List of Tables
5: Diagnosis and Classification
Introduction
This chapter considers the problems in identification of specific pathology, the classification of neck pain and the value of broad non
specific classifications. The identification of specific pathology in the cervical spine is a problem as pathological terms are commonly used, but reliable and valid means of identifying the source of neck pain are largely unavailable. Imaging studies have problems of poor sensitivity and specificity. They can identify abnormal morphology but, without targeted injections, are unable to determine if this is the symptom generator. Classification systems for the lumbar spine can be used to make initial categorisation of patients who are suitable or unsuitable for a mechanical evaluation. Except [or serious spinal pathology and nerve root problems, it is generally suggested that most spine pain is a non-specific condition (Spitzer et al. 1 987; CSAG 1 994; AHCPR 1994). McKenzie (1 981 , 1 990), in an attempt to identify like patients in the non-specific spine pain population, proposed three non-specific mechanical syndromes: derangement, dysfunction and postural, which are now widely used in musculoskeletal care.
Sections in this chapter are as follows:
• seeking patho-anatomical diagnoses
• classification systems
• diagnostic triage
• serious spinal pathology
• nerve root problems mechanical neck pain
sub-group identification - indications and contraindications for MDT.
Seeking patho-anatomical diagnoses
Several methods have been used to make patho-anatomical diagnoses and thus establish the site of patients' pain. The more traditional one is through imaging studies, initially through radiography, whilst in
CHAPTER FIVE
Iss
66 1
CHAPTER FIVE THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYmore recent years this has been superseded in accuracy by magnetic resonance imaging (MRI) or computer assisted tomography (CAT). A more direct way of sourcing the pain generator is using radiographically guided injections to provoke and/or abolish pain. Even with recent technological advances, these tools have limitations in their ability to identify the site of pain. With imaging studies, poor sensitivity and poor specificity bedevil their capacity to identify pathology.
With injections, problems exist of false positive responses, technical difficulty and availability.
Imaging studies are good at identifying morphological changes to spinal tissues, but the changes do not necessarily relate to the symptoms.
Consequently these technologies frequently cannot distinguish the true positives (those whose symptoms do relate to an imaging abnor
mality) from the true negatives (abnormalities in an asymptomatiC population) as the follOWing examples demonstrate.
In a group of patients increasing levels of spinal degeneration shown on x-ray were related to increasing chronicity of complaint; however, there was no simple relationship between degeneration and pain (Marchiori and Henderson 1 996). Findings of degeneration on x-ray lack sensitivity, as degenerative changes are common in the asympto
matic population (Gore et al. 1 986; Teresi et al. 1987; Matsumoto
et al. 1998). Radiological changes increase with age (Friedenberg and Miller 1 963; van der Donk et al. 1 991; Matsumoto et al. 1 998;
Gore et al. 1 986) as does neck pain; it could be speculated whether this is causal or merely incidental. The increase in neck symptoms stabilises around the fifth to sixth decade. However, the prevalence of degenerative changes continues to increase. By age 60 to 65, 95%
of men and 70% of women in a sample of two hundred without neck pain had at least one degenerative change on x-ray (Gore et al. 1 986).
Significant disc space narrowing was reported by magnetic resonance imaging (MRI) in 24% of individuals 45 to 54 and 67% of those older than 64, and osteophytes in 1 6% of those younger than 64 and 37%
of those older than 64 (Teresi et al. 1 987). Matsumoto et al. (1998) investigated nearly five hundred pain-free individuals with MRI and found signs of disc degeneration present in about 1 4% of those in their 20s and nearly 90% of those over 60 years old.
Disc herniation and bulge have also been found in the asymptomatic population. Protrusions were visible in 20% of those aged 45 to 54 and 57% of those older than 64 (Teresi et al. 1 987). Even cord compression
DIAGNOSIS AND CLASSIFICATION
due to disc protrusion or osteophytes is found in the asymptomatic population (Teresi et al. 1 987; Matsumoto et al. 1998; Bednarik et al. 2004). These findings make clear that the use of imaging studies by themselves may determine morphological changes, but cannot determine symptomatic pathology. To use such findings to suggest management lacks validity and is fraught with error.
Joint injections to abolish or provoke pain are a way of proving the existence of certain pathological entities, but using these as a common diagnostic tool may be neither desirable nor practical. AnalgeSiC injections into cervical zygapophyseal joints have been shown to abolish or substantially reduce patients' neck pain or headache (Bogduk and Marsland 1 988; Aprill et al. 1 990; Hove and Gyldensted 1 990; April and Bogduk 1 992; Bogduk and Aprill1 993; Bamsley et al. 1 995; Lord et al. 1994, 1 996a; Aprill et al. 2002) and provocation discography has been used to confirm disco genic neck pain (Aprill and Bogduk 1 992; Bogduk and Aprill 1 993; Cloward 1 959; Grubb and Kelly 2000; Schellhas et al. 1 996). However, these techniques are invasive, need skilled practitioners for their safe performance, and are not widely available even if it was thought they should be commonly used. Furthermore, cervical zygapophyseal joint blocks are accompanied by a rate of false positive responses to single blocks of between 21 % and 27% (Bamsley et al. 1 993a, 1 993b, 1 995), which has necessitated the use of double injections to definitively prove the diagnosis. Clearly this is not a practical way to reach a diagnosis for the majority of neck pain patients, especially as such identification does not necessarily result in an effective management strategy CBamsley et al. 1 994b).
Manual therapists advocate the use of palpation techniques in order to establish a diagnosis Gull et al. 1 988). Much is made of a Single study, in which the validity of manual diagnosis to establish a diagnosis of cervical zygapophyseal joint pain was investigated in a small group of twenty consecutive patients Oull et al. 1 988). Findings from manual palpation were compared to radiologically gUided diagnostic joint blocks. Fifteen of the twenty were diagnosed with zygapophyseal joint pain and the manual therapist was 1 00% sensitive and 100%
specific in diagnosis and segmental level. However, only one manual therapist was evaluated, the study has not been replicated and inter
tester reliability needs to be established to vindicate manual therapy palpation techniques in general.
CHAPTER FIVE
167
681
CHAPTER FIVE THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYThe ability of clinicians using palpation to detect joint dysfunctions, 'fixations', stiffness or other passive intervertebral motion abnor
malities in a reliable and consistent way is unproven (Table 9.1). If clinicians so commonly disagree about the presence or absence of such clinical phenomena, their validity is open to doubt. Poor rates of intertester reliability mean that the existence of such phenomena is unsubstantiated, and therefore these are not valid clinical tests. Palpa
tion is thus not fully vindicated as a tool for making a diagnosis.
Classification systems
Thus, methods of identifying specific pathology have problems with reliability, validity, availability or acceptability, and generally the link between diagnosis, management options and improved outcomes is unsubstantiated. It has been suggested that non-specific classification systems have several advantages (McKenzie and May 2003; Childs
et al. 2004a). The chief advantages of a classification system are in improved clinical decision-making and establishing a prognosis;
hopefully this will lead to a more effective management if treated with regard to classification. Furthermore, classification systems aid communication between clinicians and can allow increased under
standing of the different sub-groups.
The proposal that matching sub-groups of non-specific spinal pain to specific interventions will lead to improved outcomes, although logical, has until lately been hypothetical only. However, two recent studies, which both use the concept of mechanically determined direc
tional preference either wholly or as part of the classification system, have demonstrated that patients treated according to classification do better than if treated in a non-specific, even if best practice, way (Long et al. 2004; Fritz et al. 2003) Further studies also suggest that sub-groups respond better to one type of intervention than another (Childs et al. 2003, 2004b; Haldorsen et al. 2002). These studies involve lumbar spine patients; the same evidence is not available relating to cervical spine patients. However, there is every reason to believe that management could equally be improved using a classification system for patients with neck pain (Childs et al. 2004a).
Work on cervical classification systems is limited (Childs et al. 2004a).
The Quebec Task Force (QTF) classification system (Spitzer et al.
1 987) was written to apply to all activity-related spinal disorders,
DIAGNOSIS AND CLASSIFICATION
and the more recent triage classification systems for back pain (CSAG 1 994; AHCPR 1994) are just as relevant to the cervical spine. The QTF group have also produced a review and classification system for whiplash associated disorders (Spitzer et al. 1 995), which is detailed in the chapter on whiplash, and a development of this system has been suggested by another group (Sterling 2004). Other classification systems for neck pain have been proposed (Childs et al. 2004a; Wang
et al. 2003; Schenk et al. 2002) . The issues that are relevant in the lumbar spine apply equally in the cervical spine:
the value of the triage system to rule out serious spinal pathology
the difficulty of identifying anatomically specific sources of neck pain
the limitations of classifying by pain pattern as in the QTF (Spitzer et al. 1 987)
the role conservative evaluation should have in both somatic and radicular pain
the value of using non-specific mechanical syndromes based on symptom and mechanical responses (McKenzie and May 2003;
Childs et al. 2004a).
For a classification system to be of clinical value, certain character
istics must be demonstrated. Appropriately trained and experienced clinicians need to be able to differentiate the different sub-groups in a reliable way. When applied to a broad range of neck pain patients, the classification system must be shown to have a high prevalence of application. Finally, the value of the classification system needs to be evaluated by undertaking clinical trials after sub-classification to determine that the specific intervention recommended produces better outcomes than a non-specific intervention. Regarding the McKenzie classification system in the lumbar spine, all of these characteristics have been demonstrated (McKenzie and May 2003;
May 2004a, 2004b; Long et al. 2004). Currently work in these areas is less advanced as far as the cervical spine is concerned, although obviously this is on-going. Initial studies have demonstrated moderate to good levels of reliability for the McKenzie classification system in the cervical spine (Dionne and Bybee 2003; Clare et al. 2004a, 2004c). Centralisation has been demonstrated as commonly in the cervical as in the lumbar spine (Werneke et al. 1 999). In a survey
CHAPTER FIVE
169
70
I
CHAPTER FIVE THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYinvolving over eight hundred patients, of whom 1 78 had neck pain, 88% of these were classified in one of the mechanical syndromes (May 2004b). There is more detail concerning these studies in Chapter 7.
In both the lumbar and cervical spine, evidence for the McKenzie classification system is more developed than for most comparable classification systems.
Diagnostic triage
The aim of triage is to exclude patients who are unsuitable for mechanical evaluation because of suspicion of serious spinal pathology The triage concept is familiar in the field of back pain assessment (CSAG 1 994; AHCPR 1 994) and suggests three groups that are easily transposed to the neck:
• serious spinal pathology - tumour, inflammatory joint disease, myelopathy, upper cervical instability, vertebral artery insufficiency, etc.
• nerve root problems - cervical radiculopathy
• mechanical neck pain - non-specific neck pain with/without radiation in which symptoms vary with activity and time.
The majority of all patients with neck pain fit in the last category.
A much smaller percentage have nerve root problems, and both of these categories are suitable for mechanical evaluation. The smallest category, probably about 1 % of all patients with neck pain, is unsuit
able for mechanical evaluation and should be referred for further investigation.
Serious spinal pathology
It is imperative that clinicians managing musculoskeletal patients have an awareness of the 'red flags' that might indicate serious spinal pathology. The first task of the assessment is to screen out those patients, very few in number, who must then be referred for further investigations. As in back pain patients with serious spinal pathology, the key clues are usually found in the history. These pathologies and their presentations are considered in more depth in Chapter 8.
If suspicion of serious spinal pathology is not clear from the history, it should become apparent qUickly that loading strategies produce no lasting symptom reduction. Worsening of symptoms in response to all loading strategies is likely.
DIAGNOSIS AND CLASSIFICATION
Management
Any patients in whom 'red flags' feature must be referred for further investigation. If serious spinal pathology is suspected, mechanical therapy is contraindicated. Such patients in normal practice are rarely encountered, but unless a suspicion is maintained they will be missed.
Nerve root problems
Cervical radiculopathy is suspected from the history, with characteristic pain patterns and possibly the patient reporting numbness or pins and needles. Testing reflexes and myotomes may confirm initial clues (see Table 51).
Table 5.1 Typical signs and symptoms associated with nerve root involvement
Root Typical area of Common motor
level sensory loss wealmess Reflex
(4 Top of shoulder Shoulder elevation
(5 Laleral arm/deltoid Shoulder abduction Biceps area
(6 Thumblindex fingerCs) Elbow flexion Biceps
C7 Middle fingerCs) Elbow extension Triceps
(8 Little fingerCs)/ring Thumb extension
fingerCs)
Tl Medial border Finger abduction!
forearm adduction
Source: Kramer 1990; Slipman ct al. 1998; Butler 2000; Bland 1994; Lestini and Wiesel 1989
Most commonly C6, C7 or C8 nerve roots are affected causing loss of sensation in and pain down to the thumb, middle finger(s) and little finger(s) respectively (Kramer 1990). Less commonly C5 and C4 are involved, affecting the lateral arm and the shoulder respectively (Slipman et al. 1998; Butler 2000).
Although rare, it should be remembered that cervical radiculopathy can be the product of serious spinal pathology, such as sarcoidosis or giant cell arteritis (Atkinson et al. 1 982; Sanchez et al. 1 983). Be aware of symptoms that may alert to the presence of more sinister pathology, such as neurological signs/symptoms at multiple or non
adjacent levels, or atypical responses to mechanical testing.
CHAPTER FIVE
171
721
CHAPTER FIVE THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYManagement
Patients with cervical radiculopathy should be given a mechanical evaluation; within this group will be derangement responders, but also patients with irreducible derangements. A small minority of this group who fail conservative therapy may be referred for and undergo surgery. Those with less severe symptomatology are more likely to respond, and those with constant pain and neurological signs and symptoms less likely. Those patients with intermittent symptoms have a very good chance of responding.
Mechanical neck pain
This group represents the majority of individuals with neck pain and may include those with somatic referred pain into the arm. As it is mechanical in nature symptoms will vary with time and activities, and neck pain is often accompanied by a limited range of movement.
These patients are otherwise well, but suffering from a temporary and local musculoskeletal problem.
Management
Patients with mechanical neck pain will all be given a mechanical evaluation, which is described later. Most of these patients will be classified under one of the mechanical syndromes. After five sessions and failure to claSSify in a mechanical syndrome, one of the 'Other' categories may be considered.
Sub-group identification - indications and contraindications for MDT
The majority of neck pain patients, including those with neurological signs and symptoms indicating cervical radiculopathy, are thus suit
able for a mechanical evaluation using repetitive end-range motion and/or static loading. Most of these will be classified in one of the mechanical syndromes, predominantly derangement, and a few with dysfunction and postural syndrome. The effect of repeated or static end-range loading on pain patterns can determine, often on day one, the potential of that patient to respond to mechanical therapy. Treat
ment response indicators can also be observed during the mechanical evaluation when a mechanically determined directional preference or other consistent mechanical response is sought - thus indicating the presence of one of the three mechanical syndromes (derangement most commonly, followed by dysfunction and then postural syndrome). The majority of patients with non-specific spinal pain can be classified
DIAGNOSIS AND CLASSIFICATION
into one of these three sub-groups of mechanical spinal disorders described in the next chapter. Thus we are able to identify those patients who may be helped and, just as importantly, those who are unlikely to respond to mechanical therapy. Some at the severe end of the continuum will be classified as irreducible derangement, but this classification should only follow a failure to respond to several sessions. If after five sessions there is a lack of response that indicates a mechanical syndrome, one of the 'Other' categories, described in Chapter 9, may be considered. Secondary classifications should only be considered once an extended mechanical evaluation has ruled out a consistent mechanical response.
Patients whose history suggests serious pathology are absolutely unsuitable for mechanical therapy. Patients in whom there is suspicion of myelopathy, cancer, fracture or instability, systemic disease, or progressive neurological disease should be immediately referred for further investigations.
Conclusions
This chapter has described the initial classification algorithm for evalu
ation of those with neck pain. In very general terms patients either present with mechanical neck pain, nerve root pathology or serious spinal pathology. The latter, if detected, is unsuitable for mechanical diagnOSiS and therapy and any patient with the features outlined above should be referred to a specialist - these are considered in more detail in the chapter on serious spinal pathology (Chapter 8).
Ninety-eight per cent or more of patients with neck pain are suitable for a mechanical evaluation including those with signs of nerve root involvement. The full mechanical assessment, which will be described later, seeks to identify those patients whose conditions are mechani
cally responsive and fit into one of the mechanical syndromes. These are described in the chapters on derangement, dysfunction and posture syndromes, and briefly described in the next chapter. Testing for them should be carried out over several days.
Not all patients will fit neatly into one of the mechanical syndromes.
During the period of mechanical evaluation, atypical or inconclusive responses may arise. In that event one of the specific or non-specific categories described in Chapter 9 should be considered. Figure 5.1 gives an outline of initial clinical categories.
CHAPTER FIVE
173
741
CHAPTER FIVE THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYFigure 5.1 Initial management pathway - key categories, estimated prevalence in neck pain population Serious spinal
pathology <2%
Specialist referral
�
Nerve root pathology <10%
�
Simple neck pain >90%
Mechanical evaluation
/
Mechanical responders Mechanical non-responders
Other lrreducible derangements