Introduction: A school scoliosis screening (SSS) program different from those in other countries has been legislated and enforced by law in Japan since 1978. However, the device used for Moiré topography in the screening and the cost of a population-based SSS program have raised concerns in the municipalities. Additionally, based on a "Super-aging society" and the increase of social security payments, more efficient medical care should be considered. The aim of this study was to evaluate the cost of the SSS program from a medical economic perspective through a comprehensive literature review and to identify unsolved issues in the worldwide SSS program.

Material and Methods: A literature search spanning 2000 to 2020 was executed using PubMed, Mendeley, Google Scholar, Ichushi-Web, and CiNii. Keywords included "idiopathic scoliosis", "cost", and "school screening". Survey items extracted from each article were the number of patients, screening cost per person, cost per patient for those with a Cobb angle > 10° and > 20°, and cost per patient identified for surgery. Scoping reviews were conducted based on PRISMA-ScR checklists. Costs converted foreign currency to Japanese yen (JPY) on March 2021 to facilitate cost comparison (USD 1=JPY 108, EUR 1=JPY 130, SGD 1=JPY 81).

Results: A total of 33 articles from PubMed, 27 from Mendeley, 159 (Japanese) and 369 (English) from Google Scholar, 11 from Ichushi-Web, and 1 from CiNii were selected according to the PRISMA-ScR flowchart; thirteen articles met our quality criteria. Median screening cost per person was 608 JPY, median cost per patient with a Cobb angle > 10° and > 20° were 22,732 JPY and 382,844 JPY, respectively. Median cost per patient identified for surgery was 1,088,910 JPY.

Conclusion: These findings provide a rough estimate of the cost for SSS worldwide. However, it is difficult to directly compare these costs owing to the different medical insurance systems and price trends in each country. No study related to the incremental cost effectiveness ratio (ICER) of SSS has been studied so far. Future research should evaluate the true "cost-effectiveness" of SSS very soon.

Introduction: Early detection and early brace treatment before curve progression are crucial in the treatment of adolescent idiopathic scoliosis (AIS). Therefore, school screening is considered important. However, the screening method varies from area to area in Japan because each area conducts its screenings. Some areas conduct only visual examinations as school musculoskeletal screening (SMS), while others use both visual and Moiré testing. The purpose of the present study was to examine the effectiveness of school scoliosis screening (SSS) comparing preoperative patients referred from areas with visual examination only versus visual examination and Moiré testing.

Methods: Patients who underwent surgery were divided into two groups: patients referred from areas where Moiré testing were performed in addition to visual school examinations (Group X) and patients referred from areas where only visual examinations were performed (Group Y). We investigated which areas the patients were referred from and the factors that influenced patients' decision to visit our institute. Moreover, the Cobb angle immediately before surgery were also reviewed.

Results: Group X comprised 117 patients, and Group Y consisted of 40 patients. Group X was younger than Group Y at the initial consultation. The main Cobb angle immediately before surgery of Group Y (57.7±13.7 degree) was bigger than Group X (50.0±8.6 degree) (p <0.001). In group X, 84.6% of patients were detected by SSS; in group Y, SMS was able to find scoliosis in only 42.5% of the patients.

Conclusions: We found that patients referred from area with only visual examinations had greater preoperative Cobb angles than referrals from area with both visual and Moiré testing. The percentage of patients seen as a result of SSS was lower in patients from area with only visual examination than in those with both visual examination and Moiré testing. These results suggest that a screening system with only visual examination delays the appropriate timing of referral to specialists.

Introduction: The waistline asymmetry (WLA) is an important cosmetic concern in adolescent idiopathic scoliosis (AIS). However, radiological evaluating of WLA is not well established, and there is few evidence that the patient perception relates to actual WLA. Therefore, the present study aimed to investigate the relationship between torso asymmetry including WLA and SRS-22 self-image domain in AIS patients.

Methods: We retrospectively reviewed 32 AIS girls who underwent surgery between 2013 and 2019. We obtained the SRS-22 self-image score and the standing posteroanterior whole spine radiograph before and 1 year after surgery. On radiographs, waist height index (WHI), right/left waist angles ratio (WAR) and right/left waist distance index (WDI) were measured for evaluation of WLA. In addition, radiographic shoulder height, thoracic trunk shift, and coronal balance were also obtained. The correlation between there deformity parameters and the SRS-22 self-image score were investigated by multivariate analysis.

Results: The SRS-22 self-image score and deformity parameters other than coronal balance were significantly improved after surgery. In multiple regression analysis, WHI, WAR, and WDI were extracted as factors significantly related to the SRS-22 self-image score. From linear regression analysis, the SRS-22 self-image score could be predicted by the equation (self-image score = 93.7−0.41×｜WHI｜−0.65×｜WDI｜−0.76×｜WAR｜).

Conclusions: WLA was evaluated by WHI, WAR and WDI. WLA was significantly associated with the SRS-22 self-image score. Normalizing WLA is important for improving the self-image of the AIS patients.

Introduction: This study investigated the impact of spinal fusion surgery on global spinal mobility and health-related quality of life in adolescent idiopathic scoliosis (AIS) patients two years postoperatively.

Methods: The subjects were 35 patients with AIS who had undergone posterior corrective fixation. Trunk mobility tests (forward flexion, right and left lateral flexion, and extension) and SRS-22 were performed. Two groups divided by the Lowest Instrumented Vertebra (LIV) were compared: 10 cases of thoracic spine fusion (T group: fusion with LIV L1 or higher) and 25 cases of thoracic and lumbar spine fusion (T+L group: fusion with LIV L2 or lower). In the forward flexion, LIV was divided into two groups, L2 and above and L3 and below, for detailed examination. In addition, forward flexion was examined in two groups: LIV above L2 and below L3. The comparison includes spinal mobility and SRS-22 between the two groups.

Results: At 2 years postoperatively, the patients had improved to preoperative levels except for anterior flexion; there were significant differences in left lateral flexion and anterior flexion between the T and T+L groups at 2 years postoperatively. There were significant differences in left lateral flexion and forward flexion at 2 years postoperatively in the T and T+L groups. At 2 years postoperatively, there was a significant difference between the T and T+L groups in the Function of the SRS-22 score.

Conclusions: Two years postoperatively, there was still a significant decrease in mobility compared to the group with LIV of L1 or higher with LIV of L2 or lower. Forward flexion was significantly better than preoperatively in the group with LIV above L2, but did not correlate with LIV. Function of SRS-22 also showed a significant decrease in the group with LIV less than L2.

The purpose of this study was to evaluate whether selective lumbar fusion (SLF) for adolescent idiopathic scoliosis (AIS) Lenke type 5C based on thoracolumbar/lumbar and thoracic Cobb ratio (TL/L:T Cobb ratio) >1.25 index was appropriate in concerning postoperative coronal imbalance. This study included 56 AIS Lenke 5C patients (all female; mean age, 15.9 years old) who underwent posterior SLF with L3 as the lowest instrumented vertebra from 2007 to 2018. In 6 of 56 cases (10.7%), distal adjacent disc angle wedging of more than 10 degrees was observed. Even in patients with a TL/L:T Cobb ratio of 1.5 or greater, immature bone maturity may lead to a progressive thoracic curve and wedging of the distal disc angle during follow-up. In cases with a TL/L:T Cobb ratio of around 1.3, the residual thoracic curve may also cause wedging of the adjacent disc.

Introduction: For adolescent idiopathic scoliosis (AIS), an analysis of end vertebrae (EV), neutral vertebrae (NV), and stable vertebrae (SV) are used to determine the distal fusion level. These reliability has been reported, but the literature on reliability these analysis which classified by the curve type is very scent.

Our purpose is to clarified the reliability of EV, NV, and SV among thoracic and lumbar curves for adolescent idiopathic scoliosis.

Methods: We assessed twenty radiographs of AIS patients of thoracic curve and eighteen radiographs of AIS patients of lumbar curve. These radiographs were evaluated by two spine surgeons (one was senior fellow of the Japanese Society for Spine Surgety and Related Research and the other was senior resident). The observers attempted to identify the distal EV, NV, and SV. Interobserver and intraobserver reliability was assessed by means of Cohen's Kappa correlation coefficient, and raw percentages of agreement were recorded.

Results: Interobserver reliability of thoracic curve was moderate for determining the distal EV (k=0.49), NV (k=0.58), and SV (k=0.50). Interobserver reliability of lumbar curve was substantial for determining the distal EV (k=0.67), NV (k=0.45), and SV (k=0.61). Intraobserver reliability of thoracic curve by senior resident was almost perfect for determining the distal EV (k=0.92), NV (k=0.88), and SV (k=0.94) and that by senior fellow was substantial for determining the distal EV (k=0.48), NV (k=0.68), and SV (k=0.65). Intraobserver reliability of lumbar curve by senior resident was moderate for determining the distal EV (k=0.45), NV (k=0.42), and SV (k=0.64) and that by senior fellow was substantial for determining the distal EV (k=0.68), NV (k=0.57), and SV (k=0.61).

Conclusions: Radiographic determination of the EV, NV, and SV for AIS demonstrated has sufficient reliability.

Introduction: This study investigated the changes in the shape of vertebral body near to the aorta after posterior corrective fusion surgery for adolescent idiopathic scoliosis (AIS).

Methods: Among 120 patients who underwent AIS surgery in our department between January 2015 and December 2016, 42 patients (2 males and 40 females) with a mean age 15.5 years, and a mean main curve Cobb of 50.4° who underwent computer tomography (CT) scanning immediately after surgery and again two years later were retrospectively studied. Two year after the surgery, the vertebral body was considered to be deformed if the anterior surface of the vertebral body was depressed by ≥2 mm in a crescent shape on CT.

Results: Vertebral body deformity was present in 20 out of 42 patients (47.6%; all females). Lenke 5 and 6 had vertebral body deformity in all cases. The pre- and postoperative thoracolumbar lordosis was significantly greater in patients with deformed vertebrae than in patients without deformed vertebrae.

Conclusions: The vertebral body, particularly the thoracolumbar vertebrae, may deform and become depressed after AIS surgery; therefore, the length of implants, such as pedicle screws, should be carefully considered.

Introduction: Blood loss in adolescent idiopathic scoliosis (AIS) has been linked to a number of factors. In this study, we hypothesized that sagittal alignment influences the amount of intraoperative blood loss.

Methods: From 2010 to 2020, we included 270 patients aged 12-20 years who underwent surgery at our hospital for Lenke type 1 and 2 AIS with a main curve Cobb angle of 40°−60°. Gender, BMI, number of fixed vertebrae, operation time, intraoperative blood loss (IBL), IBL/blood volume (BV = bodyweight × 75 mL), main curve Cobb angle, and thoracic kyphosis angle (TK; T5-12) were all evaluated. The bleeding that exceeded 40% of the circulating blood volume was classified as massive hemorrhage, and bleeding that was less than 40% was classified as non-massive hemorrhage. Moreover, the relationship between each parameter was investigated. TK ≥0° and <0° were also examined.

Results: The amount of blood loss was related to gender, BMI, number of fixed vertebrae, operation time, main Cobb angle, and TK. When the amount of blood loss in the groups with TK <0°and >0°was compared, the amount of blood loss in the group with TK <0° was higher.

Conclusion: Blood loss was associated with thoracic lordosis in AIS Lenke type 1 and 2 corrective surgeries.

Introduction: In previous studies, several researchers have demonstrated nonoperative studies of degenerative lumbar scoliosis. However, only a few studies about severe adult spinal deformity (ASD) have been demonstrated. This study aimed to investigate the outcome of natural history and conservative treatment in patients with severe ASD.

Methods: We retrospectively reviewed 27 consecutive nonoperative severe ASD patients (mean age 71.7 years, 21 women, mean follow-up 5.4±2.4 years) with a minimum of two years of follow-up. Severe ASD was defined according to Schwab as follows; Cobb > 30° or PI-LL > 20°, SVA > 9.5 cm, PT > 30°. We examined ODI, VAS, JOABPEQ as clinical outcomes and Cobb angle, Lateral spondylolisthesis, TK, LL, PI, PT, SS, TPA, SVA, CVA as radiographic parameters at baseline and last. Moreover we examined non-type N group (Cobb ≥ 30°) and non-Type N (Cobb < 30°).

Results: The average Cobb angle progressed from 33° to 42° (1.6°/year). In clinical outcomes, the degree of pains (baseline/last; 28.8 mm/38.9 mm, p = 0.03) and numbness (23.9 mm/38.0 mm, p = 0.02) in buttocks and lower limbs were significantly increased. Walking ability and mental health in JOABPEQ were as follows; 47.3/38.9, p = 0.01, 2.3/45.0, p = 0.01. In radiographic parameter, TPA (30.5°/34.5°, p = 0.01) and SVA (82.9 mm/120 mm. p = 0.01) were significantly increased. In the non-type N group, the average Cobb angle progressed from 38° to 51° (2.4°/year) and the degree of pains and numbness in buttocks and lower limb and lateral spondylolisthesis were significantly increased as follows; 34.2 mm/45.2 mm, p = 0.02, 23.9 mm/40.3 mm, p = 0.02, 6.4 mm/8.9 mm, p < 0.01).

Conclusions: Despite radiographic parameters were worse, clinical outcomes were not worse in severe ASD patient with 5 years.

Introduction: The purpose of this study was to investigate trunk function and its relationship with sagittal spinopelvic alignment in a 6-year prospective community-based female cohort.

Methods: A total of 89 healthy female subjects were recruited since 2010. All the subjects were followed over a five-year period. Mean age was 65.2 years at baseline and 71.3 years at follow-up, and the mean follow-up period was 6.1 years. Upright whole spine radiographs were used to evaluate sagittal spinopelvic parameters including sagittal vertical axis (SVA), thoracic kyphosis, lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence. Clinical evaluations included trunk flexor (FX) and extensor (EX) muscle strength using isometric device, lumbar range of motion (ROM), trunk inclination angle at standing (sTIA) and at gait posture (gTIA), functional reach test, body mass index, visual analogue scale (VAS) of back pain, and HRQOL. The results were analyzed using paired t test or Wilcoxon test.

Results: Longitudinal changes, shown as baseline/follow-up (p value), were as follows: FX 289N/235N (p<0.001), EX 498N/471N (p=0.036), sTIA 3.9/6.2 degrees (p<0.001), and gTIA 7.7/10.4 degrees (p<0.001). VAS and HRQOL changes were not significant. Radiographically, SVA (p<0.001) and PT (p=0.013) increased significantly, while LL (p<0.001) and SS (p=0.010) decreased significantly at follow-up.

Conclusions: Longitudinal data from this study showed reduction of trunk muscle strength, postural inclination, and kyphotic spinopelvic alignment. Adult spinal deformity developed in parallel with reduction of trunk muscle strength and ambulatory controls. Physical characteristics should be an important factor as well as radiographic parameters.

Introduction: Early post-operative rehabilitation for adult spinal deformity (ASD) have been reported to affect activities of daily living (ADL) recovery. We performed this study to investigate the influence of early postoperative ADL independence on health-related quality of life (HRQOL) in 2 years after surgery for ASD.

Methods: We reviewed 48 patients (34 females, average 69-year) who underwent fixation surgery for ASD. According to Barthel Index at 1 month after surgery, patients were divided into independent group (85 points or more; 34 cases) and requiring assistance group (80points or less; 14 cases). X-ray parameters (SVA, LL, PT, PI) were compared between two groups. HRQOL were evaluated using ODI and SRS22.

Result: ODI showed improvement in both groups, and independent group significantly improved 2-year after surgery. The amount of change in SRS22 domains (Function, Pain, Self-image, and Mental-health) were significantly larger in independent group (0.8, 1.4, 1.7, 1.3) than in requiring assistance group (0.5, 1.1, 1.3, 1.1). Although, there was no significant difference in spinopelvic parameters between two groups.

Conclusion: Patients with ADL independence in the early postoperative period of ASD had better HRQOL two years after surgery than those requiring assistance. It is possible that preoperative pain and mental distress may affect ADL independence in the early postoperative period.

Introduction: Proximal junctional failure (PJF) is still common in patients after adult spinal deformity (ASD) surgery. The objective of this study was to clarify the efficacy of posterior polyethylene tethers to prevent PJF following ASD surgery.

Materials: Ninety-three patients who underwent ASD surgery from thoracic spine to pelvis with ≥6 months follow-up were retrospectively reviewed. The spinous process tether weave technique (TW group) was used on a total of 21 patients. PJF was defined as fracture at the UIV or UIV+1, pullout of instrumentation at the UIV, and posterior osseoligamentous disruption. Demographics, surgical data, and radiographic parameters were compared between the TW group and control group.

Results: The rate of PJF for the TW group was tended to be lower than those in the control group (24% vs 38%, P=0.278). There were no significant differences in age, sex, pre- and postoperative radiographic parameters. The TW group had a significantly higher rate of using a transverse hook at the UIV, use of titanium rod, pelvic fixation, and a rod diameter of 6.0 mm.

Conclusions: Spinous process tether weave technique did not significantly reduce the occurrence of PJF among ASD patients treated with long-segment posterior instrumented fusion surgery.

Design: A retrospective comparative study at a single institution.

Purpose: To retrospectively investigate whether multi-rod constructs can prevent rod breakage after adult spinal deformity (ASD) surgery.

Methods: Ninety consecutive patients (7 males and 83 females, mean age 69.5 years) who underwent posterior spinal fusion inducing the pelvis for ASD since January 2016 with a minimum 1-year follow-up were involved in this study. Patients who underwent fixation with more than three rods were defined as the group M, and patients who underwent fixation with two rods were defined as the group T. Patient demographics, surgery-related factors, pre-and postoperative radiographic parameters (SVA, TPA, TK, PI, LL, PI-LL, PT, L4-S1 angle), and clinical outcome (ODI, SRS-30), rod breakage, PJK, and reoperation rate were investigated and compared between the two groups.

Results: Group M had 45 patients and group T had 45 patients. Patient demographics, surgery-related factors, and preoperative clinical outcomes were not significantly different between the two groups. In preoperative radiographic parameters, PI and PT was statistically higher in group T (p=0.014, p=0.018). Both groups showed significant improvement in radiographic parameters after surgery. The SRS-30 scores (Function and Pain) were statistically higher in group M (p=0.032, p=0.015). There was no significant difference in the incidence of PJK and reoperation rate between the two groups. However, rod breakage was significantly more frequent in group T (Group M 0%, Group T 13%: p=0.013).

Conclusion: The multi-rod constructs reduced postoperative rod breakage with a minimum 1-year follow-up. The results may support the benefit of using multi-rod constructs for ASD surgery.

Introduction: In the current study, we studied the relationship between Body Mass Index (BMI) and patient characteristics including bone mineral density (BMD), muscle mass, nutrition status, spinal sagittal alignment, and low back pain (LBP) scores in patients with primary osteoporosis.

Methods: A total of 144 women aged ≥60 years with primary osteoporosis were enrolled in this study. BMD at lumbar spine, femoral neck and total hip, body muscle mass corrected by squaring body height, Nutritional status determined from the Controlling Nutritional Status (CONUT) score, spinal sagittal alignment including pelvic tilt, pelvic incidence minus lumbar lordosis and sagittal vertical axis (SVA), and LBP scores including Oswestry disability index (ODI) score and Visual analogue scale (VAS) were reviewed in all patients. Patients were compared after stratification based on BMI into the low BMI group (BMI <20), normal BMI group (≥20 BMI <25) or high BMI group (BMI ≥25).

Results: Patients in the low BMI group had significantly lower BMD, lower corrected body muscle mass, higher CONUT scores, lower SVA levels, lower ODI scores, and lower VAS scores compared with those in the normal group (p<0.05). By contrast, patients in the high BMI group had significantly higher corrected body muscle mass compared with those in the normal group (p<0.05). However, there were no significantly differences of others factors between the normal BMI group and the high BMI group (p>0.05).

Conclusions: Osteoporosis patients with low BMI had maintained their spinal sagittal alignment with little LBP despite reduced BMD, reduced body muscle mass, and poor nutritional status.

Growing rod (GR) surgery has become widespread as a surgical treatment for early onset scoliosis and plays an important role in scoliosis treatment. GR surgery can be preserved spinal growth, but there are some reports of complications due to multiple surgeries and instrumentation failure. The case was 7 year and 11 months old boy, diagnosed as a Marfan like syndrome and syndromic scoliosis.

We performed conservative treatment as alternative cast and brace treatment 6 times but scoliosis got worse and GR surgery was performed at 7 years and 4 months. However, rod breakage occured after postoperative surgery at 6 months, so we performed revision surgery and inserted a cross rink between inline connector and distal screw.

GR surgery for early onset scoliosis is a meaningful treatment method in terms of both correction of scoliosis and growth preservation, but on the other hand, there are some reports of adverse effects, infections, and instrumentation failure due to multiple surgeries.

We performed GR surgery this time, but we experienced a case of rod breakage in the early postoperative period.