Costovertebral joints

There exist major differences between the thoracic (Tl-10) and thoracolumbar vertebral bodies (T11-L5), since the rib cage serves as a stabilizer of the thoracic vertebral column. Four factors have to be determined (1) percentage of osteolyses in the vertebral body, (2) presence of involvement of the pedicles, (3) posterior elements, and (4) costovertebral joint involvement at the thoracic spine (Taneichi et al. 1997). 

A vertebral body is at risk of fracture in the thoracic spine if more than 50% of the vertebral body is missing or if more than 25% of osseous destruction of the vertebral body is combined with a destruction of the costovertebral joint (see above Fig 35.14). In the lumbar spine, a vertebral body is at risk of fracture if more than 35% of the body is destroyed or if a more than 20% de-... 

To date, the mechanical properties of the metastatic spine and the mechanisms of collapse have not been fuUy elucidated. Moreover, the correlation between vertebral body coUapse and the location and extent of the metastatic tumor is not fully understood. Taneichi et al. (1997) evaluated 100 thoracic and lumbar vertebrae (53 patients) with osteolytic lesions, determined risk factors for vertebral coUapse, and estimated the probability of coUapse under various states of metastatic vertebral involvement. The most important risk factor leading to vertebral coUapse in the thoracic region was involvement of the costovertebral joint. Tumor size within the vertebral body was the second most important risk factor. In-... 

Although no studies have compared the motion of the thoracic spine with and without intact costovertebral joints. White and Panjabi et al. have determined that the costovertebral joint plays a critical role in stabilizing the thoracic spine during flexion and extension. 

The costovertebral Joint is the articulation of the rib head with the bodies of one or two vertebrae. For a typical rib, the costovertebral joint includes the bodies of the vertebra at the same level and the vertebra immediately above, the annulus fibrosis of the intervening disk, and the costal facets. It is a synovial joint with a single capsule. The facets of the costovertebral joint are... 

Together, the costotransverse and costovertebral joints form a complex coupled joint. An imaginary line drawn between the two articulations is the axis that defines the direction of rib motion (Fig. 69-1). 

The heads of the second through twelfth ribs articulate with the bodies of the corresponding vertebrae and the one above, as well as with the corresponding intervertebral disk. However, the first rib articulates only with the superior aspect ofTl. The costovertebral articulation is a synovial joint, with a joint capsule that is strengthened by the radiate ligament (see Costovertebral Ligaments). 

Each rib head has two facets for articulation with the body of the next superior vertebra and the same-numbered vertebral body. These articulations jointly constitute the costovertebral articulation. The tubercle articulates with the transverse process of the same vertebra via a facet and is known as the costotransverse articulation. 

The tenth rib is typical in every respect expect its costovertebral articulation. The single articular facet on the head forms a joint with the facet on the body of the TIO vertebra. 

The axis formed by the coupled costovertebral and costotransverse joints determines the primary direction of rib movement This is influenced by the angle between the vertebral body and the transverse process and by the distance... 

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