Cervical Interbody Fusion with Cage, Plate and Screws
What is a cervical interbody?
The aim of a cervical fusion is to immediately stabilize the spine using metal or plastic hardware – allowing for the bony fusion to occur with two adjacent vertebrae fusing into one solid mass – and remove compression of the adjacent spinal cord and/or nerve roots to lead to improved function and reduced pain.
An interbody fusion results from complete removal of an invertebral disc allowing two or more adjacent vertebra to fuse through a bony union.
Reasons to consider an interbody fusion include persisting pain caused by a damaged intervertebral disc that has not responded to conservative treatment. There might be associated compression of a nerve, causing a radiculopathy with arm pain, numbness, paresthesia and weakness or anterior spinal cord compression that causes a myelopathy with associated neurological dysfunction. Traumatic vertebral fracture or dislocation, bowel and bladder dysfunctions, severe muscle weakness or severe pain that can’t be controlled by pain relievers, may require immediate surgery to prevent permanent nerve damage.
- Hot and cold pads
- Modifying activity levels to include:
- Aerobic exercise, walking, cycling and swimming
- Strength and flexibility training
- Pain relieving medications
- Weight loss
- Steroid and local anaesthetic injections
- Disc replacement surgery, or arthroplasty
Smoking damages every part of the body and decreases the chance of a successful procedure. If you smoke, you should stop now.
Before the procedure
- Your doctor will complete a medical exam to ensure that you are in good general health before continuing with the operation.
- You will be advised when to stop any medications that will increase your risk of bleeding, including aspirin, anti-inflammatories, vitamin E, and some herbal remedies such as chamomile, gingko and fish oil, among others.
- You may be admitted the day of, or the day before your procedure.
- Don’t eat or drink anything 6 hours before the procedure.
- Wear comfortable, loose-fitting clothing and leave all jewellery at home.
- An intravenous line will be inserted into a vein in your arm for ease of fluid administration.
- You may be given a sedative to make you drowsy before being given your anaesthetic.
- You will be given a general anaesthetic to put you to sleep.
- Let your doctor know if you develop a cold, fever or flu-like symptoms before your operation.
The patient lies on his/her back and the surgical area on the neck is cleaned. An incision is made and the overlying muscles are moved to the side. The trachea and oesophagus are retracted to reveal the front of the spine. Using X-ray imaging, the surgeon confirms the correct disc for removal. Any anterior vertebral body bone spurs, or osteophytes, are removed too. The vertebral endplates are prepared, the intervertebral space is measured and the correctly sized cage filled with bone is inserted. A plate and screws might be used for additional stability. The surgeon, using X-rays again, confirms the positioning of the instrumentation. The muscles are replaced and the wound is sutured closed.
- The operation typically takes 1 to 2 hours.
- You may need to spend up to 5 nights in hospital.
- Your bowels may not open for a few days after the procedure, so pain medication, muscle relaxers and laxatives can be used as directed.
- You may need to wear a soft cervical collar for 6 to 12 weeks.
- Numbness is slow to alleviate and some may persist permanently.
- Weakness may last for 6 to 12 weeks.
- Although feelings of pins and needles decrease immediately post-op, there may be fleeting recurring symptoms during the first few weeks of recovery.
- Avoid bending, twisting, lifting or making any other sudden movements.
- Don’t lift anything heavier than a bottle of milk for 2 weeks.
- Most people can resume normal daily activities after 3 weeks.
- Hardware usually doesn’t cause any problems and is permanently left in place.
- There is often some residual neck pain after the fusion from the pre-existing degenerative disease elsewhere in the neck.
- In uncomplicated cases, up to 90% of patients report good to excellent pain relief.
- The wound must be checked twice a day. If you notice any redness, swelling, green or yellow discharge, or opening of the wound, contact your GP immediately and call your surgeon.
- If you have small bandages on your incision, it’s important to keep these dry. Once they start peeling off, you may remove them (typically after 10 days). All external sutures will be removed in 1 to 2 weeks. Sub-cutaneous sutures do not require removal as they will dissolve over time. Your surgeon will inform you at time of discharge, of any sutures requiring removal.
- Keep the wound dry. While you may shower, avoid bathing, swimming or using creams for a week.
- The incision site may be gently cleaned using soap and water. Rub gently and avoid using perfumed soaps.
- An appointment with your surgeon will be booked 6 weeks after the procedure and fusion will be confirmed using radiological imaging.
- Smoking for 2 to 12 weeks after the operation can prevent bone fusion.
Despite having surgery, your neck will never return to full strength. You will always have a weak spot and you will need to commit to life long care to prevent further injury. Maintain correct posture, eliminate excess body fat, follow a daily exercise programme and avoid unnecessary stresses to your back.
The right to refuse
You have the right to informed refusal, which means you can delay or reject the recommended treatment of your condition. Be mindful, however, that this may lead to the worsening of your back pain and ask your doctor to detail what may happen should you choose not to undertake the recommended surgical treatment.
Allergic reaction to medication
This can cause a rash, swelling of the hands, joints, eyelids and throat, difficulty breathing, low blood pressure and death. An allergic reaction is easily controlled with the correct equipment and medication.
Adjacent Segment Syndrome
When a part of the spine has been fused – limiting movement in that area – stress can be transferred to the adjacent segments. This can increase wear and tear in these adjacent intervertebral discs, facet joints, pars articularis and ligamentum flava, and can lead to increased mobility and pain. Known as adjacent segment syndrome, or transitional syndrome, it is more likely when multiple segments are fused, abnormal alignment, facet joint injury during surgery, increased age and pre-existing degenerative changes. Up to 20% of fusion patients might need another operation to treat the symptoms related to the adjacent segment degeneration. A degree of pre-existing degenerative disease might be present in the adjacent segments and it is sometimes difficult to determine if abnormalities in the adjacent segments are due to adjacent segment disease or progression of pre-existing disease or a combination of both.
Any neck surgery can cause trauma to the upper airway. This trauma can cause swelling and bruising, which in turn can cause obstruction of the airway, leading to difficulty in breathing and death. Airway problems are treatable while recovering in hospital.
There are a number of different types of anaesthesia:
Local: the medication is injected into the skin around the site of the surgery to numb only surrounding tissues.
Regional: where the body part is anaesthetised by numbing major nerves or part of the spinal cord.
Conscious sedation: where a full anaesthetic is not given, rather, medications are used to create a near-sleep relaxed state.
General: where you are rendered unconscious and temporarily paralysed. In this instance, medication is given to you through an IV line, and machines breathe for you and monitor you together with the anaesthesiologist. Most spinal operations require general anaesthesia, so that you can’t move during the operation.
There are many possible complications associated with a general anaesthetic. 1 to 10% of these include:
Post-operative nausea and vomiting: this may last a few hours to several days. It can be the result of the operation, anaesthetic and pain killers.
Aches: as a result of lying immobile on a firm operation table for a long period of time.
Blurred vision/dizziness: due to low blood pressure from fluid loss or medication. Can be treated with fluid replacement and medications.
Bruising/pain: around injection and intravenous cannula sites. This usually settles by itself and the cannula can be moved if necessary.
Headaches: due to the anaesthetic, dehydration or anxiety. These may last a few hours but can be treated with medication.
Itchiness: can be an allergic reaction to drugs, sterilising fluid or sutures, or as a side effect of strong pain-relieving medication (opiates).
Memory loss/confusion: this is more common in older people who have had a general anaesthetic. There are many causes and may last a few days or even weeks.
Pain from drug injection: some drugs cause pain when they are injected.
Shivering: can be caused by medication, stress or low body temperature during the surgery. Shivering can be treated with a hot air blanket or medication.
Sore throat: from the breathing tube. This may last a few hours to a few days. Can be treated with pain-relieving lozenges.
Uncommon complications (0.1%) include:
Anaesthetic awareness: if you are ill, your anaesthesiologist may use more muscle relaxants and less general anaesthetic to reduce your risk. However, this may lead to you being aware of your body and your surroundings during the operation. Anaesthesiologists use monitors to observe your body’s reactions and adjust the medication doses. If you think you’ve been aware during the operation, it’s important to tell your anaesthesiologist afterwards.
Bladder problems: depending on the operation and the medications, men may find it difficult to urinate, while women tend to leak after the operation. If necessary, a urinary catheter is used to drain the bladder until control returns.
Chest infection: this may lead to breathing problems, but can be treated with antibiotics. This is more likely to occur in people who smoke.
Lip, teeth, tongue injury or jaw dislocation: this can be caused by difficulty placing the breathing tube, or by clenching your teeth as you recover from the anaesthetic.
Muscle pain: can be caused by a muscle-relaxing drug that is used to prevent vomiting during emergency surgery.
Slow breathing: can be due to some painkillers or muscle relaxants. Can be treated with medications.
Worsening of existing medical condition: your Anaesthesiologist will monitor your body closely and act to eliminate or reduce any medical complications.
Very rare complications (0.0005 to 0.01% of general anaesthetics) include:
Death: is very rare and usually occurs when 4 or more complication occur simultaneously. Death from anaesthesia occurs in 1 of every 200 000 cases,
Equipment failure: vital equipment can fail, but this is very rare, and monitors give immediate warnings.
Eye damage: eyelids are taped shut to protect them during surgery. Rarely, sterilizing fluid may leak under the eyelids, or you may rub your eyes while waking from the anaesthetic. Any discomfort is usually temporary.
Nerve damage – stretch, compression, incision or puncture: recovery usually occurs within 3 months of the procedure.
Serious allergic reaction to medication: This is noticed and treated quickly, but can very rarely cause death, even in healthy people.
Artery injury – Carotid
Although injury to the carotid artery (located in the front of the neck) is very rare it can lead to thrombosis, bleeding or thromboembolism – and lead to a stroke. Injury can be caused during retraction or incision while accessing the anterior cervical spine.
Artery injury – Vertebral
The vertebral artery passes close to the vertebral bodies in the neck. Injury during surgery is very rare, but laceration can cause bleeding. In the unlikely event that the bleeding can’t be controlled, injury may lead to a stroke and cause permanent disability such as blindness or paralysis, or death.
Arteries are large blood vessels that carry blood under pressure throughout the body. Surgeons take extreme care not to injure arteries near the operation site as a perforation can lead to significant blood loss. In the unlikely event that an artery is perforated, a specialist vascular surgeon will repair the artery, and a blood transfusion is administered. Late consequences of artery injury include fistula, bleeding, pseudo aneurysm formation, thrombosis, emboli and death.
Arteries are large blood vessels that carry blood from the heart to the rest of the body and the heart muscle. Arterial thrombosis is a blood clot in an artery, which can be very serious as it can stop blood reaching important organs. During surgery, it is sometimes necessary for arteries to be moved to the side or compressed to allow access to the operation site. This pressure can lead to a clot forming within the artery (this is more likely in older patients with pre-existing blood vessel disease). A large clot can block the artery, while a small clot can dislodge and become an embolus, which travels and eventually blocks a small artery. Blocked arteries lead to insufficient blood flow, or ischemia in the tissues supplied by the artery. This can cause damage to these tissues, which may be permanent, depending on the duration of the blockage. Ischemia in the legs can cause pain and gangrene, if it occurs in the brain it can cause a stroke and in the spinal cord, it can cause paralysis and altered sensation.
Bone Graft Displacement
During a bone graft, bone fragments are placed in the space between two bones. If the bones are kept still for long enough, the fragments fuse with one another – and the adjacent bones – to form a solid and pain-free single bone. However, if excess movement occurs before fusion has occurred, the graft can become displaced. This can result in pain, injury to adjacent tissues, mal-alignment of the bones or non-fusion, which is known as non-union or pseudo-arthrosis.
Bone Graft Misplacement
Every effort is made to ensure that bone grafts are placed in optimum positions. However, there are rare instances where these implants are not optimally placed and a further procedure may be required to correct this. Misplacement may be the result of anatomical variations, equipment limitations or system failures.
This is when the dura (which contains the spinal cord and the cerebrospinal fluid) is torn and cerebrospinal fluid leaks out of the sac. Symptoms include a headache when standing, back or limb pain, nausea, vomiting, dizziness, ringing in the ears or sensitivity to bright light, including a risk of infection and meningitis. The dural tear may reseal spontaneously or it may need best rest, drainage or surgery to repair.
No operation is risk-free. Complications resulting from a procedure can range from minor troubles to major disability. Even when a surgery has gone well, serious problems can still arise and result in pneumonia, heart attack, stroke or even death. The entire medical team is highly trained and committed to eliminating all risk pre-, during and post-surgery as much as is humanly possible.
Deep Vein Thrombosis
Any surgery can put you at an increased risk of deep vein thrombosis (a blood clot that forms inside the large deep veins of the legs). The reason for this is twofold: The blood’s clotting mechanism is activated by surgery, injury to blood vessels, immobility and anaesthetic effects during and after the surgery make it easier for clots to develop.
The danger of a DVT is that it can block the blood flow from the legs back to the heart, causing swelling of the legs with resultant pain. If the clot doesn’t dissolve properly, the swelling and discomfort can become permanent. Alternatively, the clot in the leg can detach and travel up the veins to the lungs, where it blocks the smaller lung blood vessels and stops the blood flow. This is called a pulmonary embolus, or PE. If the PE is large enough, or there are many of them, it can cause death.
Patients who are at additional risk of DVT are: over the age of 50, have varicose veins, have had a previous heart attack, cancer, atrial fibrillation, an ischemic stroke, diabetes, previous DVT, heart failure, combined oral contraceptive pill use, smoking, obesity, leg weakness and inherited clotting abnormalities.
The dura is a thin layer of tissue that forms a sac containing the brain, spinal cord and nerve roots. This sac is filled with cerebrospinal fluid and can be torn during spinal surgery. It’s a complication that is more difficult to avoid during repeat surgery in the same location, or when operating on severe spinal narrowing or a large disc herniation. A dural tear – and the subsequent leakage of cerebrospinal fluid – can cause a headache when standing, back or limb pain, nausea, vomiting, dizziness, ringing in the ears or eye pain from bright light. A continual leak can lead to a cerebrospinal fluid cyst under the skin or leakage of fluid from the wound. Dural tears can reseal spontaneously, or it may need bed rest, a blood patch procedure, draining or an additional operation to repair.
Difficulty swallowing food or water is common post anterior cervical spine surgery. Dysphagia may be a result of the stretching of the oesophagus (which connects the throat with the stomach) or injury to the nerves that control it. Symptoms are usually mild and temporary, but can take over a year to resolve. In rare instances, a gastroenterologist will need to perform oesophageal dilation.
Dysphonia is when the voice involuntarily sounds breathy, raspy, or strained. The voice is created when the brain sends messages to specific nerves, the laryngeal, tongue, lower jaw and soft palate muscles. Trauma to any of these structures can affect the voice production. The breathing tube used during any surgery can cause the vocal cords or nerves to become inflamed, but symptoms typically settle within a couple of days. During anterior spine surgery, however, the nerves in the neck can be stretched and torn. Symptoms may resolve in weeks or months or even up to a year. In rare instances dysphonia is permanent.
Should bleeding occur into the epidural space around the spinal cord, it can form a blood clot known as an epidural hematoma. If the hematoma is large, it can compress the spinal cord and nerve roots leading to pain, weakness, numbness and bowel and bladder problems. A surgical procedure may be needed to stem the bleeding and remove the hematoma.
During general anaesthesia the patient’s eyes are taped shut to protect them from the risk of drying or scratching. Should they become dry or scratched however, they typically heal within a day or two. Blindness is a rare complication that can be caused by too much pressure on the eyeball or decreased blood flow through the eye (ischemic optic neuropathy (ION)). Blindness due to ION is a 0,1% risk and is associated with emboli, prolonged spine surgery in patients older than 70, a face-down operating position, diabetes, intraoperative blood loss/hypotension and ankylosing spondylitis (poor position owing to a deformity of the neck).
Fluoroscopy is similar to an “X-ray movie”. A continuous X-ray beam is passed through the body part being examined, affording the surgeon instant imagery of the inside of a patient during a procedure enabling him or her to accurately position any devices. The disadvantage of fluoroscopy is that X-rays can potentially cause cancer, reproductive abnormalities, cataracts and radiation dermatitis. That said, the exposure during surgical procedures is usually not significant and doctors make use of protective lead shields and minimize the intensity and duration of exposure.
During any surgery, some blood vessels will be cut. And although the surgeon stops all significant bleeding before closing the wound, there are instances in which bleeding restarts and forms a collection of blood in the tissues. Known as a hematoma, this can cause pain, put pressure on the adjacent tissues or become infected. A drainage tube may need to be inserted or a surgical operation performed.
Surgeons may need to cut some blood vessels in order to access the spinal operation site. The surgeon will plan the surgical route to avoid large blood vessels and will make sure that all bleeding has stopped before finishing the operation. Occasionally, one of these vessels can re-bleed after the procedure and if the rate, or the location of the bleed is problematic, a further procedure may be needed to stem the bleeding and drain the accumulated blood clot.
Injury to the sympathetic nerves in the neck can cause Horner’s Syndrome, which refers to the drooping of the upper lid, slight elevation of the lower eyelid, constriction of the pupil and dryness of the face on the same side. Depending on where the injury is, some patients also experience decreased flushing and sweating.
Spinal fusion operations use screws, plates, rods and spacers to hold the vertebrae in correct alignment while the bone fuses together over the first few months. Once the bone fuses these implants are no longer necessary but are often left in place. Sometimes, before the bone has fused, an implant may break or shift from its correct position, causing pain, injury to adjacent tissues, mal-alignment (of bones) or non-fusion of bones (non-union, pseudoarthrosis). Another operation may be needed to remove or replace the implant.
Spinal fusion operations use screws, plates, rods and spacers to hold the vertebrae in correct alignment while the bone fuses together over the first few months. Rarely, because of anatomical variations, equipment limitations or system failures, the implants are not optimally placed and a follow-up procedure is needed.
Infections occur in less than 1% of spinal operations and are more likely in patients that smoke, have diabetes, are overweight, or had a hematoma. Symptoms of an infected wound include: increased pain, swelling, tenderness, redness, oozing (clear or yellow fluid), slowness to heal, or if the patient experiences fever or chills.
Infections can be superficial (involving the skin), which usually respond to oral antibiotics and washing of the site. Sometimes the wound needs cleaning and re-suturing. Deep infections (involving the vertebrae or spinal cord) are more serious and may need intravenous antibiotics and an operation to drain the infection. On rare occasions, infected bone graft or hardware may need to be removed.
This rare life-threatening condition is passed down through families and can be triggered by some drugs that are used for general anaesthesia. In susceptible people, the drugs can cause an uncontrolled increase in skeletal muscle calcium levels and muscle contraction, leading to decreased blood oxygen and increased blood carbon dioxide and body temperature. This can lead to circulatory collapse and death if not quickly treated. Symptoms usually develop within an hour of drug administration. As yet, there is no simple test to diagnose susceptibility but it is usually found during drug administration or suspected if a family member develops the symptoms. While treatment is effective, it is critical that patients, who have a family history of malignant hyperthermia, discuss this with their doctor so that the use of the potential trigger drugs can be avoided.
Neck pain (similar or different to the original neck pain) after the procedure is to be expected. It is usually temporary. However, in some patients, the original neck pain can persist or it can be worse.
Nerve Injury – Cervical nerve root
Because the vertebrae surround the spinal cord and nerve, surgery on the vertebra can injure the nerve roots. These nerves can be bruised, stretched, torn or cut while operating on the spinal abnormality. Often the nerves are already compromised because of the disease process. If a nerve is injured, it can cause pain as well as temporary or permanent, partial or complete, loss of sensation or movement in the patient’s arm.
Nerve Injury – C5
Even after a technically successful cervical surgery, injury to the C5 nerve root can occasionally happen, with symptoms sometimes occurring up to one month after the surgery. The C5 nerve root is shorter than the other nerve roots, and given its location, it is often stretched during surgery. The C5 is the only nerve supply to the muscles that elevate the shoulder, so any injury leads to an obvious weakness of this muscle. Partial recovery occurs over weeks to months, but it can take years.
Nerve Injury – Lateral Femoral Cutaneous
The lateral femoral cutaneous nerve supplies sensation to the front of the thigh. It usually passes under the inguinal ligament in front of the hip, however, in some people it passes over the anterior iliac crest, near the site of bone graft removal. This nerve can be injured during bone graft removal or by prolonged pressure while lying in surgery. Injury can cause pain, pins and needles or numbness on the front to the thigh called meralgia paresthetica. Pressure injuries usually resolve within 3 months, but if the nerve has been cut, the symptoms may be permanent.
Nerve Injury – Recurrent Laryngeal
The recurrent laryngeal nerves in the neck can be damaged by incision, pressure or stretching during anterior spinal surgery. Symptoms can include hoarseness, voice fatigue, weak or persistent cough, inhaling fluid and difficulty swallowing. Depending on the cause, symptoms may resolve in weeks or months or even up to a year. In rare instances, recurrent laryngeal nerve injury is permanent
Nerve Injury – Ulnar
During surgery the medical team carefully positions the patient’s body so that the injured region is easily accessible. This can result in the ulnar nerve (located in the arm) being compressed or stretched at the elbow. Symptoms of pain, numbness or weakness in the hand can appear up to 4 days after surgery and usually disappear over a few weeks.
Failure of the two vertebrae to fuse into one solid bone is called non-union or pseudo arthritis This occurs in about 10% of spine fusion operations. Nicotine products, including chewing tobacco, and cigarette and cigar smoking, can slow bone healing and significantly increase the likelihood of non-union. Consuming high doses of non-steroidal anti-inflammatory drugs after the operation can also increase the risk of non-union. Other causes are excessive alcohol intake, the location and number of segments fused, osteoporosis and some medical diseases. Non-union can cause worsening pain and may cause the supporting hardware to break. Additional surgery may be required to add more bone graft, replace the hardware or add an electrical stimulator to encourage the fusion to heal.
During anterior cervical spine surgery, the oesophagus (which connects the throat with the stomach) is moved to the side to allow access to the front of the spine. Sometimes it is bruised or the nerves controlling it are stretched, which can lead to difficulty swallowing after the procedure. Symptoms usually settle within 2 months.
In rare instances, the oesophagus is cut or torn during surgery or it is later worn through by implanted hardware, bone or cement. A tear can cause difficulty and pain in swallowing, shortness of breath, neck swelling, infection and oesophageal scarring.
Osteomyelitis is a bacterial infection of bone or the bone marrow. It can occur as a result of surgery, especially after the replacement of foreign material in the bone, or as a result of an adjacent infection. Symptoms can take up to 4 weeks to appear after surgery – the most common of which is worsening pain after an initial period of relief. Risk factors include age, smoking, obesity, diabetes, malignancy, chemotherapy, immune suppression, malnutrition, indwelling venous catheters, concurrent infections and extended hospitalization. Osteomyelitis is difficult to treat and often requires weeks or months of intravenous antibiotics and a surgical procedure to clean the area.
The spine surrounds and protects the spinal cord. This means that surgery to the cervical spine can damage the cervical spinal cord, resulting in loss of movement and sensation in the torso and limbs. Quadriplegia may be complete, with no movement or sensation below the level of the spinal cord injury, or incomplete with some movement or sensation. Quadriplegia may involve impairment of movement and sensation of the limbs and torso, urinary and faecal incontinence, impotence and digestion and breathing difficulties. Quadriplegics are also at an increased risk of pressure sores, osteoporosis, fractures, frozen joints, thrombosis, respiratory infections, pneumonia and cardiovascular disease.
Prolonged surgery and bed rest can result in the formation of skin pressure sores over prominent bones. The nursing team carefully place, pad and manoeuvre the patient to prevent this from happening.
Surgery can’t restore the back to a pre-diseased state. This means that some remaining post-procedural pain is very common. Furthermore, a degree of discomfort from the operation site – and pain from adjacent areas already damaged by the disease or by their own degenerative problems – can be expected. Usually, any residual pain is mild, but it may be severe or even worse than the original problem.
Urinary Tract Infection
Given that patients undergo general anaesthetic during surgery and are confined to recuperative bed rest, they aren’t able to go to the toilet to urinate. As such, a urinary catheter is passed along the urethra to freely drain the bladder and avoid bladder discomfort. The presence of a urinary catheter does increase the risk of bacteria entering the bladder and causing a urinary tract infection. Treatment usually requires the catheter to be removed, followed by a course of antibiotics.