The visible and hidden blood loss of Asia proximal femoral nail anti-rotation and dynamic hip screw in the treatment of intertrochanteric fractures of elderly high- risk patients: a retrospective comparative study with a minimum 3 years of follow-up

BACKGROUND The purpose of this study was to evaluate whether PFNA-II (Asia proximal femoral nail anti-rotation) and DHS (dynamic hip screw) carry substantial post-operative hidden blood loss and to compare PFNA-II with DHS in terms of post-operative hidden blood loss in elderly high-risk patients with intertrochanteric femur fractures(IFFs). METHODS The clinical data from Jan 2005 to Apr 2015 of 186 patients with PFNA-II and 177 patients with DHS were analyzed retrospectively. Indexes including pre- and post-operative blood routine, intra- and post-operative blood loss and blood transfusion situation were analyzed. The situation of perioperative blood loss (visible and hidden) was assessed. RESULTS The intra-operative blood loss in the PFNA-II group was 34.7 ± 2.5 ml, the post-operative visible blood loss was 54.7 ± 2.5 ml, and the hidden blood loss was 277.2 ± 7.6 ml. In the DHS group, the intra-operative blood loss was 102.0 ± 7.0 ml, the post-operative visible blood loss was 78.8 ± 4.7 ml, and the hidden blood loss was 139.3 ± 9.6 ml. The intra-operative blood loss and the post-operative visible blood loss in the PFNA-II group were significantly less than in the DHS group (p < 0.01). However, the post-operative hidden blood loss and the total blood loss in the PFNA-II group were larger than in the DHS group (p < 0.01). CONCLUSION This study demonstrated that with PFNA-II and DHS, much post-operative hidden blood loss exists in the treatment of intertrochanteric fractures in elderly high-risk patients and DHS is more favourable than PFNA-II in terms of post-operative hidden blood loss.