Effects of Andersson lesion treatment in ankylosing spondylitis: A medical record review study focused on medium- to long-term outcomes

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.

Clinical Observation of Posterior Approach for Surgical Treatment of Thoracolumbar Pseudarthrosis in Ankylosing Spinal Disorders

OBJECTIVE

The objective of this study was to evaluate the surgical effectiveness of posterior procedure with long segment stabilization for treating thoracolumbar pseudarthrosis associated with ankylosing spinal disorders (ASDs) without anterior fusion or osteotomy.

METHODS

Twelve patients with thoracolumbar pseudarthrosis in ASD were enrolled. All patients underwent posterior long-segment stabilization procedures. In some patients, the percutaneous technique or the aid of a robot or O-arm navigation was utilized for pedicle screw implantation. The clinical results were evaluated by means of the visual analog scale and Oswestry Disability Index. Radiological outcomes were evaluated for bone fusion, anterior column defect, local kyphotic correction, and position of the pedicle screws.

RESULTS

All patients experienced effective bone fusion at the sites of pseudarthrosis. The mean operative time was 161.7 ± 57.1 minutes, and the average amount of blood loss was 305.8 ± 293.2 mL. For 6 patients who underwent surgery with the assistance of a robot or O-arm navigation, there was no statistically significant difference observed in terms of operative time and mean blood loss compared to those who used the freehand technique (P > 0.05). The visual analog scale score, Oswestry Disability Index value, and mean local kyphotic angle showed significant improvements at the final follow-up (P < 0.05). The accuracy of pedicle screw placement was 96%.

CONCLUSIONS

Posterior surgery with long-segment fixation, without anterior fusion or osteotomy, can achieve satisfactory outcomes in ASD patients with thoracolumbar pseudarthrosis. The application of percutaneous techniques, as well as the assistance of robots or navigation technique may be a good choice for the treatment of pseudarthrosis in ASD patients.

Surgical Treatment of Andersson Lesion of the Lumbar Spine with Minimal Invasion: A Case Report

We present a 37-year-old female patient with AL of lumbar spine (L3-4) treated by OLIF combined with pedicle screw fixation (via Wiltse paraspinal approach) with relatively minimal invasion.

Transfer of microRNA-22-3p by M2 macrophage-derived extracellular vesicles facilitates the development of ankylosing spondylitis through the PER2-mediated Wnt/β-catenin axis

Pathological osteogenesis and inflammation possess critical significance in ankylosing spondylitis (AS). The current study aimed to elucidate the mechanisms regarding extracellular vesicle (EV)-packaged microRNA-22-3p (miR-22-3p) from M2 macrophages in the osteogenic differentiation of mesenchymal stem cells (MSCs) in AS. EVs were initially isolated from M2 macrophages, which had been treated with either restored or depleted miR-22-3p. AS-BMSCs were subsequently treated with M2 macrophage-derived EVs to detect osteogenic differentiation in BMSCs using gain- or loss-of-function experiments. The binding affinity among miR-22-3p, period circadian protein 2 (PER2), and Wnt7b was identified. Finally, AS mouse models were established for testing the effects of M2-EV-miR-22-3p on the bone metastatic microenvironment in vivo. miR-22-3p from M2 macrophages could be transferred into BMSCs via EVs, which promoted the osteogenic differentiation of AS-BMSCs. miR-22-3p inhibited PER2, while PER2 blocked the Wnt/β-catenin signaling pathway via Wnt7b inhibition. M2-EV-shuttled miR-22-3p facilitated alkaline phosphatase activity and extracellular matrix mineralization via PER2-regulated Wnt/β-catenin axis, stimulating the BMSC osteogenic differentiation. Taken together, these findings demonstrate that miR-22-3p in M2 macrophage-released EVs downregulates PER2 to facilitate the osteogenesis of MSCs via Wnt/β-catenin axis.

Ankylosing spondylitis complicated with andersson lesion in the lower cervical spine: A case report

BACKGROUND

Andersson lesion (AL) is an uncommon complication in ankylosing spondylitis (AS), which is characterized by nonneoplastic bone destruction and often appears as bone destruction and sclerosis in the vertebral body and/or the area involving the intervertebral disc. According to the literature, Andersson lesion commonly occur in the thoracic and lumbar spine and rarely in the cervical spine.

CASE SUMMARY

This case involved a 78-year-old man with a long history of AS who developed AL in the cervical spine (C5/6 and C6/7). One-stage anterior-posterior approach surgery was successfully performed. At the 6-month follow-up, the pain was significantly reduced, and the limb function was gradually improved.

CONCLUSION

AL uncharacteristically appears in the cervical spine and tends to be misdiagnosed as vertebral metastases or spinal tuberculosis. Posterior combined with anterior surgery achieves solid biological stabilization in the treatment of AL bone destruction.

Occult Andersson lesions in patients with ankylosing spondylitis: undetectable destructive lesions on plain radiographs

Background:

Andersson lesions (ALs) are not uncommon in ankylosing spondylitis (AS). Plain radiography (PR) is widely used for the diagnosis of ALs. However, in our practice, there were some ALs in AS patients that could not be detected on plain radiographs. This study aimed to propose the concept of occult ALs and evaluate the prevalence and radiographic characteristics of the occult ALs in AS patients.

Methods:

A total of 496 consecutive AS patients were admitted in the Affiliated Drum Tower Hospital, Medical School of Nanjing University between April 2003 and November 2019 and they were retrospectively reviewed. The AS patients with ALs who met the following criteria were included for the investigation of occult ALs: (1) with pre-operative plain radiographs of the whole-spine and (2) availability of pre-operative computed tomography (CT) and/or magnetic resonance imaging (MRI) of the whole-spine. The occult ALs were defined as the ALs which were undetectable on plain radiographs but could be detected by CT and/or MRI. The extensive ALs involved the whole discovertebral junction or manifested as destructive lesions throughout the vertebral body. Independent-samples t test was used to compare the age between the patients with only occult ALs and those with only detectable ALs. Chi-square or Fisher exact test was applied to compare the types, distribution, and radiographic characteristics between detectable and occult ALs as appropriate.

Results:

Ninety-two AS patients with a mean age of 44.4 ± 10.1 years were included for the investigation of occult ALs. Twenty-three patients had occult ALs and the incidence was 25% (23/92). Fifteen extensive ALs were occult, and the proportion of extensive ALs was significantly higher in detectable ALs (97% vs. 44%, χ² = 43.66, P < 0.001). As assessed by PR, the proportions of osteolytic destruction with reactive sclerosis (0 vs. 100%, χ² = 111.00, P < 0.001), angular kyphosis of the affected discovertebral units or vertebral body (0 vs. 22%, χ² = 8.86, P = 0.003), formation of an osseous bridge at the intervertebral space adjacent to ALs caused by the ossification of the anterior longitudinal ligament (38% vs. 86%, χ² = 25.91, P < 0.001), and an abnormal height of the affected intervertebral space were all significantly lower in occult ALs (9% vs. 84%, χ² = 60.41, P < 0.001).

Conclusions:

Occult ALs presented with more subtle radiographic changes. Occult ALs should not be neglected, especially in the case of extensive occult ALs, because the stability of the spine might be severely impaired by these lesions.

Case Report: Identifying Andersson-Like Lesions in Diffuse Idiopathic Skeletal Hyperostosis

Andersson lesions (ALs) in ankylosing spondylitis (AS) pose a severe risk to the stability of ankylosed spine, which might result in significant deterioration of spinal cord function after traumatic or inflammatory causes. Herein, erosive discovertebral lesions in diffuse idiopathic skeletal hyperostosis (DISH) presented important clinical similarities to AL in AS, but failed to completely recognize unstable spinal lesions. Therefore, we pioneered to identify spinal discovertebral lesions similar to Andersson-like lesions (ALLs) in DISH, followed by the characterization and summarization of the etiology, radiology, laboratory results, clinical symptoms, and treatment strategies for AL in AS with ALL in DISH. By characterizing the ALL in DISH cases, we showed that the ALL was mainly traumatic and established at the junction of focal stress between two adjacent ossified level arms. Erosive discovertebral ALLs were formed after trivial stress of direct impact and could be subdivided into transdiscal, transvertebral, and discovertebral types radiologically. Patients who presented with ALL frequently suffered from consistent back pain clinically and experienced a decrease in motion ability that could reflect skeletal stability, which received treatment effectiveness after conservative external spinal immobilization or further surgical internal fixation, indicating the significance of recognizing ALL in the ankylosed DISH spine to further maintain spinal stability in order to prevent catastrophic neurologic sequelae. Our work highlighted the clinical relevance of ALL in DISH in comparison with AL in AS, which provided broader insight to identify ALL in DISH, thus facilitating early intervention against DISH deterioration.