Pull-out strength and stiffness of meniscal repair using absorbable arrowsor Ti-Cron vertical and horizontal loop sutures

We tested pull-but strength and linear stiffness of meniscal repair using b ioabsorbable arrows and vertical and horizontal loop sutures in fresh-froze n bovine lateral menisci. In phase I, menisci repaired either with 2-0 Ti-C ron vertical or horizontal loop suture, or 10-, 13-, or 16-mm Meniscus Arro ws were loaded to failure at 12.5 mm/sec. In phase II, we examined the numb er of barbs engaged and angle of insertion using 10- and 13-mm arrows. Pull -out strengths of both suture repair groups were significantly higher than those of the arrow groups. Vertical loop sutures were significantly stiffer than horizontal sutures and 10-mm arrows. In phase II, the mean ultimate l oad to failure for the 10-mm arrows was 35.1 N, significantly stronger than in phase 1 (18.5 N); however, stiffness remained low (7.9 N/mm). Five arro ws in the 13-mm group were inserted parallel to the tibial surface and show ed no significant difference from phase I. Five arrows were inserted at mor e than a 30 degrees angle. This group was significantly weaker than in phas e I. Single vertical loop suture showed the highest overall pull-out streng th. Although weaker than sutures, arrows should provide sufficient stabilit y for meniscal healing. The number of barbs engaged and angle of insertion are critical.