Radiology Corner – The Cervicothoracic Junction

By: Terry R. Yochum, DC, DACBR, Fellow, ACCR and Michael S. Barry, DC, DACBR

History

This young female patient presents with a history of trauma to the cervicothoracic junction. What is your diagnosis?

Figure 1.

Figure 1.

Figure 1 Diagnosis: Bilateral cervical ribs. Note that the ribs extending from the C-7 transverse processes project caudally. The transverse processes of T-1 project towards the head.

Discussion

A cervical rib is a separate piece of bone that articulates with the transverse process of one or more cervical vertebrae. It is most common at the C7, C6, and C5 levels, in descending order of occurrence. These ribs may be differentiated from elongation of a cervical transverse process, which would demonstrate no joint at the transverse process, as well as a rudimentary first thoracic rib, which may require the counting of all thoracic ribs.

Cervical ribs are present in 0.5% of the population and are twice as common in females. They are bilateral in 66% of cases. If these ribs cause symptoms, it is usually after middle age when the shoulders begin to droop, resulting in neurovascular compression.

Radiologic Features

The radiographic diagnosis is made when the anomalous rib is seen to form a joint with a transverse process that is oriented in a caudal direction (which is the case in the presented image with bilateral articulations between the transverse process of C7 and the base of the cervical rib). The length of the cervical rib is quite variable, from a rudimentary stump to a fully developed rib that may also articulate with the sternoclavicular junction.

Cervical ribs may be differentiated from elongation or enlargement of the transverse process. An enlarged transverse process extends laterally beyond the transverse process of the first thoracic vertebra and does not reveal a joint.

Cervical ribs vary greatly in size and shape, and clinical symptoms bear little relation to the radiographic abnormality. One should be aware that a fibrous band may extend from the end of a small cervical rib and be the actual source of neural or vascular compression. Unfortunately, this band is unappreciated on conventional radiographs. Contrast radiographic examination demonstrating vascular occlusion would be necessary to make a preoperative diagnosis of a fibrous band creating a thoracic outlet syndrome.1,2

References

  1. Yochum TR, Rowe LJ. Essentials of Skeletal Radiology, 2nd ed. Baltimore, MD: Williams & Wilkins, 1996.
  2. DuToit J. Isolated fracture of a cervical rib. S Afr Med J 1982; 18:62.

About the Authors

Dr. Terry R. Yochum is a second generation Chiropractor and a cum laude graduate of the National College of Chiropractic, where he subsequently completed his radiology specialty. He is a Diplomate of the American Chiropractic Board of Radiology and served as its vice-president and president for seven years (1983–1990).

Dr. Michael S. Barry is a 1988 cum laude graduate of Palmer College of Chiropractic. He completed a three-year radiology residency at Logan College of Chiropractic following two years of clinical practice in Las Vegas, Nevada. He received his diplomate in radiology from the American Chiropractic Board of Radiology in 1992.