Purpose It was recently reported that 6.1% of patients undergoing surgery for adolescent idiopathic scoliosis (AIS) also had preoperative lumbar spondylolysis (LS). We investigated the physical and radiographic characteristics of AIS patients with LS and clarify the mid- to long-term clinical and radiological outcomes. Methods A total of 234 consecutive patients (212 female and 22 male; mean age: 15.0 +/- 2.2 years) with AIS who underwent posterior spinal fusion (PSF) were evaluated in this retrospective cohort study. All patients underwent PSF exclusively for the treatment of AIS. LS was determined by preoperative CT. Radiographic parameters and SRS-22r results were compared between the LS and non-LS groups preoperatively and at 2 years postoperatively. Changes in visual analog scale (VAS) scores and radiological findings were further investigated in AIS patients with LS outside the PSF fusion area preoperatively, at 2 years postoperatively, and at final follow-up. Results LS was identified in 17 of 234 patients (7.3%). Preoperatively, these patients had significantly higher BMI and lumbar lordosis compared with the non-LS group. However, no significant differences in radiographic or clinical parameters were detected between the groups at 2 years postoperatively. The respective scores for the SRS-22r pain domain in the LS and non-LS groups were 3.8 +/- 0.2 and 4.4 +/- 0.0 (P = 0.005) preoperatively and 4.4 +/- 0.1 and 4.5 +/- 0.0 (P = 0.369) at 2 years postoperatively. Fourteen patients with LS outside the PSF surgical range were followed for a mean of 6.8 years. At the last postoperative visit, SRS-22r scores for pain and satisfaction were favorable at 4.3 +/- 0.2 and 4.1 +/- 0.2, respectively. No domain scores were decreased from preoperative levels. Although VAS results decreased from 27.8 +/- 8.6 mm preoperatively to 18.3 +/- 7.1 mm at final follow-up, the prevalence of isthmic spondylolisthesis increased from 7% (1/14) and 29% (4/14). Conclusion AIS patients with LS maintained high surgical satisfaction and improved pain for 6.8 years, although isthmic spondylolisthesis increased from 7% to 29%. The short- and mid-term results of PSF in AIS patients with LS therefore appear favorable. Further long-term follow-up studies are needed to elucidate whether pars repair is necessary in these patients.

Investigate whether Cobb angle can be predicted by angle of trunk rotation (ATR) measurements with a scoliometer and identify the characteristics of hard-to-predict cases. We retrospectively analyzed 176 patients who were examined for AIS at our department between 2011 and 2021. The cohort included 160 girls and 16 boys aged 11 years (83 patients) or 12 years (93 patients). ATR was determined with an OSI-Scoliometer (Orthopedic Systems, Inc., Union City, CA, USA). Risser grade, Cobb angle, coronal balance, and clavicular angle were all measured using standing full-length frontal radiographs. Coronal balance was measured as the distance of the C7 plumb line (C7PL) to the central sacral vertebral line. We defined the underestimated group as having a predicted Cobb angle > 1 standard deviation (SD) lower than the actual Cobb angle. ATR and Cobb angle were strongly and positively correlated in the cohort (r = 0.883, P < 0.001). To investigate ATR values for use in treatment decision-making, the determined cut-off value of ATR for > 25° Cobb angle was 7.5° (area under the receiver operating characteristic curve [AUROC]: 0.895, sensitivity: 0.810, specificity: 0.838) and for > 45° Cobb angle was 10.5° (AUROC: 0.941, sensitivity: 1.000, specificity: 0.781). We observed 23 patients in the underestimation group. Actual Cobb angle was significantly higher in the underestimation group, which also included significantly more patients with larger C7PL deviation and with right shoulder up. Logistic regression analysis revealed that the larger the Cobb angle at the time of ATR measurement, the higher the risk of underestimating the Cobb angle in our prediction formula. Specifically, the odds ratio suggests that a 10° increase in the Cobb angle results in a 2.3-fold increase in this risk. ATR and Cobb angle were strongly correlated, with ATR cut-off values of 7.5° and 10.5° to predict Cobb angle > 25° and > 45°, respectively. Although the accurate prediction of Cobb angle appears difficult, especially for larger curves, this method may be useful in determining the need for bracing or surgical treatment without radiography.

The human hip joint has three degrees of freedom: flexion and extension, abduction and adduction, and external rotation and internal rotation. However, most current walking assist robots only support flexion–extension of the hip joint and may restrict the unassisted passive movements of other motions. This would cause major problems when used in daily life for such actions as changing direction, recovering from a stumble, and toileting. To solve these issues, the sliding guide system is conceptualized, a very simple and configurable joint mechanism that allows for 3D movement of the hip joint in walking assist robots. As the human femoral head is almost a perfect sphere, the sliding guide system employs two guide plates that contour spherical surfaces projected from the center of the femoral head. The motor unit assisting flexion–extension is configured with these guide plates to passively slide according to the movements of the assist device wearer and enable unobstructed abduction–adduction and external rotation–internal rotation of the hip joint. While systems of various complexities allowing 3D movement are proposed, the sliding guide system concept represents the simplest and most practical approach for implementation in both conventional and future walking assist robot hip joints.

We defined sagittal S-line tilt (SSLT) as the tilt of the line connecting the upper instrumented vertebra and the lower instrumented vertebra. This study aimed to: (1) examine the correlation between SSLT and proximal junctional angle (PJA) change values, and (2) determine the cut-off value of SSLT with respect to proximal junctional kyphosis (PJK) occurrence. Eighty-six consecutive patients (81 female and 5 male; mean age: 15.8 years) with Lenke 5C AIS who underwent posterior selective spinal fusion. Pearson’s correlation coefficients were used to examine the relationship between preoperative SSLT and changes in PJA from preoperative to 2 years postoperative. The impact of SSLT on PJK at 2 years after surgery was assessed using a receiver operating characteristic (ROC) curve. We observed a moderate positive correlation between preoperative SSLT and change in PJA (R = 0.541, P < 0.001). We identified 18 patients (21

Investigate zones where implant density should not be reduced in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) Lenke type 1A curves. 126 consecutive patients (118 female and 8 male; mean age: 15.1 ± 2.2 years) with Lenke type 1A AIS who underwent PSF using pedicle screw constructs were included. Correction loss which was calculated using immediately postoperative and 2-year postoperative Cobb angle. Implant density was assessed by dividing the instrumented levels into four zones each on the concave and convex sides. The risk factors for significant correction loss were examined using logistic regression analysis. For convex apical zone, correction loss was compared among the three groups of low (0–59

This study evaluated the impact of the Landmark Crater (LC) method on pedicle perforation rates in robot-guided surgery for pediatric scoliosis for each pedicle diameter. Seventy-six scoliosis patients underwent robot-assisted posterior spinal fusion. The cohort consisted of 19 male and 57 female patients, with a mean ± standard deviation age of 17.5 ± 7.7 years and a preoperative Cobb angle of 57.0 ± 18.5°. The LC method is a method in which craters that serves as a landmark are created in advance at the planned PS insertion site of all pedicles within the intraoperative CT imaging area. The patients were divided into the LC group, in which PS insertion was performed using the LC method, and the control group using the conventional PS insertion method. Overall and pedicle perforation rates for each pedicle outer diameter were compared between the groups by Fisher’s exact test. The LC group exhibited a significantly lower pedicle major perforation rate than did the control group (2.7

Study Design. Retrospective cohort study with interrupted time series analysis. Objective. To examine the clinical effectiveness of gelatin-thrombin matrix sealant (GTMS) on blood loss reduction after adolescent idiopathic scoliosis (AIS) surgery. Summary of Background Data. The real-world effectiveness of GTMS on blood loss reduction in AIS surgery has not been determined. Patients and Methods. The medical records of patients receiving AIS surgery were retrospectively collected during a period before GTMS approval at our institution (January 22, 2010–January 21, 2015) as well as during a postintroduction period (January 22, 2015–January 22, 2020). The primary outcomes were intraoperative blood loss, drain output over 24 hours, and total blood loss (intraoperative blood loss + drain output over 24 h). Interrupted time series analysis using a segmented linear regression model was used to estimate the effect of GTMS on blood loss reduction. Results. A total of 179 AIS patients [mean age (range): 15.4 (11–30) yr; 159 females and 20 males; 63 preintroduction patients and 116 postintroduction patients] were included. After its introduction, GTMS was used in 40% of cases. Interrupted time series analysis revealed changes of −340 mL (95% CI: −649 to −31, P = 0.03) for intraoperative blood loss, −35 mL (95% CI: −124 to 55, P = 0.44) for drain output over 24 hours, and −375 mL (95% CI: −698 to −51, P = 0.02) for total blood loss. Conclusions. The availability of GTMS was significantly associated with reduced intraoperative and total blood loss in AIS surgery. GTMS use as needed is recommended to control intraoperative bleeding in the setting of AIS surgery. Level of Evidence. 3.

Background: During the COVID-19 pandemic, hygiene awareness was increased in communities and hospitals. However, there is controversy regarding whether such circumstances affected the incidence of surgical site infections (SSIs) in the orthopaedic surgical field. Aim: To examine the impact of the COVID-19 pandemic on the incidence of SSIs after orthopaedic surgery. Methods: The medical records of patients having undergone orthopaedic surgery were extracted from the nationwide surveillance database in Japan. The primary outcomes were the monthly incidences of total SSIs, deep or organ/space SSIs, and SSIs due to meticillin-resistant Staphylococcus aureus (MRSA). Interrupted time series analysis was conducted between prepandemic (January 2017 to March 2020) and pandemic (April 2020 to June 2021) periods. Results: A total of 309,341 operations were included. Interrupted time series analysis adjusted for seasonality showed no significant changes in the incidence of total SSIs (rate ratio 0.94 and 95% confidence interval 0.98-1.02), deep or organ/space SSIs (0.91, 0.72 -1.15), or SSIs due to MRSA (1.07, 0.68-1.68) along with no remarkable slope changes in any parameter (1.00, 0.98-1.02; 1.00, 0.97-1.02; and 0.98, 0.93-1.03, respectively). Conclusions: Awareness and measures against the COVID-19 pandemic did not markedly influence the incidence of total SSIs, deep or organ/space SSIs, or SSIs due to MRSA following orthopaedic surgery in Japan. (c) 2023 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Determine the effect of using the modified S-line vertebra (MSLV) as the upper instrumented vertebra (UIV) on postoperative trunk balance, L4 tilt, and clinical outcomes in selective thoracic fusion (STF) for adolescent idiopathic scoliosis (AIS) Lenke type 1C curve. Twenty-eight consecutive patients (all female; mean age: 15.4±2.0 years) with AIS Lenke type 1C curve were retrospectively enrolled. Primary outcome measures were coronal balance (absolute distance between C7 and the center of the sacral vertical line), L4 tilt, and Scoliosis Research Society (SRS)-22r scores at 2 years postoperatively. The group with the MSLV at the UIV was designated as the MSLV group (18 patients), and the group with the MSLV proximal (12 patients) or distal (4 patients) to the UIV was defined as the non-MSLV group. We observed no significant differences between the groups regarding age, LIV and stable vertebra positioning, or preoperative X-ray parameters. Postoperative coronal balance was significantly better in the MSLV group (0.39±0.08 vs. 1.34±0.22 cm; P.

Introduction: Corrective scoliosis surgery in patients with adolescent idiopathic scoliosis (AIS) increases thoracic volume but does not improve respiratory function (RF). This study evaluates the effect of physical flexibility (PF) improvement after scoliosis surgery on RF. Methods: This study reviewed the records of 61 consecutive patients with AIS (56 female and 5 male; mean±standard deviation age: 14.8±2.2 years, range: 11-20 years) who had undergone posterior spinal fusion (PSF) of the thoracic curve. PF evaluated as finger-floor distance (FFD) was measured preoperatively and one year after surgery. After dividing the cohort into the PF improvement group and the PF nonimprovement group, RF changes at two years postoperative were statistically compared. Using logistic regression analysis, we evaluated the impact of a PF improvement on % forced vital capacity (%FVC) two years after surgery. Results: The rate of patients with increased FVC, %FVC, and forced expiratory volume 1.0 second two years after surgery was 79%, 51%, and 80%, respectively. The PF improvement group exhibited a significantly higher gain in %FVC versus the PF nonimprovement group (P=0.043). Moreover, PF improvement significantly prevented a %FVC decrease (odds ratio 8.43, 95% confidence interval 1.92-59.70; P<0.001), with an adjusted odds ratio of 11.86 (P<0.001). Conclusions: Patients with diminished PF after PSF for AIS may be less likely to achieve postoperative %FVC improvement. As increased postsurgical %FVC had a positive effect on physical function, treatment strategies that focus on maintaining and increasing PF are desirable from an RF viewpoint.

BACKGROUND CONTEXT Adult spinal deformity (ASD) patients often complain of walking discomfort. However, dynamic balance evaluation methods of gait in ASD have not been well established. DESIGN Case series study. PURPOSE Characterize the gait of ASD patients using a novel two-point trunk motion measuring device. PATIENT SAMPLE Sixteen ASD patients scheduled for surgery and 16 healthy control subjects. OUTCOME MEASURES Trunk swing width and track length of the upper back and sacrum. METHODS Gait analysis was performed using a two-point trunk motion measuring device on 16 ASD patients and 16 healthy control subjects. Three measurements were taken for each subject, and the coefficient of variation was determined to compare measurement accuracy between the ASD and control groups. Trunk swing width and track length were measured in three dimensions for comparisons between the groups. The relationship among output indices, sagittal spinal alignment parameters, and quality of life (QOL) questionnaire scores was examined as well. RESULTS No significant difference was found for the precision of the device between the ASD and control groups. Compared with controls, the walking style of ASD patients tended to have larger right-left swing of the trunk (+14.0 cm and +23.3 cm at the sacrum and upper back, respectively), larger horizontal plane movement of the upper body (+36.4 cm), less vertical movement (-5.9 cm and -8.2 cm up-down swing at the sacrum and upper back, respectively), and longer gait cycle (+0.13 sec). Regarding QOL in ASD patients, greater right-left/front-back swing of the trunk, greater movement in the horizontal plane, and longer gait cycle were associated with lower QOL scores. Conversely, greater vertical movement was associated with higher QOL. CONCLUSIONS ASD patients had unique gait characteristics, the intensity of which were associated with diminished QOL. The two-point trunk motion measuring device may be reliable and useful for the clinical assessment of balance during gait in ASD patients.

Background: To evaluate the surgical results of patients with cervical spondylotic myelopathy (CSM) with inconsistency between deep tendon reflex findings and cervical magnetic resonance imaging (MRI) findings and to analyze the differences between patients with good and poor surgical outcomes.Methods: We evaluated 50 subjects with CSM (30 males, 20 females; mean age: 70.4 years) who underwent posterior surgery and were followed for at least 1 year postoperatively. Matched CSM was defined as a consistent preoperative neurological pattern determined by deep tendon reflex and cervical MRI T2-weighted high-signal intramedullary area or stenosis in the most cranial compression levels. A lack of consistency was classified as unmatched CSM. Recovery rate (RR) according to Japanese Orthopaedic Association (JOA) scoring preopera-tively and at 1 year postoperatively were compared between the groups.Results: The matched and unmatched CSM group included 27 subjects (13 males, 14 females; mean age: 68.2 years) and 23 subjects (17 males, 6 females; mean age: 72.8 years), respectively. RR was significantly higher in the matched CSM group (56.1 symbolscript 3.7 % vs 36.8 symbolscript 2.7 %; p symbolscript 0.002). Unmatched CSM was significantly associated with a lower RR independently of sex, patient age, surgical procedure, preoperative JOA score, diagnosis levels, and complication of diabetes.Conclusions: Postoperative JOA score RR was significantly diminished among unmatched CSM patients comprising of 46% of cases. Some patients with unmatched CSM had multiple levels of spinal canal stenosis, foraminal stenosis, and peripheral neuropathy, suggesting that surgical results were poorer than those of matched CSM.

We evaluated 855 pedicle screws inserted into 58 pediatric scoliosis patients. There was no increase in violation rate with a lower dose of intraoperative navigation cone beam computed tomography. Insertion into vertebrae close to the upper instrumented vertebra and shorter patient stature were significantly associated with pedicle screw violations. Study Design. Retrospective observational study. Objective. This study aimed to determine the effect of reducing the radiation dose of intraoperative cone beam computed tomography (CBCT) during posterior spinal fusion (PSF) for pediatric scoliosis on the rate of pedicle screw (PS) violation. Summary of Background Data. Intraoperative CBCT for pediatric scoliosis improves the accuracy of PS insertion in PSF. However, few reports have addressed the PS perforation rate from reduced radiation doses in hybrid navigation. Methods. We evaluated 855 PSs inserted into 58 pediatric scoliosis patients (11 male and 47 female, mean age: 16.6 yr) who underwent PSF using CBCT. A radiation dose of 1/3 or 1/5 of the normal dose (ND) was defined as a low dose (LD). After PS insertion, intraoperative CBCT images were reviewed to assess the degree of PS perforation. G2–3 (i.e., perforations of 4 mm or more) was defined as a violation. The PS violation rate was compared between the groups, and factors associated with violations were examined. Results. A total of 567 and 288 screws were inserted in the ND group and LD group, respectively. The PS violation rate was comparable at 1.8% in the ND group and 1.7% in the LD group. Multiple logistic regression analysis showed that distance from the upper instrumented vertebra (UIV) was an independently associated factor of PS violation (+1 vertebra, operation room 0.73, P = 0.038). In addition, the mean height of patients with PS violations (148.8 ± 3.6 cm) was significantly shorter than that of patients without violations (157.9 ± 1.2 cm) (P = 0.034). Conclusion. There was no increase in PS violation rate with lower doses of radiation for intraoperative navigation CBCT. Extra care is warranted for vertebrae close to the UIV and patients of shorter stature. Level of Evidence: 3

No validated systems exist for selecting the upper instrumented vertebra (UIV) for optimal postoperative shoulder balance in Lenke type 2 adolescent idiopathic scoliosis (AIS). This study evaluated a new method for shoulder balance prediction using the modified Shinshu line (MSL) for UIV selection in AIS Lenke type 2 curves. Fifty-five consecutive AIS patients receiving posterior spinal fusion (PSF) for a Lenke type 2 AIS curve were retrospectively analyzed according to several UIV determination models. Shoulder imbalance was judged as absolute radiographic shoulder height ≥ 10 mm at the 2-year observational endpoint. The MSL was the line between the center of the spinous process of C7 and that of the lowest instrumented vertebra. The vertebral body first touched proximally by the MSL was defined as the MSL vertebra (MSLV) and recommended as the UIV. The group with the UIV matching the MSLV had a significantly lower prevalence of shoulder imbalance of 23% (odds ratio 4.08, 95% CI 1.22–13.7, P = 0.02). Setting the MSLV as the UIV in PSF for AIS Lenke type 2 may reduce the prevalence of postoperative shoulder imbalance.

OBJECTIVE:In recent years, it has become possible to predict postoperative correction and residual deformity in adolescent idiopathic scoliosis (AIS) surgery based on the technique used and extent of fixation. However, the recommended degree of correction has not yet been established. In this study, the authors aimed to clarify the extent to which a residual postoperative deformity would be acceptable according to Scoliosis Research Society (SRS)-22r and satisfaction scores after AIS surgery. METHODS:Overall, 92 patients who underwent posterior spinal fusion for Lenke type 1 or 2 AIS were retrospectively included. The Patient Acceptable Symptom State (PASS) cutoff values for each SRS-22r domain were calculated using receiver operating characteristic (ROC) curves to obtain predictive values of treatment satisfaction 2 years after surgery. Multivariate logistic regression analysis was performed with deformity parameters and demographic data as explanatory variables, and achieving the PASS cutoff value of each SRS-22r domain and treatment satisfaction were objective variables. Cutoff values were calculated using ROC analysis. RESULTS:The PASS cutoff values for SRS-22r domains were 3.69 (area under the ROC curve [AUC] 0.86) for self-image, 4.25 (AUC 0.82) for mental health, and 4.22 (AUC 0.82) for the subtotal. The residual main thoracic Cobb angle was not remarkably related to SRS-22r or treatment satisfaction. The residual thoracolumbar/lumbar (TL/L) Cobb angle was significantly associated with treatment satisfaction, with a cutoff value of 12.5° (AUC 0.75). The parameters of deformity that were significantly associated with achieving the PASS cutoff value for self-image were the TL/L Cobb angle and main thoracic apical vertebral translation, although their respective AUCs were < 0.7. CONCLUSIONS:In patients with Lenke type 1 and 2 AIS, the residual postoperative TL/L Cobb angle was significantly associated with achieving the PASS cutoff values for self-image and treatment satisfaction. Satisfaction with treatment was more likely when the TL/L Cobb angle was ≤ 12.5°.

BACKGROUND CONTEXT:Posterior spinal fusion with pedicle screws is commonly used for the treatment of adolescent idiopathic scoliosis (AIS). To reduce radiation exposure, methods other than computed tomography (CT) are desirable for preoperative determination of pedicle diameter.PURPOSE:Investigate the differences between magnetic resonance imaging (MRI) and CT measurements of pedicle diameter.STUDY DESIGN:Cross-sectional research.PATIENT SAMPLE:Twenty-one AIS Lenke type 1 patients (19 female and 2 males, mean age at surgery: 15.4 years) who underwent posterior spinal fusion between April 2009 and October 2019.OUTCOME MEASURES:Gap between CT and MRI pedicle diameters.METHODS:The inner and outer diameters of the right and left pedicles from T1 to L3 were measured separately by two spine surgeons for statistical comparisons.RESULTS:The respective minimum and maximum CT-MRI values were -3.7 mm and 4.7 mm for inner diameter and -4.6 mm and 5.3 mm for outer diameter. Regarding inter-examiner error, the probability of a 2 mm difference in measurement was less than 5% for both modalities. The probability of a 1 mm difference was also less than 5%, and that of a 3 mm or more difference was 2.1% for the inner diameter and 2.9% for the outer diameter. Whereas low body weight was significantly associated with measurement differences, pedicle laterality was not.CONCLUSIONS:MRI does not have the reliability to measure pedicle size in AIS patients at present. However, with advancements in image processing technology, the accuracy of pedicle size measurement by MRI may soon improve.

BACKGROUND CONTEXT:An increasing number of medical centers are adopting an intraoperative computed tomography (iCT) navigation system (iCT-Navi) to provide three-dimensional navigation for pediatric scoliosis surgery. While iCT-Navi has been reported to provide higher pedicle screw (PS) insertion accuracy, it may also result in higher radiation exposure to the patient. What innovations and studies have been introduced to reduce radiation exposure and further improve PS insertion? PURPOSE:Evaluate the level of evidence and quality of papers while categorizing the tips and pitfalls regarding pediatric scoliosis surgery using iCT-Navi. Compare iCT-Navi with other methods, including preoperative CT navigation. STUDY DESIGN:Systematic review. PATIENT SAMPLE:Articles on pediatric scoliosis surgery with iCT-Navi published through to June 2022. OUTCOME MEASURES:PS perforation rate and patient intraoperative radiation dose. METHODS:Following PRISMA guidelines, the Cochrane Library, Google Scholar, and PubMed databases were searched for articles satisfying the criteria of iCT-Navi use and pediatric scoliosis surgery. The level of evidence and quality of the articles meeting the criteria were evaluated according to the guidelines of the North American Spine Society and American Academy of Orthopedic Surgeons, respectively. The articles were also categorized by theme and summarized in terms of PS insertion accuracy and intraoperative radiation dose. The origins and characteristics of five major classification methods of PS perforation grade were summarized as well. RESULTS:The literature search identified 811 studies, of which 20 papers were included in this review. Overall, 513 pediatric scoliosis patients (381 idiopathic, 44 neuromuscular, 39 neurofibromatosis type 1, 28 congenital, 14 syndromic, seven other) were evaluated for PS perforations among 6,209 iCT-Navi insertions. We found that 232 (3.7%) screws were judged as major perforations (G2 or G3), 55 (0.9%) screws were judged as dangerous deviations (G3), and seven (0.1%) screws were removed. There were no reports of neurovascular injury caused by PSs. The risk factors for PS perforation included more than six vertebrae distance from the reference frame, more than nine consecutive insertions, upper thoracic level, thinner pedicle, upper instrumented vertebra proximity, short stature, and female. The accuracy of PS insertion did not remarkably decrease when the radiation dose was reduced to 1/5 or 1/10 by altering the iCT-Navi protocol. CONCLUSIONS:iCT-Navi has the potential to reduce PS perforation rates compared with other methods. The use of low-dose radiation protocols may not significantly affect PS perforation rates. Although several risk factors for PS perforation and measures to reduce radiation dose have been reported, the current evidence is limited by a lack of consistency in classifying PS perforation and evaluating patient radiation dose among studies. The standardization of several outcome definitions is recommended in this rapidly developing field.

Study Design: Retrospective cohort study.Purpose: This study aimed to evaluate the relationship between C7 plumb line (C7PL) decompensation and the Scoliosis Research Society (SRS) 22-item patient questionnaire scores, including those related to self-image, preoperatively and 2 years after surgery.Overview of Literature: In the surgical treatment of adolescent idiopathic scoliosis (AIS), inferior trunk balance caused by C7PL decompensation can negatively affect patients’ quality of life. However, there are few reports in the literature that describe or clarify how postoperative trunk imbalance affects each SRS-22 domain, including self-image domain scores.Methods: A total of 120 patients with AIS who underwent posterior spinal fusion from August 2006 to March 2017 at our facility and were followed up for 2 years or more were included. Radiological parameters were measured on whole-spine anteroposterior and lateral radiographs. Revised SRS-22 (SRS-22r) values were also recorded. Coronal trunk imbalance was defined as a deviation of ≥2.0 cm between the C7PL and the central sacral vertical line. Patients with and without coronal trunk imbalance at 2 years after surgery were defined as D (+) (decompensation type) and D (-), respectively. Mean SRS-22r values, including function, pain, self-image, mental health, and subtotal were compared between the D (+) and D (-) groups. Logistic regression analysis was performed to detect the preoperative factors related to D (+) using predictors, including curve type, maximum Cobb angle, and coronal trunk imbalance.Results: At 2 years after surgery, the D (+) group had a significantly lower self-image in the domain of SRS-22r scores compared with the D (-) group. Preoperative coronal trunk imbalance was significantly related to D (+) but not to significant changes in the postoperative SRS-22 score in any of the SRS-22 domains.Conclusions: Postoperative C7PL deviation lowers the self-image in patients with AIS. Patients with preoperative coronal trunk imbalance were significantly more likely to be D (+).

Abstract This study investigated whether postoperative rotational deformity in adolescent idiopathic scoliosis patients could be predicted by prone-position pre-operative angle of trunk rotation (ATR). Surgical rib hump correction is performed with the patient in a prone position. However, the association between pre-operative ATR in the prone position and postoperative ATR results is unknown. Thirty-four consecutive patients who underwent skip pedicle screw fixation for Lenke type 1 or 2 adolescent idiopathic scoliosis were retrospectively reviewed. All subjects were followed for a minimum of 1 year. ATR measurements were taken for the standing-flexion position with a scoliometer before surgery and at 1 year afterward. Pre-operative measurements were also taken for the prone position. Correlations between pre- and postoperative ATR were calculated by means of Pearson correlation coefficient. Associations between the correction angle from the standing-flexion position to prone position and postoperative standing-flexion correction angle were determined by linear regression analysis. Pre- and postoperative ATR for the standing-flexion position showed a moderate association (r = 0.64, P < .01). A similar correlation was seen for pre-operative prone-position ATR and postoperative standing-flexion ATR (r = 0.56, P < .01). In linear regression analysis, there was significant proportional error between the correction angle from the standing-flexion position to prone position and postoperative standing-flexion correction angle (β = 0.40, P < .01). In conclusion, pre-operative ATR in either standing-flexion or prone position and postoperative standing-flexion ATR displayed moderate associations. Linear regression analysis revealed that ATR correction angle could be estimated by calculating the correction gains of 0.4° per 1° of correction angle in the prone position.