3.3 Clinical presentations of the lumbar spine

Low back pain is one of the most common presenting complaints in orthopaedic practice. Often the cause of the pain is not understood, and consequently the diagnosis and the explanations given to patients are inconsistent. This causes uncertainty and, in some cases, prolongation of symptoms. Back pain is sometimes the presenting complaint where there is serious underlying pathology. It may be difficult or impossible to distinguish these cases from the generality of back pain complaints. Progress has been made in our understanding of back pain complaints, and it is now possible to give a structured approach to management for which there is at least some evidence.

The principal objectives of the clinician are to identify those patients with serious underlying pathology, and to try to place the rest in clinical groups relevant to the available treatment options. Generally these are non-operative, and these methods are emphasized in the chapters in this section. Surgery has a definite role in the management of root pain, particularly in the presence of progressive neurological deficit or neurogenic claudication. The place of surgery in the management of some cases of back and referred pain, which has failed to respond to conservative management, is more controversial.

A number of clinical and pathologic classifications have been reported. We use a scheme elaborated in 1990 based on history, examination, and magnetic resonance imaging (MRI). Plain x-rays have little value in this area.

This is the common type of back pain. Attacks occur acutely, and often for no obvious reason. Precipitating factors are often normal everyday events or actions. The vast majority of attacks will improve within 6 weeks, and are generally handled in family practice, by physiotherapists, chiropractors, or osteopaths. If the symptoms are prolonged or severe, specialist advice is sought. The majority of pain is felt in the lumbar spine, but there may be referral to buttocks or thighs, occasionally to the lower legs. Pain tends to be worst when sitting, and is often better with activity. Treatment is activity. Attacks are self-limiting, although they may be recurrent. Generally people will improve with or without intervention because the natural history is good. A whole variety of treatments can be helpful for pain relief and functional recovery. None of these, however, cure or prevent recurrence. Details of management can be found in Chapter 3.4.

The interface between type 1 and type 2 is indistinct. Type 2 has chronic persistent symptoms that may/may not vary in severity. Often the onset is insidious and flare ups may be anticipated by the patient. The pain is back dominant and often refers into the thigh or even further down the leg depending on severity—so-called thermometer pain. It tends to be unresponsive to a wide variety of simple conservative management. There is a trend toward managing these patients in specialized rehabilitation programmes (see Chapter 3.4) based on cognitive behavioural principles. A small number of these patients may be suitable for spinal fusion or spinal stabilization. This is discussed in Chapter 3.6. Hall has further developed this scheme to distinguish patients who are likely to benefit from rehabilitation from those likely to benefit from pain management.

These patients have back and leg pain in a dermatomal distribution with or without correlating neurological deficit. L5 can usually be distinguished from S1 in the distribution in the foot. L4 usually has a strong component of anterior thigh pain. In classical disc prolapse, the back pain precedes the leg pain, which eventually predominates. It is not usually possible to distinguish lateral recess stenosis from disc herniation clinically. Surgery provides quicker relief of leg pain and function, but not better long-term recovery. Management is discussed in Chapter 3.7.

Patients in this group present with walking-related back and leg pain. They are usually middle-aged or older, but it can occur in the young as well. These patients are intolerant of standing and walking, and relief is usually obtained by sitting, squatting, or lying. Often there is a flexed posture in walking and their symptoms are helped by any wheeled device such as a supermarket trolley or pushchair. In most, the symptoms do not deteriorate with time. Surgical management is an option for those with severe restriction of walking. Management is discussed in Chapter 3.8.

These patients have symptoms that do not fit easily in other groups. Any patients with unusual or persistent symptoms or pain which cannot otherwise be explained fall into this group. Sometimes it is clinically impossible to distinguish those patients with serious pathology, including infection and tumours from those without. The management of those with pain related to systemic pathologies is discussed in Section 2.

Diagnosis is made mainly on the basis of history, and so time must be spent with patients listening to their complaints. This process may be aided by proformas and computer-based interview systems. As so much depends on the history, it is essential to give the patient time to tell their story and to listen to what they are saying. History-takers should bear the following points in mind when listening to their patients.

Back pain is common from the age of 16 onwards. However, it is rarely severe in teenagers and tends to be most bothersome in our middle years (30–55). Serious pathology (infections and tumours) can occur in all ages but is more common in people outside this age range than within it. Therefore, patients presenting with back pain who are younger than 16 or older than 55 should be reviewed with particular care. Symptomatic disc prolapse is uncommon in teenagers and unusual over the age of 60. Neurogenic claudication is most common over age 60, unusual below the age of 40, but can occur even in teenagers with developmental spinal stenosis. Insufficiency fractures occur most often in those over age 70. Spondylolysis and spondylolisthesis may manifest themselves at any age, but they tend to cause back pain in patients under the age of 40 and neurogenic symptoms in older patients. Management is discussed in Chapter 3.17.

Pain from a specific level in the spine (e.g. a metastasis) is usually referred about two segments distal to its source in the cranial part of the spine (Figure 3.3.1). The referral tends to be further from the source of the pain in the caudal part of the spine. This pain does not, in general, go to the front of the trunk or lower limb. Localization of the source level may be aided by percussion or palpation of the spine (although, curiously, pain from discitis, which is often severe, is not always exacerbated in this way).

The clinician should be familiar with the concepts of referred pain and root pain, and the distinction between them.

Referred pain is characterized by variation in distribution with severity: the worse the pain, the further it will felt down the lower limb (‘thermometer pain’). Referred pain usually radiates posteriorly towards the knee, although in chronic cases it may go further down the leg. Referred pain is difficult, because it varies with sensitivity and is not associated with reliable clinical signs.

Root pain is usually dermatomal, although there are significant individual variations. Historically a variety of methods have been used to derive dermatome charts (Figure 3.3.2). Sometimes these can be confirmed by examination by light touch and pinprick testing. Root and referred pain can coexist. Some patients will have entirely root pain in a classical distribution without back pain. Pain felt on the front of the thigh, if it emanates from the spine, is generally from the L3 or L4 roots. L5 root pain usually radiates to the dorsomedial aspect of the foot. S1 root pain spreads to the lateral side and the sole of the foot. There are frequent variations of pattern in clinical practice. Coughing and sneezing tend to exacerbate root pain due to disc prolapse.

Patients with neurogenic claudication have difficulty in defining the site and nature of their symptoms. Some deny that they experience pain at all, preferring such terms as ‘heaviness’. The distribution of this pain is a poor guide to the nerves involved. Bilateral lower-limb pain implies a central lesion. This may be central stenosis, a central disc prolapse, or a tumour affecting the cord, conus, or cauda equina.

The term ‘myofascial pain’ describes a wide variety of musculoskeletal symptoms. These have characteristic pain patterns which may be small and localized. One such syndrome has trigger points over the posterior iliac crest and an associated pain pattern. These pains may respond to a local anaesthetic injection. Copious literature on this topic can be found in rheumatological texts.

If a pain drawing is used to identify pain patterns, some will have widespread bodily symptoms. This could be related to systemic pathology (inflammatory, thyroid, etc.). If systemic pathology has been excluded and there is associated disability and distress, then chronic pain syndrome should be considered. This needs specialist management. Many clinicians have been caught out, dismissing a patient’s symptoms of serious underlying pathology as psychogenic.

Pain from the hip is often confused with back pain. It is usually felt in the groin and/or over the greater trochanter. It can radiate over the front of the thigh to the knee. Occasionally it is felt just in the knee, notably in children. Uncommonly, hip pain is experienced in the buttock alone. Hip pain is usually exacerbated by getting out of a chair, as well as by walking, although in the early stages of osteoarthritis of the hip continued exercise can relieve pain after the initial painful movement. These symptoms can be fully evaluated by examining the hip. Gauvain’s test, in which the extended leg is gently rolled by the examiner while the patient is lying and relaxed, produces either pain or involuntary ipsilateral abdominal contracture. Rotation in flexion or abduction may also reproduce hip pain.

Night pain is common in degenerative spinal conditions so specificity is poor. However, it is also a feature of pain from fractures, metastases, and infections. It is the quality of the night pain that differs. Intractable pain at night necessitating the person to get out of bed, which is not responsive to pain relief, should raise suspicion of possible serious pathology. Especially if there are other red flags in the history.

Scoliotics tend to have fatigue pain which becomes worse through the day. Ankylosing spondylitis is characterized by severe and prolonged morning stiffness (all patients with back pain report morning stiffness to a greater or lesser extent).

Root pain is usually exacerbated by walking (and often just while standing still). Neurogenic claudication has a variable walking distance from day to day. The patient or spouse may notice a flexed posture during walking. Sometime it is easier walking up hill. Riding a bicycle may be easier than walking if severely restricted. Many patients find it much easier to walk while pushing a supermarket trolley or wheeled walker. It is often not possible for these patients to ‘walk through’ the pain as vascular claudicants can. Neurogenic claudication may be distinguished from vascular claudication by the duration of recovery. Vascular claudicants can usually carry on walking after 1–3min, whereas cauda equina claudication requires 5–20min for recovery.

Many chronic back pain patients are intolerant of sitting; there are many theories related to this incriminating the disc, ligaments, muscles, and facet joints. Driving more than 1000 miles a week is a possible risk factor for chronic back pain. Sitting tends to relieve the pain of neurogenic claudication.

The overall incidence of back pain is similar in men and women. The prevalence of disc degeneration, disc prolapse, and lytic spondylolysis and spondylolisthesis is more common in males. Degenerative spondylolisthesis is more common in females.

Back pain is common in the working age group regardless of employment status or occupation. Work is good for the health of those with back pain. Modern healthcare encourages the use of ‘fit notes’ rather than sick notes, i.e. establish what the person can do, and modified hours/duties to make work manageable. Heavy manual work is not as strong a factor as is often assumed. Disc degeneration is universal and largely driven by genetic factors. Individuals with more severe disc degeneration than their age-matched contemporaries are more likely to have back pain. Sitting and exposure to vibration are limited contributors to prevalence. Back pain undoubtedly presents more of a problem to members of social classes 4 and 5 because their work tends to be more physical and therefore harder to do with back pain. Social service payments depend on inability to work. The structure of workman’s compensation systems has a profound effect on the incidence and duration of back pain disability. The longer an individual is off work, the less likely he or she is to return to work. There are also strong confounding factors, such as smoking and litigation following actual or perceived injury to the spine. Training in manual handling may be of importance in making work more comfortable. There is some evidence that fitness programmes in the working environment can lead to significantly shorter sickness absence. In modern work environments it is rare to find jobs at the extreme of the ergonomic envelope for spinal loads.

The nature of the original onset of symptoms and how an attack starts is worth analysis. Type 1 pain usually starts acutely, frequently while performing normal activities. Often patients will admit that there was no obvious precipitating factor to an attack. Insufficiency fractures usually precipitate acute pain if they are symptomatic (only about 25% of osteoporotic crush fractures cause pain). Disc prolapse almost always start with an insidious onset of back pain followed at a later stage by root pain. The delay in onset of root pain varies from minutes to years. The appearance of the root pain may be accompanied by reduction or loss of the back pain.

There is an expectation amongst patients and their doctors that a precipitating cause for their back pain can always be found. Litigation may be a factor in this quest. In a study at the Canadian Back Institute, 70% of 6000 non-compensation responders to a questionnaire were unable to identify a specific injury to account for the onset of their symptoms.

The words used to describe back pain are often culturally determined. Some descriptive terms, such as ‘burning’, ‘pins and needles’, or ‘numbness’, may be associated with radicular pain, whereas ‘cramp’ or ‘ache’ tends to relate to vascular, neurogenic claudication or referred pain. These terms may have some value in eliciting the source of pain in the individual, but they have resisted useful analysis.

Smoking has been shown to be a risk factor in pseudarthrosis following spinal fusion. An association between smoking and disc degeneration has been established. The relationship to back pain, however, remains unclear. Heavy smokers often have poorer social circumstances and if employed have more physical occupations. It is likely that psychosocial factors will have greater predictive value for back pain related disability than smoking.

Some systemic conditions may present with back pain. Tuberculosis and other infections, metastases, lymphomas, pancreatitis, or a leaking aortic aneurysm can all cause pain in the back. Pain arising from metastases and from infection is frequently unremitting and may be worse at night. The patient should be asked about past history of cancer, weight loss, eating habits, disturbances of digestion, bowel and bladder function, night sweats, drugs, and allergies. Diabetes mellitus, hypothyroidism, osteoporosis, osteomalacia and other metabolic bone diseases, psoriasis, and pregnancy may all be factors in the development of back pain. Any patient with an unusual history should be listened to and examined with particular care.

Disc degeneration is genetically driven. Disc prolapse patients frequently have affected first-degree relatives. There is some epidemiological data linking disc degeneration to back pain, particularly if it is earlier or more extensive than expected by age. It is likely that response to pain has important genetic elements. Family patterns of psychosocial factors have an influence on perceived disability.

Listening to the patient is the most effective way of assessing the psychological component of a patient’s history. Patients with strong psychosocial factors have the same range of pathologies as those who do not. It is the response to pain which differs, not the pathology. These should always be screened during back pain assessments. Psychosocial questionnaires are widely used and have been shown to add value. Examples can be found in The Back Pain Revolution (see ‘Further reading’). In particular, high levels of disability, worklessness, and high healthcare utilization should raise concern. The structure of the social services payment system is an important factor in the rise in back pain disability in developed countries. Litigation over personal injury claims has long been recognized as having an important effect on treatment outcome and reported disability. For those with significant pain-related disability, a comprehensive biopsychosocial assessment by a clinician or multidisciplinary team is recommended as early as possible, and certainly before any surgical management is considered. Combined physical and psychological management has been shown to be effective in reducing disability, distress, medication usage, and healthcare utilization.