Single versus dual operative spine fractures in ankylosing spondylitis

Analysis of risk factors affecting postoperative neurological recovery in patients with cervical spine fracture in ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic progressive inflammatory disease that mainly affects the spine and involves the sacroiliac and peripheral joints. Low-energy trauma can often lead to spinal fractures and spinal cord injuries (SCIs), the treatment of AS is challenging. The prognosis of neurological function in patients with AS cervical fracture and SCI is a major problem that must sought clinician attention on urgent basis. A total of 106 patients with AS cervical fractures who underwent surgical treatment at Shanghai Changzheng Hospital between August 2009 and 2021 were included in this study. All the patients were divided into 2 groups (improved group and the control group) based on their neurological function improvement at 1 year mark after the surgery. The baseline characteristics, perioperative factors, and procedural outcomes of all the patients including injury type, AS drug treatment, the injured segment, ossified anterior longitudinal ligament injury, spinal hypersignal, decompression time window, operation duration, blood loss, preoperative and postoperative American Spinal Injury Association (ASIA) score were recorded and analyzed. Among the 106 patients, 79 demonstrated improved neurological function at 1 year mark after the surgery. Binary univariate logistic regression analysis revealed significant differences in injury type (P = .018), ossified anterior longitudinal ligament injury (P = .01), operation duration (P = .002), spinal hypersignal (P = .001), preoperative ASIA score (P < .001), and prior AS drug treatment (P = .012). No significant differences were observed in the other variables (P > .05). Binary multivariate logistic regression analysis identified spinal hypersignal (OR = 37.185, P = .028), preoperative ASIA score (OR = 0.16, P = .012) and previous AS drug treatment (OR = 0.296, P = .049) as factors associated with postoperative neurological function improvement. The preoperative ASIA score and previous drug treatment of AS were identified as protective factors affecting the improvement of neurological functions in patients with AS cervical fracture after surgery. Preoperative T2-weighted spinal hypersignal was identified as an independent risk factor affecting the improvement of neurological function recovery in patients with AS cervical fracture after the surgery.

Surgical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with ankylosing spondylitis

BACKGROUND

Spinal fractures in patients with ankylosing spondylitis (AS) mainly present as instability, involving all three columns of the spine, and surgical intervention is often considered necessary. However, in AS patients, the significant alterations in bony structure and anatomy result in a lack of identifiable landmarks, which increases the difficulty of pedicle screw implantation. Therefore, we present the clinical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with AS.

METHODS

A retrospective review was conducted on a series of 12 patients diagnosed with AS. All patients sustained thoracolumbar fractures between October 2018 and October 2022 and underwent posterior robotic-assisted percutaneous fixation procedures. Outcomes of interest included operative time, intra-operative blood loss, complications, duration of hospital stay and fracture union. The clinical outcomes were assessed using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). To investigate the achieved operative correction, pre- and postoperative radiographs in the lateral plane were analyzed by measuring the Cobb angle.

RESULTS

The 12 patients had a mean age of 62.8 ± 13.0 years and a mean follow-up duration of 32.7 ± 18.9 months. Mean hospital stay duration was 15 ± 8.0 days. The mean operative time was 119.6 ± 32.2 min, and the median blood loss was 50 (50, 250) ml. The VAS value improved from 6.8 ± 0.9 preoperatively to 1.3 ± 1.0 at the final follow-up (P < 0.05). The ODI value improved from 83.6 ± 6.1% preoperatively to 11.8 ± 6.6% at the latest follow-up (P < 0.05). The average Cobb angle changed from 15.2 ± 11.0 pre-operatively to 8.3 ± 7.1 at final follow-up (P < 0.05). Bone healing was consistently achieved, with an average healing time of 6 (5.3, 7.0) months. Of the 108 screws implanted, 2 (1.9%) were improperly positioned. One patient experienced delayed nerve injury after the operation, but the nerve function returned to normal upon discharge.

CONCLUSION

Posterior robotic-assisted percutaneous internal fixation can be used as an ideal surgical treatment for thoracolumbar fractures in AS patients. However, while robot-assisted pedicle screw placement can enhance the accuracy of pedicle screw insertion, it should not be relied upon solely.