The Back Pain Triage And Newer Concepts In Management Of Spinal Disorders
Back pain is a common problem encountered in general practice. It has been described as a medical disaster of 21 st century. International studies show that 17-31% of people report some back pain on the day of interview, 19-43% report back pain in the last one month and 60-70% report back pain at some time in their life. In India, booming economic growth is leading to changes in lifestyle patterns, stress of rapid urbanization and change in perception and demands of the population. There is going to be an epidemic of back pain in the years to come.
The challenge in management of back pain is reaching an exact clinical diagnosis. A good history and thorough clinical examination is necessary to reach a diagnosis and this also helps in developing a rapport with patients. However we can reach a definitive pathological diagnosis in only 15% of patients. Patients demand diagnosis, but as practitioners we need to be honest. A simple triage aids in sorting patients into three groups.
- Simple back pain
- Nerve root pain
- Serious spinal pathology
This simple triage helps in management of patients with back pain. Medical textbooks usually give a long list of differential diagnosis of back pain. Most of these conditions are rare and the commonest simple backache is given least importance. 85% of the patients belong to group A, but it is important not to miss patients in group B and group C, as their prognosis and management is different.
Pain generators of low back pain can be degenerate disc, facet joints or musculofascial structures. Intervertebral disc can start degenerating as soon as growth is complete. There is loss of water content of nucleus pulposus resulting in degeneration and release of chemicals, which is believed to cause pain.
This has been termed as degenerative disc disease (DDD). Majority of patients seen in clinical practice belong to this group. Patients usually complain of low back pain aggravated with activity and relieved with rest. There is no radiation of pain beyond knees. There are no systemic symptoms. Clinically there is tenderness in lumbosacral region but no neurological deficit or positive nerve root tension signs.
The pain in this group arises due to compression of nerve roots in the spinal canal. This also results in release of inflammatory mediators and venous engorgement of nerve roots. This can happen either due to
- Prolapse intervertebral disc (PID)
- Lumbar canal stenosis (LCS)
In PID there is tearing of outer annular fibres resulting in protrusion of degenerate nuclear material through the rent in fibres. The prolapsed material presses on the traversing nerve root. The commonest levels involved are L4/L5 and L5/S1 causing compression of L5 and S1 nerve roots respectively. Patients present with severe pain radiating down limb in ridiculer distribution. Pain usually starts after lifting heavy weight or a twisting injury to low back. Pain is aggravated on sneezing, coughing and with activity. There can associated tingling, numbness or weakness in the limb. Nerve root tension signs as straight leg raise, Lasegue’s sign, bowstring sign or femoral stretch sign are positive. Neurological examination may reveal deficit along the affected nerve root. Some patients may present with loss of bladder and bowel control with bilateral pain and weakness. This happens due to a large disc fragment pressing on the cauda equina and is termed as ?cauda equina syndrome?
In lumbar canal stenosis, there is reduction in space available for the nerve roots. With aging there is reduction in disc height, caudal migration of pedicels and thickening of ligamentum flavum which spans the laminate. This compromises the space available for the nerve roots especially on axial loading. Patients present with neurogenic claudication. They have to stop after walking some distance and have to stoop forwards or sit down to get relief of symptoms. Theses symptoms have to be differentiated from vascular claudication. In vascular etiology patients complain of calf pain rather than heaviness in legs. They get relief after stopping and do not necessarily have to sit down. On examination there are usually no signs in early stages of LCS. It is classically described as a disease of symptoms rather than signs. In late stages patients may have neurological deficit such as foot drop.
These patients have underlying significant pathology as a cause for their back pain. This could be spinal infections, tumors, fractures, inflammatory disorders such as ankylosing spondylitis etc. High index of suspicion is necessary to diagnose these conditions. Certain symptoms and signs should ring alarm bells about these conditions. These are termed as ? RED FLAGS ? (refer fig.1). These patients require immediate attention and detailed workup to reach a definitive diagnosis.
MANAGEMENT OF SPINAL DISORDERS
These patients need awareness of their problems and education about back care and ergonomics. Paracetamol, NSAID, centrally acting analgesics and muscle relaxants are useful in acute stage of disease. Bed rest and traction are useful only for 48 hours. Long term bed rest is counterproductive.
Patients should be encouraged to go back to work and undergo spinal rehabilitation programme. Emphasis should be laid on strengthening of abdominals and multifidus groups of muscles. Patients who do not respond to non-surgical treatment may benefit from facet joint injections. A select group of patients may need surgery. Spinal fusion is gold standard procedure. Newer techniques include total disc replacement (fig.2) and non fusion solutions such as Dyneses. These devices preserve motion and thereby prevent adjacent segment degeneration.
PID patients are treated with rest and analgesics in acute stage followed by spinal rehabilitation programme. 90% of patients with PID respond to non surgical treatment by 6 weeks. Patients who do not respond may benefit from nerve root blocks or caudal epidural injections. This are performed as day care procedures. Patients who do not respond to conservative treatment may need surgery. The aim of surgery is to free the nerve root and remove the offending disc fragment. This can be achieved by microdiscectomy. Cauda equina syndrome is a surgical emergency and requires urgent laminectomy and discectomy.
Patients suffering from LCS should be first treated by conservative methods which include graded exercise programme, analgesics and epidural steroids. If there is no response to conservative treatment, lumbar canal decompression should be performed taking care to preserve the facet joints and stability. Fusion may be added if there is pre-existing spondylolisthesis or degenerative scoliosis.
These patients need hematological investigations, X-rays, MR scan and bone scan to reach a definitive diagnosis. Management of few specific conditions is discussed below.
Traumatic spinal fractures which are unstable need stabilisation either by anterior, posterior or combined approach for early rehabilitation and prevention of late deformity. Paraplegics need aggressive rehabilitation. Stem cell therapy may have promising results in future for these patients. Osteoporotic vertebral fractures are treated with rest, bracing, calcium, vitamin D supplements and antiresorptive drugs such as calcitonin and biphosphonates. Patients having persistent pain benefit from vertebroplasty. This is a minimally invasive procedure wherein bone cement is injected under image guidance (fig.2)
Spinal infections need to be confirmed by doing a transpedicular biopsy under image guidance. Material should be send for culture, AFB and histopathology before commencing treatment. In spinal tuberculosis the entire spine needs to be screened to rule out skip lesions (7-10%). The incidence of atypical mycobacteria is on rise. Patients who do not respond to AKT or who develop neurological deficit may need decompression and stabilisation.
Vertebral tumors need definitive diagnosis with transpedicular biopsy. Metastases are common in vertebral column from lung, breast thyroid, prostate and kidneys. Multiple myeloma commonly affects vertebral column. Patients with unremitting pain and neurology may need decompression and stabilisation. Surgical procedures should be done before radiotherapy as this interferes with wound healing. Inflammatory disorders such as ankylosing spondylitis may result in kyphotic deformity. These may need spinal osteotomy and correction.
Conclusion
Back pain triage helps in clinic to sort patients into three groups. This aids in predicting prognosis and deciding further management. This triage is based on simple tools- history and clinical examination rather than complicated investigations. It is strongly recommended that this triage be used in daily practice.
Red Flags
- Age of onset <20 or >55k pain
- Non mechanical pain
- Significant trauma
- Thoracic pain
- Weight loss
- Systemically unwell
- PMH: carcinoma, steroids, drug abuse, HIV
- Lumbar flexion <5 cm
- Widespread neurology
- Structural deformity