Spinal fractures in patients with ankylosing spondylitis

Abstract

Thirty-one consecutive patients with ankylosing spondylitis and spinal fractures were reviewed. There were 6 women and 25 men with a mean age of 60 +/- 11 years; 19 had cervical and 12 had thoracolumbar injuries. Of the patients with cervical fracture, two had an additional cervical fracture and one had an additional thoracic fracture. Three trauma mechanisms were identified: high-energy trauma in 13 patients, low-energy trauma in 13 and insufficiency fracture in 5. One-third of the patients suffered immediate neurological impairment, a further one-third developed neurological impairment before coming for treatment and only one-third remained intact. Two patients with thoracolumbar fractures had deteriorated neurologically due to displacements during surgery at other hospitals. All patients were treated operatively except the two patients with two-level cervical fractures, who were managed in halo vests. In the cervical spine both anterior and posterior approaches were employed. In the thoracolumbar spine the majority of the patients were initially treated using a posterior approach only. Complications were common. Of the 27 patients with neurological compromise, 10 had remained unchanged; 12 had improved one Frankel grade; 4 had improved by two Frankel grades; 1 had improved by four Frankel grades. We conclude that even minor trauma can cause fracture in an ankylosed spine. A high proportion of patients with spinal fractures and ankylosing spondylitis have neurological damage. The risk of late neurological deterioration is substantial. As the condition is very rare and the treatment is demanding and associated with a very high risk of complications, the treatment of these patients should be centralised in special spinal trauma units. A combined approach that stabilises the spine from both sides is probably beneficial.

Pedicle subtraction osteotomy through pseudarthrosis to correct thoracolumbar kyphotic deformity in advanced ankylosing spondylitis

“…Additionally, a fixed and rigid thoracolumbar kyphotic deformity often develops in patients with a long history of AS [7,8]. In the advanced AS patients with complete ankylosed spine, with increased stresses in the thoracolumbar junction, a stress fracture can occur with minor trauma or even without any trauma [19,21,24]. As the stress fracture level is always the last mobile joint between two ankylosed spinal segments, the continued movement at the fracture site eventually contributes to the development of pseudarthrosis [2,20].…”

“…In addition, AS is also associated with vertebral osteoporosis [18]. Therefore, AS patients in advanced stage are more susceptible to fracture due to the rigidity of the ossified spine and osteoporosis [18,19,22]. A stress fracture is most likely to occur in thoracolumbar junction, a region with tremendous stress forces concentrated [4].…”

Treatment of fracture and complication of cervical spine with ankylosing spondylitis

“…3,4 The main fracture location is the lower cervical spine and the cervicalthoracic junction. 5 ± 8 Non-operative treatment of cervical spine fractures in patients with AS often leads to pseudarthrosis due to the changed biomechanics with long lever arms and the complicated external ®xation using a halo-vest because of the kyphotic deformity.…”

“…9,10 Therefore, operative treatment of these fractures is bene®cial. 3,5,10 Nevertheless in operative treatment there are also some major problems related to AS. Due to the kyphotic deformity the anterior approach to the cervical spine is very di cult and the postoperative immobilization using a halo-vest is complicated.…”

“…In the light of this a combined anterior and posterior plate ®xation is the standard treatment in our clinic and also recommended by others. 3,10 Since there is no bene®t for the patient with AS in short fusions, multi-level instrumentations should rather be applied for better stabilization. In order to prevent loosening of the anterior plate and to avoid postoperative halo-vest immobilization biocortical screw ®xation should be considered due to an improved biomechanical stability compared to monocortical ®xation.…”