The femur (see Figure 3.29) is the longest and heaviest bone in the body. Proximally, it articulates with the pelvis and distally with the tibia at the knee joint. The superior aspect of the femur is rounded to form a head. The head narrows into a distinct neck that, in turn, joins with the shaft at an angle of about 125°. At the junction of the neck and shaft, a projec-tion is seen laterally. This is the greater trochanter. On the posteromedial surface, inferior to the greater trochanter, is the lesser trochanter. Anteriorly, a raised surface that runs between the greater and lesser trochanter, the intertrochanteric line, marks the point where the articular capsule of the hip joint is attached.
Along the posterior aspect of the shaft of the fe-mur, the linea aspera ridge runs down the center. Distally, the linea aspera divides into two ridges: the medial and the lateral supracondylar ridge. Thelower end of the femur widens into the medial and lateral condyles. The medial and lateral supra- condylar ridges end at roughened projections, the medial and lateral epicondyles, located on the me-dial and lateral condyles, respectively. A prominence just superior to the medial epicondyle, the adductortubercle, is where the tendon of the adductor mag-nus attaches. A deep depression, the intercondylarfossa, is seen between the condyles on the posteriorsurface of the lower end of the femur. Anteriorly, there is a smooth surface between the condyles. This is the surface that articulates with the patella, the patellar surface, or trochlear femoris.