Thoracic Outlet Syndrome (TOS) is a complex of symptoms representing neurovascular compression in the supraclavicular area and shoulder girdle. Arterial thoracic outlet syndrome represents only 1% of all TOS's. We present two cases of arterial TOS's following internal fixation of clavicular fractures.

Two cases of clavicular fractures managed with internal fixation and subsequently diagnosed with symptomatic, position dependent arterial occlusion are presented. The first case of a 16-year-old male treated with an intramedullary compression screw. He developed symptoms and was diagnosed with TOS using dynamic duplex examination performed by a vascular surgeon. Revision surgery was planned to decompress the subclavian artery from the hypertrophic callus at the fracture site. Before this could be performed the patient re-fractured his clavicle and bent the intramedullary screw. This resulted in resolution of the TOS symptoms. Following this second injury the patient went on to unite the fracture.

The second case was of a 48-year-old male. He was initially treated non- operatively until the patient reported sensory and motor disturbances involving the hand and forearm. Excess callus was excised and the fracture was fixed using a locking plate. The symptoms improved, but worsened again eight weeks post operatively. Angiogram revealed vascular occlusion on arm abduction. Repeat surgery was performed in conjunction with a vascular surgeon. The plate was removed, vascular structures were released from fibrous tissue in the region of the fracture, and the posterior edge of the clavicle was debrided with a burr to reduce future impingement on vascular structures. Post operatively the TOS symptoms did not recur.

Arterial thoracic outlet syndrome is an uncommon complication of trauma involving the clavicle. It can present in the presence or absence of surgical intervention, but can require surgical intervention to resolve.