Introduction: Patients with Ankylosing Spondylitis (AS) are predisposed to thoracolumbar fractures with benign injuries.
Methods: Retrospective chart of 19 patients with AS who suffered thoracolumbar spinal fractures requiring surgery between 1992 and 2011 and with a minimum follow up of 6 months were reviewed. The average age ±SD was 63±16 (range: 43-94), 15 were males. Average follow-up was 31 months (range 6-132). Clinical and radiological outcomes were evaluated using preoperative and postoperative ASIA scoring system and Cobb’s angle.
Results: Seven patients (37%) suffered thoracic spine fractures (T1-T10), Eight (42%) thoracolumbar fractures (T11-L2), and three (33%) lumbar fractures (L3-S1). The most frequent levels injured were T11-T12 (n = 5, 26%) and T9-10 (n = 4, 21%). The mechanism of injury in 15 patients was low impact. On admission, three patients had an ASIA score of A (16%), and nine patients (47%) had an ASIA score of E. The remainder (63%) had incomplete spinal cord injury (SCI) with ASIA scores of B (n=1), C (n=3), and D (n=3). Sixteen patients (84%) had extension fractures, two patients suffered flexion distraction injuries and one burst fracture. Surgical management included dorsal long segment fixation in all patients, with pedicle screws in 15 patients. One patient required osteotomy for correction of kyphotic deformity. Complications included one wound infection, and one hardware failure requiring revision. The ASIA score improved in 4 patients (21%), and was unchanged in 14 patients (73%). One patient had deterioration from class E to D. All patients with class A did not improve. Average improvement in Cobb’s angle was 11 ±12 degrees.
Conclusions: Over 60% of patients with AS suffering from thoracolumbar fracture had associated SCI. The most common fractures are extension distraction with 3 column involvement. Dorsal long segment fixation was adequate to treat these injuries.
Patient Care: 1) increase the index of suspicion on SCI and spinal fractures in AS patients, 2) offer better care when handling AS patients and/or transferring them, 3) offer a better management to spinal fractures in AS that is evidence based, 4) counsel patients and their family on the outcome and expectation of treatment.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) understand mechanism of SCI injury in AS, 2) incidence of SCI and outcome in AS with thoracolumbar fractures, 3) recognize the necessity of surgical intervention in dealing with these cases, 4)understand the nature of fractures in AS, and their extreme instability.