Thoracic Outlet Syndrome: A Functional Dysfunction of the Upper Thoracic Aperture?

Purpose Of The Study: To determine possible malfunction of the upper thoracic aperture (an upward displacement of the first rib at the costotransverse joint) as the cause of thoracic outlet syndrome (TOS) symptoms among consecutive TOS patients admitted for conservative treatment.

Basic Procedures: Fifteen consecutive TOS patients, with a positive TOS index, admitted for conservative treatment were investigated with a three-dimensional CT scan of the upper thoracic aperture. A rehabilitation program was administered at a rehabilitation ward. The CT scans were evaluated for a possible upward displacement of the first rib at the costotransverse joint. The outcome of conservative therapy was classified as good if the patient was symptom free and poor if loading of the upper limbs still produced symptoms. Outcome follow-up time was 1 year.

Main Findings: An asymmetry of the first rib was shown on the symptomatic side, indicating an upward displacement of the first rib at the costotransverse joint, in 12 of the patients. Only three patients did not respond to therapy. Eleven patients were engaged in sedentary work.

Conclusion: Malfunction of the upper thoracic aperture, especially among patients doing sedentary work, seems to cause TOS symptoms. A carefully planned conservative therapy program based on the functional findings of the individual patient is recommended.