Next Lesson - Conditions of the Back and Neck
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Want more information on anatomy before you begin looking at conditions? Head to our article on The Spine for more information!
Spondylosis is the term used to describe chronic degenerative changes of the spine, including degeneration of the intervertebral discs and osteoarthritis of the facet joints (the small joints between neighbouring vertebrae). It most commonly affects the lumbar or cervical spine. It is usually caused by disc degeneration and marginal osteophytosis (bony spurs developing adjacent to the end plates of the disc, the layers of cartilage and bone at the top and bottom of each disc).
It can present with radiculopathy (a problem with a spinal nerve root) causing dermatome (the area of skin supplied by one nerve root) and myotome (the group of muscles supplied by one nerve root) symptoms. X-ray, MRI and CT scans can show the changes, but no scan gives the diagnosis on its own: the findings are read together with the history and examination. NICE advises against routine imaging for low back pain, and says to consider it in specialist settings only if the result is likely to change management. Treatment is conservative (non-surgical) and focuses on lifestyle modifications, pain management and physiotherapy.
Image - An X-ray showing the lateral view of lumbar spine spondylosis
Creative commons source by Nevit Dilmen and annotated by Mikael Häggström, M.D [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Spondylolisthesis is the anterior (forward) displacement of the upper vertebra on the lower vertebra. In degenerative disease it is typically seen at L4/5 (the 4th lumbar vertebra on the 5th), and it can also occur at L5/S1 (the 5th lumbar vertebra on the sacrum). Causes are divided into five categories: congenital/dysplastic (abnormal development of the vertebra from birth), isthmic (a defect in the pars interarticularis, the narrow bridge of bone between the facet joints of a vertebra), degenerative (wear and tear), traumatic (injury) and pathological (bone weakened by disease, such as a tumour).
It can be asymptomatic (without symptoms), but may present with lower back pain, sciatica and/or neurogenic claudication (leg pain or paraesthesia, meaning pins and needles or numbness, caused by compression of the nerves, that comes on when standing or walking and is relieved by sitting or bending forward). Diagnosis is usually confirmed with a standing X-ray, which demonstrates the vertebral displacement. Clinical examination may reveal signs of nerve root irritation if there is associated neural compression.
Treatment depends on severity, but often starts with rest, painkillers and physiotherapy. If very severe, surgery can be recommended to fuse the slipped vertebra to the adjacent vertebra using metal screws and rods.
Image - An X-ray of Spondylolisthesis
Creative commons source by Jojo [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Mechanical back pain is an extremely common condition. It is also called non-specific low back pain, because no specific cause such as cancer, infection, trauma or inflammatory disease has been found. The pain may come from the spinal joints, the intervertebral discs, the vertebrae themselves or the surrounding soft tissues (like ligaments or muscles). The pain comes on when the spine is loaded (put under physical strain), gets worse with activity and eases with rest. Risk factors for mechanical back pain include: being overweight or obese, physical inactivity (a sedentary lifestyle), work that involves heavy lifting, bending or twisting, and stress or depression. Management involves reassurance, advice to keep active and lifestyle modifications, and pain management. Pain relief is commonly an oral NSAID (non-steroidal anti-inflammatory drug, such as ibuprofen) at the lowest effective dose for the shortest time, if it is suitable for the patient. Paracetamol on its own is not recommended. A group exercise programme may be offered. Manual therapy (such as spinal manipulation or massage) may be considered, but only as part of a package that includes exercise.
Sciatica is pain/paraesthesia caused by compression of the sciatic nerve or by one or more of the contributing spinal nerves (L4-S3). It usually presents with pain in the buttock that radiates down one leg. There may also be lower back pain, but this is usually less severe than the leg pain. The leg pain follows one or more of the following dermatomes (areas of skin supplied by one nerve root):
- L4: Anterior thigh and knee, and medial leg
- L5: Lateral thigh and leg, and dorsum (top) of the foot
- S1: Posterior thigh and leg, and sole of the foot
Sciatica usually gets better on its own within a few weeks to a few months, but it can last longer and it often comes back. Everyone with sciatica should be advised to keep active and carry on with normal activities as far as possible.
If symptoms are severe or persistent, the GP may suggest exercises and stretches, discuss painkillers and refer to physiotherapy. NICE advises against gabapentinoids (nerve pain medicines such as gabapentin and pregabalin), other antiepileptic drugs, oral corticosteroids (steroid tablets) and benzodiazepines (sedatives) for sciatica, because there is no overall evidence of benefit and there is evidence of harm. It also advises against opioids (morphine-like painkillers) for chronic sciatica, and says the evidence of benefit from NSAIDs is limited. If the pain is severe and other treatments have not helped, a specialist may offer an epidural injection (of local anaesthetic and steroid) or spinal decompression surgery (an operation to take pressure off the nerve).
Sciatica on both sides, numbness around the genitals or anus, or new problems passing urine or controlling the bowels are red flags for cauda equina syndrome and need emergency assessment.
Image - The distribution of pain/paraesthesia in sciatica
Creative commons source by BruceBlaus [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Cauda equina syndrome is an absolute emergency and involves the compression of the cauda equina (a bundle of spinal nerves at the base of the spine), most often due to a large prolapse (the disc bulging out of place) of a lumbar disc. Rarer causes include a tumour, infection, trauma and a haematoma (a collection of blood) pressing on the spinal canal. It presents with bilateral sciatica, perianal numbness, painless retention of urine, faecal incontinence and/or erectile dysfunction.
Diagnosis is confirmed by a CT or MRI scan. Urgent surgical decompression (an operation to take the pressure off the nerves) is needed as soon as possible after the MRI scan, and within 24 hours of the scan even when the patient already has painless retention of urine. Delay can lead to permanent loss of bladder, bowel and sexual function and to paralysis of the legs.
Diagram - The bundle of lumbar and sacral nerve roots that is compressed in cauda equina syndrome. The arrow points to the cauda equina
Creative commons source by Henry Gray [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Disc herniation (also known as a slipped disc) is divided into 4 stages:
- Disc degeneration - intervertebral discs dehydrate and bulge, decreasing disc height and altering load stresses on the joint.
- Disc protrusion - localised displacement of disc material beyond the disc space, with its greatest dimension smaller than the width of its base, measured in the same plane. Protrusion describes shape, not whether the material remains contained by the annulus (the tough outer ring of the disc).
- Disc extrusion - displaced disc material extends beyond the disc space and, in at least one plane, has a dimension greater than the width of its base in that plane, or has lost continuity with the parent disc.
- Disc sequestration - an extrusion in which the displaced disc material has completely lost continuity with the parent disc. Entry into the spinal canal alone does not establish sequestration.
Disc herniation most commonly occurs at L4/5 or L5/S1. The most common type of herniation is a para-central prolapse, meaning that the disc prolapse is off-centre (96% of cases). It can also be a central prolapse or a lateral prolapse. Disc herniation commonly presents with unilateral back pain and paraesthesia that radiates into dermatomes supplied by the affected nerve roots.
Imaging is not routinely needed to diagnose a disc herniation, and NICE says to consider it in specialist settings only if the result is likely to change management. When it is needed, MRI is the most sensitive test, with CT used if MRI is contraindicated. Plain X-rays do not show disc herniation but may be used to assess alternative causes of back pain. Treatment is pain management, physiotherapy and weight control. An epidural injection (of local anaesthetic and steroid) can be considered for acute, severe sciatica. Spinal decompression surgery (an operation to take pressure off the nerve) can be considered if non-surgical treatment has not improved pain or function and the scan findings match the symptoms.
Image - An MRI of a L4/L5 disc herniation
Creative commons source by Edave [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Infections of the spine include: vertebral osteomyelitis (infection of the bone), discitis (infection of the disc) and epidural abscesses (collections of pus in the epidural space, which lies just outside the membranes covering the spinal cord). They are most commonly caused by haematogenous spread (via the blood) of an infection from another location. They can also be due to direct inoculation (bacteria introduced straight into the spine) during an invasive spinal procedure (e.g. spinal surgery, an epidural catheter or a lumbar puncture) or via spread from adjacent soft tissues. They can present with neurological damage as well as systemic (whole-body) symptoms such as fever (pyrexia). Fever is not always present: the classic triad of fever, back pain and neurological symptoms is seen in only about 10% of cases of epidural abscess.
Treatment includes IV antibiotics and in severe cases surgical intervention may be required.
Reviewed by: Dr. Thomas Burnell and Dr. Marcus Judge
Edited by: Dr. Maddie Swannack
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