Definition: Chronic disability is defined as not being able to perform the pre
injury job at levels of regular pre-injury working hours for more than 6 months up to 18 months. People who do not resume any work and those who perform their previous job during reduced daily hours in the context of a light-duty program constitute two different subgroups of this phase.
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Significance: The significance of the Chronic Disability Phase is that after six
months of work-disability, treatment and rehabilitation programs geared towards the spine alone are inappropriate and have to be supplemented or replaced by interventions focusing on the pain experience itself, psychosocial and/or occupational factors.
Frequency: About 7% of all cases of reported LBP enter this phase.30
Medical status: In Phase 7 the underlying condition of the spine cannot be
considered the primary cause for the persistence of pain in most patients. The diagnosis "chronic pain syndrome" is sometimes used in this situation. This diagnosis is based solely on the presence of continuous disabling pain for more than six months and does not refer to any specified pathology of any organ system.
Some psychologists82 maintain that this pain represents a behavior reaction, whereas neurophysiologists lean toward the hypothesis that nervous structures irritated for a prolonged period develop new mechanisms of pain generation.19 Chronic pain has also been described as a variant of depression.83 While the
"chronic pain syndrome" is sometimes associated with objective signs (i.e., limitation of motion, hyperesthesia, muscular weakness, etc.), in the majority (70- 80%) of patients, there is no evident major objective sign.26
The diagnosis "chronic pain syndrome" is not appropriate for patients with painful iatrogenic alterations of the spine due to unsuccessful, complicated or repeated surgery. The major chronic "side-effects" of spinal surgery are spinal instability and scar tissue formation, which are considered mechanical causes for chronic back pain and which may affect 2-5% of all surgical cases.67
I
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The diagnosis "chronic pain syndrome" is also inappropriate in situations in which the failure to improve an unhealthy job environment causes the recurrence of symptoms whenever the patient tries to resume his work. Thus patients with
"chronic pain syndrome" do fall into Phase 7, but the Chronic Disability Phase also includes those patients suffering from surgical complications as well as those patients experiencing recurrent symptoms due to the neglect of job-redesign that do not qualify for the medical diagnosis of a chronic pain syndrome.
Worker's compensation: Basically unchanged. However, during this period
litigation is more common than in earlier phases. The analysis of 2318 claims of back sprain or strain with more than 90 days work time lost in Washington State demonstrated that about one third of chronic claims are eventually appealed, however, no appeals were filed within 90 days of the claimant's date of injury and less than one fourth within one year.41 Legal and economic considerations influence the behavior of the patient as well as that of health care providers, insurance carriers and other players, but the effect on return to work remains controversial.84"86
Interventions: In the past 20 years more than 1000 pain clinics have been
developed in the United States for the treatment of patients with chronic pain. Even among professionals , there is a great deal of misunderstanding about the goal of
"pain clinics", which is to change a chronic pain patient into a person with chronic pain.87 This requires restoring function and decreasing disability, not necessarily eliminating pain. The patient's goal, however, is usually quite different. It is relief of pain. The patient knows only an acute pain model in which pain means tissue damage and therefore continuing pain means continuing damage. The different
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goals may lead to disappointment and misunderstanding unless they are clarified at the onset of treatment.
Pain clinic programs include a wide variety of passive therapies, such as ultrasound, manipulation, massage, acupuncture, electrical stimulation, and facet and epidural injections. Many programs share a reliance on behavioral modification. The fundamental goal of most behavioral approaches is the reduction of disability through behavioral change rather than the direct diminution of pain.
With or without the above-mentioned passive modalities, pain centers use such techniques as group and individual counseling, hypnosis, stress-management, biofeedback, educational classes, and family sessions. The intensity of these programs ranges from occasional outpatient treatment to intensive inpatient programs. Some authors recommend the use of active reconditioning like functional restoration within the setting of a pain clinic.87 As the content of these programs varies, so does the disciplinary representation by medical sub
specialists, counselors, physical and occupational therapists, and so on. However, in contrast to work hardening programs, physicians are core staff members of pain clinics.
The efficacy of the pain center approach to chronic back pain rehabilitation is controversial.88’ 89 Differences in program content and pre-treatment patient characteristics defy generalizations of therapeutic effectiveness. To date, there does not appear to be conclusive evidence that isolated aspects of pain center programs reduce subjective reports of pain, though improvements in activity level, medication use, and other pain related behaviors have been reported.89 Detoxification, particularly from narcotic analgesics, is usually more appropriate in a pain clinic setting than in less medically oriented programs.
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