INTRODUCTION
The treatment of adult spinal deformity (ASD) is one of the most significant medical issues in countries with an aging society, with 60% of patients with ASD being elderly [
1,
2]. When considering treatment options, physicians must take into account various perspectives, basing their decisions on not only the presentation of ASD upon radiological imaging, but also on patient symptoms and quality of life [
3]. In other words, careful consideration should be given to the age, symptoms, and prognosis of patients before proceeding with surgical treatment for ASD [
3,
4]. It is especially pertinent as the management of ASD can require complex procedures such as multilevel arthrodesis and occasionally also 3-column osteotomy [
5]. Therefore, selecting the most appropriate surgical treatment strategy is important for enabling patients to maintain a good prognosis and experience fewer complications.
As in other countries, both orthopedic surgeons (OS) and neurosurgeons (NS) perform spinal surgeries in Korea. Although spine surgeon specialty has not been found to be significantly associated with the risk of 30-day complications in patients with single-level fusion [
6], hospital stay length and perioperative transfusion rates significantly differ between patients treated by OS and those treated by NS [
7]. However, few studies have reported on differences in the surgical strategies adopted by surgeons practicing in these fields. While OS tend to believe that the vertebra itself is the main factor to be considered in spinal surgery, NS tend to consider nerve decompression to be most important. Therefore, whether strategies for the surgical treatment of ASD differ between OS and NS needs confirmation.
The treatment of ASD may also differ according to doctors’ experience. In a questionnaire-based study of the spine surgeon selection criteria used by patients, Manning et al. [
8] found that patients prefer physicians younger than 65 years of age. The importance of physician experience in influencing surgical procedure decisions should therefore not be overlooked or underestimated, with the effect of career length on approaches to surgery for ASD also requiring confirmation.
We therefore aimed to clarify whether there are differences in the surgical strategy adopted for ASD among spinal surgeons in Korea. To this end, the 2016 International Spine Study Group (ISSG) questionnaire, which investigated nationality- and ethnicity-related differences in physicians’ opinions regarding appropriate surgical strategies, was used to survey our participants.
DISCUSSION
Increases in life expectancy have increased the prevalence of ASD, and the number of surgeries performed to treat this disease is growing accordingly. In 2009, Li et al. [
10] showed that patients over the age of 65 who underwent surgery for adult scoliosis experienced significantly less pain and had better healthrelated quality of life, higher self-image, and better mental health than those who underwent conservative treatment. Smith et al. [
11,
12] also showed in 2 separate studies that patients who underwent surgical treatment for ASD had reduced back and leg pain, as compared to those who did not undergo surgery to correct adult scoliosis. Taken together, these studies show that surgical treatment is more effective than conservative treatment. To maximize the possibility of achieving good postoperative outcomes, surgical strategies for ASD treatment should be carefully determined with consideration from various perspectives.
Although surgical strategies may differ between each hospital, differences in the training of OS and NS, as well as physicians’ length of surgical experience, are generally thought to be more important in determining surgical strategy selection. As in many other countries, both OS and NS perform spine surgeries for ASD in Korea. The training length for both specialties is similar; after graduating from medical school, most graduates complete a 1-year internship at a qualified hospital. They then choose a specialty and complete a 4-year residency course for that specialty. Therefore, the medical training pathway in Korea can reduce the confounding effect of training length, allowing the effect of training specialty (in our case, OS vs. NS) and experience length to be analyzed more accurately.
We found no significant differences in the surgical strategy adopted (i.e., nonfusion vs. fusion) between OS and NS, nor between the M10 and L10 groups. This suggests that there was no difference in surgical treatment planning for fusion regardless of specialty and career length. However, it is necessary to more closely examine responses to cases 2, 5, 12, and 13 (
Fig. 4). For both cases 2 and 5, opinions were evenly divided, with 50% of OS and 52.9% of NS deciding to proceed with fusion surgery. This discordance may be accounted for by the perspective taken by physicians when determining the most appropriate course of action. For example, some physicians may consider stenosis symptoms to be the main therapeutic target, while others may consider the correction of deformity in terms of coronal curve severity, sagittal factors, and SRS-Schwab classification to be more important. Therefore, surgeons may have answered the question differently depending on where their treatment was focused. Opinions were similarly discordant among both OS and NS for cases 12 and 13. Stenosis symptoms were predominant in these 2 cases, with mild scoliosis curves in the lumbar area.
As with responses to the question regarding fusion, there were no significant differences in whether surgeons would proceed with 3-column osteotomy between OS and NS, nor between the M10 and L10 groups. However, opinions on the appropriateness of 3-column osteotomy were more variable than those on the appropriateness of fusion. Opinions were particularly discordant among both OS and NS for cases 3, 4, and 15 (
Figs. 1-
3). Interestingly, for case 3, relatively young or less experienced surgeons tended not to opt for 3-column osteotomy, while opinions varied among more experienced physicians. It should be noted that the patient in this case had the largest SVA value and showed thoracolumbar kyphosis. It is interesting that most physicians in the L10 group thought that such deformity could be corrected by conventional fixation. If flexion and extension radiographs were also provided, it is likely that the distribution of answers would have been different.
However, it is important for physicians to apply careful consideration before proceeding with 3-column osteotomy for ASD as the procedure has both advantages and disadvantages. Although the 3-column osteotomy techniques of PSO, BDBO, and VCR are all dramatically effective in the correction of coronal or sagittal curves, PSO and VCR result in increased blood loss and lower fusion rates in older populations. These procedures are also associated with major complications such as inadvertent extubation, malignant hyperthermia, severe hypotension, cerebrovascular accident, myocardial infarction, nerve root injury, vascular/visceral injury, instrumentation or junctional failure, and major neurological deficits [
13]. Other studies have also shown that there has been a significant increase in complications after 3-column osteotomy [
14-
20]. Therefore, the necessity of 3-column osteotomy needs to be deliberately and cautiously determined, with the discordance among our surveyed doctors reflecting this prudence.
We also conducted multi-rater agreement analysis with the kappa statistic to assess agreement between groups. Multirater kappa values ranged from 0.365 to 0.477, indicating that answers were relatively reliable. Furthermore, the questions that were skipped for each of the 16 cases did not significantly differ between OS and NS. This demonstrates that strategies for ASD treatment do not differ between these specialties, which have important implications for treatment. Patients want standardized treatment as well as patient-tailored treatment. Our results suggest that this can be achieved as cases will be approached with the same surgical strategy regardless of whether they are being handled by OS or NS. Our results also suggest scope for interdisciplinary collaboration, with spine surgeons being able to offer a greater range of treatment options to patients regardless of their specialty, as well as being able to exchange professional opinions with surgeons in other fields to reach a more informed consensus. For NS in Korea, the spine field is still very popular. Thus, although orthopedic surgery has a long history of spine correction and fixation, patients’ preferences are not clearly divided. In a study by Clark et al. [
21] in 2014, members of the American Association of Neurological Surgeons were surveyed about ASD surgery. Neurosurgeons’ experience, research, and academic activities have enhanced their ASD-related knowledge and decision-making. In Korea, the duration of the spine fellowship itself is not different between NS and OS. Likewise, there is little difference in program between the 2 groups at present. However, nowadays neurosurgeons’ research on ASD and their activities are more increasing and active than other fields, which demonstrate the results of our research and Clark’s study.
Similarly, there were no significant differences in the strategy adopted according to the length of clinical experience. This indicates that interaction between surgeons with differing levels of experience is desirable, as increased reliability in the treatment of patients regardless of physician experience enables the increased need for spinal surgery in Korea to be met. Taken together, these results suggest that other factors, such as differences in the clinical and radiological characteristics of patients, are more important in determining surgical strategy than physicians’ training background or surgical experience.
Despite the insights provided by our study, it does have some limitations. Firstly, the case information provided in this questionnaire was limited. Plain radiographs revealing sagittal and coronal deformities, as well as brief descriptions of patients’ stenosis and symptoms were provided. However, magnetic resonance imaging, computed tomography, and X-ray dynamogram data, as well as information on patient lifestyles and comorbidities were omitted, which may have increased the difficulty of the questionnaire. Secondly, the small number of respondents could also be viewed as a limitation. Lastly, physicians were instructed to answer the questionnaire intuitively without discussion with their colleagues. Therefore, individual confusion and unfamiliarity with the cases could have also limited our study by affecting the answers given.
We have also collected responses of UIV and LIV. However, the response rate was very low and we could not find commonality between respondents. Therefore, statistical analysis was impossible and the results were not presented in this study.
Likewise, respondents were divided into 10 years of experience. However, the number of detailed annual deformity operations was not known. The questionnaires were members of the Korean Society of Spine Deformity. Most of them are judged to be professional, but this study has the disadvantage of not showing their objective experience.