Cervical rib is a congenital anomaly in which one or more additional ribs extending from the lower cervical vertebrae (usually VII) are detected. It is often asymptomatic. As a rule, it manifests for the first time in adult patients, it can manifest itself with pain, sensitivity disorders, edema, cyanosis, cold extremity and other symptoms caused by disorders of blood supply and innervation on the affected side. It is diagnosed on the basis of complaints, external examination data and radiography results. Treatment – physiotherapy, rest, novocaine blockades. In case of inefficiency, surgical resection of an additional rib is indicated.
Q76.5 Neck rib
Cervical rib (cervical rib) is a fairly common malformation. It is found in 0.5% of the population and in 6% of patients with vertebrogenic diseases, it is more often diagnosed in women (according to various data, in 70-85% of cases). The first description of this pathology was compiled by the French anatomist Shede in 1740.
Additional edges can be single or multiple, located on one or two sides. Almost 85% of patients have a bilateral lesion. The degree of development of cervical ribs varies significantly – from rudiments slightly protruding beyond the transverse process to formed bone structures connecting to the sternum or I rib. Clinical manifestations caused by compression of the subclavian artery and nerve plexus are detected in about 10% of the total number of patients, usually occur for the first time after reaching adulthood.
The cause of the anomaly is a violation of the processes of intrauterine development. Initially, 29 pairs of rib rudiments are formed from the sclerotomic mesenchyme. Subsequently, 12 pairs of ribs that depart from the I-XII thoracic vertebrae continue to develop, and the rest are gradually reduced. In case of violation of reverse development, additional ribs appear. Reduction of the rudiments occurs from top to bottom, therefore, in clinical practice, additional ribs are usually observed extending from the VII, less often from the VI and V cervical vertebrae. The factors provoking dysontogenesis are not precisely established.
A sufficiently large cervical rib changes the relationship between the anatomical structures of the neck. The influence of the rudiment on the location of the brachial plexus and subclavian artery is of clinical significance. In the presence of an incompletely formed rib or fibrous cord, the vessel and nerve plexus are displaced anteriorly, with a more pronounced anomaly they are located above the additional bone structure. Sometimes the fixation points of the anterior and middle stair muscles change – they are attached not to the region of the I rib, but to the cervical or both ribs. Multiple fibrous strands may be detected in the affected area.
All of the above creates favorable conditions for compression of the neurovascular bundle. During physical activity, especially associated with a change in the position of the shoulder girdle zone (for example, when pulling the arm down), an additional rib presses on the vessel or nerves, a compression syndrome occurs. Based on observations, it was found that fully formed ribs more often provoke vascular disorders, partially formed ones cause neurological disorders. Usually both components are combined with each other in different proportions.
In traumatology and orthopedics, true and false, complete and incomplete cervical ribs are distinguished. The true rib is articulated with the transverse process of the corresponding vertebra by an ordinary joint, the false one is fixed to the process by synostosis or syndesmosis. A complete rib resembles an ordinary rib in its appearance, attached to the sternum or I rib. Incomplete is a rudimentary fragment, the end of which is not attached to anything or connected to the I rib by means of a fibrous cord. Gruber’s classification is based on the degree of development of bone structures, includes four types of cervical ribs:
- I – there is a small vestige, the length of which does not exceed the length of the transverse process.
- II – the rib is longer than the transverse process, but shorter than the bony part of the I rib.
- III – a somewhat underdeveloped rudimentary rib is revealed, fixed by a connective tissue cord to the I rib or (less often) to the sternum.
- IV – a full-fledged bone structure is determined, resembling an ordinary rib, articulating directly with the sternum.
In the absence of compression syndrome, there are no complaints. Sometimes a deformity above the collarbone is detected, a dense tumor-like formation is determined by palpation. Multiple cervical ribs manifest a typical appearance, including a thickened neck in the shape of a cone and lowered shoulders, which look like an extension of the neck. Often there is an asymmetry of the upper arms, which is a consequence of the uneven development of additional ribs or a unilateral lesion.
The most common complaint with compression of the neurovascular bundle is considered to be a pain syndrome that occurs or increases after physical exertion, with movements of the neck and head, lifting of the arm, lowering of the upper arm. The area of soreness usually corresponds to the area of innervation of the ulnar nerve, sometimes there is a spread of pain to the proximal part of the limb, the upper arm, the head. Pain syndrome is often combined with a decrease, increase or absence of sensitivity in the areas of innervation of the radial and ulnar nerves. Involvement of the median nerve is rarely observed. There may be a cold snap, increased sweating and pallor of the limb due to a violation of the autonomic regulation of vascular tone.
With compression of the subclavian artery, patients note significant limitations when performing certain movements, for example, lifting weights, driving a car, etc. An external examination reveals swelling and cyanosis of the limb, the pulse on the radial artery is weakened or not determined. Lifting the chin and turning the head to the sick side on inspiration is accompanied by a weakening of the pulse wave and a decrease in pressure on the affected arm. In a number of patients, ladder muscle syndrome is detected.
In severe cases, trophic disorders develop, gangrene of the limb is possible. Due to compression of the arterial trunk in its wall, changes occur that increase the risk of blood clots and the formation of subclavian artery aneurysm. In case of untimely operation, residual sensitivity disorders may be noted. Pathology causes the restriction of physical activity, the inability to engage in certain types of activities, which can cause a forced change of profession.
Diagnosis usually does not cause difficulties, it is carried out by an orthopedic traumatologist. Assessment of the degree of compression of the arterial trunk and nerves of the brachial plexus, determination of optimal treatment tactics are performed by a neurologist and vascular surgeon. The survey plan includes the following objective and instrumental methods:
- Survey, inspection. The doctor specifies the time of appearance and dynamics of the development of symptoms (if any). During examination, a deformity of the upper arm is often detected, with palpation one or more ribs can be determined. With compression of the vessel and nerves, neurological disorders, circulatory disorders are observed. Special tests are performed, in which the patient occupies a position that narrows the space between the ribs and the collarbone. In the presence of a cervical rib, the result of the tests are symptoms indicating a transient violation of the blood supply to the limb.
- Spondylography. X-ray examination of the lower cervical and upper thoracic vertebrae, the area of the upper arm is prescribed. The pictures show additional ribs of various lengths, often resembling enlarged transverse processes. The ratio of the additional ribs to the sternum and the I rib is evaluated, the presence or absence of bone growths is determined. Based on the cervical x-ray, the differentiation of cervical ribs from exostoses, neoplasias of nearby bone structures is performed.
- Angiography. It is possible to conduct a traditional radiopaque examination or MR angiography of the subclavian artery. During the diagnostic procedure, the features of the location of the vessel, the degree of its narrowing are established. In the presence of an aneurysm, a fusiform expansion of the distal sections of the artery is visible.
Differential diagnosis of cervical ribs is carried out with radiculomyelopathy, osteochondrosis of the cervical spine, neuralgia, tunnel syndrome, pain with herniated intervertebral disc, neoplasms of the brachial nerve plexus. If neoplasia is suspected, the patient is referred to an oncologist for consultation.
Therapeutic tactics are determined by the existing symptoms. In the absence of manifestations, treatment is not required. Despite the fact that early removal of the additional rib provides a better effect in the long term compared to the operation performed at the stage of extensive clinical changes, preventive resection is not performed due to the low probability of symptoms and the high traumatic nature of the intervention.
Conservative therapy is indicated for patients with stair muscle syndrome. The affected area is provided with rest by applying a Trench collar and immobilizing the hand with a soft bandage. Vasodilators, medicinal electrophoresis with lidase and painkillers are used, novocaine blockades are produced. It is recommended to refrain from loads that provoke the occurrence or intensification of symptoms.
With severe compression syndrome, the effect of conservative therapy is questionable. With the progression of the disease and prolonged refusal of radical treatment, irreversible degenerative changes may develop in the tissues of the nerve plexus, the artery wall. Rib resection or excision of muscle structures is recommended. surgical intervention is performed using one of the following techniques:
Rib resection by anterior access. It is performed in the position of the patient on his back through a horizontal incision in the supraclavicular region (Resurrection incision). Superficially located muscles are dissected, vessels are bandaged, nerves and subclavian artery are isolated and diverted to the side. The cervical rib is removed piece by piece using Luer wire cutters.
Rib resection by posterior access. It is performed in the patient’s position on the abdomen using paravertebral access (Kimbarovsky method). It includes muscle dissection and resection of the transverse processes of the cervical vertebrae. After gaining access to the rudimentary rib, it is held by a bone holder, isolated from soft tissues and removed.
Resection of the anterior stair muscle. It is carried out from the anterior supraclavicular access. It involves cutting off the muscle at the attachment point and removing its lower part. The adhesions between the nerves and the artery are dissected, fragments of adipose tissue are placed in the gap to prevent scarring. The complete rib is partially resected together with other formations (for example, fibrous cords) that compress the neurovascular bundle.
In type IV pathology, resection is sometimes carried out through an angular incision, the horizontal part of which runs parallel to the clavicle, and the vertical part is located in the region of the edge of the deltoid muscle. The main stages of surgical intervention are the same as when using anterior access. In the postoperative period, immobilization is carried out in all cases, antibiotics and painkillers are used, massage, physiotherapy procedures, physical therapy are prescribed.
Prognosis and prevention
With mild symptoms, adequate conservative treatment and compliance with the regime of physical exertion, there is a decrease or disappearance of clinical manifestations. With a detailed clinical picture, the prognosis is determined by the severity of degenerative changes in the nerves and the subclavian artery wall. Timely operation allows to eliminate compression, completely restore blood supply, eliminate neurological disorders. With degeneration of the nerve plexus and changes in the vascular wall, residual phenomena may be observed (limb weakness, sensitivity disorders, etc.). Preventive measures have not been developed due to the congenital nature of the pathology and the lack of accurate data on the causes of its development.