Many studies have analyzed complications or adverse outcomes in scoliosis surgery, but none describes a radiographic classification of adverse events for adolescent idiopathic scoliosis. Previous studies have been comprehensive surgeon-reported complication rates [1
]; descriptions of particular complications, such as infections [11
], superior mesenteric artery syndrome [4
], etc; complications related to a certain technique, such as thoracoscopic treatment [8
]; or complications compared between different techniques, such as hooks versus screws [5
]. Our aim was to define a radiographic system of adverse events and then test the system in 466 patients with Lenke Type 1 adolescent idiopathic scoliosis.
As with many descriptive studies, there are possible limitations to our study. First, the goal of our study was not to address all complications but only to classify complications visible on radiography. As a result, we did not include neurologic complications, wound problems, pain, and other symptoms that would not be visible on a radiograph. Second, we recognize some of these complications identifiable on radiographs require supplemental clinical material that can be evaluated after the complication is identified. As stated before, this study was not meant to try to establish a classification system based on radiographs that would predict whether a complication would happen. Our study was meant to describe postoperative complications seen on radiographs. Third, we focused on only patients with Type 1 curves so we could observe a cohesive subject population for this study. While this gave small numbers for statistical analysis, the overall goal of this study was to simply establish a classification scheme for surgical complications that can be further researched. Fourth, the criteria established for our classification was developed by a study group of more than 20 experienced spine surgeons and therefore is essentially based on expert opinion. However, there is no standard in the literature with which we can compare our criteria. The research presented here is important to further evaluate rates of postoperative complications among different surgical techniques and implants used during treatment for adolescent idiopathic scoliosis.
Several recent studies report complications related to the surgical treatment of scoliosis, some of which report a relatively high complication rate. An extensive review of the English language literature was recently published, focusing on 287 published scoliosis studies in which “rate of complication” was among the keywords [14
]. The authors included studies related to all different underlying diagnoses and found a complication rate from 0% to 89%. While comprehensive, this literature review does not offer the sort of specific adverse event data necessary to vet different technique options. One recent study exclusively evaluated inpatient complications in the United States between 1993 and 2002, using the National Inpatient Sample administrative database [9
]. Of the 51,911 patients who underwent surgery for idiopathic scoliosis over this 10-year period, the inpatient complication rate for “pediatric patients” was 14.9%, while the inpatient complication rate for adult patients was 25.1%. Pulmonary and postoperative bleeding were the most common complications in this series. Like the recently published literature review mentioned above, this study gives general complication rates (in this case just during hospital stay) but does not compare treatment methods or new technologies. Another recent study reported a 0.69% rate of neurologic complications in 1301 children undergoing spinal fusion and instrumentation for adolescent idiopathic scoliosis [3
]. In a study of nonneurologic complications in a cohort of 702 patients who underwent surgical correction of adolescent idiopathic scoliosis, it was concluded the complication rate was 15.4% [1
]. There were 10 respiratory complications (1.42%), six cases of excessive bleeding (0.85%), five wound infections (0.71%), and five cases of wound hematoma, seroma, or dehiscence (0.71%). Five patients, two with an early infection and three with late failure of the implant, required reoperation. The Scoliosis Research Society published a society-wide evaluation of complications in 2006 [2
]. The study reported, of the 1164 patients who underwent anterior fusion and instrumentation, 5.2% had complications; of the 4369 who underwent posterior instrumentation and fusion, 5.1% had complications; and of the 801 who underwent combined instrumentation and fusion, 10.2% had complications (Table ). There were two patients (0.03%) who died of their complications. The populations are quite large in these studies compared with our sample population, and therefore, their percentages of complications are smaller.
Comparison of presented complication data with cited literature
Regulatory bodies, third-party payors, and patients will increasingly scrutinize treatment methods based on the frequency of adverse events. We developed a simple, radiographic classification that can be applied objectively to any patient who has had surgical treatment of adolescent idiopathic scoliosis and who has had postoperative plain radiographs. Patient records are needed only in the case of unplanned trips to the operating room; in this scenario, perioperative images would signal the event, and then the operative note can be evaluated to identify the cause and treatment.
Of the four different treatment methods analyzed for this particular study of 466 healthy adolescents, none appeared inherently safer, although the complications did vary among the different treatment methods used. A prospective evaluation of our radiographic classification and others is underway, further enhancing its utility by surgeons, patients, payors, and regulatory bodies.