Costotransverse Joints

Costotransverse joints are synovial joints formed between the tubercles of ribs and the transverse processes of their corresponding thoracic vertebrae. These joints contribute to the mobility of the thoracic cage during respiration by permitting slight gliding and rotational movements of the ribs.

Location

These joints are located in the posterior thoracic region. Each costotransverse joint is formed between:

• The posterior tubercle of a rib (typically ribs 1–10)
• The transverse process of the same-numbered thoracic vertebra

For example, the tubercle of rib 5 articulates with the transverse process of T5.

Vertebral Levels Involved

• Present: T1 to T10 (ribs 1–10 form costotransverse joints)
• Absent: T11 and T12 (floating ribs do not articulate with transverse processes)

Joint Type

Synovial plane (gliding) joints – allow small translational or rotational movements depending on rib level.

Ligaments

Costotransverse joints are supported and stabilized by the following ligaments:

• Costotransverse ligament: Connects the rib neck to the anterior aspect of the transverse process
• Lateral costotransverse ligament: Extends from the rib tubercle to the tip of the transverse process
• Superior costotransverse ligament: Connects the rib neck to the transverse process of the vertebra above

Movements

• Upper ribs (1–6): Primarily rotational movements (pump-handle action)
• Lower ribs (7–10): Primarily gliding movements (bucket-handle action)

Function

• Permit rib elevation and depression during respiration
• Help maintain the flexibility and integrity of the thoracic cage
• Transmit mechanical forces between the ribs and vertebrae

Innervation

• Posterior rami of thoracic spinal nerves (T1–T10)

Clinical Relevance

• Joint dysfunction: Restricted mobility or inflammation may cause localized thoracic back pain
• Trauma: Rib fractures can disrupt the costotransverse joint and lead to instability or pain
• Arthritis: Degenerative changes in older adults may affect joint surfaces and reduce thoracic flexibility
• Surgical consideration: Important landmarks during spinal or thoracic surgical approaches