Vertebral Column Resection for Ankylosing Spondylitis Kyphosis

Radiographic findings of ankylosing spondylitis including ankylosis of sacroiliac joints and facet joints of the spine, progressive sclerosis, ossification of annulus fibrosus, anterior longitudinal ligament, interspinous ligament, and interlaminar ligament. With the progression of disease, back pain gradually fades away while interspinous and interlaminar bony ankylosis forms. Finally, the spine presents a “bamboo segment,” indicating ankylosis of the vertebral body and vertebral arch of multiple levels. At this time, pathological changes cause severe loss of motion as well as lumbar lordosis. Meanwhile, compensatory kyphosis of thoracic and cervical segments occurs, forming a long curve of kyphosis which looks like a wheel on the lateral X-ray (Fig. 6.1). The ankylosing deformity keeps the head in flexion. The patient is forced to maintain balance and look straight ahead by a compensatory knee and hip flexion (Fig. 6.2). With kyphosis, the patient has to lie in a lateral position instead of a supine position (Fig. 6.3). As explained earlier, structural spinal deformity of ankylosing spondylitis affects patients’ physiological function and even causes psychological depression.