A novel, resorbable suture anchor: Pullout strength from the human cadavergreater tuberosity

The pullout strength of a collagen bone anchor that creates interference fi xation as the result of radial swelling on hydration was compared with a Mi tek rotator cuff anchor after insertion into the greater tuberosity of huma n cadaver humeri. Bones were fully hydrated at 37 degreesC. Stiffness, peak load, and the mode of failure were recorded. Real and apparent bone densit ies were measured Peak load for the collagen anchor at 15 minutes (127.0N /- 81.3N) was greater than at 2 minutes (60.5N +/- 38.5N) after insertion ( P < .05). At between 5 and 60 minutes after insertion, peak loads for the M itek and the collagen anchors did not differ. After 30 minutes From inserti on, the mode of failure of the collagen anchor changed from pullout with mi nor body damage to pullout with major body damage. Peak load at pullout cor related with bone density for the Mitek (P < .05, r = 0.516) but for the co llagen bone anchor appeared unaffected by bone density.