Why this operation has been suggested¶
This operation is called anterior cervical discectomy and fusion. In plain terms, the surgeon works from the front of your neck, removes a worn-out disc that is pressing on nerves or the spinal cord, and joins the two vertebrae together so they heal as one solid piece. We usually suggest it when non-operative care such as activity change or physiotherapy has not given you enough improvement. It suits people whose symptoms match the findings on their scans, especially arm pain from a trapped nerve, pressure on the spinal cord, or neck pain with nerve symptoms. If you have noticeable muscle weakness, we may suggest operating sooner rather than later. The aim is to relieve your pain, settle your nerve symptoms, and help you return to your usual activities.
Before the operation¶
Once your operation is booked, we will give you clear instructions to follow in the days before you come in. You will need to stop eating and drinking for seven hours before surgery. We ask for seven hours rather than a shorter time so we can bring you forward if the theatre list runs early. Some medicines can affect your surgery, so tell us everything you take, and we will let you know which ones to pause and when. Bring a written list of your current medications with you. Arrange for someone to drive you home afterwards, as you will not be able to drive yourself. Wear loose, comfortable clothing on the day. If you have other medical conditions, you may also need blood tests or a review with the anaesthetist before surgery.
On the day¶
You will arrive at the hospital's surgical admissions unit, where you are checked in and prepared for theatre. You will then meet the anaesthetist, the doctor who puts you to sleep and looks after you during the operation. This operation is done under general anaesthetic. A regional nerve block is sometimes added for post-operative pain relief; the anaesthetist will discuss this with you on the day. You are then taken into the operating theatre, where the operation is performed. Afterwards, you will wake up in the recovery area, where nurses keep a close eye on you while the anaesthetic wears off. Once you are stable, you will either move to a ward or go home, depending on the procedure and how your recovery is going.
What the operation involves¶
The word 'anterior' means 'from the front'. Your surgeon makes a small cut on the front of your neck and works through to your spine from there. This way of reaching the spine means the worn-out disc can be removed without disturbing the spinal canal, the space that holds your spinal cord. Your surgeon removes the disc at the exact level that is causing your symptoms, then joins the two vertebrae together so they heal as one solid piece. This joining is called fusion.
To hold the bones together while they heal, your surgeon places a spacer made of a safe implant material into the gap where the disc used to be. Sometimes a small plate is added over the front of the spine for extra support. The choice depends on how many disc levels need treatment, and your surgeon will explain which approach suits you. If more than one disc is worn, the surgeon may instead remove a small piece of bone from a vertebra to reach the compressed nerves or cord, then fill the gap with a spacer.
The cut on your neck is closed with stitches, and a dressing goes over it. You will keep that dressing on for about 10 days, as described in the recovery section.
The aim of all of this is simple: take the pressure off the nerve or spinal cord, and give your neck a stable, healed structure in place of the worn-out disc.
After the operation¶
You will wake up in the recovery area, where nurses watch you closely as the anaesthetic wears off. Your team will tell you whether you go home the same day or stay one night in hospital. Pain relief is planned for you before you leave, and the nurses will check in with you regularly to make sure it is working. You will have a dressing over the small cut on your neck. We leave the dressing on for about 10 days; please do not take it off before then unless we tell you to. We change or remove it when we see you. Most people are up and walking within hours of surgery, and gentle movement around your home helps your recovery. Please arrange for someone to stay with you for the first 24 hours after you get home.
Recovery¶
The first few days bring some soreness at the front of your neck and some trouble swallowing. This is expected. Swallowing usually feels easier as the swelling settles, and soft foods and plenty of fluids help in the meantime. Your pain relief plan from hospital will keep you comfortable while you move around at home.
You will be up and walking soon after surgery, as described above, and gentle movement around your home helps you heal. Your physiotherapist will guide you through simple neck and shoulder movements as your recovery progresses. You will not wear a brace. You can do light daily tasks at home, but avoid heavy lifting and strenuous activity until your surgeon tells you the bone has healed solid. Sleeping propped up with extra pillows can be more comfortable in the early days.
Milestones come as events rather than dates. Once the swelling settles, eating and talking feel normal again. Once your own surgeon clears you to drive, you can return to the road; after neck surgery the questions that matter are whether you can turn your head far enough to check your mirrors and blind spots, whether you can brake hard without hesitating, and whether you are off strong pain medication. If a collar has been prescribed, ask your surgeon about driving in it before you try. As your neck strength returns, you can build back towards work and the activities you enjoy.
Recovery varies from person to person. Your timeline may differ, and your surgeon and physiotherapist will guide you along the way.
What can go wrong¶
Most patients do well, but problems can occasionally happen. Your surgeon and the team monitor you closely to spot any issue early.
The front-of-neck approach means some structures near the spine are moved aside during surgery. This can irritate the nerves that control your voice and your swallowing. You might notice a hoarse voice, or find that food or drink goes down slowly or feels like it sticks. This is common in the first days and usually settles as the swelling goes down. If swallowing stays difficult after the early days, or your voice does not return to normal, bring it up at your next review.
Some people feel more neck pain in the first few days after surgery than they expected. This usually eases with your pain relief plan. A smaller number of people have a deep, aching pain in the neck that lasts much longer. If pain is still troubling you months later, tell us at your review so we can look into it.
The two vertebrae are meant to heal together as one solid piece. Sometimes they do not join fully. You might notice neck pain that keeps coming back, or pain that never really settles the way you hoped. If this happens, we can check whether the bones have healed at your review appointments.
The spacer or plate holding the bones can occasionally shift before the fusion has healed. Warning signs include new or worsening neck pain, or a feeling that something has changed in your neck. Infection is also possible. Watch for redness spreading out from the wound, swelling, warmth, or fluid leaking from the cut. If you notice any of these, contact the clinic straight away. If you feel unwell with a fever, go to the emergency department.
Because one disc level above or below the fusion takes on extra load, it can wear out over time. This may cause new arm or neck pain years later. If that happens, bring it up at your review and we can arrange scans.
The complications table on this page lists typical rates if you want the specifics.
When to call us¶
Call us if you notice redness, swelling, warmth or fluid leaking from your wound, or if you feel hot and feverish. Call us if pain suddenly gets much worse, or if new pain appears that was not there before. Go to emergency if you have calf swelling or pain, or shortness of breath. Go to emergency straight away if you lose feeling in an arm or leg, or cannot move it.
Evidence & references
This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.
Anatomy & Pathophysiology¶
Osseous Anatomy¶
- The spinal column consists of 33 vertebrae divided into five regions: 7 cervical, 12 thoracic, 5 lumbar, 5 fused sacral, and 4 or 5 fused coccygeal vertebrae [3].
- The vertebral body is a cylindrical mass of bone connected by pedicles to the posterior arch, which consists of the lamina and spinous process [3].
- The spinal canal is formed by the vertebral body anteriorly, the lamina posteriorly, and the pedicles laterally [3].
- Vertebral bodies function primarily to bear weight and transfer forces to the pelvis and hips [3].
- The posterior elements provide protection to neural structures and function as a tension band [3].
- The cervical spine is composed of seven vertebrae and assumes a lordotic curvature [8].
- The thoracic spine is composed of 12 vertebrae and assumes a kyphotic curvature [8].
- The lumbar spine is composed of five vertebrae and assumes a lordotic curvature [8].
- The sacral vertebrae are fused and form a portion of the pelvis [8].
- The coccyx consists of four small, fused vertebrae at the most caudal extent of the spinal column [8].
- Each vertebra is composed of an anterior vertebral body and a posterior arch formed by the pedicle, facet, lamina, and spinous process [8].
- The vertebral body is composed of an inner region of cancellous bone surrounded by a thin shell of cortical bone [8].
- The thoracic spine represents two transitional zones: from the highly mobile cervical spine to the rigid thoracic region, and then to the more mobile lumbar spine [5].
- The thoracic spine forms a bony "cube" with the ribs and sternum, providing protection to the heart and lungs [5].
- Thoracic vertebral bodies are larger than cervical vertebrae but smaller than lumbar vertebrae [5].
- Thoracic pedicles arise more superiorly from the posterior vertebral body than in the cervical or lumbar spine and project obliquely from superodorsal to inferoventral [5].
- The spinal canal is narrowest in the thoracic region [5].
- The spinous processes of the upper four thoracic vertebrae project more horizontally with slight inferior angulation [5].
- In the midthoracic spine, spinous processes project sharply obliquely, overlapping the lamina and spinous processes inferiorly [5].
- From T10 to T12, thoracic spinous processes transition to a more horizontal projection consistent with lumbar vertebrae [5].
- The rib heads articulate with the lateral aspect of the vertebral bodies, with a shared articulation at the disk space referred to as a demifacet [5].
- The first, eleventh, and twelfth vertebral bodies have only a single articulation for the same-numbered rib head [5].
- The transverse processes of the thoracic spine project obliquely superolaterally [5].
- There is no costotransverse articulation at T11 or T12 [5].
- The cervical vertebral body is an oblong structure with a coronal diameter larger than its sagittal diameter [20].
- Cervical endplates have a cup-in-saucer configuration, distinct from the flat endplates of the thoracic and lumbar vertebrae [20].
- The posterior aspect of the cervical transverse process guides the cervical spinal nerves as they exit the spinal canal [20].
- The cervical spinal nerves lie posterior to the vertebral artery within the transverse process [20].
Intervertebral Disc Anatomy¶
- The intervertebral disc (IVD) separates each successive vertebral body except between C1 and C2 [8].
- The IVD provides a combination of compressive stiffness and flexibility to support normal spine biomechanics [8].
- The IVD is composed of an inner nucleus pulposus (NP) and an outer ring termed the anulus fibrosus (AF) [8].
- The nucleus pulposus serves as an osmotic pump to attract water and generate hydraulic pressure under load [8].
- The anulus fibrosus encapsulates the nucleus pulposus and provides mechanical support to contain NP pressure and constrain intervertebral rotations [8].
- The outer anulus fibrosus is integrated with the vertebral rim via a fibrocartilage enthesis consisting of a thin layer of calcified cartilage, or "tidemark" [8].
- The end plate is a bilayer of cartilage and bone that separates the disc from adjacent vertebrae [8].
- The cartilage end plate integrates with the inner anulus fibrosus to fully encapsulate the nucleus pulposus [8].
- The end plate must be strong and thick to resist loads but also permeable to favor chemical transport and disk cellular vitality [8].
Ligaments and Soft Tissue¶
- The spinal column is stabilized by the anterior longitudinal ligament, posterior longitudinal ligament, ligamentum flavum, facet joint capsule, interspinous ligament, and supraspinous ligaments [8].
- The erector spinae muscles run longitudinally on the dorsal surface of the spinal column and function to extend the spine [8].
- The psoas muscles run longitudinally on the ventrolateral surface of the spinal column and serve to flex the hip or laterally bend the trunk [8].
- The multifidus muscles connect intersegmentally to stabilize the spine by acting like a bowstring to maintain lordosis [8].
Biomechanics and Alignment¶
- Normal cervical alignment is approximately 15° of lordosis [7].
- The thoracic spine generally ranges from 20° to 40° of kyphosis [7].
- The lumbar spine has approximately 40° to 50° of lordosis [7].
- Kyphotic segments (thoracic, sacral) are considered "primary" curvatures present in utero and at birth [7].
- Lordotic curvatures of the cervical and lumbar spine develop secondarily later in life to allow upright posture [7].
- The center of gravity of the spinal column runs from the odontoid process proximally through the sacral promontory caudally [7].
- Changes in sagittal balance that shift the center of gravity too far ventrally can result in significant pain and disability [7].
- The functional spinal unit consists of two vertebrae, the disk between them, and the facet joints and their capsules [7].
- Vertebral bodies bear 70% to 90% of the static axial load of the spine [7].
- Facet joints support 10% to 20% of axial load in a standing, neutral alignment [7].
- In extension, facet joints may bear up to 30% of the axial load [7].
- In flexion, facet joints may be burdened with up to 50% of the anterior shear load [7].
- The nucleus pulposus deforms under compressive forces, redistributing axial forces radially [7].
- The anulus fibrosus resists radial pressure through the tensile properties of its alternating bands of fibers [7].
- Spinous and transverse processes act as lever arms providing mechanical advantage for inserting muscles [7].
Vascular Anatomy¶
- The cervical spine derives its circulation primarily from the vertebral arteries [12].
- The vertebral arteries arise from the subclavian arteries and typically enter the transverse foramen at the C6 level [12].
- The vertebral arteries run proximally through the transverse foramina to C1, then course posteriorly over the superior aspect of the C1 ring before entering the foramen magnum [12].
- Segmental branches to each cervical vertebra arise from the vertebral artery and the deep cervical branch of the costocervical trunk [12].
- The vertebral artery anatomy is variable, with one side typically more dominant than the other [12].
- The vertebral artery may enter through the transverse foramen of C7 rather than C6 [12].
- Anomalous courses of the vertebral artery, such as looping through a cervical vertebral body, are not uncommon [12].
- The vascular supply of the spinal cord is primarily from the medullary branches of the segmental spinal arteries [12].
- The anterior spinal artery supplies approximately 80% of the vascular supply to the spinal cord [12].
- The arteria medullaris magna (AMM), also known as the artery of Adamkiewicz, typically arises on the left side between T8 and L1 [12].
Neural Anatomy¶
- A typical mixed spinal nerve has three distinct components: motor, sensory, and sympathetic [13].
- Motor rootlets leave the anterolateral sulcus of the spinal cord and unite to form each motor root [13].
- Motor fibers arise from anterior horn cells and innervate skeletal muscles [13].
- Sensory fibers arise from pain, thermal, tactile, and stretch receptors with cell bodies located within the dorsal root ganglia [13].
- Axons of sensory fibers enter the posterolateral sulcus of the cord via several rootlets [13].
- The sympathetic component of all 31 mixed spinal nerves leaves the spinal cord along only 14 motor roots [13].
- Sympathetic cells of origin are in the intermediolateral cell column extending throughout the thoracic and upper lumbar cord segments [13].
- White rami pass anteriorly to the corresponding sympathetic ganglion [13].
- Postganglionic fibers pass back to the mixed spinal nerve as a gray ramus [13].
- Mixed spinal nerves branch into anterior and posterior primary rami after leaving the intervertebral foramina [13].
- Posterior primary rami supply the paraspinal musculature and skin along the posterior aspect of the trunk, neck, and head [13].
- The upper three cervical posterior rami are larger than their corresponding anterior rami [13].
- Anterior primary rami of all cervical, the first thoracic, and all lumbosacral nerves join to form plexuses [13].
- The upper four cervical anterior rami form the cervical plexus [13].
- The lower four cervical and first thoracic anterior rami form the brachial plexus [13].
- The area of skin supplied by the fibers of a single spinal root is called a dermatome [13].
- Segmental dermatomal patterns are well preserved in the thoracic region but not in the limbs [13].
Pathophysiology of Degeneration and Stenosis¶
- Degeneration of the disc occurs with disc narrowing and subsequent ligamentous redundancy, which compromises the spinal canal area [17].
- Instability resulting from disc degeneration precipitates the formation of facet overgrowth and ligamentous hypertrophy [17].
- The ligamentum flavum may be markedly thickened into the lateral recess where it attaches to the facet capsule, causing nerve root compression [17].
- Central spinal stenosis denotes involvement of the area between the facet joints occupied by the dura and its contents [17].
- Symptomatic central spinal stenosis results in neurogenic claudication with generalized leg pain [17].
- The lateral recess begins at the medial border of the superior articular process and extends to the medial border of the pedicle [17].
- Facet arthritis most frequently causes stenosis in the lateral recess zone [17].
- The foraminal region lies ventral to the pars and is bordered by the lateral recess medially, posterior vertebral body and disc ventrally, pars and intertransverse ligament dorsally, and lateral border of the pedicle laterally [17].
- The dorsal root ganglion and ventral motor root occupy 30% of the foraminal space [17].
- The exit zone is identified as the area lateral to the facet joint [17].
- The most common type of spinal stenosis is caused by degenerative arthritis of the spine [17].
- Degenerative spinal stenosis is most commonly localized to the facet joints and ligamentum flavum [17].
- The L4-5 level is the most commonly involved in degenerative spinal stenosis, followed by L5-S1 and L3-4 [17].
- Hypertrophy and ossification of the posterior longitudinal ligament usually are confined to the cervical spine [17].
- Diffuse idiopathic skeletal hyperostosis (DISH) syndrome may result in an acquired form of spinal stenosis [17].
- Congenital spinal stenosis usually is central and evident on imaging studies [17].
- In achondroplasia, the canal is narrowed in the anteroposterior plane owing to shortened pedicles and in lateral diameter because of diminished interpedicular distance [17].
Investigations¶
Magnetic Resonance Imaging (MRI)¶
- MRI is the standard for advanced imaging of the spine and is superior to CT in most circumstances, particularly for identifying infections, tumors, and degenerative changes within the discs [23].
- MRI is superior to CT for imaging the intervertebral disc and directly imaging neural structures [23].
- MRI typically shows the entire region of the spine, including cervical, thoracic, or lumbar segments [23].
- MRI provides the ability to image the nerve root in the foramen, which is difficult even with postmyelography CT because the subarachnoid space and contrast agent do not extend fully through the foramen [23].
- MRI evidence of disc degeneration has been reported in the cervical spine in 25% of patients younger than 40 years [23].
- MRI evidence of disc degeneration has been reported in the cervical spine in 60% of patients 60 years and older [23].
- MRI evidence of lumbar disc degeneration was found in 35% of patients aged 20 to 39 years [23].
- MRI evidence of lumbar disc degeneration was found in 100% of patients older than 50 years [23].
- The best way to obtain meaningful clinical information from MRI is to have a specific question derived from the patient’s history and physical examination before the study [23].
- Specific questions for MRI evaluation should be posed using the parameters of neural compression, instability, and deformity [23].
- Only abnormalities in one or a combination of the categories of neural compression, instability, and deformity are important for operative treatment [23].
- Failure to interpret MRI in the context of specific clinical questions leads to poor clinical choices and outcomes [23].
- A normal intervertebral disc exhibits signal hyperintensity on T2-weighted images due to its high water content [22].
- The aging process results in gradual desiccation of disc material and loss of T2-weighted signal hyperintensity [22].
- Disc herniations or extrusions appear as convex or polypoid masses extending posteriorly into the ventral epidural space [22].
- Disc herniations or extrusions frequently maintain a signal intensity similar to that of the disc of origin [22].
- Sagittal T2-weighted or gradient-echo images create a “myelographic” effect useful for evaluating compromise of the subarachnoid space [22].
- Sagittal T1-weighted images should be closely examined to identify narrowing of the neuroforamina [22].
- Normal T1-weighted hyperintense perineural fat in the foramina provides excellent contrast to darker displaced disc material [22].
- Far lateral disc herniations are best seen on selected axial images localized through disc levels [22].
- Free disc fragments appear discontinuous with the intervertebral disc and usually have intermediate T1-weighted signal in contrast to hypointense cerebrospinal fluid [22].
- MRI detects significant spinal cord compromise, with edema within the cord demonstrated as hyperintensity on T2-weighted images [22].
- Diffusion tensor imaging has been reported to demonstrate spinal cord impairment in patients with early stage cervical spondylosis before it is visible on plain MRI scans [26].
- Diffusion tensor imaging information can be helpful in early identification of patients in whom operative treatment is indicated [26].
Computed Tomography (CT)¶
- CT has largely supplanted plain radiographs as the initial screening study of choice for spine injuries due to its combination of high sensitivity and specificity [24].
- CT allows for the identification of subtler fractures that might have remained undiagnosed on plain radiographs [24].
- CT provides additional three-dimensional detail, including the degree of canal compromise and the amount of fracture comminution [24].
- CT is particularly useful in differentiating compression fractures from burst fractures [24].
- CT identifies subtle features of injury such as the presence of facet widening [24].
- The primary disadvantage of CT imaging compared to MRI is that it does not provide as good a visualization of soft tissues [24].
- CT myelography is reserved for patients who have contraindications to MRI or who have equivocal MRI examinations [22].
Diagnostic Principles¶
- The most common indication for MRI of the spine is evaluation of intervertebral disc disease [22].
- After routine radiography, MRI is the procedure of choice for screening patients with low back or sciatic pain [22].
- In the lumbar and thoracic spine, MRI has supplanted CT myelography because it is noninvasive and less expensive [22].
- The demonstrated findings on MRI must be carefully correlated with the clinical impression [23].
- The specific location of an abnormality should be suspected before MRI and confirmed with the study [23].
- Ideally, an advanced imaging study should be used for confirmation, not reevaluation [26].
References¶
[3] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Spinal Anatomy > Osseous Anatomy.
[5] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Spinal Anatomy > Osseous Anatomy > Thoracic Vertebrae.
[7] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Spinal Anatomy > Biomechanics.
[8] Orthopaedic Basic Science Fifth Edition Print Ebook. Biology and Mechanics of the Skeletal Extracellular Matrix > Anatomy.
[12] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Spinal Anatomy > Vascular Anatomy.
[13] Campbell S Operative Orthopaedics 4 Volume Set. PERIPHERAL NERVE INJURIES OF THE UPPER AND LOWER EXTREMITIES > ANATOMY OF THE SPINAL NERVES > COMPONENTS OF MIXED SPINAL NERVES.
[17] Campbell S Operative Orthopaedics 4 Volume Set. OVERVIEW OF LUMBAR AND THORACIC DISC DEGENERATION AND HERNIATION > STENOSIS OF THE THORACIC AND LUMBAR SPINE > ANATOMY.
[20] Rockwood And Green S Fractures In Adults. Imaging of Cervical Spine Fractures and Dislocations > Lower Cervical Spine (C3–C7).
[22] Campbell S Operative Orthopaedics 4 Volume Set. INTERVERTEBRAL DISC DISEASE.
[23] Campbell S Operative Orthopaedics 4 Volume Set. OVERVIEW OF LUMBAR AND THORACIC DISC DEGENERATION AND HERNIATION > MAGNETIC RESONANCE IMAGING.
[24] Rockwood And Green S Fractures In Adults. Imaging of Cervical Spine Fractures and Dislocations > Computed Tomography.
[26] Campbell S Operative Orthopaedics 4 Volume Set. POSTERIOR APPROACH TO THE LUMBAR SPINE, L1 TO L5 > MAGNETIC RESONANCE IMAGING.
