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

We tested pull-out strength and linear stiffness of meniscal repair using bioabsorbable arrows and vertical and horizontal loop sutures in fresh-frozen bovine lateral menisci. In phase I, menisci repaired either with 2-0 Ti-Cron vertical or horizontal loop suture, or 10-, 13-, or 16-mm Meniscus Arrows were loaded to failure at 12.5 mm/sec. In phase II, we examined the number 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 load to failure for the 10-mm arrows was 35.1 N, significantly stronger than in phase I (18.5 N); however, stiffness remained low (7.9 N/mm). Five arrows in the 13-mm group were inserted parallel to the tibial surface and showed no significant difference from phase I. Five arrows were inserted at more than a 30 degrees angle. This group was significantly weaker than in phase I. Single vertical loop suture showed the highest overall pull-out strength. Although weaker than sutures, arrows should provide sufficient stability for meniscal healing. The number of barbs engaged and angle of insertion are critical.