Cervical Spine

SURGICAL TREATMENT OF CERVICAL SPINE CONDITIONS

Introduction


Surgical treatment of conditions of the cervical spine is based on the correct preoperative evaluation of the nature and location of the lesion with the help of clinical, neurological, radiological, electrophysiological  and neurosurgical examination by a specialist neurosurgeon.

For discopathy, spinal stenosis and spondylosis the following should have particular evaluation and interpretation :

• the duration of radiculopathy (pain-findings peripheral nervous system) or myelopathy (findings in the  upper & lower extremities  ie the central nervous system or spinal cord)
• the age and
• the history of diseases that may contribute to the clinical picture (angiopathy, diabetes).

Neurosurgical intervention accordingly:

• for radiculopathy (neck-shoulder-brachial neuralgia with or without motor-radicular symptoms) is decided together with the patient,
• if the myelopathy and clinical symptoms are causing difficulty in fine movements of hands and gait (pronounced spasticity or instability) is imperative and immediate.

 

CONDITIONS OF THE CERVICAL SPINE

The cervical spine is the first segment of the spine. It consists of 7 cervical vertebrae which support the skull. The cervical spine is designed to allow movement of the head. It is surrounded by many muscles which contribute both to the support of the head and to mobility. The cervical nerves emerge from between the cervical vertebrae.

Degenerative lesions of the cervical spine appear in most people above the age of 40, however the type and extent vary considerably. The clinical severity of  degenerative lesions vary significantly, therefore the mild forms remain asymptomatic yet the more severe forms can even cause serious disability.

The main clinical manifestations of disease are stiffness, pain, radiculitis and myelopathy. Degenerative disease can affect all individual anatomical structures of the cervical spine such as: a) the intervertebral disc (discopathy), b) the small joints (osteoarthritis), c) the vertebral bodies (especially the epiphyseal plates), d) the ligaments mainly the ligamentum flavum and posterior longitudinal and e)paravertebral muscles.

Depending on which anatomical structure of the cervical spine is affected, degenerative disease is distinguished as degenerative disease of the small joints, degenerative disease of intervertebral discs, etc. Because the different anatomical structures function as a unified mechanical whole, the degenerative lesion of one anatomical structure  through interaction cause degeneration of adjacent anatomical structures, which result in practice to degenerative lesions occurring in more than one anatomical structure eg  reduction in height of the intervertebral disc increases the load and the mobility of articular apophysis, with result the development of osteoarthritis.
Conditions of the cervical spine cause a sensation of pain which is located basically in the neck area. Depending on the cause of the pain, it can reflect to other areas or be accompanied by other symptoms.

One condition of the cervical spine is discopathy. Between the cervical vertebrae are intervertebral discs which are responsible for the flexibility and mobility of the cervical spine. In case of intervertebral disk displacement, a phenomenon not at all uncommon due to the gradual deterioration induced is pressure on nerves resulting in pain and the onset of neurological disorders.

Another condition of the cervical spine is cervical syndrome. The cervical spine is surrounded by many muscles and there is a big risk of it being injured or for a muscle to stretch suddenly, only by weight of the head they support. In this case intense pain can also appear as a result of an accident and by whiplash injury.

The term cervicalgia  (sometimes rather incorrectly referred to as cervical syndrome) simply means pain in the area of the neck, although in several cases the pain may extend to the shoulder region, shoulder, arm or whole arm.

The most common cause of cervicalgia is of a mechanical nature, in other words it is caused by the various movements or  prolonged work in the office, bending and other activities. The most common cause is the deterioration of the intervertebral discs and joints of the cervical spine.(Of course, various injuries can cause pain in the neck, however these are not “cervicalgia”).

Regarding the extension of  pain(and also numbness and/or muscular weakness) into the areas of the shoulder, shoulder blades, arm and/or upper extremity, all of these problems can be caused by pressure, local irritation or inflammation of various nerves that are close to the affected intervertebral discs and joints.

The various methods of therapy can help relieve the acute, very painful problems, but the degeneration (mainly due to age) of the intervertebral discs and joints cannot be reversed.

DIAGNOSIS OF CERVICAL SPINE CONDITIONS

Pain in the neck is a warning of various problems but very rarely leads to severe disability, unless neglected for a long time. Simple  X-rays and computed tomography (CT scan) may help to clarify the cause or causes of the problem in some cases but are not usually useful as initial tests as soon as a problem in the neck appears.


 

Magnetic Resonance Imaging (MRI scan) of the cervical spine is the most useful test to lead to the diagnosis of  the source and nature of the problem, which is why it is considered as test of choice.

The MRI may reveal the following medical conditions with absolute clarity:

• Degeneration of the intervertebral disc: The first two findings of degeneration of the intervertebral disc are dehydration of the nucleus pulposus and the reduction in height of the intervertebral disc.
• Vacuum Phenomena: The term “Vacuum Phenomena” refers to the concentration of gas in the fissures which are created within the degenerated intervertebral disc.
• Calcification of the disc: Calcification is observed in the fibrous ring and secondarily in the nucleus pulposus.
• Osteophytes: Osteophytes are bony projections from ectopic osteogenesis which are formed as a result of   minor movements & injuries caused at the point of adhesion of the fibers of the fibrous ring with the vertebral body. 
• Degenerative lesions of epiphyseal plates: Degenerative lesions of the epiphyseal plates of the cervical vertebrae are found to a lesser extent compared to the lumbar vertebrae.
• Herniated disc: In the cervical spine, in order of frequency herniated discs are formed in the C5-C6 intervertebral disk (51%), the C6-C7 intervertebral disc (24%), the C4-C5 (17%) and less on the remaining disks. (types: bulging disc, focal protrusion, disc extrusion,  disc sequestration)
• Stenosis of the spinal canal: We refer to the reduction in the diameter of the spinal canal as stenosis

TREATMENT

The patient with a cervical condition must seek the help of a Neurosurgeon or Orthopedic Surgeon, always however to a spine specialist, when:

• The pain is so intense that it becomes intolerable,
• Pain worsens progressively (progressive)
• Simultaneous presence of various other symptoms (such as numbness, muscle weakness) of the upper or lower limbs.

The experience and specialization which every modern center for the treatment of spine conditions should have will help to determine which patients could benefit significantly from surgical treatment and which not. Patients with persistent neurological problems(in other words symptoms resulting from  pressure or inflammation of the nerves of the cervical spine) belong in the first category as well as patients with symptoms resulting from “reversible” conditions ,in other words conditions of the cervical spine which the specialist surgeon knows can have good results following surgical treatment (e.g. development of instability in specific levels of the cervical spine).
With modern diagnostic and technical developments the results of surgery of the cervical spine are very good, above 90% (for pain in the upper arm) and more than 60% (for neurological problems such as numbness or weakness in the limbs) when the treatment is not delayed more than 3 months from the appearance the  first complaints.

Recent studies have confirmed the necessity for intraoperative neurophysiological monitoring in order to minimize intraoperative complications.

Types of surgical treatment

The main criterion for selecting the type of surgical approach and technique is the correlation of clinical-imagery findings.
The surgical approach and technique has two objectives: the treatment(decompression) of the stenosis, which results in the release of the neural structures and the stabilization or spinal fusion in order to mobilize the patient rapidly.

Modern surgery of the cervical spine is  based on the experience of the specialist surgeon, the surgical microscope, the microsurgical techniques, the surgical equipment (bipolar diathermy, high-speed drill, micro instruments, special dilators), the implants and  stabilization / fusion materials, the intraoperative radiographic examination.

Radiculopathy. In cases of focal stenosis  -discopathy of the intervertebral foramina (by disc material with or without the presence of osteophytes) causing shoulder-brachialgia and dysesthesias with or without objective radicular findings, microdiscectomy – micro-osteophytectomy  with anterior cervical approach and stabilization with a special implant is preferred.

The  further screwing of a metal plate on the upper and lower vertebral bodies is decided mainly by the coexistence or not of preoperative instability-listhesis of the specific intervertebral space. In general and especially in the younger ages placement of a plate is not required, since the spinal fusion may cause future damage to the adjacent intervertebral disc due to uneven distribution of forces (the two  'fused'  vertebral bodies press against the  adjacent one).

Myelopathy . For patients suffering from myelopathy the criterion to choose the approach is associated with the direction of  the stenosis –compression of the spinal cord. The most common stenosis is caused by chronic dehydration and degeneration of the intervertebral disc and subsequent anterior pressure of the spinal cord. Thus the surgical approach of choice is the anterior cervical decompression-stabilization. The goal of this surgical approach and technique is excision of the bulging disc, the osteophytes and the posterior longitudinal ligament via anterior tracheal approach. In rarer cases the stenosis affects the posterior structures of the spinal canal (ligamentum flavum hypertrophy) and osteophytes are formed on the vertebral arch and pedicle.The appropriate surgery in these cases is posterior approach with laminectomy at the levels which require decompression.In very rare situations, the stenosis is concentric that a combination of anterior and posterior surgical treatment in one or two surgical sessions is required. By contrast, the coexistence of stenosis in more than one level causing radiculopathy or myelopathy is relatively common. In such cases a clinical-radiological correlation that allows the surgeon to decide whether to the decompress  more than one level is essential.

Results - Expectations

Surgical treatment of the cervical spine is generally considered a safe and successful operation with a very low risk of complications (<3%) and a high success rate (95%). The main objective is the treatment of pain (shoulder-brachialgia), the gradual restoration of muscular strength, balance and sensation, with a simultaneous decrease of spasticity. Rare complications of the surgery are hoarseness ("deepening" of the voice), or difficulty swallowing, implant displacement, contamination and hematoma of the wound, and lesion-injury , of the nerve root, the spinal cord, a large vessel (commonly the carotid or vertebral artery), esophagus or trachea or sympathetic plexus.