Lumbar Posterior Discectomy
What is lumbar disc herniation?
A disc is the “shock absorber” between two vertebrae. A herniated disc occurs when some of the softer inner disc tissue pushes out through a tear in the tougher disc capsule. Lumbar disc herniations are very common and although a herniated disc’s contents can’t be “pushed back” into place, the tissue often dries out and shrinks away and generally doesn’t cause any symptoms. However, if the damaged disc is pressing on spinal nerves and causing severe pain, noticeable leg weakness or bowel and bladder problems that don’t improve after conservative treatment, then surgery can be considered.
- Acupuncture (speak to your doctor about this controversial topic)
- Avoidance of bending, lifting, twisting and prolonged sitting
- Pain relieving medications
- Physical therapy
- Weight loss
Smoking damages every part of the body and decreases the chance of a successful procedure. If you smoke, you should stop now.
The patient is placed in a kneeling position and the skin on his back is cleaned. An incision is made in the middle of the back and the overlying muscles are moved to the side. Using x-ray imaging, the surgeon confirms the correct disc for the procedure. Part of the lamina is removed and the adjacent ligamentum flava is also removed. The overlying nerve is retracted to the side. Sometimes a sequestrated fragment is the cause of the compressed nerve. This can be removed. Sometimes a window is cut into the disc capsule and the protruding or extruded disc fragment is removed. The muscles are replaced and the skin is sutured closed.
- A lumbar posterior discectomy typically takes 1 to 2 hours.
- On average, you will spend 2 to 3 nights in hospital.
- Numbness is slow to alleviate and some may persist permanently. Only after 18 months will the full extent of improvement or the permanent damage be quantified.
- Weakness may last for 6 to 12 weeks. Again, the full extent of improvement or the permanent damage as a result of the compression will be quantified after 18 months.
- Although feelings of pins and needles decrease immediately post-op, there may be fleeting recurring symptoms during the first few weeks of recovery.
- You should not work for 2 –3 weeks after the surgery.
- Avoid bending, twisting or lifting.
- Don’t lift anything heavier than a bottle of milk for 2 weeks.
- For the first 4-6 weeks, only walking and the exercised given to you by the physiotherapist is permitted. Thereafter you can return to normal activities, while constantly caring for your back.
- In uncomplicated cases, up to 90% of patients report good to excellent leg 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 surgeon immediately.
- If you have steri-strips on your incision, it’s important to keep these dry. Once they start peeling off, you may remove them (typically after 2 weeks). They are used in conjunction with dissolvable sutures under the skin.
- All external sutures will be removed in 1 to 2 weeks.
- 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.
- A follow-up appointment with your surgeon will be booked for 4-6 weeks after the surgery.
- 5 -15% of patients might develop another herniation somewhere in the lower back. The time of greatest risk is during the first 6 weeks after surgery.
Despite having surgery, your back will never return to full strength. You will always have a “weak spot” and you will need to commit to lifelong care to prevent further injury. Maintain correct posture, eliminate excess body fat, follow a daily exercise program and avoid activities that might strain 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.
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.
Back pain (that is similar or different to the original back pain) after the procedure is to be expected and is usually temporary. Sometimes the original back pain can persist or can even be worse.
Cauda Equina Syndrome
Cauda equina syndrome (CES) is a rare but serious condition. It develops due to compression of the cauda equina bundle of nerves located at the base of the spinal cord in the spinal canal. These nerves transmit movement and sensation information to and from the lower body and also manage the bladder, bowels and sexual function. Should pressure be applied to these nerves as a result of a damaged disc, tumour, infection or bleeding, they can become damaged. If the pressure is not rapidly alleviated, permanent nerve damage can occur. Cauda equine syndrome can cause leg paralysis and numbness, impaired bladder or bowel control, loss of sexual sensation and other problems.
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.
Disc herniation – recurrent
Between 5 and 15% of patients experience a recurrence of a disc herniation after repair. A third of these cases are the result of an isolated event, but it can happen without any obvious trigger. While the herniation can be removed with a revision discectomy, repeat recurrences may indicate that the disc can’t heal properly and may need to be replaced or fused.
Discitis is an infection of the intervertebral disc and can occur spontaneously or after surgery. Risk factors for discitis include age, smoking, obesity, diabetes, malignancy, chemotherapy, immune suppression, malnutrition, indwelling venous catheters, concurrent infections and extended hospitalization. Post-operative discitis can occur up to 6 weeks after a disc operation and in most instances causes worsening back pain after an initial period of relief. Discitis is treated with antibiotics over a long period of time (months).
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.
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.
Post-operative ileus is a temporary paralysis of the bowel. This condition is usually caused by narcotic pain-killing medications, intra-abdominal, spine or chest surgery. Symptoms include abdominal discomfort and bloating, constipation, nausea or vomiting. Through fasting and minimizing the use of narcotic medication, most cases will settle within three days. Occasionally though the stomach may need to be emptied using nasogastric suction tubes and intravenous feeding and fluid is required.
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.
Nerve injury – lumbar
Vertebrae surround the spinal nerve roots. This means that accessing or repairing damaged vertebra can potentially bruise, stretch, tear or cut these nerves roots – either within the spinal canal – or as they leave the spinal canal through the invertebral foramen. Locating, protecting and mobilising the spinal nerves can be the most sensitive and time-consuming part of spinal surgeries. If a nerve is damaged, the injury can cause temporary or permanent pain or bladder and bowel dysfunction as well as partial or complete loss of sensation or movement in the patient’s leg.
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.
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 any surgery to the spine carries a degree of risk and the surgeon takes great care when working on the operation site. Damage to the thoracic, lunar or sacral spinal cord can cause loss of movement and sensation in the lower half of the body. It can be complete, with no movement or sensation below the level of the spinal cord injury, or incomplete with some movement or sensation. Paraplegic patients generally need to use wheelchairs or other walking aids. Urinary and faecal incontinence and impotence are common and paraplegics are at an increased risk of pressure sores, thrombosis and pneumonia.
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.