Abstract
Introduction
Surgical outcomes for adult patients with residual adolescent idiopathic scoliosis (AdIS) with a major thoracic curve are expected to be inferior to those of AIS but have not been well reported. This study aimed to evaluate surgical, radiographical, and clinical results in adult patients with AdIS and to characterize these patients by comparing their results with those of patients with adolescent idiopathic scoliosis (AIS).
Methods
Thirty-five patients with AdIS, who were diagnosed with AIS Lenke type 1 or 2 before the age of 19 years and underwent surgery after the age of 20 years, were included in the study. As a control group, 84 patients with AIS Lenke type 1 or 2 who underwent surgery before the age of 19 were included. Both groups were matched on the basis of the preoperative main thoracic (MT) and proximal thoracic (PT) Cobb angles, causing 30 patients to be selected in each group.
Results
The AdIS group exhibited a greater preoperative bending Cobb angle of the MT and PT curves (MT: 35.1° vs. 31.3°, PT: 17.8° vs. 13.8°) and a lower MT curve flexibility index than in the AIS group (36.6% vs. 42.2%). Postoperatively, the AdIS group had a higher number of fused intervertebral segments than did the AIS group (8.2 vs. 7.4), but the correction rate was comparable in the 2 groups. Moreover, the intraoperative time was longer and blood loss was larger in the AdIS group. In the Scoliosis Research Society (SRS)-22 score, self-image and mental health domains were significantly lower preoperatively in the AdIS group. Postoperative improvement of self-image domain was significantly greater in the AdIS group (Δ self-image: 1.6 vs. 0.9), and postoperative satisfaction was similar in the 2 groups.
Conclusions
Surgical invasiveness was increased in AdIS, and preoperative SRS-22 scores were lower in self-image and mental health domains than in AIS. However, postoperative SRS-22 scores were comparable, and postoperative self-image improvement was significantly greater in AdIS than in AIS.
Keywords: adolescent idiopathic scoliosis, adult, clinical outcome, major thoracic curves
Introduction
Adolescent idiopathic scoliosis (AIS) is a type of scoliosis that develops during adolescence and is the most common form of spinal deformity. Severely progressed AIS can lead to self-image issues, cosmetic concerns, and an inferior quality of life, including pain, disability, and pulmonary dysfunction1-6). Therefore, posterior correction and fusion surgery (PCF) has been recommended for patients with AIS with severe progressive curvature. However, patients with AIS and their families often delay or avoid the surgery owing to concerns about potential complications and the impact on daily activities, schooling, and social life, leading to residual untreated AIS in adulthood.
AIS with a major thoracic curve is the most common type of curve in AIS, and surgical outcomes for AIS with a major thoracic curve have been well documented. Postoperative health-related quality of life (HRQOL) in patients with AIS is generally favorable7-14). However, surgical outcomes for adult patients with residual AIS (AdIS) with major thoracic curve are less frequently reported15). In skeletally mature adult patients with idiopathic scoliosis, an increased Cobb angle, decreased curvature flexibility, and increased surgical invasiveness have been observed as patients age16-18). Other studies have compared the clinical outcomes of AIS and AdIS with similar preoperative radiographic parameters19). The surgical outcomes for patients with AdIS with a major thoracic curve are expected to be inferior to those of patients with AIS. However, none of these studies focuses exclusively on AdIS with major thoracic curve. Therefore, if patients with AIS with a major thoracic curve delay surgery until adulthood, it remains unclear whether clinical outcomes will be inferior to those of patients with AIS who underwent PCF during adolescence.
The purpose of this study was to evaluate the outcomes of PCF in AdIS with a major thoracic curve and to clarify the clinical characteristics by comparing these results with those of patients with AIS who underwent PCF during adolescence, matched by preoperative proximal thoracic (PT) and main thoracic (MT) curve angles.
Materials and Methods
Study design, patient demographics, and characteristics
A total of 119 patients with AISs with major thoracic curves (6 male and 113 female patients) who underwent PCF at our hospital from 2014 to 2018 were included. The inclusion criteria were 1) diagnosis of AIS Lenke type 1 and 2 at an age between 12 and 19 years; 2) PCF applied at an age between 12 and 39 years; 3) absence of neuromuscular disorders, trauma, congenital vertebral deformity, or other pathological conditions; 4) no prior spinal surgery; 5) availability of clear preoperative and postoperative radiographs; and 6) a minimum of 2 years of follow-up after surgery. All demographic, diagnostic imaging, and surgical data were obtained retrospectively from patient records and radiographic reviews.
Patient categories and preoperative MT and PT cobb angle matching
We divided the patients into 2 groups based on the age at which they underwent PCF. The AdIS group comprised patients who underwent surgery between the ages of 20 and 39 years, whereas the AIS group comprised patients who underwent surgery at the age of 19 years or younger. There were 35 patients in the AdIS group (mean age 24.7±5.6 years; 33 female patients) and 84 in the AIS group (mean age 15.6±1.8 years; 80 female patients). Propensity score matching analysis was used to match 35 patients in the AdIS group with 84 patients in the AIS group. Covariates used to perform propensity score matching were the preoperative MT and PT Cobb angle, and 30 patients were selected from each group. Pre- and postoperative radiographic parameters, surgical outcomes, and the results of pre- and postoperative self-administered questionnaires (Scoliosis Research Society [SRS]-22) were compared in the 2 groups.
Surgical protocol
All surgeries were performed by 1 or both of the 2 attending surgeons (K.W. and M.M.) using a consistent surgical strategy and techniques for correcting spinal deformity. The procedure involved segmental pedicle screw placement, scoliosis correction, and creation of thoracic kyphosis (TK) by rod rotation technique on the concave side, followed by in situ rod bending for additional coronal correction. An under-bent convex rod was placed for derotation of the vertebral bodies, followed by segmental compression and distraction to horizontalize each vertebra. The upper-instrumented vertebra (UIV) was generally selected at the end vertebra or 1 level below the end vertebra. The lower instrumented vertebra (LIV) was selected at the last touching vertebra on the preoperative standing radiograph14). The distribution of UIV and LIV, the number of patients with Ponte osteotomy, the number of pedicle screws, and pedicle screw density in each group are presented in Table 3.
Radiographic and operative data collection
Preoperative data collected included age, height, weight, body mass index, and radiographic parameters; Cobb angles of MT spine, PT spine, and thoracolumbar/lumbar spine (TL/L) curves, Cobb angles of bending MT, PT, and TL/L curves, MT Cobb angle flexibility index, clavicle angle, T1 tilt, L3 tilt, L4 tilt, T1 slope, TK, lumbar lordosis (LL), sacral slope, pelvic tilt, and pelvic incidence. Operative outcomes included intraoperative time, estimated blood loss (EBL), and length of hospital stay. Postoperative data included levels instrumented in the fusion area and MT Cobb angle correction rate, along with preoperative measured parameters.
HRQOL assessment
HRQOL was assessed using the SRS-22 questionnaire, administered preoperatively and 2 years postoperatively.
Statistical methods
Differences between the groups were examined using the Mann-Whitney U test and χ2 analysis, when applicable. Statistical significance was defined as a P value of <0.05. Data were analyzed with SPSS Statistics, version 28.0.1.0 (IBM Corp., Armonk, NY).
Ethics statement
All the patients provided written informed consent, and the study protocol was approved by the institutional review board before data collection and analysis (approval number 20110142). The first author assumes complete responsibility for maintaining the integrity of the data and ensuring the accuracy of the data analysis.
Results
Comparisons of radiological parameters in the AdIS and AIS groups
In the AdIS group, the mean preoperative bending MT Cobb angle was significantly greater than that in the AIS group (AdIS vs. AIS group: 35.1±6.9° vs. 31.3±5.0°; p=0.04) (Table 1). The mean bending PT Cobb angle was also significantly greater in the AdIS group (AdIS vs. AIS group: 17.8±6.2° vs. 13.8±6.4°; p=0.04). Consequently, the mean MT and PT curve flexibility index were significantly lower in the AdIS group than in the AIS group (MT; AdIS vs. AIS group: 34.6±8.8% vs. 41.9±10.8%; p=0.01, PT; AdIS vs. AIS group: 26.3±18.6% vs. 45.3±23.5%; p<0.01).
Table 1.
Demographic Data and Preoperative Radiological Parameters.
| AdIS (n=30) | AIS (n=30) | p value | |
|---|---|---|---|
| Age (years) | 24.7±5.4 | 15.6±2.3 | <0.01 |
| BMI (kg/m2) | 19.4±2.1 | 19.6±2.7 | 0.78 |
| Coronal parameters | |||
| Preop. MT (°) | 54.4±8.2 | 53.9±8.6 | 0.80 |
| Preop. PT (°) | 24.3±7.9 | 24.3±6.6 | 1.00 |
| Preop. TL/L (°) | 29.0±9.4 | 30.1±9.4 | 0.68 |
| Preop. bending MT (°) | 35.1±6.9 | 31.3±5.0 | 0.04 |
| Preop. bending PT (°) | 17.8±6.2 | 13.8±6.4 | 0.04 |
| Preop. bending TL/L (°) | 6.2±5.5 | 6.7±5.3 | 0.76 |
| MT Cobb flexibility index (%) | 34.6±8.8 | 41.9±10.8 | 0.01 |
| PT Cobb flexibility index (%) | 26.3±8.6 | 45.3±23.5 | <0.01 |
| Preop. Clavicle angle (°) | 2.3±2.1 | 2.6±1.8 | 0.64 |
| Preop. T1 tilt (°) | 3.1±2.5 | 2.6±2.0 | 0.45 |
| Preop. L3 tilt (°) | 9.4±5.7 | 9.3±9.3 | 0.97 |
| Preop. L4 tilt (°) | 7.0±5.4 | 8.4±5.5 | 0.40 |
| Sagittal parameters | |||
| Preop. T1 slope (°) | 11.2±8.7 | 11.3±7.6 | 0.85 |
| Preop. TK (°) | 15.1±11.2 | 15.4±7.3 | 0.89 |
| Preop. LL (°) | 49.5±8.3 | 46.1±6.9 | 0.15 |
| Preop. PI (°) | 54.9±9.3 | 48.7±15.2 | 0.11 |
| Preop. PT (°) | 14.3±5.9 | 12.6±9.3 | 0.66 |
| Preop. SS (°) | 39.1±7.7 | 35.2±10.6 | 0.28 |
Values are presented in mean±SD. AdIS, adult patients with residual AIS; AIS, adolescent idiopathic scoliosis; BMI, body mass index; MT, main thoracic; PT, proximal thoracic; TL/L, thoracolumbar/ lumbar; TK, thoracic kyphosis; LL, lumbar lordosis; SS, sacral slope; PT, pelvic tilt; PI, Pelvic Incidence
Postoperatively, the mean number of fused intervertebral segments was significantly larger in the AdIS group than in the AIS group (AdIS vs. AIS group: 8.2±1.6 vs. 7.4±1.1; p=0.04). Postoperative MT Cobb angle was comparable in the 2 groups (AdIS vs. AIS group: 16.4±3.6° vs. 15.2±5.3°; p=0.36). Similarly, correction rates were similar in the 2 groups (AdIS vs. AIS group: 69.6±6.5% vs. 69.4±12.2%; p=0.96) (Table 2).
Table 2.
Postoperative Radiological Parameters.
| AdIS (n=30) | AIS (n=30) | p value | |
|---|---|---|---|
| Level fused | 8.2±1.6 | 7.4±1.1 | 0.04 |
| Coronal parameters | |||
| Postop. MT (°) | 16.4±3.6 | 15.2±5.3 | 0.36 |
| Postop. PT (°) | 11.9±5.5 | 9.1±4.6 | 0.08 |
| Postop. TL/L (°) | 9.4±5.8 | 11.5±8.8 | 0.32 |
| % correction MT | 69.6±6.5 | 69.4±12.2 | 0.96 |
| Postop. Clavicle angle (°) | 2.2±4.1 | 2.0±1.5 | 0.86 |
| Postop. T1 tilt (°) | 3.1±2.7 | 3.1±2.6 | 0.99 |
| Postop. L3 tilt (°) | 4.0±2.9 | 5.2±3.2 | 0.19 |
| Postop. L4 tilt (°) | 4.2±3.1 | 5.9±4.0 | 0.10 |
| Sagittal parameters | |||
| Postop. T1 slope (°) | 15.4±9.9 | 11.3±7.6 | 0.13 |
| Postop. TK (°) | 18.8±8.0 | 16.9±7.7 | 0.41 |
| Postop. LL (°) | 45.6±7.2 | 41.8±9.9 | 0.11 |
| Postop. PI (°) | 54.9±9.3 | 48.7±15.2 | 0.11 |
| Postop. PT (°) | 21.1±6.9 | 18.2±9.1 | 0.52 |
| Postop. SS (°) | 33.2±6.7 | 29.8±8.5 | 0.12 |
Values are presented in mean±SD. AdIS, adult patients with residual AIS; AIS, adolescent idiopathic scoliosis; MT, main thoracic; PT, proximal thoracic; TL/L, thoracolumbar/ lumbar; TK, thoracic kyphosis; LL, lumbar lordosis; SS, sacral slope; PT, pelvic tilt; PI, Pelvic Incidence
Comparisons of operative data between the AdIS and AIS groups
Intraoperative data are listed in Table 3. The AdIS group had a significantly longer mean intraoperative time than did the AIS group (AdIS vs. AIS group: 138±37.4 min vs. 117±27.2 min; p=0.02). The mean volume of EBL was significantly larger in the AdIS group (AdIS vs. AIS group: 306±205 mL vs. 211±146 mL; p=0.04), and the number of patients who underwent Ponte osteotomy was significantly higher in the AdIS group (AdIS vs. AIS group: 11 patients vs. 3 patients; p=0.03). The number of pedicle screws was significantly higher in the AdIS group (AdIS vs. AIS group: 18.1±2.8 vs. 16.3±2.4; p=0.01). However, pedicle screw density was similar in the 2 groups, as was the mean length of hospital stay.
Table 3.
Operative Data.
| AdIS (n=30) | AIS (n=30) | p value | |
|---|---|---|---|
| Operative time (minutes) | 138±37.4 | 117±27.2 | 0.02 |
| EBL (ml) | 306±205 | 211±146 | 0.04 |
| UIV | |||
| T2 | 3 | 0 | |
| T3 | 1 | 1 | |
| T4 | 1 | 1 | |
| T5 | 13 | 19 | |
| T6 | 10 | 7 | |
| T7 | 2 | 2 | |
| LIV | |||
| T11 | 1 | 5 | |
| T12 | 9 | 11 | |
| L1 | 8 | 6 | |
| L2 | 5 | 5 | |
| L3 | 7 | 3 | |
| Number of patients | 11 | 3 | 0.03 |
| with Ponte osteotomy | |||
| Number of pedicle screws | 18.1±2.8 | 16.3±2.4 | 0.01 |
| Pedicle screw density | 1.95±0.1 | 1.98±0.1 | 0.14 |
| Length of stay (days) | 13.5±2.7 | 12.8±1.9 | 0.31 |
Values are presented in mean±SD. AdIS, adult patients with residual AIS; AIS, adolescent idiopathic scoliosis; EBL, estimated blood loss; UIV, The upper-instrumented vertebra; LIV, The lower instrumented vertebra; T, thoracic; L, lumbar. *p<0.05.
Comparisons of SRS-22 in the AdIS and AIS groups
The mean preoperative and postoperative SRS-22 scores are listed in Table 4. The mean preoperative total SRS-22 scores of patients with AdIS was lower than that of patients with AIS (AdIS vs. AIS group: 3.8±0.3 vs. 4.2±0.3; p<0.01), particularly in the self-image and mental health domains (AdIS vs. AIS group: self-image domain, 2.7±0.6 vs. 3.3±0.7; p<0.01; mental health domain, 3.8±0.6 vs. 4.4±0.5; p<0.01).
Table 4.
Comparisons of SRS-22 Scores between the AdIS and AIS Groups.
| AdIS (n=30) | AIS (n=30) | p value | ||
|---|---|---|---|---|
| Preoperative | Function | 4.8±0.3 | 4.8±0.3 | 0.62 |
| Pain | 4.5±0.5 | 4.6±0.4 | 0.22 | |
| Self-image | 2.7±0.6 | 3.3±0.7 | <0.01 | |
| Mental health | 3.8±0.6 | 4.4±0.5 | <0.01 | |
| Total | 3.8±0.3 | 4.2±0.3 | <0.01 | |
| Postoperative | Function | 4.5±0.3 | 4.8±0.3 | <0.01 |
| Pain | 4.4±0.4 | 4.5±0.4 | 0.15 | |
| Self-image | 4.3±0.4 | 4.2±0.5 | 0.81 | |
| Mental health | 4.0±0.6 | 4.3±0.8 | 0.24 | |
| Satisfaction | 4.3±0.7 | 4.2±0.6 | 0.50 | |
| Total | 4.3±0.3 | 4.4±0.3 | 0.12 | |
| Postoperative – Preoperative | Δ Function | −0.3±0.3 | −0.1±0.2 | 0.02 |
| Δ Pain | 0.0±0.6 | −0.1±0.4 | 0.57 | |
| Δ Self-image | 1.6±0.8 | 0.9±1.0 | 0.02 | |
| Δ Mental health | 0.1±0.6 | −0.1±0.8 | 0.34 | |
| Δ Total | 0.4±0.4 | 0.2±0.4 | 0.06 |
Values are presented in mean±SD. HRQOL, health related quality of life; AdIS, adult patients with residual AIS; AIS, adolescent idiopathic scoliosis; Δ=postoperative score – preoperative score. *p<0.05.
Postoperatively, the function domain score in the AdIS group was significantly lower than in the AIS group (AdIS vs. AIS group: 4.5±0.3 vs. 4.8±0.3; p<0.01). However, no significant differences were observed postoperatively in the self-image and mental health domains, which had significant differences preoperatively (AdIS vs. AIS group: self-image domain, 4.3±0.4 vs. 4.2±0.5; p=0.81; mental health domain, 4.0±0.6 vs. 4.3±0.8; p=0.24). The satisfaction domain scores were also comparable in the 2 groups.
In terms of the pre- and postoperative score difference (Δ), the mean Δ self-image was significantly greater in the AdIS group (AdIS vs. AIS group: Δ self-image, 1.6±0.8 vs. 0.9±1.0; p=0.02).
Case examples from each group (Fig. 1, 2)
Figure 1.
Radiographic and operative outcomes of the AdIS case example.
In a 22-year-old patient with AdIS, the preoperative MT, PT, and TL/L Cobb angles were 63°, 36°, and 32°, respectively. The bending MT, PT, and TL/L Cobb angles were 45°, 26°, and 12°, respectively. The MT and PT curve flexibility index was 28.6% and 27.9%, respectively. The preoperative TK and LL angles were 15° and 40°, respectively. PCF at T2-L1 corrected the MT, PT, and TL/L curve to 14°, 16°, and 14°, respectively. The postoperative TK and LL angles were 12° and 35°, respectively. The operative time was 180 minutes, and the EBL was 360 mL.
AdIS, residual adolescent idiopathic scoliosis; EBL, estimated blood loss; LL, lumbar lordosis; MT, main thoracic; PCF, posterior correction and fusion surgery; PT, proximal thoracic; TK, thoracic kyphosis; TL/L, thoracolumbar/lumbar spine
Figure 2.
Radiographic and operative outcomes of the AIS case example.
In a 14-year-old patient with AIS, the preoperative MT, PT, and TL/L Cobb angles were 63°, 35°, and 41°, respectively. The bending MT, PT, and TL/L Cobb angles were 40°, 9°, and 17°, respectively. The MT and PT curve flexibility index were 28.6% and 27.9%, respectively. The preoperative TK and LL angles were 18° and 47°, respectively. PCF at T5-T12 corrected the MT, PT, and TL/L curve to 14°, 17°, and 25°, respectively. The postoperative TK and LL angles were 13° and 39°, respectively. The operative time was 115 minutes, and the EBL was 110 mL.
AIS, adolescent idiopathic scoliosis; EBL, estimated blood loss; LL, lumbar lordosis; MT, main thoracic; PCF, posterior correction and fusion surgery; PT, proximal thoracic; TK, thoracic kyphosis; TL/L, thoracolumbar/lumbar spine
AdIS case: A 22-year-old woman (Fig. 1)
The preoperative MT and PT Cobb angles were 63° and 36°, respectively. The bending MT and PT Cobb angles were 45° and 26°, respectively. The MT and PT curve flexibility index was 28.6% and 27.9%, respectively. PCF at T2-L1 corrected the MT curve to 14°. The operative time was 180 minutes, and the EBL was 360 mL.
AIS case: A 14-year-old girl (Fig. 2)
The preoperative MT and PT Cobb angles were 63° and 35°, respectively. The bending MT and PT Cobb angles were 40° and 9°, respectively. The MT and PT curve flexibility index was 36.5% and 73.4%, respectively. PCF at T5-T12 corrected the MT curve to 14°. The operative time was 115 minutes, and the EBL was 110 mL.
Discussion
Comparisons of radiological results in the AdIS and AIS groups
Our findings revealed that the mean bending Cobb angle and flexibility of the MT and PT curves were significantly more rigid in the AdIS group than in the AIS group before surgery. However, the postoperative MT and PT Cobb angles were comparable in the 2 groups, suggesting that modern spinal implants, including pedicle screw with cobalt-chromium alloy rod, and meticulous release techniques, such as resection of the inferior articular process and Ponte osteotomy, enabled correction to the same extent as in AIS. Meanwhile, the AdIS group required a greater number of fused intervertebral segments (0.8 segments more), in addition to increased intraoperative time and intraoperative blood loss, to achieve comparable correction with AIS. These may be the disadvantages of having the PCF in adulthood.
Previous studies have pointed to a decrease in the flexibility of the curvature of approximately 5%-10% for every 10 years of age15,20). In our study, although the absolute bending Cobb angle differences between the 2 groups were clinically minor, a 6% difference in flexibility index was observed, which may be attributed to the matched preoperative angles. These findings underscore the biomechanical properties of the curves and their significance for surgical planning and patient outcomes. Furthermore, Lonner et al.18) indicated that the number of fused intervertebral segments increased by approximately 3.5 levels in patients with AdIS. In our study, the difference in the number of fused intervertebral segments between the 2 groups was approximately 1 level. In this study, the average age of patients with AdIS was lower than in the study by Lonner et al.18) (24.7±5.4 years vs. 43.7±15.8 years), and this difference in the mean age of patients with AdIS may have influenced the difference in the number of fused intervertebral segments between our study and previous studies.
Comparisons of operative data between the AdIS and AIS groups
The patients with AdIS exhibited a significantly longer intraoperative time and greater intraoperative blood loss, findings that are consistent with those reported by Lonner et al.18), who noted increased surgical invasiveness in adult patients. However, Zhu et al.15) reported no significant difference in surgical invasiveness between the 2 groups, which might be attributed to variation in correction techniques. Although the specifics of the surgical techniques were not detailed in their studies, meticulous releases such as Ponte osteotomies can enhance the correction while increasing invasiveness, operative time, and intraoperative blood loss. Our study also showed a difference in the number of patients who underwent Ponte osteotomy between the 2 groups, which may explain the differences observed in previous studies.
Comparisons of HRQOL between the AdIS and AIS groups
Function domain
Postoperatively, the AdIS group had significantly lower scores in the function domain than did the AIS group. In the previous studies, Lonner et al.18) also reported a significant reduction in postoperative function domain in the AdIS group. However, our study and the study by Lonner et al.18) cannot be directly compared owing to differences in curve type and patient age. Although the AdIS group scored lower in the functional domain than the AIS group, their mean score was still higher than the mean functional score for women of the same age without a history of scoliosis21), suggesting that there was no functional decrease.
Pain domain
In the pain domain, our study found no significant differences between the AdIS and AIS groups, both pre- and postoperatively. A previous report indicated that 77% of patients with AdIS experienced acute or chronic low back pain, significantly more than 35% of controls5). In contrast, Watanabe et al.22) revealed that patients with AdIS with TL/L curve and double-major curve had significantly higher Visual Analogue Scale (VAS) for low back pain than did patients with AdIS with single MT curve. Our study included only patients with MT curves, suggesting that MT curves have less impact on pain, similar to the findings of Watanabe et al.22).
Self-image domain
Significant preoperative differences in self-image decreased in the postoperative period. In the preoperative self-image domain, Lonner et al.18) also reported a significant difference, and only Zhu et al.15) reported that there was no significant difference. The mean age of patients with AdIS in the Zhu et al.15) study, which did not differ significantly preoperatively, was 22.2±3.3 years, the youngest of the 3 studies. This suggests that as patients age, those with a lower self-image may be more likely to be the final decision-makers about whether to proceed with surgery. However, in all studies, the AdIS group showed improvement postoperatively, indicating that surgery in adulthood can improve self-image. In particular, in our study, the Δ self-image score of the AdIS group was significantly greater than that of the AIS group. In this study, the patients with AdIS improved to a level comparable to that of women of the same age who had no history of scoliosis after surgery21). This suggests that spinal deformity was the primary cause of the preoperative self-image of the patients with AdIS in our study.
Mental health domain
Similarly to the self-image domain, significant preoperative differences in the mental health domain decreased postoperatively. Although there is concern that AIS may negatively affect body image, leading to decreased mental health, there are few studies with high-level evidence regarding the relationship between AIS and reduced mental health. Previous reports, including our study, suggest that the decrease in mental health may not only be due to poor self-image but may also be related to age and pain15,18).
Satisfaction domain
The satisfaction domain was comparable in the 2 groups. In the previous studies, Lonner et al.18) did not provide details on the postoperative satisfaction domain, making it unclear, but Zhu et al.15) reported that satisfaction was comparable in the 2 groups, which aligns with our findings. Our results indicate that surgical outcomes can be expected to be generally similar to those of patients with AIS 2 years postoperatively, despite reduced preoperative HRQOL.
Limitation of this study
This study is limited by a lack of a long-term outcomes assessment. Although no patients in the study underwent additional surgery within the first 2 years after surgery, the potential for distal adding-on and subsequent surgeries has been reported in several studies8,14). Furthermore, the results of the SRS-22 scores may be biased by a shift in the final decision-maker regarding whether to proceed with surgery in patients with AIS and AdIS. As patients age, the decision-making responsibility tends to shift from their parents to the patients themselves.
This study focused on patients transitioning from adolescence to young adulthood without surgery and suggested that delaying surgery until young adulthood does not necessarily compromise surgical success. However, comparing teenage patients with those in their 40s and 50s is also clinically interesting and an extremely important area for future research. Investigating long-term outcomes in older patients is a key issue moving forward.
Conclusions
When comparing patients with AdIS and AIS with major thoracic curve and matched curve angles, patients with AdIS exhibited decreased preoperative curve flexibility and increased surgical invasiveness. In addition, SRS-22 scores indicated a decrease in self-image and mental health before surgery whereas self-image improved significantly after surgery and was generally equivalent in all domains. These findings suggest that delaying surgery until adulthood increases the difficulty of the procedure, but the postoperative HRQOL is generally comparable with AIS. These results may assist in guiding surgical timing decisions for patients with AIS or AdIS and their families.
Conflicts of Interest: The authors declare that there are no relevant conflicts of interest.
Author Contributions: YK and KW collected and analyzed the data and wrote the manuscript, and YK, SS, TI, KT, YT, OT, NN, MM, MN, and KW read, reviewed, and approved the manuscript.
Ethical Approval: All the patients provided written informed consent, and the study protocol was approved by the institutional review board before data collection and analysis (approval number 20110142). The first author assumes complete responsibility for maintaining the integrity of the data and ensuring the accuracy of the data analysis.
Informed Consent: All participants in this study gave informed consent for publication.
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