Spinal cord injury, spinal fracture, and spinal stenosis in ankylosing spondylitis

Abstract

The authors report a retrospective review of 105 patients with ankylosing spondylitis (AS) diagnosed over a 6-year period in Tucson, Arizona. In the series, there were 13 patients with spinal fractures and eight with severe spinal cord injury. Two patients with central cord contusion had no demonstrable cervical spine fracture. Injury was often trivial and dislocation at fractures sites was minimal, demonstrating the extreme fragility of these patients. Spinal stenosis, which has not previously been associated with AS, was documented in three cases. Pseudarthrosis, a destructive vertebral lesion that does not require surgical decompression or fusion, was found in four patients; this entity is believed to originate as a pathological or traumatic fracture. Atlanto-axial subluxation and basilar invagination associated with spinal ankylosis occurred in one patient. The study emphasizes the value of computerized tomography scanning of the spine for diagnosis, and halo-vest application as a nonoperative treatment for cervical immobilization. Early diagnosis and appropriate therapy to decompress, reduce, and immobilize unstable spinal lesions may result in reduction of the 29% mortality rate and 45% permanent neurological morbidity rate observed after spinal fracture in this series of AS patients. Because of the high operative complication rate observed, nonsurgical immobilization is the recommended treatment unless spinal dislocation or bone fragment displacement has occurred at the fracture site.

Cervical spinal cord injury complicating ankylosing spondylitis

“…Wilkinson and Bywaters (1958) noted two patients with lumbar fracture in a review of 222 AS patients who were followed for from one to 20 years (mean, 4.6 years). Weinstein et al (1982), in their study of 105 consecutive cases of AS, noticed that the frequency of spinal fracture was 12 per cent and the frequency of myelopathy was 8 per cent. In our study, the incidence of cervical cord injury in AS patients was 1.5 per cent over a period of 12 years.…”

Occult vertebral fractures in ankylosing spondylitis

“…Prompt rigid immobilization by either surgical or external means is required. 10,11 The consequence of delayed diagnosis of a spinal fracture in this population of patients is illustrated in two series by Trent et al and Broom and Raycroft. In the former, six of seven cases had diagnoses missed on initial examination and two of these developed a complete paraplegia.…”

Double spinal cord injury in a patient with ankylosing spondylitis

“…6 Weinstein et al stated that AS patients with spinal pain should be handled carefully during transfer and transport because of the risk of fracture or dislocation at a previous fracture site. 16 The second SCI in our patient was at T9, and was clearly detected as cord infarction on MRI performed in the second month after injury. The absence of any bone lesion and/or hematoma at that level on both CT and MRI indicated that the problem was vascular insu ciency.…”

“…2 ± 4 Another characteristic feature of spinal lesions in AS patients is discovertebral destruction or pseudoarthrosis, as was seen in our patient, in which the development of ®brous connective tissue at the site of fracture results in mobile nonunion. 2,5,15,16 It is suggested that the radiological appearance of pseudoarthrosis can be very similar to discovertebral infection, and recognition of this entity in AS patients may eliminate the need for needle biopsy or surgical exploration. 16 On MRI we detected severe bone destruction, and soft tissue component causing marked spinal stenosis in our patient at L2,3.…”

“…2,5,15,16 It is suggested that the radiological appearance of pseudoarthrosis can be very similar to discovertebral infection, and recognition of this entity in AS patients may eliminate the need for needle biopsy or surgical exploration. 16 On MRI we detected severe bone destruction, and soft tissue component causing marked spinal stenosis in our patient at L2,3. We postulated that the patient's previous fracture resulted in nonunion or pseudoarthrosis at the level of L2,3 and that his second fall caused a cauda equina syndrome due to the progression of stenosis, as he had described motor and sensory loss only in the distal portions of his lower extremities prior to cardiac arrest.…”