Chronic pain
is major public health problem, and is now of epidemic proportions [1].
Medicare, social security, disability programs, workers’ compensation programs,
and the private healthcare system all struggle to keep up with the never ending
cost of chronic pain patients. Resulting in higher insurance premiums, loss of
worker productivity, increased burdens on state and federal governments and a
decrease in quality of life. Direct and indirect losses from chronic pain in
the United States costs billions of dollars each year [1].
Chronic pain
is defined as [2], “pain that extends beyond the expected period of healing or
is related to a progressive disease. It
is usually elicited by an injury or disease but may be perpetuated by factors
that are both pathogenically and physically remote from the original cause. Because the pain persists, it is likely that
environmental and psychological factors interact with the tissue damage,
contributing to the persistence of pain and illness behavior.” Initially,
general diagnosis’s such as cervical sprain / strain injury or acceleration /
deceleration injury are appropriate when used within accepted guidelines. As
the patient heals and time passes it is essential to obtain a specific
anatomical diagnosis such as, a C5 cervical disc herniation or a right C5
cervical facet syndrome.
The
scientific literature is very clear that cervical facet joints are the cause of
chronic pain in 54% to 67% of chronic neck pain patients [3-9]. Despite the high prevalence of pain, the
clinical diagnosis of the cervical facet joint as the primary source of pain is
often overlooked [5].These undiagnosed patients typically go through
unproductive treatment such as; physical therapy, chiropractic, injections,
medications and other procedures to relieve their pain. With the proper
diagnosis, these patients may benefit from specific interventions designed to
manage cervical facet joint pain [5]. The purpose of this chapter is to lay the
ground work for the diagnosis of cervical facet pain in a clinical setting. A
specific (I) history, (II) physical examination, (III) motion x-ray examination
and / or (IV) a diagnostic facet block are instrumental in the diagnosis of
chronic cervical facet joint dysfunction. With sound clinical judgment, a firm
diagnosis can be made as to the probable level and structure of pain
generation.
Background:
The cervical
spine is generally separated into two distinct functional and structural
parts: the upper cervical (Occiput to
C2) and the lower cervical (C3-C7). The
upper cervical spine has many muscle and ligamentous attachments, no
intervertebral disc, and has uniquely shaped bones and joint surfaces. A
typical lower cervical vertebra has a vertebral body, intervertebral disc, a
right and left superior articular facet, and a right and left inferior
articular facet. Facet joints are hinge-like structures that link the vertebrae
together. They are located at the back of the spine and are true synovial joints. This means that each joint is
surrounded by a thin ligamentous capsule of
connective tissue, hyaline cartilage covers the
articular surfaces, and synovial fluid nourishes as well as lubricates
the joint.
Cervical facet joints have both mechanoreceptors and nociceptive (pain) nerve endings
[10,11]. Within the joint are synovial folds, these folds are also pain
sensitive [11]. The facet joints are richly innervated by the medial branches
of the segmental dorsal rami and the medial branches of the segments above and
below [10,11]. This multilevel innervation of the
facet joint is one of the reasons for the broad referral pattern [12]. The
facet joints are heavily innervated by nerves, but have poor blood supply. This
poor blood supply impedes the healing process, which triggers scar tissue
formation and adhesive capsulitis within the joint, resulting in chronic
dysfunction and pain [12].
The
multifidus are the deep muscles of the cervical spine and help to provide
segmental stability. The multifidus are essential in a patient with facet pain
because this muscle has been found to insert into the facet joint capsular
ligaments. They have been found to cover 22.4 ± 9.6% of the facet joint capsule
surface area [13]. The multifidus muscle insertion into the cervical facet
capsular ligament provides a mechanism for injury to this ligament and the
facet joint as a whole [13,14]. This anatomical fact may also play a major role
in rehabilitation of cervical facet joint injuries.
A recent
study identified the, “facet articular cartilage, the synovial fold, and the
facet capsule as structures at risk for injury during whiplash due to excessive
facet joint compression or capsular ligament strain.” [16]. It also found that, “facet joint components
may be at risk for injury due to facet joint compression during rear-impact
accelerations of 3.5g and above. Capsular ligament strains exceed the
physiologic strains at 6.5g and were largest at the lower cervical spine.”[16].
Therefore, relatively low impact collisions can cause facet injuries[13,14,16].
“It is
consistent with known biological models that injuries to the osseous or soft
tissues of a joint predispose that joint to premature, painful, osteoarthritic
change.”[17]. Long term, the facet
joints will undergo degenerative changes characteristic of osteoarthritis as
seen in other synovial joints [18]. As the facet joint degeneration progresses
the radiographic changes are more visible and often result in spinal stenosis,
affecting both the nerve root and central canals [18].
Epidemiological
studies, crash test studies and anatomical evidence all corroborate the reality
that the cervical facet joints are prone to injury during a motor vehicle
collision, have a rich nerve supply, heal poorly and are a source of pain
[3-20]. Pain for prolonged periods of
time can lead to reconditioning, neuroplastic changes
and hyperexcitability of the nervous system
[12].
1. American Medical Association: Disability
Evaluation, second edition. Chicago, American Medical Association, Mosby, 2003, pp 552.
2. American Medical Association: Guides to
the Evaluation of Permanent Impairment, fifth edition. Chicago, American Medical Association, Mosby, 2001,pp
600.
3. Lord S, Barnsley L, Wallis BJ, Bogduk
N. Chronic cervical zygapophysial joint pain after whiplash: a placebo- controlled prevalence study. Spine
1996;21:1737-1744.
4.Harrison P. The prevalence of
zygapophysial joint disease as a cause of chronic neck pain/headache. World Congress on Whiplash-Associated
Disorders 1999;120.
5. Manchikanti L, Boswell M, Singh V,
Pampati V, Damron K,and Beyer C. Prevalence of facet joint pain in chronicspinal pain of cervical, thoracic,
and lumbar regions. BMC Musculoskeletal Disorders 2004, 5:15 [http://www.biomedcentral.com/1471-2474/5/15]
6. Manchikanti L, Singh V, Pampati V,
Damron K, Beyer C, Barnhill R: Is there correlation of facet joint pain in
lumbar and cervical spine? [ -page365-371.htm]
Pain Physician 2002,5:365-371.
7 Barnsley L, Lord SM, Wallis BJ, Bogduk
N: The prevalence of chronic cervical zygapophyseal joint pain after whiplash. Spine 1995, 20:20-26.
8.Manchikanti L, Singh V, Rivera J,
Pampati V: Prevalence of cervical facet joint pain in chronic neck pain. [http://www.asipp.org/Journal/JULY-2002/Vol-5-3-page243.htm]
Pain Physician 2002, 5:243-249.
9. Barnsley L, Lord S, Bogduk N. Whiplash injury. Pain. 1994
Sep;58(3):283-307.
10.Bogduk N: The clinical anatomy of the
cervical dorsal rami. Spine 1982, 7:35-45.
11.Giles LGF, Harvey AR.
Immunohistochemical demonstration of nociceptors in the capsule and synovial
folds of human zygapophyseal
joints. Br J of Rheumatol. 1987; 26: 362-364.
12. Cramer G, Darby S . Basic and Clinical
Anatomy of the Spine, Spinal Cord and ANS. page 399. St. Louis Missouri; Mosby, 1995.
1 comment:
a specialty is always a welcome part.
Houston Orthopedist
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