What is cervical rib?
Cervical rib in human is an extra rib which arises from 7th neck (cervical) vertebra.
It’s an abnormality present at birth, an extra rib located above the normal 1st rib. A cervical rib is estimated to occur in 0.2% (1 in 500 people) to 0.5% of the population. People may have a cervical rib on the right, left or both sides {1}.
Most of cases of cervical ribs does not cause any symptoms, most of the time they are accidental findings on the x rays.
In rare cases they may cause problems contributing to compression of the nerves, arteries, or veins in the passageway from the lower neck to the armpit (thoracic outlet syndrome).
A cervical rib represents a persistent fusion of the bone (ossification) of the C7 neck vertebra. During the early development this fusion of the vertebra is re absorbed, hence failure to this may cause cervical rib.
How to diagnose symptomatic cervical rib?
Along with the investigations like x rays clinical findings like significant weakness in the muscles of the hand and base of the thumb.
Compression of artery (mainly Subclavian) is diagnosed by Adson’s sign.
Adson's sign is the loss of the radial pulse in the arm by rotating head to the ipsilateral side with extended neck following deep inspiration. It is sometimes used as a sign of thoracic outlet syndrome (TOS). It is named after Alfred Washington Adson.
What are the symptoms?
People with symptomatic cervical rib may present pain in the neck region, numbness or tingling in arms or fingers. Muscle wasting at the base of thumb.
Compromised grip strength. Weak pulse in the affected arm along with swelling, lack of pallor in the fingers or entire arm. Cold fingers hand or arms. In rare cases dislocation of the shoulder.
How do we treat cervical rib?
If the nerve related symptoms worsen then surgery is treatment .Excision of the cervical rib along with division of scalene group of muscle is done {2}.
Physiotherapy treatment in cervical rib mainly aims to reduce pain, normalize the radial pulse, maintaining the strength of the muscles around the shoulder, arm and hand.
Shoulder blade / Scapular strengthening exercises
Mulligan mobilization –SNAGs for C6-C7 and Reverse SNAGs for C7-T1 {3}.
Grade 2 and grade 3 Maitland mobilisations at lower cervical and upper thoracic spine {4}.
If a person experiencing these type of symptoms may not assume that he / she has a cervical rib, always it is important to undergo a complete physical exam or X ray before formulating a treatment plan.
References-
1] Walden, Michael; et al. (2013). "Cervical ribs: identification on MRI and clinical relevance".
2] Henry BM, Vikse J, Sanna B, et al. Cervical Rib Prevalence and its Association with Thoracic Outlet Syndrome: A Meta-Analysis of 141 Studies with Surgical Considerations. World Neurosurg. 2018;110:e965-e978. doi:10.1016/j.wneu.2017.11.148.
3] Shafique S, Ahmad S, Shakil-Ur-Rehman S. Effect of Mulligan spinal mobilization with arm movement along with neurodynamics and manual traction in cervical radiculopathy patients: A randomized controlled trial. J Pak Med Assoc. 2019;69(11):1601-1604. doi:10.5455/JPMA.297956.
4] Lee KS, Lee JH. Effect of maitland mobilization in cervical and thoracic spine and therapeutic exercise on functional impairment in individuals with chronic neck pain. J Phys Ther Sci. 2017;29(3):531-535. doi:10.1589/jpts.29.531