Fused loop of filamentous material and apparatus for making same

Ultrasonic apparatus including a first member having a first suture-contacting surface and being capable of vibrating and delivering mechanical energy at ultrasonic frequencies, a second member having a second suture-contacting surface means for moving said first member relative to said second member to define a gap between the respective suture-contacting surfaces, wherein said second member is stationary relative to said first member, and fixture means adapted to receive and maintain two or more segments of a material to be welded in a predetermined alignment in said gap between said first and second suture-contacting surfaces of the first and second members during a welding operation,

• wherein one of the first and second suture-contacting surfaces includes a first surface pattern and the other suture-contacting surface includes a second surface pattern,
• wherein said first and second surface patterns are adapted to impart said respective patterns to a joint region of said materials to be welded between said surfaces and are adapted to form a substantially continuous weld in said joint region between said materials, and wherein said materials have an increased surface area in said joint region.