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

Overview

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.