Ankylosing Spondylitis: Surgical Management - History

HISTORY

Ankylosing spondylitis (AS) is a systemic inflammatory disease that results in ossification of joints and entheses primarily of the hip, spine, and peripheral joints. The first signs of AS were first unearthed in the skeletal remains of a 5000 year–old Egyptian mummy. (9) Since then, such notable physicians as Realdo Columbo, (4) Bernard Connor, (14) Sir Benjamin Brodie (31) Charles Fagge, (31) and Carl von Rokitansky (31) all reported similar findings of AS in cadaveric specimens and patients. However, the first well–known description of AS was reported by W. von Bechterew in 1883.(3) Others, such as Adolph Strumpell in 1897 (39) and Pierre Marie in 1898 (33) were also among the first to offer a classic description of AS. Therefore, AS is also known as Bechterew Disease or Marie–Strumpell Disease.

GENERAL OVERVIEW

Ankylosing spondylitis belongs to a group of seronegative spondyloarthropathies. A chronic form of arthritis, AS is estimated to affect 1.4 % of the general population. (15) Severity of the disease varies among individuals as well as remission and exacerbation periods. Ankylosing spondylitis primarily affects the spine and hip joints causing progressed bone fusion including fusion of the costovertebral joints, erosion, destruction of the vertebral endplates, osteophytes, subchondral sclerosis, squaring of vertebral bodies, ossification of the intervertebral disc, narrowing of joints, and osteoporosis. Fusion of the spine mainly occurs at the lumbar level with progression cranially to the cervical spine. Enthesopathy, or inflammation of bone attachment to tendons, ligaments, and joint capsules also occurs. The spine adopts a long bone persona and is easily susceptible to fracture. As the spine undergoes chronic inflammation, the patient develops a more pronounced curvature to lessen the severity of pain (Fig. 1). The result is a fixed flexion deformity of the spine or otherwise referred to as a "bamboo spine" when viewed radiographically (Fig. 2). Such an irregular posture contributes to a loss of horizontal gaze, physiologically incorrect sagittal contour, physical embarrassment, respiratory restriction, and a higher risk for trauma.

The etiology of AS is unknown. More males seem to develop AS than females, but that may be due to the severity of the disease in males to seek medical attention. However, scientists believe that a genetic component exists which could account for AS. Calin and Fries reported that 90 % of U.S. Caucasians with AS tested positive for the HLA–B27 antigen. (10) Nevertheless, other studies believe that the HLA–B27 antigen is a weaker indicator for AS than originally reported. Furthermore, elevated ESR is also associated with AS. (48)

Diagnostic criteria were established by Calin in 1977 that composed of five items. (11) Sacroiliitis is predominately the first sign of AS manifesting as low back pain. Other criteria were established, such as the Rome criteria in 1961,(24) the New York criteria in 1966, (43) the Modified New York criteria in 1982. (43) Nevertheless, physicians generally look for signs of tenderness in the sacroiliac joints, Schober's test for lumbar flexion, Mennell's sign, chest expansion measurements, onset of pain, radiographic evaluation, and measurement of kyphotic deformity by the Cobb method and the chin–brow technique.