Morphologic Analysis of Fracture Patterns in the Anterior Region of Femoral Intertrochanteric Fractures Using Computed Tomography

Purpose: Intertrochanteric fractures often involve comminuted fractures, particularly around the intertrochanteric ridge, including the greater and lesser trochanters.In cases with comminuted fractures in the posterior region, maintaining a stable reduction of the anteriormedial region of the fracture surface is essential.Therefore, this study examined the morphologic features of the anterior femur for stable reduction by analyzing the anterior region of intertrochanteric fractures using three-dimensional computed tomography.Materials and Methods: This retrospective study analyzed the imaging data of 51 patients aged 60 years and older who underwent a surgical treatment for intertrochanteric fractures at a single institution from April 2013 to March 2023.The sample contained 15 male patients with an average age of 81.9 years and 36 female patients with an average age of 83.7 years.Forty patients (78.4%) had two or more comorbidities.The bone mineral density was assessed in all cases except for five (9.8%).Results: In 49 cases (96.1%), the anterior fracture line followed the intertrochanteric line and passed through two bony prominences.In two cases (3.9%), the fracture line ran below the intertrochanteric line and involved a large fragment of the lesser trochanter.As the fracture line passed through the inferior medial bony prominence, it exhibited an S-shaped pattern rather than a straight line.The inferior medial bony prominence consisted of cortical bone, with an average thickness of 6.41.4 mm, which was significantly thicker than the surrounding average cortical bone thickness (1.50.6 mm) but thinner than the cortical bone thickness of the femoral shaft (7.31.3 mm).The fracture line in the superior lateral region of the intertrochanteric line included cancellous bone with a cortical bone thickness of 1.10.6 mm, which was thin.Conclusion: The anterior fracture line followed the femoral intertrochanteric line and curves as it passed through the inferior medial bony prominence.The inferior medial bony prominence, consisting of cortical bone, was significantly thicker than the surrounding average cortical bone.