To compare the results between Proximal femoral nail antirotation II (PFNA II) and Zimmer natural nail Asia type (ZNN) for the treatment of stable intertrochanteric fractures.

Between September 2011 and September 2012, 40 consecutive patients with stable intertrochanteric femoral fractures were treated with PFNA II or ZNN. We reviewed 20 cases of PFNA II and 20 cases of ZNN prospectively. We evaluated the operation time, amount of bleeding, mean hospital day, and capability of mobility and function using 'mobility score of Parker and Palmer' and 'social score of Jensen'. We also evaluated the reduction state by the Fogagnolo, Cleveland index, change of tip and apex distance (TAD), sliding distance of cervical screw, change of neck shaft angle and bone union time.

There were no significant differences between the groups treated with PFNA and ZNN. Both groups showed good clinical results. PFNA showed less TAD change and ZNN showed a shorter sliding distance of cervical screw, but they were not statistically different. The bone union time was approximately 13 weeks in both groups.

PFNA and ZNN produced good clinical and radiologic results in the treatment of stable intertrochanteric fractures. There were no significant differences between the groups. Both implants provide good stability and union, so we can conclude that they are both suitable for the treatment of stable intertrochanteric fractures.