Abstract
This study attempts to clarify the internal structure of the patella and, furthermore, to consider its function. Patella were surgically removed from amputated limbs, dehydrated by alcohol solution and perfused in polyester resins. Samples (500μm) were observed by soft X-ray. Trabeculae in horizontal section were divided into tnree patterns by running scanner. The findings were as follows: Trabeculae are at right angles to the articular surface, cross in parallel along the articular surface, cross the superior surface of the patella. Trabeculae in the sagittal section were divided into four patterns and are at right angles to the articular surface. They cross in parallel along both medial and lateral articular surfaces and run obliquely toward the apex of the patella in the subarticular surface. Trabeculae traverse the patella in its superior surface. Trabeculae in a frontal section differ from the form in the horizontal and sagital sections and have a netlike structure. Patellar trabeculae rise with compression and tension forces, and trabeculae appear to be more easily influenced be dynamic effects rather than static. In a form of trabeculae, under tension, they are thick are continuous and sufficiently high density and have sturdy moorings in all directions. Accordinly, the patella works as a fulcrum on the articular surface of the femur condylus and is helpful for stabilization of the knee joint and in insuring smooth mobilization in the femur and tibia.
