Non-degenerative factors are presumed to account for as high as 90% of spinal deformities in young adults [10]. ASD patients often undergo long-segment thoracolumbar arthrodesis that extends to the lower lumbar spine or the sacral region, and this procedure is associated with more perioperative complications [6]. The treatment for adult non-degenerative scoliosis aims not only to prevent further progression but also seeks to improve the existing manifestations [14]. In this study, we collected a cohort of data on the perioperative complications after surgical treatment of adult non-degenerative scoliosis. The results of multivariate analysis reveal that the change in Cobb angle and spinal osteotomy are independent risk factors for the development of perioperative complications, the change in Cobb angle is an independent risk factor for the development of minor perioperative complications, the change in Cobb angle and spinal osteotomy are independent risk factor for the development of major perioperative complications.
Surgical treatment is recommended when conservative treatment proves unsatisfactory, and decompression surgery is essential for alleviating symptoms. Most surgeons recommend fusion and instrumentation techniques for decompression [15]. Thus, choosing the proper extent of the fusion is key to a successful surgery. Long fusion and instrumentation proved successful in correcting scoliotic curvature and coronal imbalance. For patients with a large Cobb angle and rotatory subluxation, long fusion should be carried out to minimize adjacent segment disease [6]. All the patients selected for our study had long fusions, and their levels of distal fusions were different. Stopping a fusion at L5 can lead to subsequent degeneration at L5-S1. If the fusion extends to the sacrum, the procedure would be more complex, and there is a higher likelihood of pseudarthrosis at the lumbosacral junction. However, studies have found that long fusions terminating at L5 or the sacrum was similar in overall complication rate and improvement in pain and disability [16, 17]. In our study, we found no association between the incidence of perioperative complications and the level at which the fusion stopped (P = 0.952). There is a new instrument method, the S2AI iliac screw, which is designed to fix drawbacks such as screw site prominence and wound complication, that can successfully avoid the complications associated with conventional iliac screws [18]. However, this presumed reduction in perioperative complications in the S2AI group was not detected by our study, which might be due to our limited sample size.
Focused on adult non-degenerative scoliosis patients who underwent long fusion surgeries, we collected and analyzed all the parameters deemed relevant according to our clinical expertise and previous research, which involved collecting the patients’ medical history, radiographic data, and clinical evaluations. Owing to the fact that most of our patients were relatively young, there was relatively little data on history of lumbar operation, previous medication use, or whether there were any age-associated comorbidities such as diabetes and osteoporosis, some of which could be potential risk factors for ADS. Several studies have reported a direct correlation between parameters such as the ASA grade, Cobb angle, total operation time, PT, level of fusion, LOS, staging, multiple surgeries and the incidence of perioperative complications in ADS [9, 19,20,21,22]. However, further research is needed to identify the risk factors for perioperative complications in adult non-degenerative scoliosis.
In this study, change of main Cobb angle were significantly associated with the risk of minor and major perioperative complications. We included changes of all parameters in our analysis, which have rarely been reported in previous studies. Previous studies have shown that preoperative magnitude of the spinal curvature and coronal imbalance was associated with the likelihood of complications. Some author reported that an increased Cobb angle is associated with impaired pulmonary function due to airway blockage [23]. A higher risk of postoperative non-neurological complications, pulmonary compromise in particular, could be caused by a larger Cobb angle in adults and juvenile scoliosis patients [24]. An increased Cobb angle causes abnormal chest and lung development and results in less reserved space for ventilation.
Osteotomy is an effective procedure to correct spinal deformity, but it is often accompanied by some complications. In the Sciubba’s study, they found that the most common complication after three-column osteotomies was neurological deficits [25]. In the Buchowski’s study, they reported that the incidence of neurological complications was 11.1% after lumbar pedicle subtraction osteotomies (PSO) [26]. In our study, osteotomy procedure was significantly associated with the risk of total perioperative complications (P = 0.043, OR = 3.565, 95% CI = 1.039, 12.236) and major perioperative complications (P = 0.036, OR = 4.475, 95% CI = 1.960, 20.861). We consider that osteotomy procedure is usually associated with large surgical injury, which not only causes a high incidence of nerve injury, but also leads to abnormal homeostasis and stress states in patients. The combined effect of these factors may lead to the occurrence of complications.
There are some limitations to our study. First, the most significant being its retrospective nature. Second, in this study, all of the data was obtained from single medical center, and results were not validated by other centers. Third, due to the relatively young age of many of our patients, the effect of comorbidities that are more prevalent in elderly populations could not be adequately investigated.
In summary, we observed a 21 of 146 patients experienced complications during the perioperative periods. The change in Cobb angle and spinal osteotomy may contribute to the development of perioperative complications. The identification of these risk factors has potential to help stratify preoperative risks and reduce the incidence of complications.