Ankylosing spondylitis (AS) is a chronic progressive inflammatory disease that primarily
It affects the medial bones, including the spine, sacroiliac joints, and hip joints, causing local pain and progressive joint stiffness, and eventually leading to bony ankylosis and deformity of the joints. The pathology of AS predisposes AS patients to spinal fractures, and when fractures do occur, they often have serious consequences. AS
The spinal fracture associated with AS has its own characteristics in terms of mechanism of injury, incidence, location, imaging features, diagnosis, treatment, and complications, which are different from the general spinal fracture. Therefore, misdiagnosis, underdiagnosis or improper management of spinal fractures are
The report is common. The normal intervertebral discs and ligaments are flexible, making it possible for the spine to move in all directions and to slow down the shock forces. AS
After ossification of the intervertebral discs and ligaments, the elasticity and mobility of the discs and ligaments are significantly reduced, and the texture of these ossified ligaments is often brittle, making it easy for the ossified ligaments to rupture when the spine is stretched backward. In addition, AS
In addition, AS often causes osteoporosis of the vertebral body, resulting in a significant decrease in the ability of the vertebral body to resist compression and tension. These changes increase the risk of spinal fracture in patients with AS, and a minor trauma or chronic strain can result in a fracture of the spine.
Minor trauma or chronic strain can cause transverse fractures of the vertebral body or rupture of the ossified discs and ligaments. Because the anterior longitudinal ligament p intervertebral disc p posterior longitudinal ligament p interspinous ligament and joint capsule ligament of the spine can ossify, causing the straightened spine to move toward a long bone, AS
Once a fracture occurs, it often involves the anterior, middle, and posterior spinal columns at the same time, making the fracture very unstable. The posterior deformity of the spine is often associated with AS, which increases the leverage of the spine and concentrates the strong leverage on the fracture line.
The strong leverage force is concentrated on the fracture line, making the fracture prone to dislocation and pseudarthrosis formation. The incidence of AS spinal fractures varies from 1.5% to 23%. Although the overall incidence is not too high, the incidence of AS with spinal fracture is 3.5 times higher than the normal incidence of spinal fracture.
The incidence is 3.5 times higher than normal. The disease is most likely to occur in the lower cervical spine and the cervicothoracic junction, which may be related to the anatomical features of the lower cervical spine, the cervicothoracic junction and the
The thoracolumbar segment is the junction of the relatively fixed thoracic spine and the more mobile cervical and lumbar spine, where stresses are relatively concentrated. Traumatic injuries leading to AS spine fractures tend to be mild. The mechanism of injury is mostly hyperextension injury. Most fractures are tricolumnar and are prone to subluxation. AS spine fractures are more likely to be associated with spinal cord (nerve) injury, particularly cervical spine fractures with cervical spinal cord injury. This may be due to the fact that AS
This may be due to the fact that most spinal fractures in AS involve the anterior, middle, and posterior columns at the same time, so the fractures are often relatively unstable. In addition, patients with ankylosing spondylitis have osteoporosis of the vertebral body, and cancellous bone bleeds after fracture.
In addition, patients with ankylosing spondylitis have more cancellous bone bleeding after fracture and are more prone to epidural hematoma, which may also contribute to nerve injury after fracture. The incidence of thoracolumbar fractures with nerve injury is less common in AS than in the cervical spine. The mortality rate of AS spinal fractures is high. The main causes of death are pulmonary failure and cerebrovascular accidents. Most AS spinal fractures are transverse to the intervertebral space, which is the weakest point of the ankylosing spine. AS spinal fractures can be characterized by three types of imaging: fresh fractures and/or dislocations, also known as shear fractures ( s hearing fracture
The fractures are: fresh fractures and/or dislocations, also known as shear fractures ( s hearing fracture ); pseudoarticular formation or stress fractures; and vertebral compression fractures. These fractures occur mostly in the cervical spine, often with a clear history of minor trauma, and the mechanism of injury is mostly hyperextension. After the injury, there are symptoms such as local pain and limitation of movement, and most of them are accompanied by nerve (spinal cord) injury. Fracture lines can be seen on radiographs in fresh fractures, and fractures usually involve all three columns. In anterior and middle column fractures through the vertebral body, the
The fracture line can be seen on the vertebral body in a transverse or oblique direction. When the fracture passes through the intervertebral space, the fracture line is often difficult to see in the intervertebral disc
The fracture line is often difficult to see in the intervertebral disc, but an ossified rupture of the anterior longitudinal ligament can be seen. Posterior column fractures often present as a fracture of the vertebral plate in the same segment, a fracture of the articular process in the same or adjacent segments, or a fracture of the posterior column.
Fractures of the articular processes in the same segment or adjacent segments may also present as a disruption of the continuity of the interspinous ligaments with ossification and fusion. Due to the altered biomechanical properties of the spine, the fracture is often accompanied by
The fracture is often accompanied by displacement, including anterior separation of the intervertebral space and posterior angular displacement, and in severe cases, subluxation or subluxation, but the degree of displacement and subluxation is often mild. Stress fractures (or pseudarthrosis) and their radiographic manifestations This type of lesion often occurs in the thoracic and lumbar spine, and is particularly common in the thoracolumbar segment. There is often no clear history of trauma. It is most often found incidentally during radiographs for low back pain or other diseases. Nerve injuries are rare and, if present, are often mild. The characteristic change on radiographs of stress fractures is the presence of a destructive disc-vertebral body lesion (Anderssons lesion) in the disc at the fracture plane.
Andersson’s lesion is characterized by extensive subchondral bone destruction on the endplates of the two adjacent vertebral bodies, with irregular margins and surrounding osteochondral sclerosis. The intervertebral disc space may be irregularly widened. Although AS spine fractures are not difficult to diagnose, the trauma that causes the fracture is often more severe. However, because the trauma causing the fracture is often mild, or even without obvious trauma, it is easy to miss or misdiagnose the fracture.
It is easy to miss or misdiagnose, especially when the patient does not have paraplegia after the injury. Once the diagnosis is missed or misdiagnosed
This can often lead to serious consequences. There have been reports of pseudarthrosis being misdiagnosed as vertebral tuberculosis and vertebral tumor, and there are also reports of lower cervical fractures being misdiagnosed as clavicle fractures. The main reasons for delayed diagnosis are as follows: ( 1 ) the violence causing the fracture is often small, most of them are falls while walking, and some of them have no obvious history of trauma and do not attract the attention of patients and physicians; ( 2 ) ankylosing spondylitis
(2) The long-term pain of ankylosing spondylitis increases the patient’s tolerance for pain, and the pain caused by the fracture is either masked by the pain of AS itself or mistakenly perceived as a “relapse” of ankylosing spondylitis by the patient and physician; ( 3) These fractures tend to occur in the lower part of the spine.
(3) These fractures tend to occur in the lower cervical spine and at the cervicothoracic junction, where the obstruction of the shoulder often makes it difficult to detect the fracture on plain radiographs; (4) Calcification of the ligaments and osteoporosis in the ankylosing spine itself sometimes make the fracture line difficult to identify.
The fracture line is sometimes difficult to identify. (5) Ischemic necrosis at the fracture end and traumatic osteosclerosis are easily misdiagnosed as chronic bacterial inflammation of the vertebral body; (6) some physicians lack adequate knowledge of the fracture. Therefore, for a patient with a history of AS, if there is a new or aggravated neck pain p thoracic back pain or low back pain, which is not significantly relieved by bed rest, there is no significant relief.
without significant relief after bed rest and a history of mild or severe (often milder) trauma, the possibility of an accompanying spinal fracture should be highly suspected.
The possibility of a spinal fracture is highly suspected. In the absence of a clear history of trauma, the possibility of a spinal fracture should also be considered. Once a spinal fracture is clinically suspected
A full frontal and lateral spine film should be taken routinely on the basis of a careful clinical examination to identify the presence and location of fractures and to avoid missing less symptomatic or asymptomatic fractures. If there is a high clinical suspicion of a fracture and plain X-rays do not provide evidence of fracture, a full ortho-lateral radiograph is routinely taken.
If there is a high clinical suspicion of fracture and plain X-rays do not provide evidence of fracture, additional tomography or CT (including 3D reconstruction) should be performed. If the tomogram and CT are still normal
If the fracture is still normal on tomography and CT and cannot be completely excluded clinically, a bone scan may be useful to clarify or exclude the diagnosis. MRI is also a valuable adjunct in patients with concomitant nerve injury, or in cases of pseudarthrosis, and in those with clinically suspected epidural hematoma.
MRI is also a valuable adjunctive test in patients with associated nerve injury or pseudarthrosis, and in those with clinical suspicion of epidural hematoma. Since most spinal fractures associated with ankylosing spondylitis are unstable fractures, once the diagnosis is established, close attention should be paid to the patient during transport and transport.
Once the diagnosis is established, close attention should be paid to the patient’s position and reliable fixation of the fracture site during transport and transportation, otherwise it may cause serious consequences. Unlike a
Unlike normal spinal fractures, the direction of preoperative traction for ankylosing spondylitis fractures should be consistent with the direction of the original deformity and should not be excessive in weight. The early literature on the treatment of spinal fractures associated with ankylosing spondylitis recommended conservative treatment. The main reason for this is that some
The main reason is that ankylosing spondylitis is a systemic disease, often associated with damage to other organs of the body, especially the respiratory organs.
There are many surgical complications, high surgical risk and high mortality. However, in recent years, with the advancement of anesthesia and surgical techniques, more and more scholars advocate surgical treatment.
These authors believe that surgical treatment can better stabilize the spine than conservative treatment.
These authors believe that surgery is a better way to stabilize the spine than conservative treatment, as well as a more direct way to relieve nerve compression and to avoid complications associated with long-term traction and external fixation.
Therefore, for patients with ankylosing spondylitis combined with spinal fractures, surgical treatment is feasible as long as the patient is physically able to do so. The main goal of surgical treatment for this disease is also decompression and fusion stabilization. The choice of decompression method is not very different from that of a normal spinal fracture.
The choice of decompression depends on the source of compression, but most scholars believe that simple laminectomy decompression is unacceptable for patients with ankylosing spondylitis spinal fractures. Because the fracture involves all three columns and has poor stability, ankylosing spondylitis spinal fractures, unlike normal spinal fractures, require more fusion and stability.
The fusion and stability requirements for fractures are higher. Most scholars advocate a 360-degree fusion in cases of tricolumn fractures and pseudoarthrosis.
fusion. Internal fixation is also necessary for patients with ankylosing spondylolisthesis fractures. In order to reduce the stress on the internal fixation
In order to reduce the stress on the internal fixation and to avoid loosening of the fixation due to osteoporosis, it has been suggested that posterior fixation should not be limited to the fracture gap, but should be extended 1-2 segments up and down. Because of the relatively low stress on the cervical spine, simple anterior interbody fusion with plate fixation may also be able to stabilize the fracture locally and thus promote fracture healing. Because ankylosing spondylitis is a systemic disease, the incidence of pulmonary and cardiovascular complications after fracture is higher than that of a typical spinal fracture.
The mortality rate is also much higher than that of a typical spinal fracture. In addition, the osteoporosis of the vertebral body causes more intraoperative bleeding
In addition, the osteoporosis of the vertebral body makes intraoperative bleeding more frequent, and the ossification of the ligaments makes the normal bone structure illegible, which makes the operation more risky. Therefore, care should be taken to avoid such complications.