What is the most common cause of thoracic outlet syndrome?

Narrow space. The most common cause is a narrow space between the first rib and a muscle tendon from the anterior scalene muscle. Other causes included an aberrent cervical rib.
Biomechanical Injury. Speculation of abnormal soft tissue scalene muscle structure wrong.  my clinic data proves cause is function of one cm space between bony clavicle and first rib (costoclavicular dimension), the true thoracic outlet for major arm artery and nerves; acromioclavicular joint laxity from acute injury and/or one shoulder drooped from unilateral thin/weak trapezius due to chronic head tilt (@ quora.Com).
Trauma. Many people are born with cervical ribs, elongated transverse vertebral processes, and narrow nerve tunnels in the spine and other areas of the body. Certain injuries can add to compression where nerves pass, and symptoms can ensue. Chronic activities overhead may result in tos issues, but an acute trauma seems more common.

Related Questions

If scapular instability is the cause of thoracic outlet syndrome, would rib resection/scalenectomy resolve neck & scapula pain?

More complex. Thoracic outlet syndrome surgery includes, often, first rib resection and/or scalenectomy, but there are different surgical approaches and also, pectoralis minor decompressions. Scapular instability may or may not be present, and this may represent problems in the upper brachial plexus. Since this is so individualized and particular in most cases, best to discuss with experienced vascular surg. Read more...

Is a second operation for thoracic outlet syndrome common?

TOS. TOS is complex and usually responds to physical therapy. Before surgery, multiple tests and physical therapy are done. If you continue with symptoms after a TOS operation, you may need more evaluation, possibly a second opinion before consenting to a second operation. Take a friend with you to consult. Be well. Read more...
No. It is not and should only be considered by a surgeon VERY experienced in the surgical treatment of TOS. If you tryly need reoperative surgery, you should travel to a center and surgeon with appropriate expertise. Read more...

Does surgery for thoracic outlet syndrome cause long term pain?

Caution. Surgery is done to relieve pain. "Long term pain" is probably referring to failure of the surgery to relieve the pain of TOS. TOS is complicated. Vascular TOS needs surgery. Neurogenic TOS should only have surgery after ALL CONSERVATIVE therapy has failed. The surgery is not always successful. Your thoracic outlet is filled with nerves, blood vessels and muscles: serious complications can occur! Read more...

Can thoracic outlet syndrome be caused by MS or fibromyalgia?

No. Thoracic outlet is related to vascular compression and is not related to the other 2 diseases. Read more...
No. Three very different conditions, and although fibromyalgia and TOS can be caused secondary to trauma, MS has no real relationship to injury, and does not cause either problem. Read more...

What causes the recurrence of thoracic outlet syndrome after having decompression surgery?

Poor luck. I'm so sorry that you've not found relief. This must be very painful and discouraging - but it is a very challenging condition and treatment often fails or is only partly successful. This info may explain: http://emedicine.medscape.com/article/462166-treatment#showall Keep trying w/ Drs and find psychotherapy support to help you manage the pain and feelings. Best wishes! Read more...