The patella is located within the extensor apparatus of the knee.
Anatomical features include the proximal articular body, with an extraarticular anterior surface and a posterior articular surface, and the extraarticular distal pole.
The rectus femoris and vastus intermedius muscles insert at the superior pole of the body and the vastus medialis and vastus lateralis muscles on either side.
The patellar tendon originates from the inferior pole and inserts into the tibial tuberosity.
The articular surface has the thickest layer of cartilage in the body, up to 5 mm, reflecting the very high resultant loads across the patellofemoral joint, rendering it susceptible to chondromalacia and degenerative joint disease.