The facet of the tubercle of the rib forms an articulation with the adjacent transverse process of a thoracic vertebra. This is a plane type synovial joint

Synovial joint

A Synovial joint, also known as a diarthrosis, is the most common and most movable type of joint in the body of a mammal. As with most other joints, synovial joints achieve movement at the point of contact of the articulating bones....

 called the costotransverse joint.

This articulation is present in all but the eleventh and twelfth ribs. Ribs 1 to 10 have two joints in close proximity posteriorly; the costovertebral joints and the costotranseverse joints. This arrangement restrains the motion of the ribs allowing them to work in a parallel fashion during breathing. If a typical rib had only one joint posteriorly the resultant swivel action would allow a rib to be non-parallel with respect to the neighboring ribs making for a very inefficient respiratory mechanism.
The ventral rami innervate the costotransverse joints. Therefore, therapeutic medial branch blocks are ineffectual.

The ligaments of the joint are:

• Articular capsule
• Costotransverse ligament
  Costotransverse ligament
  A Costotransverse ligament is a short fibrous band that connects the dorsal surface of the neck of a rib with the anterior surface of the transverse process of the corresponding vertebra....
  
  
  • Posterior costotransverse
  • Anterior costotransverse
• Ligament of neck of rib
• Ligament of tubercle of rib