tibia midshaft cross-sectional area tibia midshaft cortical cross-sectional area 2016-11-30T15:21:44Z CMO:0002700 The portion of the cross-sectional area of the tibia, measured midway between the two ends of the bone, that corresponds to the area of the cortex, the outer layer of the bone. The cross-sectional area of the tibia is a measurement of the extent of a plane through, i.e. perpendicular to the axis of, the tibia, the medial and larger of the two bones of the lower leg of bipeds or hindlimb of quadrupeds which articulates with the femur, fibula, and talus. clinical_measurement_ontology jesmith tibia midshaft cortex cross-sectional area