Proximal femoral nails anti-rotation versus dynamic hip screws for treatment of stable intertrochanteric femur fractures: an outcome analyses with a minimum 4 years of follow-up

Background: Dynamic hip screws (DHSs) and proximal femoral nails anti-rotation (PFNAs) are well-documented implants for stable intertrochanteric femur fractures(IFFs); however, there is no consensus regarding which type of implant is the better option for stable IFFs. This study aimed to compare DHSs with PFNAs in the management of stable intertrochanteric fractures. Methods: A retrospective study was performed in our institution. Between June, 2005 and November, 2015, 267 patients (267 hips) with stable IFFs (AO/OTA Type 3.1A1) were treated with a DHS or a PFNA. Inclusion and exclusion criteria were designed to focus on isolated stable IFFs in ambulatory patients. Follow-up was undertaken at 1, 3, 12, 15, 18, 21, 24, 36, 48 postoperative months, and at final follow-up. Radiograph outcomes were obtained at all visits. The primary outcome measure was re-operation rate. The secondary outcome was patient function, evaluated using Harris hip score (HHS). Tertiary outcomes included: intra-and post-operative orthopaedic complications. Results: Two hundred twenty two patients (110 in the PFNA group and 112 in the DHS group) were evaluated with a mean follow-up period of 53 months (range, 48-60 months). There was an increased risk of reoperation after DHS in one-year follow-up: 0 % and 5.4 % for PFNA and DHS, respectively (P = 0.029). The difference persisted with time: 6.4 % and 13.4 % at last follow-up (P < 0.05). There are statistical differences in postoperative HHS at 12, 15, 18, 21, 24, 36, 48 months postoperatively and at final follow-up. No statistical differences in medical complications was observed between the two groups. The orthopaedic complications were more in the DHS group (n = 42) compared with the PFNA group (n = 18) (P < 0.05). Conclusion: Compared with PFNA device, DHS device might not be the preferred implant for stable intertrochanteric femur fractures.