Free fibers offer two major advantages.

1. Mechanical resistance:

• In the active zone of the implant (Z-lig®), the residual fatigue resistance (combined tension, flexion, and torsion) of free fibers is significantly higher than all other tested structures (12 million cycles), whether woven, knitted, or braided, which degrade more or less rapidly (structure elongation) and release debris into the joint before mechanical failure.

Free fibers produce no particle debris, and elongation after this testing phase was approximately 2%.

2. Promotes fibroblast colonization and growth of new collagen aligned with the direction of tension

• The architecture of free fibers is porous and conducive to fibroblast infiltration (unlike braided structures, which are dense, opaque, and minimally permeable).
  When a healthy remnant of the cranial cruciate ligament (CCL) is present, it should be preserved as much as possible, as it facilitates fibroblast regrowth and the development of collagen oriented along the direction of tension.