Rheumatoid disease of the spine is a morbid consequence of untreated longstanding severe cervical spinal

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...

(RA)–an inflammatory autoimmune disease that attacks the

ligament A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal li ...

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw ...

s, and bones of the neck. Although the

anterior Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

subluxation A subluxation is an incomplete or partial dislocation of a joint or organ. According to the World Health Organization (WHO), a subluxation is a "significant structural displacement", and is therefore always visible on static imaging studies, suc ...

of the atlantoaxial joint is the most common manifestation of the disorder, subluxation can also occur with posterior or vertical movement, and subaxial (below C2) joints can also be involved.

Signs and symptoms

Atlantoaxial instability is a common asymptomatic finding in rheumatoid arthritis patients. However, it can lead to cervical

myelopathy Myelopathy describes any neurologic deficit related to the spinal cord. The most common form of myelopathy in humans, '' cervical spondylotic myelopathy (CSM)'', also called ''degenerative cervical myelopathy'', results from narrowing of the spina ...

. Patients with atlantoaxial instability can experience neck pain and headaches in the back of the head (occipital headaches). Myelopathic symptoms include: weakness,

gait disturbance Gait deviations are nominally referred to as any variation of standard human gait, typically manifesting as a coping mechanism in response to an anatomical impairment. Lower-limb amputees are unable to maintain the characteristic walking pattern ...

, paresthesias, and loss of dexterity (e.g. difficulty buttoning clothing).

Causes

The inflammatory mediators of RA including

cytokine Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...

growth factor A growth factor is a naturally occurring substance capable of stimulating cell proliferation, wound healing, and occasionally cellular differentiation. Usually it is a secreted protein or a steroid hormone. Growth factors are important for regu ...

metalloproteinase A metalloproteinase, or metalloprotease, is any protease enzyme whose catalytic mechanism involves a metal. An example is ADAM12 which plays a significant role in the fusion of muscle cells during embryo development, in a process known as myogen ...

s destroy

articular cartilage Hyaline cartilage is the glass-like (hyaline) and translucent cartilage found on many joint surfaces. It is also most commonly found in the ribs, nose, larynx, and trachea. Hyaline cartilage is pearl-gray in color, with a firm consistency and h ...

, subchondral bone, tendons and ligaments. Destructive

synovitis Synovitis is the medical term for inflammation of the synovial membrane. This membrane lines joints that possess cavities, known as synovial joints. The condition is usually painful, particularly when the joint is moved. The joint usually swell ...

leads to bone erosion and causes the ligaments of the spine to become too laxed (loose), eventually resulting in cervical spinal instability (loose neck bones).

Diagnosis

Physical exam

On palpation, the examiner may find crepitus at the neck joint and unstable movement including a positive "clunk test" (palpable subluxation).

Lhermitte's sign Lhermitte phenomenon, also called the barber chair phenomenon, is an uncomfortable "electrical" sensation that runs through the back and into the limbs. The sensation can feel like it goes up or down the spine. It is painful for some, although oth ...

may be elicited with head flexion.

Imaging

As many as 50% of people with radiographic instability are actually asymptomatic. Initial radiography should include flexion and extension lateral X-rays in addition to static anterior/posterior and lateral views. These views are often repeated every 2–3 years, especially in patients with new symptoms or possibly requiring future

intubation Intubation (sometimes entubation) is a medical procedure involving the insertion of a tube into the body. Patients are generally anesthetized beforehand. Examples include tracheal intubation, and the balloon tamponade with a Sengstaken-Blakemo ...

. Progression of disease is measured via anterior atlantodental interval (AADI), and posterior atlantodental interval (PADI). Other techniques include the Ranawat Index, MacGregor Line, the Clark stations, and the Redlund-Johnell measurement.

Management

Up to 10% of patients with rheumatoid arthritis are at risk of sudden death due to unrecognized cord compression. Thus surgical intervention is a reasonable choice in the presence of a neurologic deficit as a result of instability. In fact, early surgery for atlantoaxial subluxation may actually delay the debilitating progress of myelopathy.

References

External links

{{Medical resources , DiseasesDB = 29409 Spine Rheumatology Arthritis