Abstract: A high-strength ligament prosthesis having biological acceptability, flexibility, porosity and resistance to prolonged stress in excess of 100 Kg with little change in modulus, and less than 20% ultimate elongation is provided. These characteristics make the high-strength prosthesis favorable for critical applications, such as knee and ankle repair. The high-strength prosthesis is constructed of a biological compatible yarn having an outer shell with an "H-beam" cross-section and a velour surface to encourage rapid invasion by host tissue and a reinforcing core of the same yarn. The ends of the reinforcing core and outer wall are fitted with end tips to limit displacement of the core within the outer shell and to facilitate positioning of the prosthesis during surgery with minimal effort. An enlarged elongated end tip is particularly well adapted for special surgical procedures, such as arthoscopic procedures.

Abstract: Polyester fabric which may be in the form of a warp-knitted lock-stitched or tricot-stitched tubular construction is compacted by treatment with NO.sub.2 either in the gaseous phase or in solution. The product, after neutralization, washing and crimping is suitable for vascular prostheses. In one form, the compacted product is crimped and bifurcated. Shrinkage in both the longitudinal and transverse directions is at least 30%. The porosity of the fabric is reduced by the compacting treatment.