Intertrochanteric fractures ( Figure 1(a) ) are common injuries among the elderly aged population [1] [2] . Non-operative management of hip fracture has higher mortality rates [3] . Surgical intervention is necessary for better outcome. The main aim of surgery is early rehabilitation for normal functional outcome. Proximal Femoral Nail (PFN) ( Figure 1(b) ) consists of intramedullary nail with two screws. One is lag screw and others act as anti-rotational screw. Proximal Femoral Nail Antirotation for Asia (PFNA2) ( Figure 1(c) ) has intramedullary nail and single proximal screw also known as helical screw. PFNA2 has advantage as it prevent back out of screw and cutting of femoral head which helps in early weight bearing [4] [5] . Biomechanical studies show that helical blade has good bone compaction, superior resistance to both Varus collapse and rotational movement [6] . The quality of reduction, choice of implant and its placement depends on surgeon choice. This study focused on the various aspects of PFN and PFNA2 fixation in Intertrochanteric fractures (AO/OTA as 31A1.2).

This is a Prospective study with aimed to compare among two groups of Intertrochanteric fractures treated with PFN and PFNA2 where below points are to be emphasized:

It is a Prospective and comparative Study involving 40 patients.

The study was conducted at Janaki Medical College and Teaching Hospital, Janakpurdham, Nepal.

This study was done between September 2022 - September 2024. The case was randomly selected on the basis of inclusive and exclusive criteria.

The Patients followed up was at 6 weeks, 3 months and 6 months.

Statistical evaluation was done with SPSS Software-Version 20. The statically analysis was done using the student’s t-test. Comparison between the groups was based on chi-sqaure test (x2 test). P-value of 0.05 or less was statically significant.

All the Patient after admission where kept under skin traction. After pre-Anesthetic evaluation, patients were accessed for surgery. Informed consent was taken for surgery. Surgical intervention was done under spinal Anesthesia over operating traction table. Surgical approach for all patients were similar with reduction achieved and confirmed under fluoroscopy. Maintaining sterility, incision of 2 - 3 cms was made around tip of greater trochanter of femur. Tensor Fascia lata was incised and using awl entry point ( Figure 2(a) ) was made followed by guide wire insertion. All the above steps were under fluoroscopy guidance. Further Proximal reaming was done with proximal reamer and PFN or PFNA2 inserted using jig ( Figure 2(b) ). Finally reaming with 8mm and 6.4mm reamers for PFN done ( Figure 2(c) ). Lag and de-rotation screws are kept ( Figure 2(d) ). On another hand for PFNA2 appropriate size helical blade is fixed with help of impactor and locked with clockwise turns. The Helical screw size was confirmed under C-arm. In some cases, Helical screw were immediately changed during intraoperative period if the size appeared larger or if the screw is loosening. Lastly Distal locking was done. After implant placement, operated site was washed and closure done in layers. Postoperative x-rays of both PFN ( Figure 3(a) and Figure 3(b) ) and PFNA2 ( Figure 4(a) and Figure 4(b) ) were taken on 1^st postoperative day of surgery.

The mean age of the patients in PFN and PFNA2 groups were 63.4 and 62.6 respectively. The mean age group were almost similar in both groups. In PFN

group 12 Patients had injury due to road traffic accident while 8 patients were admitted resulting from fall injury. In PFNA2 group 14 cases were from Road traffic accident and 6 cases were of fall injury. In both PFN and PFNA2 groups more cases were resulted from road traffic accident. In PFN group 14 cases have right side injured limb and 6 cases have left limb injury. In PFNA2 group 12 cases have injured right side limb and 8 cases have left limb injury. Prominent side affected were right intertrochanteric fracture of femur. Mean operative time in PFN was 58.09 whereas in PFNA2 it was 46.54. Blood loss was 90.37 ml in PFN and 69.27ml in PFNA2. Average Fluoroscopy shots number was 54.39 and 32.55 in case of PFN and PFNA2. There was statically significant in Operative time, blood loss, Fluoroscopy exposure shots and weight bearing time in case of PFN and PFNA2 patient groups. Duration of hospital stay was almost similar in both groups and has no any significant difference statistically. Early weight bearing was in case of PFNA2 i.e. 5 days ( Table 1 ). Delayed weight bearing was in case of PFN to prevent from Z-effect and screw back out due to osteoporotic nature of bone. Mean Neck shaft angles achieved were 130.78 and 130.49 in PFN and PFNA2 groups patients respectively. Mean Neck shaft angles achieved was almost similar in both groups.

9 complication cases in PFN and 5 complication cases in PFNA2 were seen related to surgery ( Table 2 ). Implant related complications as z-effect ( Figure 5(a) ), Reverse Z-effect ( Figure 5(b) ), screw cut out, implant breakage and guide wire breakage were noted in 4cases of PFN. No any implant related complication seen in PFNA2 group ( Table 3 ). Harris Hip Score was measured in both groups at 3 weeks, 3 months and 6 months. Comparatively better outcome noticed in PFNA2 groups than PFN groups patients ( Table 4 ).

Treatment of intertrochanteric femur fracture is a challenging issue [7] [8] . Proximal Femoral nail is a standard method for treating these types of fractures. Generally, Intertrochanteric femur fracture occurs in age above 55years where there is high probability of implant failures and other complications if proper treatment is not done. Technical errors like intraoperative implant placements, screw cut out, Z-effects and Reverse Z-effects seen in many cases and were reported in literature as well [9] . PFNA2 is designed basically to minimize these complications. Helical screw prevents it as there is more surface contact between the cancellous bone of femur head and the holding device [4] [10] . Therefore, it has more biomechanical advantages than PFN.

In our study, PFNA2 group has less blood loss, less surgical duration and less number of fluoroscope shots which supports similar studies which have been done before. Functional results also favor PFNA2 over PFN. There were complications related to surgery and implant noticed more in cases with treatment done with PFN. Early weight bearing and rehabilitation were seen in case of PFNA2. Other studies and literature have also similar result compared to our study [5] [10] - [13] .

As the study was time bound, the patients were followed up for a period of 6 months only and the long term effects of these interventions have to be assessed in future. In this study, the radiological union of fractures was assessed only for 6 months. Hence, the comparison as to which implant provides earlier fracture union cannot be commented from this study. A longer follow-up study would shed light in this matter. Though the scoring system employed in the present study is used widely all over the world, it is inadequately described.

PFNA2 is better implant in terms with less intraoperative complications, blood loss, union rates and functional outcome.

For Orthopedic Surgeon, PFNA2 has made easier to perform surgery of Intertrochanteric fracture of femur with less complication encountered during and after surgery with early rehabilitation for the patient.