Since the early 2010s, twenty spine surgeries have been performed on 20 AS patients in our center. Of 20 patients, 4 (25%) were women, 16 (75%) were men, and the mean age was 49.5 ± 9.73 years.
The duration between the initial diagnosis of AS and the surgery ranged from 5–17 years, with a mean of 9.95 ± 3.77 years.
Nine surgeries were performed in acute post traumatic phase for management of gross instability and/or neurological deficit due to trauma, out of which three were caused by falls, and the rest were consequences of motor-vehicle accident.
Other patients were surgery candidates due to the progressive disabling kyphotic deformity as a result of subacute or old traumatic spinal column injury.
The mean T-score for the neck of the femur was 2.46 ± 0.56, and for the vertebral body was − 2.2 ± 0.27.
Evaluation of the subjective pain, using the VAS scale, revealed a significant decrease from 7.70 ± 0.97 before the surgery to 3.20 ± 1.19 one year after the surgery (P-value < 0.05).
Among patients with gross instability following acute spinal trauma(n = 9), the site of the main fracture was the cervical region in five patients, and the proper surgical procedure was chosen considering the clinical and radiological status of the patients. In the other four patients, the lower thoracic levels were affected.
Neurological status was examined and compared with the Frankel scale. Of the nine patients with instability, the exam was completely intact in 5 patients, which remained unchanged after the surgery. Of the other four patients who had a deficit in the pre-operation evaluation, 3 had improvement after the surgical intervention, and only one patient with initial Frankel-A remained unchanged.
Disability was assessed with ODI for the deformity group and showed significant improvement with surgery (46.6 ± 1.7 vs. 17.22 ± 1.9, P-value < 0.05).
Osteotomy in all patients of the deformity group was single-level pedicle subtraction osteotomy (PSO), and the posterior spinal fixation (PSF) was performed in multiple levels based on the condition of the patients. The characteristics of the patients are presented in Table-1.
Radiologic evaluation of fusion was also performed for all patients utilizing plane X-rays, Computed Tomography (CT) scans, and Magnetic Resonance Imaging (MRI) both before and after the surgery. The spinal alignment indices such as sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and thoracic kyphosis(TK) were measured in every patient with deformity. The details of these indices are presented in Table-2.
The comparison of the pre-and post-operation indices revealed a significant correction, which was comparable to the normal population. The details of the changes in parameters are presented in Table-3.
Durotomy was the most common complication, with 11 cases of 20 (55%). During the surgical procedure, the mean estimated blood loss was 751 ± 460 ml, and the average duration of the hospital stay was 6 ± 3.67 days.
Figures 1 and 2 illustrate patients with progressive kyphotic deformity following traumatic spinal column injury and acute instability due to trauma before and after the surgery, respectly.