Lower extremity of femur extended. Where the groove ceases laterally the patellar surface is seen to be continued backward as a semilunar area close to the anterior part of the intercondyloid fossa; this semilunar area articulates with the medial vertical facet of the patella in forced flexion of the knee-joint. The tibial surfaces of the condyles are convex from side to side and from before backward. Each presents a double curve, its posterior segment being an arc of a circle, its anterior, part of a cycloid. Lower extremity of femur The lower extremity of femur (or distal extremity) is the lower end of the
Tuberosity of the tibia Tuberosity of the tibia The tuberosity of the tibia or tibial tuberosity or tibial tubercle is a large oblong elevation on the proximal, anterior aspect of the tibia, just below where the anterior surfaces of the lateral and medial tibial condyles end. It gives attachment to the patellar ligament, which attaches to the patella from where the suprapatellar ligament forms the distal tendon of the quadriceps femoris muscles. The quadriceps muscles consist of the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. These quadriceps muscles are innervated by the femoral nerve. The tibial tuberosity thus forms the terminal part