The satisfactory results in terms of function of the present study confirm what has already been described regarding functional outcome after pertrochanteric femoral fractures treated with a GN [7, 12, 22–24]. Results according to the HHS were comparable to the findings of Cheng et al  using a LGN for the treatment of femoral fractures in 16 patients. Adams et al  reported worse HHS results in a series of 203 pertrochanteric fractures.
Hip flexion at 12 months postoperatively in our patient set was 113° ± 13 degrees whereas Utrilla et al  showed slightly worse results for patients treated with a GN or a compression hip screw. Yaozeng et al  reported a mean of 96 ± 15 degrees of hip flexion after pertrochanteric fractures treated with a GN and a proximal femoral nail. Our patients scored similar with respect to hip flexion as 31 patients treated for sports related proximal femoral fractures with a DHS or GN published by Habernek et al  Leg length discrepancies were not significant in our cohort which is comparable to other authors [5, 17, 24].
In order to focus on patient related outcome assessment the SF-36 has become a reliable instrument for outcome evaluation of hip fracture patients. The SF-36 has been validated among healthy individuals and those with various chronic and acute medical conditions. It was easy to administer and to process even in elderly patients . The present study is unique as no other work on GN fixation of pertrochanteric femoral fractures has evaluated the SF-36 and compared results with U.S. and age- and sex-adjusted Austrian population norms. Our patients scored significantly worse in three out of eight subscales and in the Physical Component Summary score of the SF-36 compared to the Austrian population norm, which outlines the fact that a linear correlation does not necessarily exist between the functional capacity and patients’ quality of life. Surprisingly, we found a 12-point advantage in the MCS of patients with a trochanteric fracture compared to the population norm. A reason for this result might be the patients’ general satisfaction after a successful operation due to a severe injury to the musculoskeletal system.
Only a few studies in the English literature focused on quality of life and used the SF-36 for outcome evaluation after operatively treated pertrochanteric fractures [12, 13]. Mattson et al  reported 57 patients with unstable pertrochanteric fractures treated by DHS with slightly better results in general health, social functioning and mental health subscales on the SF-36 at six months postoperatively compared to our cohort. In contrast to our study Mattson et al  excluded AO type A3 pertrochanteric fractures, which may have worse outcomes when treated with DHS  Barton et al  treated 100 patients with AO type A2 pertrochanteric fractures with a LGN and reported a deterioration in health related quality of life in home independence and mobility at one year postoperatively, which supports our findings. Miedel et al  too, investigated and documented a statistically significant deterioration in quality of life between prefracture and the 12 months follow-up examination of 109 unstable pertrochanteric fractures treated with a GN. Comparable to the findings of 2005  Miedel et al. published a study with 53 patients treated with a LGN for subtrochanteric fractures showing worse outcomes in musculoskeletal function and quality of life after a 12 months follow-up .
When comparing the results of the SF-36 with the HHS we found significant correlations in four out of eight subscales and a highly significant correlation with the physical component summary score at the 12 months postoperative follow-up.
The neck-shaft angle of the injured side did not differ significantly from that of the uninjured side 12 months postoperatively. Our results agree with Pajarinen et al  who investigated 28 patients after intramedullary nailing of unstable pertrochanteric fractures. In contrast to our findings Min et al  analyzed eleven patients with reverse obliquity intertrochanteric fractures and reported a change of neck-shaft angle of 3.75 degrees, which was three times as much as we measured in our cohort.
The reoperation rate of 5% in our study group falls in the lower half of the recent literature [3, 7, 14, 22, 23, 28]. Consistent with previous authors, [10, 11, 17] we had a technical failure rate of 3%. Earlier studies have reported higher complication rates associated with the use of previous versions of GN [2, 27] Secondary femoral fractures did not occur in our study but have been reported in other studies with an incidence up to 17% . Cut-out of the lag screw, which we observed in one patient, might have been avoided by positioning the tip of the lag screw in the subchondral bone of the femoral head . Previous authors reported similar numbers of lag screw cut-outs [11, 14, 17, 29]. In contrast to Robinson et al  we found only one patient with delayed boney union resulting in reoperation. Infection rates seem to be very rare in most studies using any type of intramedullary femoral nail, most likely reflecting the advantages of the percutaneous technique [14, 29].
The present study has several limitations; First, the fractures were not randomized, making an accurate comparison with other operative treatment options impossible. Another weakness of the study is the relatively small number of patients included.
A possible drawback might further be that all patients were treated by three senior physicians with long experience in hip surgery who overcome the learning curve. It remains unknown whether the results of the present study can be generalized to patients who are managed at other centers. Finally, the generality of the SF-36 quality of life instrument means that medical disorders other than the one under study may affect the results. For this reason we feel that the assessment of a region specific disability measure like the HHS remains essential in order to complement patients’ outcome evaluation. Future multi-center trials should focus on the importance of patients’ physical demands and activity levels as well as quality of life across different age subgroups to further evaluate the relationship between clinical outcome and radiographic alignment.