Are The Lateral Wall Reduction And Ideal Tip-Apex Distance Important In Reverse Oblique And Transverse Intertrochanteric Femoral Fractures (31-A3) Treated With Gamma Nail?

Abstract

Purpose: Reverse oblique and transverse intertrochanteric femoral fractures (31A3 AO/OTA classification) have their own mechanical and anatomical properties. The aim of our study is to verify whether the reduction of the lateral femoral wall and ideal tip-apex distance are important predictive factors in the future of these fractures treated by gamma nails in terms of healing and complication rates. Methods: The radiological and clinical outcomes of 35 fractures of this type treated by short and long gamma nail from June 2014 to April 2021 were retrospectively reviewed. The elements considered were the quality of the lateral femoral wall reduction, the tip-apex distance (TAD), the lag screw position and overall quality reduction using the Baumgaertner criteria. Union, nonunion, cutout, screw sliding, nail or screw breakage were also radiographically evaluated during follow-up. Results: The union rate was 97%. A significant association was not observed between the state of reduction of the lateral wall and the three types of complications considered (cutout: p=0.31; sliding screw: p=1.00; varus displacement: p=0.30), and the linear regression model obtained indicates that in subjects with a non-reduction of the lateral wall, the consolidation time is increased on average by approximately 3 months (β= 2.99; 95%CI: 1.79-4.20, p<0.001). No significant association was found between TAD and complications (cut-out: p=1.00; sliding screw: p=1.00; varus displacement: p=0.13). Conclusion: Anatomic reduction of the lateral wall and an ideal TAD ≤ 25mm might not be as significant for 31A3 fractures treated with gamma nails. Acceptable reduction of the lateral wall and stable internal fixation are sufficient elements to achieve fracture healing and functional recovery.