AO universal interlocking femoral nail: technical faults with the entry hole and with locking

ABSTRACT

One hundred and twenty six fresh femoral fractures treated using the universal AO interlocking femoral nail were studied to evaluate the technical faults with the entry hole and with locking. An entry hole from the piriform fossa was used in 105 femora and resulted in a straight nail in all cases except one. An entry hole from the greater trochanter was used in 21 femora and resulted in a good reduction with a mild nail bend in 15 femora, a good reduction with a straight nail in 4 femora and a varus malalignment in 2 femora. The decision to lock was based on Winquist, et al recommendations. The technical errors with locking included unnecessary locking, no locking although needed, difficult locking, inability to lock, bent screw, broken screw, and long screw. It was concluded that the piriform fossa is the recommended entry point, but the greater trochanter can be used in middle and distal third fractures if needed. Stable isthmic fractures can be treated by unlocked nailing. Axially stable extraisthmic fractures can be treated by dynamic locking, while unstable fractures are treated by static locking