Topography of diaphyseal nutrient foramina of femora and their implications in bone grafting

Abstract

Background : Long bones derive their nutrition through a nutrient artery that enters the bone through a foramen in its diaphysis. An orthopedic surgeon must be familiar with the topography of the nutrient foramina to avoid vascular compromise during surgery. Aim: This study attempts to analyze the topography of primary nutrient foramina of femora. Materials and method : One hundred dry adult femora were used for this study. The primary diaphyseal nutrient foramina were identified macroscopically using hand lens. The number of foramina and their position were noted and the foraminal index was calculated. Results : It was observed that 79% of femora had single primary nutrient foramen, 20% had double foramina and 1% had three foramina. All the foramina were located between 30.8%-89.6% of total length of femur. 11.47 % of foramina were in the upper third, 1.64 % in the lower third and the majority 86.88% of foramina were in the middle third of femur. The mean foraminal index was 46.01. 82.78% of foramina were located on the linea aspera, 14.75% on the medial surface and 2.46% on the lateral surface. Conclusion : An orthopedic surgeon operating on femur must be careful in the middle l/3rd, especially over the linea aspera as majority of primary diaphyseal foramina were observed in this region. A cogent knowledge of vascular topography ensures preservation of vasculature of the bone during surgeries. This enables rapid healing of surgical wound increasing the success rates of fracture fixation, bone grafting, vascularized microscopic surgeries and hip and knee replacement procedures.

Keywords

• bone grafting
• femur
• foraminal index
• nutrient foramina
• topography