A comparative analysis of distal locked and unlocked long proximal femoral nail antirotation (PFNA-II) in the fixation of stable intertrochanteric fractures

PurposeLong proximal femoral nail anti-rotation (PFNA-II) is a preferred implant in recent years for fixation of pertrochanteric fractures, especially in osteoporotic patients. The purpose of this study is to prospectively investigate the effect of distal locking in long PFNA-II fixation of stable intertrochanteric fractures.MethodsA total of 58 patients with isolated stable intertrochanteric fractures and treated in our hospital during the study period of 2017–2019 by distal locked or unlocked long PFNA-II fixation were included in this study. Patients who had multiple injuries or open fractures were excluded. There were 40 female and 18 male patients, with 33 affecting the left side and 25 the right side. Of them, 31 belonged to the distal locked group (group A) and 27 to the unlocked group (group B). Surgical procedures and implants used in both groups were similar except for the distal locking of the nails. General data (age, gender, fracture side, etc.) showed no significant difference between two groups (all p > 0.05). The intraoperative parameters like operative time, radiation exposure and follow-up parameters like functional and radiological outcomes were recorded and compared. Statistical tests like the independent samples t-test Fischer's exact and Chi-square test were used to analyze association.ResultsThe distribution of the fractures according to AO/OTA classification and 31A1.2 type of intertrochanteric fractures were most common in our study. All the included fractures united and the average functional outcome in both groups were good and comparable at the end of one year. The operative time (mL, 107.1 ± 12.6 vs. 77.0 ± 12.0, p < 0.001) and radiation exposure (s, 78.6 ± 11.0 vs. 40.3 ± 9.3, p < 0.001) were significantly less among the patients in group B. Fracture consolidation, three months after the operative procedures, was seen in a significantly greater proportion of patients in group B (92.6% vs. 67.7%, p = 0.025). Hardware irritation because of distal locking bolt was exclusively seen in group A, however this was not statistically significant (p = 0.241).ConclusionWe conclude that, in fixation of stable intertrochanteric fractures by long PFNA-II nail, distal locking not only increases the operative time and radiation exposure but also delays the fracture consolidation and increases the chances of hardware irritation, and hence is not required.