Lumbar discectomy: when it is offered, what happens and recovery

The discs of the spine are soft cushions of tissue between the bones. The NHS describes a slipped disc, also called a prolapsed or herniated disc, as one that bulges outwards and can be painful if it presses on a nerve. When this happens in the lower (lumbar) spine, the pressure on a nerve root can cause pain, tingling, numbness or weakness that travels down the leg, which is the pattern known as sciatica.

A lumbar discectomy is the operation that removes the part of the disc pressing on the nerve. A leaflet from Norfolk and Norwich University Hospital explains that in a micro-discectomy it is the protruding part of the disc, and any fragments pressing on the nerve root, that are removed rather than the whole disc. It is done through a small incision at the back of the spine, under general anaesthetic, and the incision is closed with dissolvable stitches and a small dressing.

The Oswestry hospital leaflet describes discectomy as one of the commonest operations performed on the lower back and stresses its purpose. It is directed at leg pain caused by a compressed nerve. It is not designed to cure low back pain, which is a point worth understanding before deciding whether the operation is right for you.

The NHS lists lower back pain, numbness or tingling in the arms, hands, legs or feet, muscle weakness and pain in the buttocks, hips or legs among the possible symptoms of a slipped disc. It also points out that not all slipped discs cause symptoms, and many people never know they have had one.

Most back and leg pain from a disc improves slowly with time, gentle activity and painkillers. Some features, however, need prompt attention. According to the NHS, you should call 999 or go to A&E if you have back pain together with numbness around your bottom or genitals, you cannot pee, you lose feeling in one or both legs, you cannot control when you pee or poo, or it started after a serious accident such as a car crash. Do not drive yourself; ask someone else to drive you or call an ambulance.

The NHS adds that you should see a GP if you have back pain and painkillers are not helping, the pain is not improving after a few weeks, you have a very high temperature or feel hot, cold or shivery, you have unexplained weight loss, a swelling in your back, or the pain is worse at night.

• Numbness around the bottom or genitals, difficulty peeing or loss of bladder or bowel control: 999 or A&E.

• Loss of feeling in one or both legs, or worsening weakness: 999 or A&E, or urgent medical review.

• Pain not improving after a few weeks, or not controlled by painkillers: see a GP.

• Fever, unexplained weight loss, a swelling in the back or night-time pain: see a GP.

The NHS says a slipped disc can happen because of ageing, exercising too hard, lifting heavy objects the wrong way, sitting or driving for long periods, or being inactive or overweight. It also notes that nicotine weakens the disc tissue in the spine, which is one reason stopping smoking is part of its prevention advice.

Diagnosis usually begins with your symptoms. The NHS says a slipped disc can usually be diagnosed from the symptoms, sometimes with a physical examination in which you may be asked to raise your arms or do simple leg exercises to locate the problem. If symptoms do not get better, you may be referred for further tests such as an MRI scan. The Oswestry leaflet says an MRI scan will have confirmed nerve compression in the lower back before a discectomy is planned.

For most people the first approach is non-surgical. The NHS recommends keeping active, with gentle exercise such as walking, swimming or yoga as soon as possible, and taking anti-inflammatory painkillers such as ibuprofen regularly if they are suitable for you; a pharmacist can advise. Stronger painkillers containing codeine can help for pain that has just started but can cause addiction and should only be used for a few days.

If that is not enough, a GP may prescribe a stronger painkiller, a steroid injection or a muscle relaxant for short-term use, and you may need physiotherapy. The NHS notes that in many areas you can refer yourself to NHS community musculoskeletal (MSK) services without seeing a GP, that NHS physiotherapy is not available everywhere and waiting times can be long, and that physiotherapy can also be obtained privately.

The reason most people go on to surgery is that leg pain has remained significantly troubling after non-surgical treatment. The Oswestry leaflet describes it as a joint decision between you and the surgeon, made when the possible rewards of the operation outweigh the small risks.

Before the operation you will usually attend a pre-admission assessment. The Norwich leaflet says this takes place 1 to 6 weeks beforehand and may include blood tests, a heart tracing (ECG) and a chest X-ray. The operation itself is done under general anaesthetic, and the same leaflet says many people are admitted and discharged on the day of surgery, with someone needed to drive them home and stay with them for at least 24 hours. The Oswestry leaflet says you may go home the same day with your consultant's approval, otherwise it is likely to be the next day.

A small drain tube may be left in the wound for around 24 hours, according to the Oswestry leaflet, and patients are normally walking the day after surgery. Wounds usually take about 2 weeks to heal, while muscles and bone take around 6 weeks, and lifting and bending should be avoided for at least 6 weeks.

Both leaflets describe the risks as small but real. The Norwich leaflet lists wound infection, blood clots in the legs, other infection, a leak of the fluid that surrounds the nerves, injury to nerves as they leave the spine and worsening back pain. The Oswestry leaflet says the fluid-filled sac around the nerves may tear during surgery in 4 to 5 in 100 first-time operations; if so, it may need repair and you may be asked to lie flat for 1 to 2 days, and rarely a second operation is needed. It also sets out the general risks of a general anaesthetic, ranging from common temporary effects such as bruising or sickness to very rare serious complications.

On results, the Oswestry leaflet says it is reasonable to say that 80 to 90% of people who have a discectomy are satisfied with the relief of leg pain. Tingling often settles. Numbness or weakness is harder to predict: the leaflet puts the chance of recovery at 6 in 10, with equal chances whether or not surgery is done, and says improvement may continue for up to two years. It also cautions that some minor residual symptoms are not uncommon and that results cannot be guaranteed.

After going home, the Norwich leaflet tells people to contact the spine team if they notice constant pain that is getting worse, new or worsening numbness, new or worsening muscle weakness, a change in bladder function, or dressings repeatedly soaked with blood.

On the NHS the route usually runs from a GP or MSK service, through a trial of physiotherapy and medicines, to an MRI scan and a referral to a spinal surgeon if surgery is being considered. Waiting times for physiotherapy and for surgery can be long in some areas.

Some people choose to see a private spinal surgeon or pay for physiotherapy to shorten waiting. The operation and the tests are the same in principle; what differs in practice is access and choice of consultant and hospital. Whichever route you use, it is reasonable to ask how many of these operations the surgeon performs, what outcomes the unit records, who to contact after discharge and what the plan is if symptoms return.