Purpose: Purpose of the study is to compare the changing Tip Apex Distance (TAD) and therefore the cut out development risk during fracture healing in two different types of implant.

Materials and Methods: 166 patients with intertrochanteric femur fracture were operated with proximal femoral nail between the years 1999 and 2006 in our clinic. 117 patients with avaible radiological data were studied. Group I defined as PFN, had 90 patients. Median age was 74.2 (25–93) years, 44 female and 46 male. Grup II defined as PFN-A had 27 patients. Median age was 75 (33–88) years, 18 females, 9 males. The mean of following time of patients was 48 months (12–84 months). We measured in AP radiograph the tip-apex distance (TAD) both of early postop and fracture healing time.

Results: In group I change in TAD was observed in 70 (%77.7) patients. Average TAD change rate was %29 (%4–%230). In group II, change in TAD was observed in 15 (%55.6) patients, and the average TAD change rate was %12 (%5–%40). Among Group I, 3 patients had a revision surgery with cut-out complications (%3.3). Among Group II no patient had cut out complication.

Discussion: While cut out was developed in 3 PFN patients, no cut-out was observed in any of PFN-A patients. Among the patients without cut-out development, 77.7 % of PFN patients and 55.6 % of PFN-A were under cut out risk. Average TAD change rate was 29% in PFN Group whereas 12% in PFN-A Group. When TAD change rates are considered, no cut-out was determined in PFN-A Group while its development risk was lower. When we investigate the cut out complication, the 3 cut out complications (%3.3) was seen in PFN. PFN-A group had no cut out complications.