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This page provides general information about the procedure called lumbar microdiscectomy. Your neurosurgeon will discuss your particular procedure with you in detail.

It is intended for use by patients (or their families or carers) referred to our service who may be offered this procedure. It is not intended to replace discussion with your consultant. If you have any questions, please do not hesitate to contact a member of the team caring for you.

You are having your back surgery at Queen Square. This page will give you a brief overview of your procedure and general advice on how to prepare for surgery and discharge. Your procedure requires a short stay in hospital. You will be discharged either on the day of surgery or the next day after your procedure.

If you have existing medical conditions, such as high blood pressure or diabetes, you may like to visit your GP practice to make sure that you are as fit as for your surgery.

Make sure you arrange your domestic and social situation so that it will be possible and comfortable for you to go home at the correct time. For instance: 

  • Arrange for somebody to collect you on discharge
  • Make sure you have shopped for adequate food supplies for when you get home
  • Tidy your house so you do not need to do housework when you get home  
  • Ensure you have a supply of simple pain killers available at home, such as paracetamol
  • If you think you will need some social support after discharge please speak to your GP and let us know as soon as possible.

We will:

  • Arrange a pre-assessment check to make sure you are fit for an anaesthetic
  • Organise appropriate scans or x-rays for your operation if necessary
  • Write to you to let you know when your operation will be
  • Answer any questions you may have about your operation

A lumbar microdiscectomy is a spinal surgical procedure to remove part of a slipped (prolapsed) disc which is compressing a nerve root (the point at which the nerve leaves the spine). The disc is soft and spongy and separates the bones of the spine (vertebrae). The disc makes the spine more flexible and acts as a ‘shock-absorber’.

Sometimes, part of this disc slips out and presses on a nerve root. This may be the result of several years of ‘wear and tear’, or an injury. The lower back (or lumbar area) is a common site for this to occur.

The aim of surgery is to free up (decompress) the nerve root. There is a very high chance (over 90 percent) that leg pain or sciatica caused by nerve root compression (radiculopathy) will improve after surgery.

If you have back pain it may improve, but this is less likely. If you have symptoms of power or sensory (feeling) loss due to disc herniation, there is a chance that this operation may help. This will depend on how long the nerve root has been affected.

All treatments and procedures carry risks and we will talk to you about all the risks and benefits of a lumbar microdiscectomy. Your consultant will explain the risks to you in detail. The procedure is performed under a general anaesthetic and your anaesthetist will talk to you about the risks of general anaesthesia.

Female patients must tell their anaesthetist and surgeon if they are or could be pregnant. Anaesthetic drugs and x-rays used during the procedure can be harmful to unborn babies.

Problems that may happen straight away

There is a small risk (one percent) of nerve root injury resulting in loss of leg power and sensation, loss of bladder, bowel or sexual function or pain.

  • Leakage of cerebrospinal fluid (risk of two to five percent) which surrounds the brain and spinal cord can also occur.
  • There is a small risk of a blood clot developing around the nerve roots resulting in a serious neurological problem. If this happens you would need an urgent operation to remove the blood clot.

Problems that may happen later

  • The surgeon will only remove those parts of the prolapsed disc which are pressing on the nerve root, not the whole disc. Some of the remaining disc tissue may become displaced in the future causing a recurrence of your symptoms.
  • Infection can develop in the skin wound or deeper in the disc space - this is called discitis. We minimise this risk by giving a dose of an antibiotic at the start of the anaesthetic. We will ask you to keep the wound clean and dry.
  • Scar tissue may develop around the decompressed nerve root resulting in pain or changes in the feeling in your leg.

Problems that are rare, but serious

  • Very rarely, injury to a major blood vessel may occur when the prolapsed disc is being removed.
  • Instability of the spine can occasionally occur caused by the removal of bone. If this happens you will require further treatment or surgery.

Sometimes the ‘slipped’ part of the disc shrinks back, so there is a chance that your leg pain may get better by itself. This becomes less likely after a longer period of symptoms.

Problems with power or sensory loss, passing urine or controlling your bowels are unlikely to improve without surgical intervention.

Your surgeon will discuss all alternative treatments and their risks and benefits with you.

Alternative treatments include:

  • Physiotherapy. Physiotherapists can give advice about exercises to strengthen the muscles of the spine and improve posture.
  • Nerve root injection for radiculopathy can be done as a day-case procedure. However, this may offer only temporary relief of symptoms.
  • Pain-relieving medicines. Consult your pharmacist or GP about the safety and suitability of these medicines. Your GP may prescribe stronger pain-relieving medicines but these may have other side-effects such as constipation.

We want to involve you in all the decisions about your care and treatment. If you decide to go ahead with treatment, by law we must ask for your consent and will ask you to sign a consent form. This confirms that you agree to have the procedure and understand what it involves, including the risks.

Staff will explain all the benefits, risks and alternatives before they ask you to sign a consent form. If you are unsure about any aspect of your proposed treatment, please don’t hesitate to speak with a senior member of staff again.

Before going to the operating theatre the nurse will complete a pre-operative checklist and give you a gown and elastic stockings to wear. A surgeon will place a mark on your skin to indicate the site of your operation. A member of the operating team will confirm your details. This is a safety check to confirm your identity and what operation you are having.

Once the anaesthetic is started and you are ‘asleep’ you will be moved to the operating theatre. The surgeon will make a small incision (cut) of about two inches (five centimetres) on your lower back. The muscles are pulled away from the bone on the side of the herniated disc. A small part of the bone is removed (lumbar fenestration) to allow the surgeon to reach the disc space. If necessary, another X-ray will be taken at this stage.

The nerve root is identified and carefully moved to one side to reveal the herniated disc. The surgeon will then carefully cut away fragments of disc until the nerve root is no longer being compressed. The muscles are sewn up with dissolvable stitches and the skin wound is closed using metal clips or dissolvable stitches. The operation takes approximately two hours.

After surgery you will go to the recovery ward for a short period of observation before going back to the ward.

  • You can mobilise out of bed later that day. A nurse or nursing assistant will help you until you feel steady on your own.  
  • You will be given regular pain-relieving medicine. Please tell your nurse if this is not effective so we can give you more or have you reviewed by the doctor. Good pain relief is important to your recovery.
  • Routinely no physiotherapy will be required. Ward staff will provide information as required.
  • We expect that you will be well enough to go home the following day.
  • Most people feel the improvement in their leg pain immediately after the operation. Others feel the benefits after a few weeks. In a minority of patients, the pain does not go away despite adequate decompression. Before going home, you will be given an information booklet concerning your wound care. It is important to know how to care for your wound so please do not hesitate to ask any questions you may have.

It is normal to experience some mild wound soreness for the first week. Taking simple painkillers such as paracetamol regularly at the recommended dose can help. You will need to take care of your back and this includes knowing how to lift correctly. We may ask a physiotherapist to see you to give advice.

You may find that sitting down is the least comfortable position. If you start to feel uncomfortable, try walking around, lying or standing for a few minutes. It is normal to feel tired for a couple of weeks after an operation. Try to do a little activity often instead of trying to do too much at once. Depending on the type of work you do, you may need to take four to six weeks off work. You should discuss when you can go back to work with your surgeon or physiotherapist before you leave hospital.

You may drive when you feel comfortable and can operate the controls safely. We will make a follow up appointment approximately six weeks after your operation. You will be notified by a letter in the post.

If your wound becomes red, very painful or throbbing, swollen or leaks blood or fluid, then you should seek medical advice straight away. You can contact your Consultant or the Spinal Nurse Specialist via their secretary (during working hours). The ward, your GP or your local Accident and Emergency Department can give you help or information at other times.

You may find the following websites helpful:

  • www.spinesurgeons.ac.uk
  • www.brainandspine.org.uk
  • www.spine-health.com
  • www.spineuniverse.com
  • www.back.com
  • www.patient.co.uk

UCLH cannot accept responsibility for information provided by other organisations.

Victor Horsley Neurosurgical Department
National Hospital for Neurology and Neurosurgery
Queen Square
London WC1N 3BG

Switchboard: 0845 155 5000 / 020 3456 7890
Direct line: 020 3448 3568 / 3150 / 3395/ 3514
Fax: 0203 448 3340


Page last updated: 28 May 2024

Review due: 30 June 2025