BIOMECHANICAL COMPARISON BETWEEN BIOSCREW AND TITANIUM-ALLOY INTERFERENCE SCREWS FOR BONE-PATELLAR TENDON-BONE GRAFT FIXATION IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

This investigation compared the maximum load at failure of BioScrew (L invatec Corp, Large, FL) and titanium ahoy interference screw femoral fixation using a human cadaveric model that approximated the anatomica l orientation and physiological strain rate of in vivo bone-patellar t endon-bone (BPTB) graft loading following anterior cruciate ligament r econstruction. Eighteen fresh-frozen human BPTB allografts (10-mm wide , 10-mm thick, 25-mm long bone plugs) with either BioScrew or titanium alloy (Ti 6A14V) screw (7 x 25 mm) fixation were compared for maximum load at failure at a strain rate of 20 mm/minute. Nine cadaver femurs with bone mineral densities of 0.88 +/- 0.18 g/cm(2) (anterior/poster ior) and 1.3 +/- 0.24 g/cm(2) (lateral) received the allografts. No st atistical differences were observed in maximum load at failure (P = .9 5) or failure mode (P = .11) between specimens fixed with either screw type. When biomechanically tested with anatomic orientation and at fu nctionally relevant strain rates, the BioScrew provided maximum load a t failure equal to a titanium alloy screw.