European Journal of Cardiovascular Medicine

Cervical rib is the most common cause of thoracic outlet syndrome (TOS), causing pain in the region of root of neck, shoulder & arm. The condition is often under-recognized and diagnosis is missed by the clinicians. The patients of cervical rib with thoracic outlet syndrome have often been neglected by the orthopaedic surgeons as well as the thoracic surgeons due to various reasons, like inadequate exposure, lack of clear guidelines for diagnosis and treatment etc. Literature available on the topic are not enough, and several confusions exist regarding co-morbidities, associations, treatment protocol, prognosis etc. The statement that, “cervical rib are asymptomatic”, is over-simplified and incomplete. Purpose of this study was to establish the association of the cervical ribs with the symptoms, and also to establish the effectiveness of the axillary resection of the first rib as the surgical method of treatment.

From March of 2009 to February of 2018, 680 patients including 332 females and 348 males were selected for this study form different hospitals of Bihar, India. Persons of the age between 18 years to 40 years, having vague, deep seated, and poorly localized pain with or without numbness/ weakness of more than 30 days duration, anywhere between the root of the neck up to the arm were included in this study. Patients with grade-2 and grade-3 pain only were included in this study; patients having grade-1 pain, which can be ignored easily, and grade-4 pain which is excruciating and incapacitating, were not included in this study. Patients with painful &/or restricted movements of neck or shoulder were excluded from this study assuming that the symptoms is probably from intraarticular aetiology. Patients with history of recent trauma were also not included.

The selected patients were clinically examined for peripheral pulse, peripheral nerve dysfunction, and thenar wasting. A provocative test to reproduce the symptoms was done over all the patients. The arm of the affected side was abducted and externally rotated with the hand in overhead position, as if he or she is trying to throw something, for three minutes or the appearance of the symptoms, whichever came earlier. The oxygen saturation of the finger was measured by pulse oximeter in this pain provocative position.

The patients were advised X-Ray of cervical spine from C-1 to D-2, AP and Lateral view. MRI was done in those patients in which cervical rib was seen on X-Ray, but did not respond to conservative treatment to rule out other pathologies.

The patients were advised shoulder shrugging exercises along with NSAID, i.e. Aceclofenac 100mg + Paracetamol 325 mg in twice daily doses for 10 days. Those patients who didn’t respond to this regime, were given Tramadol 37.5 mg + Paracetamol 325 mg in morning & Pregabalin 75 mg in evening for 10 days. The treatment protocol was empirical as no clearcut guideline is available.

The patients, who had no relief with conservative treatment for 20 days, undergone MRI to rule out other pathologies. In nonresponsive patients having no other pathology seen in MRI, axillary resection of the first rib was done. The patient was placed and stabilized in lateral position. One assistant held the arm in abducted position during the whole procedure to keep the neurovascular structures away from the incision line as well as the first rib. A transverse skin incision was given at the upper part of the medial wall of the axilla, extending from the anterior axillary fold to the posterior axillary fold. After incising superficial fascia and axillary fascia, the Subscapularis muscle with overlying Thoracodorsal nerve &/or Lower subscapular nerve, was retracted posteriorly (fig-1). Then, the Serratus anterior muscle was divided, taking care to prevent the injury of overlying long thoracic nerve (fig-2). The first rib or even the cervical rib can be palpated now. The periosteum over the first rib is incised now, with the blade kept and guarded between two fingers, kept over superior and inferior borders if the first rib to prevent the slippage of the blade and injury to the pleura. The first rib is dissected subperiosteally and its middle part is resected as much as possible under direct vision (fig-3). The haemostasis was secured and the wound was closed in layers. Upper limb was kept in broad arm sling till stich removal, and exercises were started thereafter.

Out of 680 patients, 74 (11 %) in which 36 were male & 38 female had cervical rib on X-ray. The prevalence of cervical rib was significantly more than the general population, which is around 1 %. X- ray findings of cervical ribs were extremely variable. They vary from a mere extension or elongation of the transverse or lateral process of C-7 as in case of incomplete rib, to a large broad osseous structure extending downwards and anteriorly from the transverse process of C-7 to the first rib.

Unlike elongated transverse process which is more or less straight structure, an incomplete cervical rib is nearly always curved downwards in AP view.

In contrast to first rib or normal rib, Cervical rib was more radiolucent than normal rib. They look broader in AP view and may have two distinctly separate parts (fig-4). May be unilateral in AP view, but were mostly bilateral.

It was difficult to visualize cervical rib on lateral view, even when it is easily visible on AP view, probably due to overlapping by vertebral bodies and great vessels. Sometimes, the only evidence of cervical rib on lateral view was an area of increased radio-density or sclerosis in the C-7 vertebral bodies (fig-5). When present on lateral view, the cervical rib was more oblique than normal or first rib and usually makes an angle of more than 45 degree with the clavicle or horizontal plain in contrast to the first rib which usually makes an angle of 30 degree or less with the horizontal plain. Cortex of the cervical rib was thinner than the normal rib (fig-6).

Surprisingly, 26 out of 74 patients with cervical rib in X-Ray shown SpO2 below 30 %, when their arms were fully abducted with the elbow extended and the probe of the pulse oximeter attached to their fingers in the overhead positions. In all these patients, oxygen saturation returned to normal level when the arm was brought down to normal or adducted position. Out of 74 patients, 29 had pain when the arm of the affected side was abducted & externally rotated mimicking the presenting complains.

Out of 74 patients with cervical ribs in X-Ray, 46 recovered well with NSAID & exercises. Among the others, 14 more patients recovered after addition of Tramadol & Pregabalin. Total 14 patients were symptomatic after the conservative treatment and they undergone MRI of cervical spine. Cervical disc diseases were found in MRI of 2 patients, who were excluded from the study. Total 12 patients, who didn’t have improvement with conservative treatment, were offered surgery. Only 10 of them agreed and undergone first rib resection of only one side having relatively severe symptom, through axillary approach. Out of ten first rib resections, iatrogenic pneumothorax occurred in one patient which required chest tube insertion for 3 days. Two patients had mild weakness preoperatively (power Ge IV) in hand which recovered after surgery in one patient & didn’t recover in one patient.

Out of 10 operated cases, 9 were satisfied from the operation up to 2 years of follow up, while 1 still had symptoms.

The exact incidence of cervical rib in general population is not known, but it is estimated to be between 1-2% according to different available literatute.^[1,2] The many times higher incidence of 11% in our target population having dull ache in the root on neck region for prolonged duration, without tender &/or restricted movements of neck or shoulder signifies that there is association between presence of cervical rib and symptoms of thoracic outlet syndrome.

The reduction in the oxygen saturation shown by finger pulse oximeter in pain provocating position indicates that some degree of compression of subclavian vessels leading to transient ischemia may be there due to presence of cervical rib but further study is required to prove this fact. Vascular aneurysm may occur due to cervical rib^[3] but angiography was not done in this study dealing with neurogenic symptoms.

As nearly one third of the conservatively treated persons required neural acting medicines like Tramadol & Pregabalin for improvement, some nerve compression is likely which is suggested by symptoms also.

There was no big difference in prevalence in male & female overall.

Opinion is divided regarding ideal surgical treatment of symptomatic cervical rib not responding to conservative treatment.^[4] Some authors recommend cervical rib resection while some authors advocate indirect decompression by first rib resection.^[5] Debate is also regarding incision,^[6] whether axillary incision should be used or supraclavicular incision should be used. In this study, axillary first rib resection because of two reasons- 1. Reports of lesser blood loss in this approach 2. Cosmetically better incision. Some authors have advocated division of scalenus anticus muscle also.^[7]

Cervical ribs are not as asymptomatic as assumed. They are important causes of TOS. They are more easily seen in AP views, and are often seen with difficulties or even not seen in lateral views. Most of the cases of cervical rib & associated thoracic outlet syndrome are successfully treated conservatively. Sometimes, surgery may be needed and axillary first rib resection gives reasonably good results.

1. Brewin J, Hill M, Ellis H. The prevalence of cervical ribs in a London population. Clinical Anatomy: The Official Journal of the American Association of Clinical Anatomists and the British Association of Clinical Anatomists 2009;22(3):331-6.
2. Guttentag AR, Salwen JK. Keep your eyes on the ribs; the spectrum of normal variants & diseases that involve the ribs Radiographics 1999;19:1125-42.
3. Chang KZ, Likes K, Davis K, et al. The significance of cervical ribs in thoracic outlet syndrome. Journal of Vascular Surgery 2013;57(3):771-5.
4. Brown SC, Charlesworth D. Results of excision of a cervical rib in patients with the thoracic outlet syndrome. J Br Surg 1988;75(5):431-3.
5. Sanders RJ, Hammond SL. Management of cervical ribs and anomalous first ribs causing neurogenic thoracic outlet syndrome. Journal of Vascular Surgery 2002;36(1):51-6.
6. Jayaraj A, Duncan AA, Kalra M, et al. A comparison of surgical approaches for cervical rib resection for neurogenic thoracic outlet syndrome. Journal of Vascular Surgery 2014;59(2):568.
7. Adson AW, Coffey JR. Cervical Rib*: a method of anterior approach for relief of symptoms by division of the Scalenus Anticus. Annals of Surgery 1927;85(6):839-57.