Diagnostic assessment
It is important to assess those presenting with back pain especially if pain is not resolving. While the majority of people presenting to you will have simple mechanical back pain, a minority will have conditions that require urgent referral to secondary care. Therefore:
- Conduct a focussed history and examination to triage patients into the following categories:
- Non-specific low back pain
- LBP associated with radiculopathy or spinal stenosis
- LBP associated with another specific spinal cause
- History-ask questions about the nature of pain including:
- previous episodes, treatments and responses to treatments
- duration and frequency
- Location - people often complain of back pain where the pain is actually located in adjacent structure, eg. the hip
- if there is pain in more than one site, take a separate history of each
- distribution and radiation of pain
- time and nature of onset
- severity
- impact on daily activities
- character and quality of pain
- whether it is aggravated or relieved by certain postures
- whether the pain is inflammatory, characterised by pain that worsens during the second half of the night or on waking
- is associated with morning stiffness of more than 30 minutes duration
- unrelieved by activity
- Assess for features of:
- serious disease and exclude serious pathology (see Red flag presentations)
- sciatica (lumbar radiculopathy) ie. pain, tingling and numbness radiating to below the knee arising from nerve root
- compression in the lumosacral spine accompanied by nonspecific low back pain
- non-specific low back pain which is normally poorly defined with tension, soreness and/or stiffness in the lower backwhere there is no specific cause of the pain and may radiate into the buttocks and upper legs
- Check for psychosocial factors that could be contributing to the problem, including problems with:
- understanding the cause of back pain
- work
- illness behaviour e.g. reluctance to resume physical activity or belief that it will be harmful
- overprotective family
- lack of social support
- workers compensation or other claims
- low mood or depression
- inappropriate expectations for treatment, such as little desire to be an active participant in treatment
- somatisation (exaggerated response to sensations that are perceived as painful and includes hypervigilance)
- validated assessment tool such as the PQ-9D or the Hospital Anxiety and Depression Scale (HADS) may be used to facilitate this process.
- Examination:
The minimum examination that a patient presenting with low back pain should include:
-
- inspect and palpate the back
- examine the range of movement of the spine and the hip joint
- perform a neurological examination checking dermatomal sensation in lower limb, lower limb reflexes, muscle strength associated with each of the lower nerve root levels
- test for flexion, abduction and external rotation of the hip to screen for nerve root tension or hip involvement respectively
- check anal tone and perianal sensation if cauda equina is suspected
NB Reasons why MRI scans are not helpful in this patient group:
- Back pain is usually due to conditions that cannot be diagnosed on imaging and most images do not help routine management of simple back pain
- Imaging is extremely sensitive which increases the number of false positives
- 90% of patients recover spontaneously within 4 weeks following an episode of back pain, scanning can falsely label age related changes on imaging (age older than 30) was the cause of the pain
- Imaging rarely provides information that changes the clinical approach to acute low back pain
- While patients wait for their MRI, they assume there is something serious with them so are unlikely to comply with evidence based self management – keep active, return to work etc. Therefore the early management window of opportunity has been lost. Catastrophization and increase in anxiety and depression becomes problematic and makes pain management complex
Providing a positive finding with an MRI will lead to changes in how patients perceive their pain, they can become more disabled with the pain especially if the scan results are inappropriately conveyed ‘crumbling spine’, ‘disc degeneration’ and are unlikely to embrace rehabilitation in a chronic pain setting