Introduction
Low back pain is an extremely common problem that is often poorly managed. Back pain is a particular challenge because it is so common, demanding of medical resources and a major cause of physical, psychological and social disability. Most back pain is simple and self-limiting but it is important to recognise that which is not.
The aims of back pain assessment are:
– To recognise serious pathology
– To relieve pain
– To improve function
– To recognise and assess level of disability
– To identify barriers to recovery
– To prevent recurrence or persistence of symptoms
Most backache (85-90%) will be so-called simple low back pain (or ‘mechanical low back pain’) in which the symptoms by definition cannot be ascribed to a particular pathology (infection, tumour, osteoporosis, fracture, radicular syndrome, cauda equina syndrome (CES)). Simple low backache is also called uncomplicated or nonspecific low back pain and will vary with posture, activity, time and treatment.
Radicular (or nerve root pain) may occur with low back pain. Sciatica is a lay term for pain extending into the leg (buttock, thigh, calf or heel).
The classification into acute (less than 6 weeks), subacute (6-12 weeks) and chronic (more than 12 weeks) has been used in research but is less useful clinically because of the variable and recurrent nature of symptoms.
Recurrent low back pain has been defined as a new episode of pain after a symptom-free period of 6 months.
Epidemiology
Back pain is extremely common. 60-80% of people in the UK report back pain at some time in their lives.
Low back pain has an estimated lifetime prevalence of 84% worldwide. The worldwide prevalence of chronic low back pain is about 23%.
Simple back pain tends to affect those between 30 and 60 years of age, starting between 30 and 50. First onset outside this range should arouse suspicion of a sinister cause.
Back pain is second only to the common cold as a cause of lost days at work. In 2005 the Trades Union Congress (TUC) estimated that 4.9 million working days per year are lost due to back pain. Research by the British Chiropractic Association found that 48% of people in Britain suffer from back or neck pain at any one time, possibly associated with spending an increasing amount of time seated at office desks.
Highly demanding jobs, prolonged standing and awkward lifting are the most consistent factors predisposing to low back pain. A systematic review did not identify occupational carrying as an independent risk factor.Psychosocial work-related stress is an associated factor. Genetics may play a part. Smoking and obesity increase risk.
Presentation
History should include:
– Establishing when the pain started.
– Confirming whether pain was sudden or gradual in onset.
– Identifying the location of the pain.
– Enquiring whether there is pain radiation to anywhere else.
– Establishing whether there are aggravating or relieving factors.
– Confirming whether the patient has had this problem previously.
– Noting the patient’s occupation, what it involves and hobbies or sport.
– Asking the patient to confirm what they think caused the pain.
– Noting past medical history. Steroid use predisposes to osteoporosis. Establish whether there has been malignancy that metastasises to bone (lung, breast, prostate, thyroid, kidney) or myeloma.
– Asking the patient to confirm how they have been managing the condition. This includes analgesics taken, whether they have been adequate and the patient’s attitude to the condition.
Red flags from history
Red flags for possible serious spinal pathology from the history are:
– Recent violent trauma (such as a vehicle accident or a fall from a height)
– Minor trauma, or even just strenuous lifting, in people with osteoporosis
– Age at onset less than 20 or over 50 years (new back pain)
History of:
– Cancer
– Drug abuse
– HIV
– Immunosuppression
– Prolonged use of corticosteroids
– Constitutional symptoms – eg, fever, chills, unexplained weight loss
– Recent bacterial infection – eg, urinary tract infection
Pain that is:
– Worse when supine
– Severe at nighttime
– Thoracic
– Constant and progressive
– Non-mechanical without relief from bed rest or postural modification
– Unchanged despite treatment for 2-4 weeks
– Accompanied by severe morning stiffness (rheumatoid arthritis and ankylosing spondylitis)
– Severe and leaves patients unable to walk or self-care
– Accompanied by saddle anaesthesia or recent onset of difficulty with bladder or bowels
Examination
A brief examination for acute back pain is recommended with the patient undressed, revealing the spine and standing.
The brief examination should incorporate: inspection, palpation, brief neurological examination and an assessment of function.
More detailed neurological examination will be necessary if the history suggests any red flags – eg, confirming saddle anaesthesia and diminished anal tone if CES is suspected.
Passive straight leg raising is often used to assist diagnosis of nerve root pain. A Cochrane review of 16 cohort studies found that it was highly sensitive but specificity varied widely.[10]
Red flags from examination
– Structural deformity
– Severe or progressive neurological deficit in the lower extremities
– Unexpected laxity of the anal sphincter
– Perianal/perineal sensory loss
– Major motor weakness: knee extension, ankle plantar eversion, foot dorsiflexion
CES should be suspected if there is:
– Bladder dysfunction (usually retention, sometimes overflow)
– Sphincter disturbance
– Saddle anaesthesia
– Lower limb weakness
– Gait disturbance
Differential diagnosis
Red flags may suggest spinal fracture, cancer, infection or serious pathology associated with a prolapsed intervertebral disc.
Other causes of back pain include:
– Primary malignancy:
– Reticulo-endothelial system (myeloma is the most likely)
– Carcinoma of pancreas
– Osteosarcoma (this does not usually affect the spine)
Secondary cancers are usually from:
– Bronchus
– Breast
– Prostate
– Thyroid
– Kidney
Bone disorders including:
– Paget’s disease of bone (affects the pelvis in 72% of cases and the lumbar spine in 58%)
– Osteoporosis (leading to vertebral collapse)
– Spinal stenosis
– Inflammatory disease – for example:
Ankylosing spondylitis which tends to present:
– Slowly in men under the age of 40 years with a rigid back
– With aggravation by inactivity and relief with exercise
Psoriatic arthritis (rash or a family history of psoriasis)
– Reiter’s syndrome (symptoms including urethritis)
– Arthritis associated with inflammatory bowel disease (usually arthritis is peripheral)
Infection:
– Never forget tuberculosis (osteomyelitis can occur)
– HIV predisposes to infections (including tuberculosis)
– Renal tract infection (pyelonephritis can also cause referred back pain)
Causes from outside the spinal column include:
– Dissecting aortic aneurysm
– A posterior duodenal ulcer presenting as back pain, which may be difficult to diagnose. If a gastric ulcer presents for the first time over the age of 40 years, malignancy needs to be excluded.
– Nephrolithiasis
– Pyelonephritis
Traditionally, factors suggesting malignancy have included age greater than or equal to 50 years, previous history of cancer, duration of pain greater than one month, failure to improve with conservative therapy, elevated ESR and anaemia. However, a Cochrane review has sounded a note of caution with respect to interpreting individual ‘red flags’. Further research on the reliability of combinations of features are recommended.
Investigations
Note: if the diagnosis would appear to be simple back pain then no investigation is required.
If other diagnoses are entertained, appropriate investigations are in order, depending upon the suspicion.
Diagnostic imaging
This is indicated only if serious or specific pathology is likely – eg, red flags
– Plain X-ray of the lumbar spine:
– Provides the same dose of radiation as around 120 chest X-rays and, in return, offers very limited information and rarely affects management.
– Should not be used routinely. One study found that in patients with no features of serious underlying disease, early radiology made no difference to the outcome. Imaging may be appropriate in the following circumstances:
– If fracture is suspected, X-ray is of value.
– With metastatic carcinoma.Those from prostate are sclerotic, those from lung, thyroid and kidney are osteolytic and those from breast may be either. Lesions below 2 cm in diameter may not be seen on plain X-ray but a scintillation scan with technetium 99m Tc is much more sensitive.
– Collapse from osteoporosis or myeloma may be seen.
– Paget’s disease of bone may be seen.
– CT scans often show stress fractures and spondylolisthesis best.
MRI:
– Gives a good picture of soft tissues, including discs and anything impinging on nerves or the spinal cord.
– Disc lesions are best displayed by MRI scans. MRI is the most useful investigation in nerve root compression, discitis and suspected neoplastic disease.
Blood and urine tests
– FBC, ESR, CRP, urine analysis if cancer, infection or inflammation is suspected.
– LFTs may be helpful. Alkaline phosphatase can be elevated in metastatic disease and Paget’s disease of bone.
– PSA will be raised particularly in carcinoma of the prostate.
– Urinary hydroxyproline will be markedly elevated (with increased bone turnover) in Paget’s disease of bone.
– Nephrolithiasis may produce red cells in the urine.
Other investigations
A wide variety of further investigations may be required when other pathologies are suspected. For example:
– CXR may show primary or secondary carcinoma or pulmonary tuberculosis.
– Ultrasound will show renal stones and is the best way to visualise the pancreas. It can also give a good picture of an aneurysm allowing it to be measured accurately and to detect possible dissection.
– Endoscopy may confirm a posterior ulcer and allow tests for Helicobacter pylori infection or malignancy.
Management
Doctors and patients can use Decision Aids together to help choose the best course of action to take.
In 1994 the Clinical Standards Advisory Group (CSAG) published a report that radically changed teaching and practice.[16] Until then, rest – perhaps with a board under the bed – was recommended for back pain. The new guidelines recommended active rehabilitation. The new principles of management involve keeping the patient active and giving analgesia to facilitate this. Now only in exceptional cases is rest allowed and then for no longer than 48 hours.
The basics of management
Recognition of those causes of back pain that are a cause for concern and taking appropriate action (red flags)
Planning a simple route for recovery with the patient, being positive and reassuring
Recognising and addressing any factors that may mitigate against a swift recovery, including negative attitudes and even compensation neurosis (yellow flags)
Relief of pain
Addressing issues that may predispose to further episodes, including poor practice at work or poor ergonomics
Management of simple low back pain
Give information, reassurance and advice.
DO NOT prescribe bed rest.
Advise the patient to stay as active as possible.
Prescribe regular pain relief (paracetamol, non-steroidal anti-inflammatory drugs) and consider a short course of muscle relaxants.
Management of suspected serious pathology or red flags
If a red flag has shown, appropriate action must be taken. This will mean referral for investigation and for treatment. In the case of CES, for example, urgent referral to a neurosurgeon or specialist orthopaedic surgeon is required.
Management of chronic pain, psychosocial factors and yellow flags
Patients may, quite reasonably, assume that pain is a warning sign that tells us that if something hurts we should not do it. Very often this is true but with back pain it is necessary to work through the pain and to overcome it. There may well be psychosocial barriers to active rehabilitation with prolongation and chronicity as risks. These are called yellow flags. They include:
– Belief that pain and activity are harmful
– Sickness behaviours, such as extended rest
– Social withdrawal
– Emotional problems such as low or negative mood, depression, anxiety and stress
– Problems and/or dissatisfaction at work
– Problems with claims or compensation, or time off work
– Overprotective family; lack of support
– Inappropriate expectations of treatment, including low expectations of active participation in treatment
Although there has been some doubt about the value of this approach, the overall evidence suggests that targeting yellow flags, particularly when they are at high levels, does seem to lead to positive results.
Discuss work and predisposing factors for back pain.
– If heavy lifting is involved, establish whether there was an induction course when techniques were taught.
– Often it is not so much the weight but a large, awkward package that causes injury.
– Seating and posture are often more important nowadays:
– Consider desks, chairs, computer screens and keyboards at work.
– Look at time spent in the car and how comfortable it is and adjustment of the seat and steering wheel.
– Fork lift trucks and large goods vehicles may transmit vibration all day.
– Discuss getting back to work.
– Discuss what improvements may be made to the workplace to reduce the risk of recurrence.
– Give the patient a positive attitude and enthusiasm to recover.
Not everyone finds that those in authority at work are sympathetic or wish to make the environment safer but where work is supportive, the prognosis is better.
Remember, when assessing whether to refer, that motor deficits and bowel or bladder disturbances are more reliable than sensory signs.
If red flags suggest a serious condition, refer with appropriate urgency. This means immediately for CES.
If there is progressive, persistent or severe neurological deficit, refer for neurosurgical or orthopaedic assessment, preferably to be seen within one week.
If pain or disability remain problematic for more than a week or two, consider early referral for physiotherapy or other physical therapy.
If, after six weeks, sciatica is still disabling and distressing, refer for neurosurgical or orthopaedic assessment, preferably to be seen within three weeks.
If pain or disability continue to be a problem despite appropriate pharmacotherapy and physical therapy, consider referral to a multidisciplinary back pain service or a chronic pain clinic.
Summary of referral guidance
These can also still be thought of usefully as ‘immediate’, ‘urgent’ and ‘soon’ referrals:
Immediately:
CES
Urgently:
Serious spinal pathology suspected
Progressive neurological deficit
Nerve root pain not resolving after six weeks
Soon:
Inflammatory conditions suspected – eg, ankylosing spondylitis
Simple back pain and not resuming normal activities after 2-3 months
Physical, cognitive and behavioural therapies
A Cochrane review – albeit of a small number of trials – found spinal manipulation to be no better than other therapies. However, a study of men and women aged between 18 and 35 years with acute back pain found that chiropractic manipulative therapy in conjunction with standard GP care afforded significant advantages in decreasing pain and improving physical functioning compared to standard care alone. A systematic review of osteopathy for the treatment of chronic low back pain was inconclusive and recommended more research. Manipulation and acupuncture are each discussed in the separate article Complementary and Alternative Medicine. A systematic review of acupuncture found some evidence of benefit but further trials are needed. Traction is not recommended.
The evidence base for the value of physiotherapy per se is surprisingly small. However, recent evidence suggests that its effectiveness can be increased when used in conjunction with a validated tool such as the STarT Back screening tool developed at Keele University. This allocates patients to different treatment pathways based on their prognosis (low, medium, or high risk of poor outcome) and is designed for ease of use in primary care.
It is important to be active and positive to prevent back pain from becoming chronic. If it does, cognitive and behavioural therapy with relaxation therapy may be helpful. A Cochrane review reported that no type of behavioural therapy is better than any other. There may also be benefit from ‘back schools’ and from exercise therapy.
Neither motor control exercises (designed to improve control and co-ordination of trunk muscles) or graded activity (individually tailored exercises that target specific weak and dysfunctional muscles) are better than any other form of exercise therapy.
Evidence to support the use of peripheral nerve-field stimulation for the management of chronic back pain is limited. The National Institute for Health and Care Excellence (NICE) recommends that any clinician using this treatment should explain the risks and benefits to individual patients, inform the clinical governance lead of their trust and register the patient’s details with the UK Neuromodulation Register.
Complications
Acute back pain may become chronic. This may be because of failure of active management or behaviour by the patient that predisposes to chronicity rather than cure. Targeted care as described above, with the early recognition and management of yellow flags and the use of a validated tool to tailor management to prognosis, may help to minimise the risk of chronicity.
Failure to diagnose CES and to take immediate action may lead to long-term neurological damage.
Other sinister causes of back pain may have a fatal outcome. The prognosis may be improved by early and effective intervention.
Prognosis
This will depend entirely on the diagnosis. Generally for simple low back pain, if chronicity can be prevented, then recovery should be full but in a variable time. Back pain in old age probably is, as many assume, simply a feature of advancing years. Analgesics may help but it is most important to stay active.
A systematic review found that the majority of patients with acute or persistent low back pain improved within six weeks. Improvement slowed after that time and a minority of patients still had pain and disability after one year.[36]
Prevention
The prevention of back pain in the workplace depends on the nature of the work and reference has already been made to the increasing number of office-based rather than manual workers suffering from the condition. There are European guidelines for the prevention of low back pain. These were published in 2004 and there has been surprisingly little in the literature since with respect to primary prevention. There is no evidence for the effectiveness of lumbar supports or education and limited evidence for the efficacy of exercise.
Much more work has been done on secondary prevention, addressing physical and psychosocial issues, once an episode of back pain has occurred.
Further reading & references
Back Pain; Health amd Safety Executive
Hill JC, Whitehurst DG, Lewis M, et al; Comparison of stratified primary care management for low back pain with current best practice (STarT Back): a randomised controlled trial. Lancet. 2011 Oct 29;378(9802):1560-71. doi: 10.1016/S0140-6736(11)60937-9. Epub 2011 Sep 28.
Sanders T, Foster NE, Bishop A, et al; Biopsychosocial care and the physiotherapy encounter: physiotherapists’ accounts of back pain consultations. BMC Musculoskelet Disord. 2013 Feb 19;14:65. doi: 10.1186/1471-2474-14-65.