Intraoperative Fracture during the Insertion of Advanced Locking Screws (T2 Alpha Femur Retrograde Intramedullary Nailing System): Report of Two Cases and Identifying Causes and Prevention.

Background : Recently, the T2 alpha nailing system (Stryker, Inc.), which has advanced locking screws that can attach a screw to a rod, has been used worldwide and is expected to improve fracture fixation. We analyzed two cases of supracondylar femoral fractures in older adult patients, in which intraoperative fractures occurred during the insertion of advanced locking screws of the T2 alpha femur retrograde intramedullary nail. Case presentation : A 93-year-old and an 82-year-old woman each underwent T2 alpha femur retrograde nail fixation for supracondylar femur fractures at separate hospitals, and advanced locking screws were used as the proximal transverse locking screws. In both patients, a fracture line was observed at the proximal screw postoperatively, and the fractures were refixed with distal cable wiring and/or femoral distal plates. The patients were subsequently discharged from the same facility with no remarkable pain. Conclusions : When inserting advanced locking screws, it is necessary to enlarge the screw hole in the near-bone cortex with a counterbore drill, which might add torque to the bone cortex that could result in fractures. If the sleeve is distant from the bone, the counterbore drill will not reach the bone, the screw hole will not expand, and the insertion of advanced locking screws will apply a strong torque to the bone cortex and may result in fracture. Moreover, it is important to confirm that the counterbore drill is securely inserted under fluoroscopy and to carefully enlarge the bony foramen manually to prevent fractures during screw insertion.