Definition (Cervical rib): A cervical rib in humans is a supernumerary (or extra) rib which arises from the seventh cervical vertebra. Sometimes known as “neck ribs”, their presence is a congenital abnormality located above the normal first rib. A cervical rib is present in only about 1 in 500 (0.2%) of people; in even rarer cases, an individual may have two cervical ribs.
- Cervical rib is generally seen only on one side of the body, more often on the right.
- It may be a complete or partial rib.
- This condition is present in approximately 0.5 percent of the population.
- It is caused by a congenital defect during bone formation.
Symptoms and signs: Cervical rib is usually asymptomatic and is detected when a chest or neck X-ray is taken for some other purpose.
In other cases the condition produces symptoms in middle age due to sagging of shoulders and decline of muscle tone.
Symptoms are seen in women more often than in men. The symptoms occur due to the rib pressing on the nerves or blood vessels, as they go from the spinal column to the arm.
Sensory symptoms like pain and tingling numbness are complained of in the forearm and hand, especially the inner side corresponding to the little finger.
Motor symptoms include weakness of the arm and hand and impaired fine movements like writing and sewing.
Vascular symptoms – If the blood vessels like the subclavian artery are compressed, there may be bluish discolouration of the skin of that limb due to diminished blood supply or in rare cases frank gangrene of the fingers and the pulse at the wrist may be weak or absent.
Diagnosis: The diagnosis may be incidental during a routine check up or if the patient complains of these symptoms the doctor may suspect the condition and order an X-ray of the neck. The diagnosis may be confused with carpal tunnel syndrome, cervical disc prolapsed and neuritis of the ulnar nerve supplying part of the forearm and hand.
Investigations: Apart from an X-ray, arteriography is required if vascular symptoms are seen. In this procedure, dye is injected to outline the blood vessels in that region and then films are taken.
Physiotherapy: In mild cases, shrugging exercises of the shoulder are advised to tone the shoulder muscles and the toned muscles keep the cervical rib from compressing the vital structures. The patient is advised against lifting heavy objects like suitcases, grocery bags etc.
In moderate to severe cases, surgery is the only treatment option. The rib can be removed surgically after which there is no recurrence of the problem.