PFNA and DHS for AO/OTA 31-A2 fractures: radiographic measurements, morbidity and mortality

Abstract

Purpose: For this retrospective cohort study, we assessed pertrochanteric fracture types AO/OTA 31-A2. PFNA and DHS were the devices used. We determined both devices in relation to peri-operative variables, postoperative radiographic measurements, implant-related complications and mortality up to 2 years. The null hypothesis was no effect between the two devices.

Methods: This single-centre study was conducted based on our computerized data. The treatment period ranged from 2006 to 2015. Only patients with type AO/OTA 31-A2 fractures and an age ≥ 65 years were included. Apart from descriptive variables, the following measurements were assessed: (1) duration of surgery, (2) blood loss, (3) transfusion, (4) hospitalization, (5) tip-apex distance (TAD), (6) fracture reduction, (7) screw position, (8) implant-related complications, and (9) mortality. The follow-up was 2 years for each living patient. Missing data were evaluated by telephone call.

Results: A total of 375 consecutive patients were enrolled into three groups: (1) 75 patients treated with DHS and antirotation screw (ARS); (2); 100 patients treated with DHS + ARS + TSP (trochanteric stabilization plate); and (3) 200 patients treated with PFNA. Apart from dementia, the descriptive data (e.g., age and BMI) demonstrated no effects between the three groups. Compared to PFNA, DHS with or without TSP was adversely affected by a longer operation time, higher blood loss, increase in transfusion, and more implant-related complications including cut-out, infection and failure. The rate of cut-out was significantly higher in TAD ≥ 25 mm (p = 0.005), and PFNA demonstrated significantly better TAD measurements (p = 0.001), better fracture reduction (0.002), more central-central screw positions (p = 0.014), and less poor screw placement (p = 0.001). The mortality rate was without effect between the three groups (log rank 0.698).

Conclusions: DHS with or without TSP was associated with significantly higher rates of implant-related complications based on inferior radiographic measurements. Therefore, we only recommend PFNA for the treatment of proximal type AO/OTA 31-A2 femoral fractures.

Level of evidence: Therapeutic level III.

Keywords: Complication; DHS; Mortality; Osteosynthesis; PFNA; Revision; Trochanteric fracture.