Spinal Discectomy is the surgical removal of part or all of a vertebral disc that has herniated. The disc is removed by first cutting the outer annulus fibrosis and removing the nucleus pulposus to relieve pressure on the nerve root. Dissection is then performed to remove a ligament that runs from front to back in order to access the spinal canal and remove any bone spurs or disc material protruding through the ligament.
A discectomy (also called open discectomy, if done through a 1/2 inch or larger skin opening) is the surgical removal of abnormal disc material that presses on a nerve root or the spinal cord. The procedure involves removing a portion of an intervertebral disc, which causes pain, weakness or numbness by stressing the spinal cord or radiating nerves. The traditional open discectomy, or Love’s technique, was published by Ross and Love in 1971. Advances have produced visualization improvements to traditional discectomy procedures (e.g. microdiscectomy, an open discectomy using an external microscope typically done through a 1 inch or larger skin opening), or endoscopic discectomy (the scope passes internally and typically done through a 2 mm skin opening or larger, up to 12 mm). In conjunction with the traditional discectomy or microdiscectomy, a laminotomy is often involved to permit access to the intervertebral disc. Laminotomy means a significant amount of typically normal bone (the lamina) is removed from the vertebra, allowing the surgeon to better see and access the area of disc herniation.
Indications of Spinal Discectomy
Urgent lumbar discectomy is necessary in cases of cauda equina syndrome and progressive or new motor deficit. Elective lumbar discectomy is indicated in cases of unremitting radicular symptoms that correspond to radiographic evidence of nerve root compression by a herniated disc in patients that have failed conservative treatment methods. A thorough understanding of the expected outcomes is necessary on the part of the patient before proceeding with surgery. Specifically, the relatively higher reliability of improvement in radicular leg pain as compared to back pain must be stressed. Recurrence risk is an important topic, as well. Revision discectomy remains a viable option should recurrent herniation occur, though with the removal or more disc material and especially in the setting of large or repeated annular injury the option to proceed with spinal fusion at the injured level may be a consideration. Prior to surgery, a high level of correspondence between a patient’s symptoms and pathology on magnetic resonance imaging must be confirmed to improve the reasonable likelihood of a positive outcome.
Technique of Spinal Discectomy
Open Discectomy
After administering general anesthesia, the patient gets positioned prone on a spine frame (Wilson or Allen Bow) or a dedicated table. Transverse pads at the iliac crest and chest allow for flexion of the hips to increase interlaminar distance while avoiding pressure on the abdomen to reduce central venous pressure. Palpation of bony landmarks including the sacrum and iliac crests corresponding the to L4-L5 disc level may guide the start point and trajectory of the surgical approach. After appropriate sterile skin prep, localization using a spinal needle and fluoroscopic control confirms the target level. A 3 to 4 cm longitudinal incision is marked at the midline centered about the radiographic marker.
The skin incision is made with a sharp scalpel, and subcutaneous dissection with electrocautery reveals the lumbar fascia; this is incised just off of midline, as identified by palpating the spinous processes, ipsilateral to the disc pathology addressed. This fascia should span the interspinous distance at the target level. A radiographic marker may be used to confirm the spinal level and cranially directed trajectory in line with the interspinous space on a lateral fluoroscopic image. Using electrocautery, a subperiosteal elevation of paraspinal musculature from the superior and inferior spinous processes is completed down to the laminar junction. Lateral dissection continues bluntly with a Cobb elevator as far laterally as the facet joint taking care not to violate its capsule. Visualization of the interlaminar space is essential; removal of dissected muscle tissue in the surgical field, proper retraction and diligent hemostasis using electrocautery are crucial. At this point, the surgeon releases the ligamentum flavum from its attachment on the anterior aspect of the lamina of the superior vertebra using a curette. An angled Woodson elevator may then be inserted anterior to the ligamentum, directed caudally, to protect the dura beneath. The ligamentum is then incised sharply to allow for its retraction with a Penfield elevator and visualization of the exiting nerve root and associated epidural fat. The medial aspect of the inferior facet of the superior vertebra may require resection to allow for adequate exposure. A Penfield or blunt probe is then passed into the neuroforamen to mobilize the root, enabling its medial retraction. With adequate visualization of the intervertebral disc space, removal of fragmented or herniated tissue may then be carried out using pituitary rongeurs. If a portion of the herniation remains beneath the posterior longitudinal ligament, a scalpel may be necessary to incise the annulus for access. Care must be taken to probe the epidural space using a Woodson elevator in all directions for any additional disc or ligamentous tissue.
Additionally, it is advisable to irrigate the disc space with saline via bulb syringe to express any loose disc fragments that may have gone unvisualized. Meticulous hemostasis via bipolar electrocautery is achieved, and the wound is liberally irrigated with saline. The fascial and subcutaneous layers are closed with absorbable suture, and the skin closure is by surgeon preference.
Minimally Invasive Surgery (MIS) Tubular Discectomy
The patient is positioned and prepped as described above. A 1.5 to 2.0 cm surgical incision is marked longitudinally, 1.5 cm off of midline on the affected side. A stab incision with a #15 scalpel allows the introduction of a guide pin or K-wire, which is advanced under lateral fluoroscopy to ensure appropriate depth as well as docking to the lamina cranial to the affected level. Once the start point and trajectory are confirmed, the full skin incision is made as well as fascial incision centered over the wire. Sequential dilator retractors are placed to create a working channel which may be anchored to the operating table. Magnifying surgical loupes or intra-operative microscopic are useful adjuncts to aid in visualization. Utilizing instruments appropriately designed for a tubular approach, the remainder of the procedure takes place as described above. Meticulous hemostasis is achieved, the tubular retractor system is removed, and closure of subcutaneous tissue and skin completes the case.
MIS Endoscopic Discectomy
The patient is positioned and prepped as described above. Beginning at a start point 1 to 2 cm off of midline ipsilateral to pathology, the anatomical space bound by traversing nerve root, exiting nerve root, and superior aspect of the caudal vertebra known as a Kambin triangle is approached at the target level using a spinal needle. A 5 to 10mm skin incision is made, and successive cannulated dilators allow for the introduction of an 8 mm working cannula through which the endoscope, for visualization of the disc space, traversing and exiting nerve roots, and the passing of instruments. A laminotomy of the cranial vertebra may be made, and targeted nerve roots may be decompressed using endoscopic curettes, rongeurs, drills, and bipolar electrocautery. Herniated disc material may thus be removed. A single small endoscopic incision is closed with a subcuticular suture.
Post-Operative Care
Typically, patients may be discharged on the first postoperative day after an uncomplicated discectomy. An additional postoperative stay may be necessary for physical therapy rehabilitation or oral pain control. Discectomy on an outpatient basis has been described and practiced at some centers.[rx] No external bracing is necessary for spinal stability. Most surgeons advise limiting significant bending, lifting and twisting motions for 3 to 6 weeks after surgery due to concerns for re-herniation, though more expedient or immediate unrestricted activity may yield equivalent outcomes without increased re-herniation rates.[rx][rx]
What happens during a lumbar discectomy?
There are several options for the surgery. Your surgeon can help explain the details of your procedure. It may take about 1 hour. Here is an example of what you might expect:
- You will receive a local anesthetic so that you won’t feel any pain or discomfort during the procedure. And you will still be awake. Or you may have general anesthesia and sleep through the procedure.
- A healthcare provider will carefully watch your vital signs during the procedure. This includes things like your heart rate and blood pressure.
- Your surgeon will make a small incision on your back, at the level of the affected disc.
- During the procedure, your surgeon will use a special type of X-ray to make sure of the correct location.
- Your surgeon will first insert a wire into the intervertebral space. Your surgeon will push a slightly larger tube over this wire. Then your surgeon will push a second, larger tube over that one. He or she may even push a third tube over the second one. This will gently push apart the tissue down to the vertebra. Finally, your surgeon will remove all except the largest tube.
- Your surgeon will put special small tools through this tube, including a camera and a light.
- Your surgeon will remove the herniated part of the disc using small tools. He or she will also do any other needed repairs.
- The tools and tube are removed.
- A small bandage is placed to close your wound.
What happens after a lumbar discectomy?
The surgery is usually an outpatient procedure. This means you can go home the same day. You will probably need to stay for a couple of hours after the procedure. Make sure you have someone who can drive you home.
Your healthcare provider will give you instructions about how you can use your back. You might need to limit lifting or bending. Your provider might have you wear a back brace for a limited time after the procedure. Most people can go back to work within a week or so. You may need physical therapy after surgery to help strengthen your back.
You may see some fluid draining from your small incision. This is normal. Tell your provider right away if there is a large amount of drainage from the incision site. Also call your provider if you develop a fever or if you have a lot of pain in the area.
Sometimes the procedure causes slightly more pain for a while. But you can take pain medicines to ease the pain. Usually this goes away quickly. Your pain should become less than it was before your surgery.
Make sure to follow all your provider’s instructions and keep your follow-up appointments.
Next steps
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure
Complications
A wound or deep infection occurs at a rate of 2 to 3%, with dehiscence or other wound infections occurring at a rate of 1 to 2%. Direct intra-operative nerve root injury has been described to affect 1 to 2% of cases. The rate of incidental durotomy ranges from 0 to 4% in the literature. Durotomy can lead to leakage of cerebrospinal fluid with a subsequent risk of developing meningitis. Instability following discectomy by the techniques described here is understood to be exceedingly rare, though the difficulty in its definition and metric make objective quantification difficult.
Lumbar disc herniation recurrence rate following discectomy ranges from 1 to 25%, and the rate of intragenic dural tear approaches 9%.[rx][rx][rx] Male gender, smoking status, and heavy labor are risk factors.[rx] Those with concomitant retrolisthesis at L5-S1 appear to have the same long term clinical outcomes as those without retrolisthesis according to an 8 year follow up from the SPORT database.[rx] As recurrence has been investigated at widely varying follow-up times and by several outcome measures, including recurrent symptoms and reoperation, patient-specific factors should inform a candid discussion preoperatively regarding the risk of recurrent disease.
The patient may have persistent pain following lumbar disc surgery, which may be a part of failed back surgery syndrome.[rx]
Discharge instructions
Discomfort
- Take pain medication as directed by your surgeon. Narcotics can be addictive and are used for a limited period of time.
- Narcotics can also cause constipation. Drink lots of water and eat high-fiber foods. Laxatives and stool softeners such as Dulcolax, Senokot, Colace, and Milk of Magnesia are available without a prescription.
- Ice your incision 3-4 times per day for 15-20 minutes to reduce pain and swelling.
Restrictions
- Avoid bending, lifting or twisting your back for the next 2 weeks.
- Do not lift anything heavier than 5 pounds for 2 weeks after surgery.
- No strenuous activity for the next 2 weeks including yard work, housework and sex.
- Do not drive for 2 weeks after surgery or until discussed with your surgeon.
- Do not drink alcohol for 2 weeks after surgery or while you are taking narcotic medication.
- Do not smoke. Smoking delays healing and inhibits bone growth.
Activity
- You may need help with daily activities (e.g., dressing, bathing) for the first few days. Fatigue is common. Let pain be your guide.
- Get up and walk 5-10 minutes every 3-4 hours. Gradually increase your walking time, as you are able.
Bathing/Incision Care
- Wash your hands thoroughly before and after cleaning your incision to prevent infection.
- If you have Dermabond (skin glue) covering your incision, you may shower the day after surgery. Gently wash the area daily with soap and water. Pat dry.
- If you have staples, steri-strips or stitches, you may shower 2 days after surgery. Remove the gauze dressing and gently wash the area with soap and water. Replace the dressing or completely remove it if no drainage. Inspect and wash the incision daily.
- Do not submerge or soak the incision in water
(bath, pool or tub).- Do not apply any lotions or ointments over the incision.
- Some drainage from the incision is normal. A large amount of drainage, foul smelling drainage, or drainage that is yellow or green should be reported to your surgeon’s office.
- Staples, steri-strips, and stitches will be removed at your follow-up appointment.
When to Call Your Doctor
- If your temperature exceeds 101.5° F, or if the incision begins to separate or show signs of infection, such as redness, swelling, pain, or drainage.
- Swelling and tenderness in the calf of one leg.
- New onset of tingling or numbness in the legs or numbness in the groin area.
THE SPECIFIC RISKS INCLUDE (BUT ARE NOT LIMITED TO):
- Fail to benefit symptoms or to prevent deterioration
- Worsening of pain/weakness/numbness
- Infection
- A blood clot in wound requiring urgent surgery to relieve pressure
- Cerebrospinal fluid (CSF) leak
- Surgery at the incorrect level (this is rare, as X-rays are used during surgery to confirm the level)
- Blood transfusion
- Implant failure, movement, or malposition (when a fusion is also done)
- Recurrent disc prolapse or nerve compression
- Nerve damage (weakness, numbness, pain) occurs in less than 1%
- Quadriplegia (paralyzed arms and legs)
- Incontinence (loss of bowel/bladder control)
- Impotence (loss of erections)
- Chronic pain
- Instability or forward collapse of the neck (kyphosis) (may require further surgery)
- Stroke (loss of movement, speech etc)
References