The costotransverse joints are the articulations on each side of the spinal column of a given thoracic rib with the transverse process of its corresponding thoracic vertebra:
- a costovertebral, synovial joint
- anterior attachment is the medial articular facet on the tubercle of a given rib
- posterior attachment is articular facet of transverse process
- capsule attaches to the margins of these cartilaginous surfaces
- ribs 11 and 12 have no costotransverse synovial joints, only direct ligamentous connections
In the upper 6 ribs, the facets are reciprocally concave and convex. Inferior ribs have planar facets in apposition. This has implications for respiratory movements. The upper ribs are rotated upwards and laterally about their axis of rotation on external oblique contraction whereas the lower ribs are elevated just laterally.
The costotransverse joints are reinforced by the costotransverse ligaments.