Effect of distal locking type on radiological results of proximal femoral nails used in the surgical treatment of hip fractures

Purpose: The aim of our study is to obtain data that will shed light on the effect of the distal locking type of proximal femoral nails (PFN) on fracture healing, causes of general complications, especially those in the distal of the nails, and reduction of possible complication rates. Materials and Methods: Patients who underwent surgery with the diagnosis of trochanteric hip fracture between 01.01.2015 and 01.01.2020 and completed the second year follow-up time were examined from the medical records. Patients were grouped first according to AO/OTA subtypes (Three groups as AO A1, A2 and A3), then grouped according to distal locking type (Two groups as group 1: dynamic, group 2: static distal locking with 2 screws). The fracture type, healing status, fracture healing time, complication rates and reoperation because of complication development data were evaluated. Results: 339 patients enrolled in the study [189 women, 150 men, mean age: 76.24 (60-102) years]. The overall complication rate was 15.6%. AO A3 type fractures had long fracture healing times in each distal locking group compared to the other fracture sub-types. AO A3 type fractures had more frequent complication rates than the other subtype groups. AO A3 type fractures in group 2 had higher overall complication rates than in group 1. There was a significant correlation between group 1 and lag screw cut-out complication occurrence in females and between group 2 and pseudoarthrosis occurrence in males. In addition, there was a statistically significant relationship between the AO fracture sub-type and total rate of complication occurrence, AO A2 fracture type and lag screw cut-out complication occurrence and AO A3 fracture type and pseudoarthrosis complication occurrence. Conclusion: Patients with AO/OTA 31 A3 type fractures with static distal locking have a longer fracture healing time and a higher complication rate compared to dynamic locking. However, dynamic or static distal locking is not associated with other implant-related complications, especially those in the distal to the tip of PFN's.