A Comparison of the Clinico-Radiological Outcomes with Proximal Femoral Nail (PFN) and Proximal Femoral Nail Antirotation (PFNA) in Fixation of Unstable Intertrochanteric Fractures

INTRODUCTION: Management of unstable intertrochanteric fractures poses challenges in terms of obtaining stable fixation and good postoperative outcomes. There is a paucity of clinical data comparing the commonly used Proximal Femoral Nail (PFN) and Proximal Femoral Nail Antirotation (PFNA) implants, especially in relation to osteoporosis. AIM: To assess comparative performance of PFN and PFNA in the setting of osteoporosis. MATERIALS AND METHODS: Patients presenting with unstable intertrochanteric fractures (AO 31.A2 and 31.A3) were included and treated with either PFN or PFNA. Preoperative radiographs of normal side were used to grade osteoporosis by Singh's index. Grade 3 or less was considered significant. Postoperative radiographs were assessed for tip-apex distance, Cleveland index and quality of reduction. Patients were followed up for a minimum of nine months and any complications noted. Comparison of functional outcomes was done using the Harris Hip Score and Parker-Palmer mobility score at final follow up. Statistical analysis was done using the unpaired t-test/Mann-Whitney U test and Chi-square test/Fisher's-exact test. A p-value of < 0.05 was considered significant. RESULTS: The study included 48 patients with unstable intertrochanteric fractures, of which 23 were treated with PFN and 25 with PFNA. Average age of PFN group was 60.78 years and of PFNA group was 74.12 years. In PFN group 8 patients (38.09%) and in PFNA group 13 patients (54.1%) had Singh's osteoporotic index of ≤ 3. The average Harris Hip Score was 75.37 and 78.85 in PFN and PFNA groups (p=0.54) respectively. From PFN and PFNA groups, 35% and 32% patients respectively were able to return to pre-injury mobility status as assessed by the Parker-Palmer mobility score (p=0.83). Out of eight implant related complications; seven were in patients treated with PFN (p=0.02). Among patients with Singh's grade ≤ 3, 3 (37.5%) in PFN group suffered from implant failure whereas all 13 patients in PFNA group had successful outcome (p=0.04). CONCLUSION: Although functional outcomes achieved with both implants are similar (p=0.83), number of implant related complications were fewer with PFNA (p=0.02), even in osteoporotic group (p=0.04). We recommend use of the PFNA in unstable fractures, especially in the elderly osteoporotic population.