Microdiscectomy (Microdecompression) Spine Surgery

Typically performed for a herniated disc, a microdiscectomy, also called a microdecompression, relieves the pressure on a spinal nerve root by removing the material causing the pain.

During the surgery, a small part of the disc material and/or bone impinging the nerve root is taken out.

The procedure may also be performed in the cervical spine (neck) to treat herniated discs in the neck and is called posterior cervical decompression. 

How Microdiscectomy Works in the Lower Back

Microdiscectomy is considered the gold standard surgical procedure for treating most lumbar (low back) disc herniations¹Dowling TJ, Munakomi S, Dowling TJ. Microdiscectomy. [Updated 2023 Feb 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK555984/ – a condition where the disc’s inner soft core (nucleus pulposus) starts to leak into cracks or tears in the outer layer (annulus fibrosus).

• The surgery involves removal of the herniated disc material that compresses the spinal nerve or spinal cord.
• During the surgery, surrounding muscles and ligaments may be cut or spread (depending on the approach) to access the disc area. 
• A laminectomy (spinal decompression) surgery may also be performed at the same time where a very small amount of bone is cut and removed to provide more space between the vertebrae and relieve impingement of the nerve. 

Patients normally feel pain relief almost immediately after a microdiscectomy and go home from the surgery with significant pain relief. For numbness, weakness, or other neurological signs in the leg and foot, it may take weeks or months for the nerve root to heal and reduce or eliminate any residual numbness or weakness.²Huang P, Sengupta DK. How fast pain, numbness, and paresthesia resolves after lumbar nerve root decompression: a retrospective study of patientʼs self-reported computerized pain drawing. Spine. 2014;39(8):E529-E536. doi:10.1097/BRS.0000000000000240

A microdiscectomy is typically performed by an orthopedic surgeon or neurosurgeon who specializes in treating musculoskeletal spinal conditions. 

Microdiscectomy Success Rates

Microdiscectomy is considered to have relatively high rates of success, especially in relieving leg pain (sciatica). Patients are usually able to return to a normal level of activity fairly quickly.³Dohrmann GJ, Mansour N. Long-Term Results of Various Operations for Lumbar Disc Herniation: Analysis of over 39,000 Patients. Med Princ Pract. 2015;24(3):285-90. doi: 10.1159/000375499. Epub 2015 Mar 27. PMID: 25832729; PMCID: PMC5588202.^,4Andersen MØ, Ernst C, Rasmussen J, Ankjær T, Carreon LY. Predictive Factors of Successful Return to Work Following Discectomy. Global Spine J. 2022 May;12(4):627-630. doi: 10.1177/2192568220960399. Epub 2020 Sep 24. PMID: 32969278; PMCID: PMC9109552.

Microdiscectomy vs nonsurgical treatment 

Medical literature points to some benefits of a microdiscectomy surgery when compared with only nonsurgical treatment, though the difference lessens over time in certain cases. 

One large study found that people who had surgery for a lumbar herniated disc had greater improvement in symptoms for up to two years than those who did not have surgery.⁵Abraham P, Rennert RC, Martin JR, et al. The role of surgery for treatment of low back pain: insights from the randomized controlled Spine Patient Outcomes Research Trials. Surg Neurol Int. 2016;7:38. Published 2016 Apr 13. doi:10.4103/2152-7806.180297

As a general guideline, an appropriate course of nonsurgical care is tried for 6 to 8 weeks prior to considering surgery, unless there is severe pain with or without progressive weakness and/or numbness that needs urgent intervention

See Non-Surgical Treatment for a Lumbar Herniated Disc

When Microdiscectomy May Be Recommended

Lumbar microdiscectomy may be indicated when⁶Ahn Y. Endoscopic spine discectomy: indications and outcomes. International Orthopaedics (SICOT). 2019;43(4):909-916.^,7Kulkarni AG, Tapashetti S. Outcomes of Discectomy in Young Adults With Large Central Lumbar Disc Herniations Presenting With Predominant Leg Pain. Global Spine J. 2020 Jun;10(4):412-418. doi: 10.1177/2192568219856871. Epub 2019 Jul 9. PMID: 32435560; PMCID: PMC7222677.:

• Imaging evidence (eg, a magnetic resonance imaging (MRI) or computed tomography (CT) scan with contrast) shows a disc herniation that corresponds with the patient’s signs and symptoms
• Progressive neurological symptoms and disabling pain are constant or worsen despite 6-8 weeks of nonsurgical treatments
• Leg pain is the dominant symptom and more severe than back pain 

Microdiscectomy is not performed when medical emergencies, such as cauda equina syndrome, spinal tumors, or spinal infection are suspected or confirmed.⁶Ahn Y. Endoscopic spine discectomy: indications and outcomes. International Orthopaedics (SICOT). 2019;43(4):909-916.

The procedure is also not considered when there is segmental instability due to severe degeneration in the affected spinal segment or multiple levels of the spine. In such cases, a microdiscectomy and lumbar spinal fusion surgery may be performed simultaneously.⁶Ahn Y. Endoscopic spine discectomy: indications and outcomes. International Orthopaedics (SICOT). 2019;43(4):909-916.

Deciding to Have Microdiscectomy

Leg pain due to a disc herniation generally gets better within 8-12 weeks of the onset of pain.⁸Dydyk AM, Ngnitewe Massa R, Mesfin FB. Disc Herniation. [Updated 2023 Jan 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441822/ As long as the pain is tolerable and the patient can function adequately, it is usually advisable to postpone surgery and see if the pain resolves with non-surgical treatments.

If the leg pain is severe, however, it is also reasonable to consider surgery sooner. For example, if despite nonsurgical treatment the patient experiences severe pain that affects sleep, work, or the ability to perform everyday activities, surgery may be considered.

The results of surgery are somewhat less favorable 3-6 months have passed since the onset of symptoms, so doctors usually advise people not to postpone surgery for an extended period (beyond 3-6 months).⁹Jacobs WC, van Tulder M, Arts M, et al. Surgery versus conservative management of sciatica due to a lumbar herniated disc: a systematic review. Eur Spine J. 2011;20(4):513-522. doi:10.1007/s00586-010-1603-7

Surgical Approaches for Microdiscectomy 

A microdiscectomy can be done in 2 ways:

• Traditional microdiscectomy: Surgery performed with the use of a magnification device, such as a microscope or surgical loupes. This approach uses smaller incisions compared to an open discectomy surgery and less soft tissue resection to view the disc space.
• Endoscopic discectomy: A minimally invasive surgery that causes minimal tissue damage and accesses the disc through an endoscope. 

Endoscopic microdiscectomy may be further classified as transforaminal percutaneous discectomy (the disc is accessed from the side) and percutaneous interlaminar discectomy (the disc is accessed from the back).¹⁰Kim S, Park GJ, Lee JU, Kim KH, Kim DH. Comparative study of the outcomes of unilateral biportal endoscopic discectomy and tubular microdiscectomy based on the visual analogue scale, oswestry disability index, and short-form 36. J Minim Invasive Spine Surg Tech. 2022;7(2):243-250. doi: https://doi.org/10.21182/jmisst.2022.00570

Endoscopic Discectomy: A Minimally Invasive Alternative to Microdiscectomy

Endoscopic discectomy, also called percutaneous discectomy or micro-endoscopic discectomy, is a less invasive alternative to microdiscectomy surgery.¹¹Meyer G, DA Rocha ID, Cristante AF, Marcon RM, Coutinho TP, Torelli AG, Petersen PA, Letaif OB, DE Barros Filho TEP. Percutaneous Endoscopic Lumbar Discectomy Versus Microdiscectomy for the Treatment of Lumbar Disc Herniation: Pain, Disability, and Complication Rate-A Randomized Clinical Trial. Int J Spine Surg. 2020 Feb 29;14(1):72-78. doi: 10.14444/7010. PMID: 32128306; PMCID: PMC7043817.

In an endoscopic discectomy, a working channel that connects the incision to the spinal disc is created with the help of surgical dilators. A tube-shaped surgical instrument equipped with a light and camera lens, called an endoscope, and other surgical instruments, such as forceps, are inserted through this working channel to access and treat the disc.¹¹Meyer G, DA Rocha ID, Cristante AF, Marcon RM, Coutinho TP, Torelli AG, Petersen PA, Letaif OB, DE Barros Filho TEP. Percutaneous Endoscopic Lumbar Discectomy Versus Microdiscectomy for the Treatment of Lumbar Disc Herniation: Pain, Disability, and Complication Rate-A Randomized Clinical Trial. Int J Spine Surg. 2020 Feb 29;14(1):72-78. doi: 10.14444/7010. PMID: 32128306; PMCID: PMC7043817.

Patients are discharged based on their pain level, ability to walk without assistance, and the ability to use the restroom independently.¹¹Meyer G, DA Rocha ID, Cristante AF, Marcon RM, Coutinho TP, Torelli AG, Petersen PA, Letaif OB, DE Barros Filho TEP. Percutaneous Endoscopic Lumbar Discectomy Versus Microdiscectomy for the Treatment of Lumbar Disc Herniation: Pain, Disability, and Complication Rate-A Randomized Clinical Trial. Int J Spine Surg. 2020 Feb 29;14(1):72-78. doi: 10.14444/7010. PMID: 32128306; PMCID: PMC7043817.

See Lumbar Discectomy Outpatient Spine Surgery

Potential benefits of endoscopic discectomy

Potential benefits offered by the endoscopic procedure when compared to microdiscectomy are:

• A smaller incision
• Less muscular retraction
• Less bone removal
• Minimal manipulation of nervous tissue
• May be performed under local anesthesia 
• Less blood loss
• Shorter operative time

These benefits may allow for quicker recovery, enabling an early return to activities of daily living.

Types of Disc Disorders Treated with Microdiscectomy

Microdiscectomy is typically indicated for herniated lumbar discs. 

A disc can herniate in 3 ways: 

• Disc protrusion: when the nucleus pulposus leaks into the outer layer but not beyond its boundary
• Disc extrusion: when the nucleus pulposus starts to leak beyond the boundary of the outer layer
• Disc sequestration: when a part or fragment of the disc separates from the rest of the disc

Depending on the area they protrude into, the herniated part of the disc may affect the spinal cord and/or spinal nerve root(s). 

Herniated discs may be further classified as:

• Central herniations: discs that herniate into the spinal canal
• Lateral recess herniations: discs that herniate between the spinal cord and the intervertebral foramen (the space through which the nerves exit the spinal canal)
• Foraminal herniations: discs that protrude or herniate directly into the intervertebral foramen
• Far lateral herniations: discs that herniate beyond the intervertebral foramen

Lateral, foraminal, and far lateral herniations are usually more common than central herniations.⁷Kulkarni AG, Tapashetti S. Outcomes of Discectomy in Young Adults With Large Central Lumbar Disc Herniations Presenting With Predominant Leg Pain. Global Spine J. 2020 Jun;10(4):412-418. doi: 10.1177/2192568219856871. Epub 2019 Jul 9. PMID: 32435560; PMCID: PMC7222677.

Central herniations may affect the spinal cord and lateral recess herniations can affect the spinal cord and/or the spinal nerves. Foraminal and far lateral herniations typically cause nerve root-related symptoms and signs in the leg, such as sciatica. 

All of the above types of herniations may be treated with microdiscectomy.

Amount of Disc Material Removed in Microdiscectomy

The amount of disc material removed in microdiscectomy varies and may range from removing small fragments of the disc to cutting out a significant part of the disc. 

The surrounding bony tissue, such as the lamina, facet joints, or enlarged bone (bone spurs) may be undercut or trimmed to relieve nerve root pressure.

Since almost all the joints, ligaments, and muscles are left intact, a microdiscectomy does not change the mechanical structure of the patient's lower spine (lumbar spine).

Microdiscectomy vs Lumbar Spinal Fusion for Herniated Discs

Microdiscectomy is considered the most common spinal surgery and the one that produces the most reliable outcomes for a lumbar herniated disc.¹²Rajagopal TS, Marshall RW. Microdiscectomy. In: Bentley G, ed. European Surgical Orthopaedics and Traumatology: The EFORT Textbook. Springer; 2014:557-580.

Extensive research indicates that lumbar microdiscectomy may be more effective at improving leg pain, functional disability, and quality of life than other common spine procedures, such as lumbar spinal fusion.¹³Lebow RL, Adogwa O, Parker SL, Sharma A, Cheng J, McGirt MJ. Asymptomatic same-site recurrent disc herniation after lumbar discectomy: results of a prospective longitudinal study with 2-year serial imaging. Spine (Phila Pa 1976). 2011;36(25):2147-2151. doi:10.1097/BRS.0b013e3182054595

In cases where additional stability is needed due to degeneration or trauma, spinal fusion may be performed simultaneously with the microdiscectomy. 

Disc Healing and Recurrent Herniation After Microdiscectomy

Research indicates that 3% to 10% of surgically treated herniated discs may eventually recur. Recurrence of herniation may or may not cause symptoms. Around 10% of people who experience symptoms from a recurred herniation eventually opt for surgery to manage their symptoms.¹³Lebow RL, Adogwa O, Parker SL, Sharma A, Cheng J, McGirt MJ. Asymptomatic same-site recurrent disc herniation after lumbar discectomy: results of a prospective longitudinal study with 2-year serial imaging. Spine (Phila Pa 1976). 2011;36(25):2147-2151. doi:10.1097/BRS.0b013e3182054595

It is essential to have clear and detailed conversations about the type of herniation and the choice of surgical approach, including the risks, benefits and alternatives to surgery. Patients are also encouraged to discuss the healing process and return to activity, which can help them manage their expectations and goals after surgery.