers, in contrast, was not significantly prolonged by changin g the initial fiber diameter. This result is important because prolong ed degradation of the fibers can lead to implant encapsulation instead of neoligament formation. By minimizing the diameter, fiber strength can be increased without prolonging the fiber degradation rate. Low-di ameter, dehydrothermal-cyanamide crosslinked fibers have greater tensi le strength and a more rapid degradation rate than medium-diameter, gl utaraldehyde crosslinked fibers, and are therefore more suitable for u se in a degradable ligament reconstruction device. (C) 1993 John Wiley and Sons, Inc.