Cervical Rib(Thoracic Outlet Syndrome):Overview,Diagnosis & Treatment
Thoracic Outlet Syndrome: A cervical rib is a rudimentary(extra) rib which appears from the seventh cervical vertebra. It is a congenital abnormality located on the right, left, or on both sides above the normal first rib. It doesn’t usually cause problems, but if its compression of the brachial plexus may be identified by the weakness of the muscles around the muscles in the hand, near the base of the thumb and it can cause neck pain, which collectively known as thoracic outlet syndrome. Compression of the subclavian artery is usually diagnosed by determining a positive Adson’s sign on examination, where the radial pulse in the arm is lost throughout abduction and external rotation of the shoulder.It may be a fully-formed bony rib or just a thin strand of tissue fibers. The thoracic outlet is signified by the anteriorly on the anterior scalene muscle, the middle scalene posteriorly, and the first rib inferiorly.Thoracic outlet syndrome usually starts between 20 and 50 years of age and is more likely to affect men than women. About 1 in 200 people are born with an extra rib called a cervical rib.
Causes & Risk Factors for Thoracic Outlet Syndrome
An inadequate passageway for nerves and blood vessels between the base of the neck and the armpit causes thoracic outlet syndrome. This can be constant or intermittent. Risk factors for cervical rib include that involve heavy usage of the upper extremities against resistance, including poor posture, dentists, weight lifting, pregnancy, and obesity.
Thoracic Outlet Syndrome Symptoms
Cervical rib symptoms may vary which nerves or blood vessels are compressed. When nerves are compressed, neurological thoracic outlet syndrome include-
- Aching pain in the neck includes arm or hand
- Muscle wasting in the fleshy base of your thumb
- Numbness or tingling in your arm or fingers
- Weakening Grip
- Your range of motion may be limited.
Pressure on the blood vessels can reduce the flow of blood out of your arm, resulting in swelling and redness of your arm. The vascular cervical rib can include:
- Bluish color of your hand
- Arm pain and Swelling, due to blood clots(although this is rare)
- Weak or no pulse in the affected arm
- Cold fingers, hands or arms
- Weakness of arm or neck (Arm fatigue with activity)
- Throbbing lump near your collarbone
- Raynaud's phenomenon – a condition that impairs the blood supply to the fingers and toes, turning them white
Diagnosis of Thoracic Outlet Syndrome
The examination of thoracic outlet syndrome is intimated by the symptoms and supported by findings of the physician during the examination. Certain procedures of the arm and neck can produce symptoms and blood vessel "pinching," causing a loss of pulse. This includes
- Elevated Arm Stress/ Roos test- the patient has arms at 90° abduction and the physicians set downwards pressure on the scapula as the patient opens and closes the fingers. If the thoracic outlet symptoms are generated within 90 seconds, the test is positive.
- Wright's test- the patient’s arm is hyper abducted. If there is a reduction or absence of a pulse on one side then the test is positive.
- Adson's test- the patient is asked to rotate the head and elevate the chin toward the affected side. If the radial pulse on the side is absent or decreased then the test is positive, showing the vascular component of the neurovascular bundle is compressed by the scalene muscle or cervical rib.
The further supportive examination can include electrical tests, such as electromyogram(EMG), somatosensory evoked responses and angiogram X-ray tests that demonstrate the pinched area of the blood vessel involved.
Cervical Rib Treatment
The first approach for cervical rib treatment usually is successful with conservative measures.Your physicians may refer you for physiotherapy, which focuses mainly on patient education, pain control, range of motion, nerve gliding techniques, strengthening and stretching. Massage may also help to release any tight or shortened neck tissues.
- Shoulder exercises to restore the range of motion and so provide more space for the neurovascular structures.
- ROM of the upper cervical spine.
- Activation of the scalene muscles are the most relevant exercises that help to normalize the function of the thoracic aperture as well as all the malfunctions of the first rib.
Nonsteroidal anti-inflammatory medications such as naproxen and ibuprofen can ease the pain and reduce swelling. In some cases, botulinum injections to the anterior and middle scalenes have also found to temporarily reduce pain and spasm from neurovascular compression. If you develop blood clots you may be prescribed thrombolytics to break them up, and anticoagulants to prevent further clots developing.
If these treatments don't help, cervical rib surgery may be an option. Surgery to treat thoracic outlet syndrome may be performed- transaxillary approach, supraclavicular approach, and infraclavicular approach.