These joints are created by articulation of articular facets on the head of ribs and costal facets on the bodies of thoracic vertebrae.
The head of typical rib articulates with the body of numerically corresponding vertebra and also with the body of next higher vertebra.
Synovial type of plane joint.
1. Capsular ligament (joint capsule): It’s the fibrous capsule that covers/encloses the joint and is connected to the articular margins.
2. Radiate ligament/triradiate ligament: It stretches from the anterior aspect of the head of rib and breaks up into 3 bands: upper, lower, and middle. The upper and lower bands are connected to the sides of upper and lower vertebrae. The middle band (also referred to as intra-articular ligament) gets connected to the intervertebral disc.
3. Intra-articular ligament: It stretches from the crest between the 2 articular facets on the head of rib to the intervertebral disc and splits the joint cavity into 2 parts.
The 1st, 10th, 11th, and 12th ribs joint with the bodies of numerically corresponding vertebrae.
Costovertebral joint of typical ribs got 2 joint cavities and those of atypical ribs have single joint cavity.