The original model of modern Halo vest was first introduced by Perry and Nickel in 1959 for the treatment of patients with poliomyelitis . Holla M found that the halo-vest was the most restrictive immobilizer and reduced movement of the cervical spine substantially for flexion-extension and lateral bending, and nearly complete for rotation . So we use halo vest to achieve reduction and immobilization by regulating the length of anterior and posterior bars of the halo vest for upper cervical spine fracture-dislocation in patients with AS. According to our experiences, there are three following advantages. First, they can walk freely with the vest in the ward for those neurologic intact patients. No lying in bed makes nursing convenient and decreases the perioperative complication. Secondly, there is no worry about displacement of fracture sites when an awake nasoendotracheal intubation and prone position was performed. Thirdly, closed anatomical reduction via halo vest make surgery to be simple. A standard internal fixation and fusion is enough and there is no need to perform open reduction via screws and rods in operation. In our case study, no secondary displacement occured before and during operation after halo vest and all patients obtained satisfactory restoration before incision.
It was reported that secondary deterioration of neurological status was observed in 13.9% AS patients . The risk of incurring a new onset neurodeficit after a cervical injury in patients with AS is at least 3 times that of the general population . After halo vest fixation in our cases, no patient presented with secondary neurologic deterioration, even they walk freely in the ward. Although halo vest has so many advantages in the reduction and immobilization for upper cervical spine fracture-dislocation in patients with AS, it has a high rate of complications when it is as a non-surgical treatment for these patients, including patient discomfort, dysphagia and aspiration, pin loosening, pin site infection, spinal instability, pin site infections, loss of reduction, and pressure sores [19–21]. The poor tolerability of the halo vest in the elderly has been also questioned . So, halo vest is only used for closed reduction and temporary fixation before and during operation in our case study.
Surgical management is still indicated in patients with neurological deficit, secondary deterioration of neurologic status, unstable fracture configuration, and the presence of an epidural hematoma . The options for surgical fixation of cervical spine fractures are anterior fixation, posterior fixation, and combined anterior- posterior fixation. Because anterior fixation has been associated with higher failure rates, posterior or combined anterior-posterior fixation should be considered [23,24]. Numerous case reports and series have demonstrated successful management of cervical spine fractures in patients with AS using posterior fixation alone[25–27]. Payer M concluded that combined surgical approach with posterior–anterior fixation/fusion has been reported to have many advantages, such as excellent deformity correction, direct and indirect decompression of the spinal cord, immediate stability, permission of early mobilisation without external immobilisation, and excellent maintenance of correction in the absence of relevant neck pain . However, the operation time, total costs, hospitalization lengths and complicationa are higher in combined anterior-posterior approach compared with posterior approach alone . According to Robinson Y, even though surgical treatment is associated with a considerable complication rate, it improved the survival of spinal fractures related to AS . After closed reduction via halo vest, we performed only posterior internal fixation and fusion. All the patients achieved bony fusion in one year. There was a significant improvement in the neurologic function.
Published complication rates of spinal fractures in patients with AS are high, ranging from 30–50% . Complications are reported at equally high rates in nonsurgically and surgically treated cohorts. Pneumonia and respiratory insufficiency, postoperative deep venous thrombosis, and wound infections are frequent postoperative complications. Westerveld et al found high complication rates in surgically treated patients, including instrumentation failure in 35%, neurologic deterioration in 14%, and wound infection in 10% .The rate of complications in this study is lower than previous estimates because our study only included patients with upper cervical spine fracture who usually presenting with minor neurologic defecit and therefore likely substantially underestimates the true likelihood of adverse events in this patient population.