Tibia "anterior surfaces" of the condyles are continuous with one another, forming a large somewhat flattened area; this area is triangular, broad above, and perforated by large vascular foramina; narrow below where it ends in a large oblong elevation, the tuberosity of the tibia, which gives attachment to the patellar ligament; a bursa intervenes between the deep surface of the ligament and the part of the bone immediately above the tuberosity. "Posteriorly," the condyles are separated from each other by a shallow depression, the posterior intercondyloid fossa, which gives attachment to part of the posterior cruciate ligament of the knee-joint. The
Tibia Clausa rank. A few of the largest theatre organs, and some church organs, may have a separate 32′ Tibia Clausa rank of 12 pipes. In smaller organs, a "Bourdon" or "Stopped Diapason" may be substituted for a Tibia Clausa at 16′ pitch. The Tibia may be voiced on wind pressures from 10″ to 25″. The Tibia is generally used as a chorus stop, with or without tremulant; it is not normally used as a solo stop due to its relatively dull tone. Other variants of the Tibia Clausa include: Tibia Bass, Tibia Flute, Tibia Major, Tibia Plena (open tibia) and Tibia