Can the Bio-Transfx pin fail during initial ACL graft insertion?

The Bio-Transfix pin is a biodegradable device used for femoral tunnel anterior cruciate ligament (ACL) graft fixation. Recent clinical studies have suggested the possibility of the pin's postoperative failure. This investigation evaluates the initial strength of several Bio-Transfix pin ACL fixations in a simulated femoral tunnel model. The forces generated by five surgeons during simulated ACL graft tensioning were also measured. Average strengths of the pins ranged from 1075 to 2160 N for 10 and 8 mm tunnels, respectively, whereas the maximum surgeon-generated forces were 535 N. These results imply that initial fracture of the pin itself is unlikely; however, failure of the supporting bone or a decrease in pin strength due to biodegradation could account for early loss of the fixation.