Ankylosing Spondylitis

Ankylosing spondylitis, which is more common in men than women, involves ossification of ligaments at their attachment to bone. Progressive ossification involves the joint cartilage and disk space of the axial skeleton, with eventual ankylosis. Arthritis and ankylosis may also develop in the hips, shoulders, and costovertebral joints.^[14]

Lung function is somewhat impaired from the development of rigidity of the rib cage. Vital capacity is minimally reduced if diaphragmatic activity is preserved.^[15] Aortic regurgitation and bundle branch block may develop, necessitating aortic valve replacement or pacemaker insertion. ^[16] Because there is an ever-present risk of spine fracture and cervical spine instability in these patients, careful positioning in the operating room is important^[17] ( Table 61-3 and Table 61-4 ).

Anesthetic considerations include use of fiberoptic techniques for tracheal intubation,^{[13] [18] [19]} positioning the patient while the patient is awake, and the choice of axillary rather than interscalene blocks when using regional techniques in the upper extremity. Caudal anesthesia can be readily obtained. The vertebral column is usually fused, making lumbar epidural or spinal anesthesia difficult or impossible. In patients who can still move the neck, fusion of the lumbar spine may be incomplete,^[20] enabling epidural or spinal anesthesia to be performed successfully.