Prediction of postoperative curve correction based on the supine radiographs for adult idiopathic scoliosis (AdIS) patients.

BACKGROUND CONTEXT: Preoperative supine radiographs are mandatory in the new adult idiopathic scoliosis (AdIS) classification. Supine radiographs are easily reproducible and highly predictive of side bending radiographs. However, few studies evaluated the use of supine radiographs in predicting postoperative curve correction after posterior spinal fusion (PSF) in AdIS. PURPOSE: To investigate the use of supine and side bending (SB) radiographs in predicting postoperative curve correction in AdIS patients who underwent PSF. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: 93 AdIS patients who underwent PSF between 2022 and 2023 were included. OUTCOME MEASURES: Demographic data were age, gender, height, weight, body mass index (BMI), Risser grade, Lenke curve types and Cobb angles. Main outcome measures were preoperative and immediate postoperative Cobb angle (proximal thoracic [PT], main thoracic [MT] and thoracolumbar/lumbar [TL/L] curves), Supine Cobb angle and Flexibility rate (PT, MT and TL/L), and Correction rate (PT, MT and TL/L). METHODS: Correlation study was performed between Supine Cobb angle vs. postoperative Cobb angle for PT, MT and TL/L curves. A predictive formula was derived from the correlation plots. RESULTS: A total of 93 subjects were included in our study with a median age of 24.7 years and comprised of 80 females (86.0%). Preoperative Supine Cobb angle (r=0.835, r=0.881, r=0.767, p<.001) and preoperative SB Cobb angle (r=0.815, r=0.872, r=0.801, p<.001) showed similar strong positive correlation with postoperative PT, MT and TL/L Cobb angle, but preoperative Supine Cobb angle had slightly stronger correlation in PT and MT, whereas preoperative SB Cobb angle had stronger correlation in TL/L curve. Using the derived predictive formulae, there was a significant, strong, positive correlation between the predicted value and actual value of postoperative standing Cobb angle, (r=0.852, p<.001), with 71.0% of the patients had predicted postoperative Cobb angle from the supine radiographs within 5 degrees of the actual value. CONCLUSION: Both supine radiographs and side bending radiographs had strong predictability of the postoperative Cobb angle for PT, MT and TL/L curves. In 71.0% of patients, the actual postoperative Cobb angle was within 5 degrees of the predicted postoperative Cobb angle using the predictive formulae.

The widths of the medial and lateral pedicle walls in adolescent idiopathic scoliosis (AIS) with major thoracic curves.

BACKGROUND CONTEXT: The widths of medial and lateral pedicle walls in the normal spine of middle-aged and elderly adults have been investigated and these studies found that the medial pedicle wall was thicker than the lateral pedicle wall. However, none had evaluated the widths of medial and lateral pedicle walls on adolescent or young adult scoliotic spines. PURPOSE: This study aims to identify the distribution and variation of medial and lateral pedicle wall widths throughout the different vertebral levels of the scoliotic spine and its differences according to age, gender, body mass index (BMI), maturity, curve types and curve severity in adolescent idiopathic scoliotic (AIS) patients with major thoracic curves. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: A total of 6,230 pedicles (right: 3,064, left: 3,166) from 191 patients were included in this study, with 264 (right: 183, left: 81) fully corticalized pedicles excluded from analysis. OUTCOME MEASURES: Demographic data were age, gender, height, weight, BMI, Risser grade, Lenke curve types and Cobb angles. The main outcome measures were medial and lateral pedicle wall widths. Associations between pedicle wall widths and demographic data were calculated. METHODS: This was a subanalytical retrospective study done on the same patient population as the previously published study on pedicle grading. The data was obtained from the main computed tomography (CT) scan pedicle study dataset. Medial and lateral pedicle wall widths were measured in the axial slices of CT scans from T1 to L5 vertebrae. RESULTS: A total of 6,230 pedicles (right: 3,064, left: 3,166) from 191 patients were included in this study with 264 (right: 183, left: 81) fully corticalized pedicles excluded from analysis. Right-sided medial pedicle wall widths were narrower from T4-T10 (0.75±0.23 mm) compared to T1-T3 (0.89±0.28 mm) and T11-L5 (0.92±0.30 mm). Left-sided medial pedicle wall widths were narrower from T4 to T7 (0.76±0.24 mm) compared to T1-T3 (0.88±0.26 mm) and T8-L5 (0.90±0.27 mm). Medial cortical wall widths were significantly thicker compared to lateral cortical wall widths for all vertebras from T1 to L5 (right medial 0.85±0.28 mm vs. lateral 0.64±0.26 mm (p<.001), left medial 0.86±0.26 mm vs. lateral 0.64±0.26 mm (p<.001)). The left medial pedicle wall widths were marginally significantly (p<.001) thicker than the right side (right medial 0.85±0.28 mm vs. left 0.86±0.26 mm). The main notable significant differences were located at the periapical region of the thoracic curve between T7 to T10 with the left concave medial pedicle width being thicker than the right convex medial pedicle width. The thinnest medial pedicle walls were located at right concave T7 (0.73±0.24 mm) and T8 (0.73±0.23 mm). We generally found no significant associations between the medial and lateral pedicle wall widths with age, gender, BMI, Risser grade, Cobb angle and curve types. CONCLUSIONS: Knowledge on the widths of medial and lateral pedicle walls, their distribution and differences in a scoliotic spine is important for pedicle screw fixation, especially during pedicle probing to find the pedicle channel. The medial pedicle wall widths were significantly thicker than the lateral pedicle wall widths in AIS patients with major thoracic curves. The right concave periapical region had the thinnest medial pedicle walls.

Analysis of duration of different stages of surgery in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) patients: comparison between severe versus non-severe AIS.

PURPOSE: Prolonged surgical duration in severe adolescent idiopathic scoliosis (AIS) patients is associated with increased blood loss and perioperative complications. The aim of this study was to compare the duration of each stage of posterior spinal fusion (PSF) in severe AIS (Cobb angle ≥ 90°) with non-severe AIS patients. This analysis will identify the most time-consuming stage of PSF and help surgeons formulate strategies to shorten operative time. METHODS: Retrospective study whereby 90 AIS patients (Lenke type 2, 3, 4, and 6) who underwent PSF from 2019 to 2023 were recruited. Twenty-five severe AIS patients were categorized in Gp1 and 65 non-severe AIS patients in Gp2. Propensity score matching (PSM) with one-to-one with nearest neighbor matching (match tolerance 0.05) was performed. Outcomes measured via operation duration of each stage of surgery, blood loss, number of screws, fusion levels and screw density. RESULTS: Twenty-five patients from each group were matched. Total operative time was significantly higher in Gp1 (168.2 ± 30.8 vs. 133.3 ± 24.0 min, p < 0.001). The lengthiest stage was screw insertion which took 58.5 ± 13.4 min in Gp1 and 44.7 ± 13.7 min in Gp2 (p = 0.001). Screw insertion contributed 39.5% of the overall increased surgical duration in Gp1. Intraoperative blood loss (1022.2 ± 412.5 vs. 714.2 ± 206.7 mL, p = 0.002), number of screws (17.1 ± 1.5 vs. 15.5 ± 1.1, p < 0.001) and fusion level (13.1 ± 0.9 vs. 12.5 ± 1.0, p = 0.026) were significantly higher in Gp1. CONCLUSION: Screw insertion was the most time-consuming stage of PSF and was significantly longer in severe AIS. Adjunct technologies such as CT-guided navigation and robotic-assisted navigation should be considered to reduce screw insertion time in severe AIS.

Variations in the Number of Vertebrae, Prevalence of Lumbosacral Transitional Vertebra and Prevalence of Cervical Rib Among Surgical Patients With Adolescent Idiopathic Scoliosis: An Analysis of 998 Radiographs.

STUDY DESIGN: Retrospective Study. OBJECTIVE: This study aims to investigate variation in the number of thoracic and lumbar vertebrae, the prevalence of lumbosacral transitional vertebra (LSTV) and the prevalence of cervical ribs among surgical patients with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Due to variation in the number of thoracic or lumbar vertebrae, inaccurate identification of vertebral levels has been found to be a contributory factor to wrong-level surgery. METHODS: This was a retrospective study on AIS patients who underwent posterior spinal fusion. Demographic and anthropometric data (age, gender, height, weight, and body mass index), radiographic data (Lenke curve type, pre-operative Cobb angle, vertebra numbering of cervical, thoracic, and lumbar spine, presence of LSTV based on the Castellvi classification and the presence of cervical ribs) and clinical data were collected. Data were analysed and reported with mean and standard deviation for quantitative parameters and number and percentage for qualitative parameters. Multinomial logistic regression analyses were performed to identify factors associated with the outcomes of interest. RESULTS: A total of 998 patients met inclusion criteria, of which 135 (13.5%) were males and 863 (86.5%) were females. The vertebrae number varied between 23 to 25 total vertebrae with 24 vertebrae considered as the typical number of vertebrae. The prevalence of atypical number of vertebrae (23 or 25) was 9.8% (98 patients). We found a total of 7 different variations in number of cervical, thoracic, and lumbar vertebrae (7C11T5L, 7C12T4L, 7C11T6L, 7C12T5L, 7C13T4L, 7C12T6L, and 7C13T5L) with 7C12T5L considered as the typical vertebrae variation. The total prevalence of patients with atypical vertebrae variation was 15.5% (155 patients). Cervical ribs were found in 2 (0.2%) patients while LSTV were found in 250 (25.1%) of patients. The odds of 13 thoracic vertebrae were higher in males (OR 5.17; 95% CI: 1.25, 21.39) and the odds of 6 lumbar vertebrae were higher in LSTV (OR 3.93; 95% CI: 2.58, 6.00). CONCLUSION: In this series, we identified a total of 7 different variations in the number of cervical, thoracic, and lumbar vertebrae. The total prevalence of patients with atypical vertebrae variation was 15.5%. LSTV was found in 25.1% of the cohort. It is important to ascertain atypical vertebrae variations rather than the absolute number of vertebrae because variants such as 7C11T6L and 7C13T4L may still have typical numbers of vertebrae in total. However, due to the differences in the number of morphologically thoracic and lumbar vetrebrae, there may still be a risk of inaccurate identification.

What is the prevalence and distribution of narrow dysplastic and fully corticalized pedicles in Asian adolescent idiopathic scoliosis patients with major main thoracic curves? A computed tomography scan analysis of 6,494 pedicles.

BACKGROUND CONTEXT: Patients with adolescent idiopathic scoliosis (AIS) have higher prevalence of abnormal or dysplastic pedicles. PURPOSE: To investigate the prevalence and distribution of narrow dysplastic and fully corticalized pedicles in Asian AIS patients with major main thoracic curves. DESIGN: Retrospective study. PATIENT SAMPLE: A total of 6,494 pedicles in 191 patients were measured and evaluated. OUTCOME MEASURES: The primary outcomes measures were the pedicle width measurements (total transverse pedicle width, transverse cancellous width, total transverse cortical width) and classification of pedicles. Demographic data (age, gender, height, weight, body mass index), proximal thoracic Cobb angle, main thoracic Cobb angle and lumbar Cobb angle were also obtained. METHODS: AIS patients with major (largest Cobb angle) main thoracic curves and had computed tomography (CT) scans prior to corrective spine surgery were reviewed. The pedicles were classified as Grade A: cancellous channel >4 mm; Grade B: cancellous channel 2 to 4 mm; Grade C: cancellous channel <2 mm or corticalized pedicle >4 mm; Grade D: corticalized pedicle ≤4 mm. Grades B, C, and D were dysplastic pedicles while grades C and D were narrow dysplastic pedicles. RESULTS: The prevalence of dysplastic pedicles (grades B, C, and D) was 61.7%. There were 22.6% narrow dysplastic pedicles (grades C and D) and 4.1% fully corticalized pedicles (grade D). In the thoracolumbar region, there was a sharp transition from larger and less dysplastic pedicles at T11 and T12 to narrower and more dysplastic pedicles at L1 and L2 (narrow dysplastic pedicles at T11: 3.1%, T12: 3.1%, L1: 39.8% and L2: 23.6%). Higher prevalences of narrow dysplastic pedicles were located at right T3 to T5 (71.2%-83.7%) and left T7-T9 (51.3%-61.2%). Higher prevalences of fully corticalized pedicles were located at right T3 to T5 (20.9%-34.0%) and left T7 to T8 (11.0%-12.0%). These were the concave pedicles of proximal thoracic and main thoracic curves, respectively. CONCLUSION: There were 95.9% pedicles with cancellous channels (grades A, B, and C) can allow pedicle screw fixation and only 4.1% fully corticalized pedicles (grade D) that require an alternative method of fixation. For grade C pedicles (18.5%), pedicle screws can still be attempted with caution. Precautions should also be observed at the L1 and L2 levels as there was a transition to narrower pedicles.

Association between intraoperative remifentanil use and postoperative hyperalgesia in adolescent idiopathic scoliosis surgery: a retrospective study.

BACKGROUND: The liberal use of remifentanil in spine surgery has been associated with an increased incidence of postoperative hyperalgesia. Nevertheless, controversies remain as the existing evidence is inconclusive to determine the relationship between remifentanil use and the development of opioid-induced hyperalgesia. We hypothesized that intraoperative infusion of higher dose remifentanil during scoliosis surgery is associated with postoperative hyperalgesia, manifesting clinically as greater postoperative morphine consumption and pain scores. METHODS: Ninety-seven patients with adolescent idiopathic scoliosis (AIS) who underwent posterior spinal fusion surgery at a single tertiary institution from March 2019 until June 2020 were enrolled in this retrospective study. Anesthesia was maintained using a target-controlled infusion of remifentanil combined with volatile anesthetic desflurane in 92 patients, while five patients received it as part of total intravenous anesthesia. Intravenous ketamine, paracetamol, and fentanyl were administered as multimodal analgesia. All patients received patient-controlled analgesia (PCA) morphine postoperatively. Pain scores at rest and on movement, assessed using the numerical rating scale, and the cumulative PCA morphine consumption were collected at a six-hourly interval for up to 48 h. According to the median intraoperative remifentanil dose usage of 0.215 µg/kg/min, patients were divided into two groups: low dose and high dose group. RESULTS: There were no significant differences in the pain score and cumulative PCA morphine consumption between the low and high dose remifentanil group. The mean duration of remifentanil infusion was 134.9 ± 22.0 and 123.4 ± 23.7 min, respectively. CONCLUSION: Intraoperative use of remifentanil as an adjuvant in AIS patients undergoing posterior spinal fusion surgery was not associated with postoperative hyperalgesia.

A Comparison Between the Perioperative Outcomes of Female Adolescent Idiopathic Scoliosis (AIS) Versus Adult Idiopathic Scoliosis (AdIS) Following Posterior Spinal Fusion: A Propensity Score Matching Analysis Involving 425 Patients.

STUDY DESIGN: Retrospective propensity score matching (PSM) study. OBJECTIVE: To investigate the perioperative outcomes comparing adolescent idiopathic scoliosis (AIS) and adult idiopathic scoliosis (AdIS) patients following posterior spinal fusion (PSF). METHODS: 425 female AIS and AdIS patients who were operated (between January 2015 to March 2020) using a dual attending surgeon strategy were stratified into G1 (AIS aged 10-16 years old) and G2 (AdIS > 20 years old). PSM analysis with one-to-one, nearest neighbor matching technique with match tolerance of 0.001 was used to matched 357 AIS patients to 68 AdIS patients. Operation duration, intraoperative blood loss (IBL), blood loss percentage, hemoglobin drift, blood salvaged, postoperative wound length, allogenic blood transfusion requirement, postoperative hospital stay, postoperative Cobb, correction rate and postoperative complications were documented and reported. RESULTS: Following PSM, G1 and G2 each had 50 patients with comparable and balanced covariates. As anticipated, G2 patients were heavier, taller and had higher body mass index compared to G1 patients (P < 0.05). We could not find any significant differences in the perioperative outcome comparing this 2 groups. AIS and AdIS patients had similar operation duration (125.9 ± 27.2 min vs 127.3 ± 37.8 min), IBL (749.8 ± 315.7 ml vs 723.8 ± 342.1 ml) and length of hospital stay (3.3 ± 0.4 days vs 3.5 ± 0.8 days) (P > 0.05). Hemoglobin drift and amount of blood salvaged were comparable (P > 0.05). G2 had stiffer curves. There was a trend toward a lower correction rate in G2 in the immediate postoperative period, however it did not reach statistical significance (61.8 ± 11.2% vs. 66.3 ± 11.6%, P = 0.051). No patients required blood transfusion and none had any postoperative complications. CONCLUSION: Adolescent and adult female scoliosis patients had comparable perioperative outcome following PSF surgery that was carried out using a dual attending surgeon strategy.

Preoperative "Cervical Axis" Deviation Increases the Risk of Distal Adding-On Following Surgery in Lenke 1 and 2 Adolescent Idiopathic Scoliosis Patients.

STUDY DESIGN: Retrospective. PURPOSE: To evaluate the relationship between shoulder/ neck imbalance with distal adding-on phenomenon and to identify other risk factors in Lenke 1 and 2 (non-AR curves) adolescent idiopathic scoliosis (AIS) patients. METHODS: 100 Lenke 1 and 2 AIS patients with lowest instrumented vertebra (LIV) cephalad to or at L1 were recruited. Medial shoulder/ neck balance was represented by T1-tilt and cervical axis (CA). Lateral shoulder balance was represented by clavicle angle (Cla-A) and radiographic shoulder height (RSH). Distal adding-on phenomenon was diagnosed when there was disc wedging below LIV of >5o at final follow-up. Predictive factors and odds ratio were derived using univariate and multivariate logistic regression analysis. RESULTS: Mean age of this cohort was 15.9 ± 4.4 years. Mean follow-up duration was 30.9 ± 9.6 months. Distal adding-on phenomenon occurred in 19 patients (19.0%). Only Risser grade, preoperative CA and final follow-up lumbar Cobb angle were the independent factors. A positive preoperative CA deviation increased the odds of distal adding-on by 5.4 times (95% CI 1.34-21.51, P = 0.018). The mean immediate postoperative T1-tilt, CA, RSH and Cla-A were comparable between the group with distal adding-on and the group without. CONCLUSION: Distal adding-on phenomenon occurred in 19.0% of patients. Preoperative "Cervical Axis" was an important factor and it increased the risk of distal adding-on by 5.4 times. Other significant predictive factors were Risser grade and lumbar Cobb angle at final follow-up. Immediate postoperative shoulder or neck imbalance was not a significant factor for postoperative distal adding-on phenomenon.

Patients' Perception and Satisfaction on Neck and Shoulder Imbalance in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Cross-sectional. OBJECTIVES: To evaluate the perception and satisfaction among adolescent idiopathic scoliosis (AIS) patients on Neck Tilt with Medial Shoulder Imbalance and Lateral Shoulder Imbalance. METHODS: Lenke 1 and 2 AIS patients were stratified into 6 groups of preoperative/ postoperative Balanced (B), Lateral Shoulder Imbalance (LSI) (>2 cm), and Neck Tilt with Medial Shoulder Imbalance (NT) (Grade 3). Patients were interviewed using Modified Neck and Shoulder Appearance and SRS-22r questionnaires. T1 tilt, Cervical Axis (CA), Clavicle Angle (Cla-A) and Radiographic Shoulder Height (RSH) were measured. RESULTS: A total of 120 Lenke 1 and 2 AIS patients were recruited. NT patients were aware and unhappy with their abnormal neck with medial shoulder appearances (P < .001). Similarly, LSI patients were aware and unhappy with their abnormal lateral shoulder appearances (P < .001). NT group had larger preoperative/ postoperative T1 tilt (9.2 ± 5.0°; 9.5 ± 5.3°) and CA (4.6 ± 3.1°; 7.0 ± 2.0°) (P < .01). LSI group had larger preoperative/ postoperative Cla-A (4.8 ± 2.8°; 4.0 ± 1.3°) and RSH (20.1 ± 9.4 mm; 17.0 ± 6.6 mm) (P < .001). Postoperative B group scored higher in overall SRS-22r scores, self-image and satisfaction domains (4.2 ± 0.3; 4.0 ± 0.5; 4.4 ± 0.5) while preoperative LSI scored the lowest comparatively (3.5 ± 0.4; 2.4 ± 0.5; 3.3 ± 0.5) (P < .001). CONCLUSION: NT and LSI were major concerns among AIS patients. Both NT and LSI groups were unhappy with their appearances. NT group had larger T1 tilt/ CA whereas LSI group had larger Cla-A/ RSH. Postoperative B group scored higher in overall SRS-22r scores, self-image and satisfaction domains.

Severe Lenke 1 and 2 adolescent idiopathic scoliosis had poorer perioperative outcome, higher complication rate, longer fusion and higher operative cost compared to non-severe scoliosis.

PURPOSE: To compare the perioperative outcome and operative cost of posterior spinal fusion (PSF) surgery between severe and non-severe Lenke 1 and 2 adolescent idiopathic scoliosis (AIS) patients. METHODS: A total of 509 AIS patients who underwent single-staged PSF between 2013 and 2020 were reviewed. Fifty-four severe scoliosis patients (Cobb angle ≥ 90°) were categorized into Gp1, and 455 non-severe scoliosis (Cobb angle < 90°) patients into Gp2. Propensity score matching (PSM) analysis using one-to-one nearest neighbor matching and match tolerance of 0.001 were performed. Outcome measures were operative time, intraoperative blood loss (IBL), allogeneic transfusion rate, perioperative complication, length of stay, fusion level, number of screws used, postoperative Cobb angle, correction rate (CR), side bending correction index (SBCI) and operative cost. RESULTS: From the PSM analysis, 35 patients from each group were matched. The operative time was 155.9 ± 41.4 and 130.0 ± 30.3 min for Gp1 and Gp2, respectively (p = 0.004). The IBL was 1349.2 ± 1019.0 and 781.9 ± 325.1 mLs for Gp1 and Gp2, respectively (p = 0.003). Fusion level (12.5 ± 0.8 vs. 11.2 ± 1.3, p < 0.001) and number of screws used (16.4 ± 1.6 vs. 14.6 ± 1.4, p < 0.001) were higher in Gp1. Four perioperative complications were observed in Gp1 compared to none in Gp2 (p < 0.039). Gp1 had larger postoperative Cobb angle (p < 0.001), lower CR (p = 0.005) and higher SBCI (p < 0.001). The operative cost was higher in Gp1 (p < 0.001). CONCLUSIONS: Severe Lenke 1 and 2 AIS patients had poorer perioperative outcome, higher complication rate, longer fusion and higher operative cost than non-severe AIS.

Feasibility of Single-Stage Posterior Passive Correction and Fusion Surgery for Congenital Scoliosis in Adolescent Patients Who Have Attained Skeletal Maturity.

STUDY DESIGN: Retrospective study. PURPOSE: To report the perioperative and radiological outcomes of single-stage posterior passive correction and fusion (SSPPCF) in adolescent patients who present with congenital scoliosis. OVERVIEW OF LITERATURE: The surgical treatment for congenital scoliosis is complex. There is no definitive guide on surgical options for skeletally matured adolescent patients who have congenital scoliosis. METHODS: Patients with congenital scoliosis who underwent SSPPCF using a pedicle screw system were reviewed. We identified the following three surgical indications: (1) hemivertebra or wedge vertebra over the thoracic or thoracolumbar region with structural lumbar curves, (2) hemivertebra or wedge vertebra at the lumbar region with significant pelvic obliquity or sacral slanting, and (3) mixed or complex congenital scoliosis. The demographic, perioperative, and radiographic data of these patients were collected. RESULTS: Thirty-four patients were reviewed. The mean patient age was 14.6±3.4 years. There were 13 hemivertebrae, three wedged vertebrae, two butterfly vertebrae, three hemivertebrae with butterfly vertebra, eight unsegmented bars, and five multiple complex lesions. The average surgical duration was 219.4±68.8 minutes. The average blood loss was 1,208.4±763.5 mL. Seven patients required allogeneic blood transfusion. The mean hospital stay duration was 6.1±2.5 days. The complication rate was 11.8% (4/34): one patient had severe blood loss, one had rod breakage, and two had distal adding-on. The Cobb angle reduced from 65.9°±17.4° to 36.3°±15.3° (p<0.001) with a correction rate (CR) of 44.8%±17.4%. The regional kyphotic angle decreased from 39.9°±20.5° to 27.5°±13.9° (p=0.001) with a CR of 19.3%±49.6%. Radiographic parameters (radiographic shoulder height, clavicle angle, T1 tilt, cervical axis, pelvic obliquity, coronal balance, and apical vertebral translation) showed significant improvement postoperatively. CONCLUSIONS: SSPPCF was a feasible option for adolescent patients with congenital scoliosis who were skeletally matured.

Factors Affecting Operation Duration in Posterior Spinal Fusion (PSF) Using Dual Attending Surgeon Strategy Among Lenke 1 and 2 Adolescent Idiopathic Scoliosis (AIS) Patients.

STUDY DESIGN: This was a retrospective study. SUMMARY OF BACKGROUND DATA: Prolonged operation duration in adolescent idiopathic scoliosis (AIS) surgery was associated with increased perioperative complications. However, the factors affecting operation duration in AIS surgery were unknown. OBJECTIVE: The aim of the study was to investigate the factors affecting operation duration in posterior spinal fusion (PSF) surgery using a dual attending surgeon strategy among Lenke 1 and 2 AIS patients. METHODS: In all, 260 AIS patients with Lenke 1 and 2 curves who underwent PSF were retrospectively reviewed. Preoperative and intraoperative factors affecting operation duration such as age, sex, height, weight, body mass index, Risser grade, Lenke subtypes, number of fusion level, number of screws, screw density, wound length, upper and lowest instrumented vertebrae level, preoperative Cobb angle, and flexibility of the major curve were assessed using univariate and multivariate linear regression analyses. Independent factors were determined when P-value <0.05. RESULTS: The mean operation duration was 122.2±28.6 minutes. Significant independent factors affecting operation duration in PSF among Lenke 1 and 2 AIS patients were Lenke 2 subtypes (ß=8.86, P=0.008), number of screws (ß=7.01, P<0.001), wound length (ß=1.14, P=0.009), and flexibility of the major curve (ß=-0.25, P=0.005). The overall model fit was R2=0.525. Operation duration can be predicted using the formula: (8.86×Lenke subtypes)+(7.01×number of screws)+(1.14×wound length)-(0.25×flexibility)-0.54, where Lenke 2=1 and Lenke 1=0. CONCLUSION: The factors affecting operation duration in PSF among Lenke 1 and 2 AIS patients were Lenke 2 curves, number of screws, wound length, and curve flexibility. The knowledge of these factors enables the spinal deformity surgeons to plan and estimate the operation duration before AIS surgery.

Mid-long-term outcome and degeneration of the remaining unfused lumbar intervertebral disc in adolescent idiopathic scoliosis patients who had posterior spinal fusion surgery.

PURPOSE: To investigate mid-long-term effects of the lowest instrumented vertebra (LIV) selection on adolescent idiopathic scoliosis (AIS) patients who had posterior spinal fusion (PSF) surgery. METHODS: Forty-eight patients were recruited. Inclusion criteria were AIS patients who have had PSF surgery more than 10 years ago. Patients were divided into G1: LIV L3 or higher and G2: LIV L4 or lower. MRI evaluation was classified using Pfirrmann grades. Pfirrmann scores were average of Pfirrmann grades for all unfused discs below LIV. SRS-22r, SF-36, Oswestry Disability Index (ODI) and Modified Cincinnati Sports Activity Scale (MCSAS) were used. RESULTS: There were 19 patients in G1 and 29 patients in G2. Demographic parameters showed no significant differences. We found no significant differences in Pfirrmann grades or scores between G1 and G2. There was significant correlation between age and mean Pfirrmann scores (r = 0.546, p < 0.001), Pfirrmann grade for adjacent disc + 1 below LIV (r = 0.475, p = 0.001) and adjacent disc below LIV (r = 0.365, p = 0.011). G2 had significantly lower scores for SRS-22r pain (G1: 4.3 ± 0.5, G2: 4.0 ± 0.6, p = 0.044) and the SF-36 bodily pain (G1: 88.7 ± 12.3, G2: 77.8 ± 18.7, p = 0.018) domains. There were no significant differences in ODI and MCSAS between the two groups. CONCLUSIONS: Patients with fusion to L4 or lower had more significant back pain. However, both groups had similar physical function, self-image, satisfaction with treatment, mental health, and functional sports activity. We did not find any significant association between lumbar discs degeneration and the selection of LIV.

Perioperative outcome and complications following single-staged Posterior Spinal Fusion (PSF) using pedicle screw instrumentation in Adolescent Idiopathic Scoliosis (AIS): a review of 1057 cases from a single centre.

BACKGROUND: There has been a growing interest in using all pedicle screw construct in posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) surgery in recent years. However, studies focusing on perioperative outcome and complications utilizing only pedicle screw system in AIS population are lacking. This study aims to evaluate perioperative outcomes and to determine the prevalence of major and minor complications following single-staged PSF for AIS. METHODS: In this retrospective study of prospectively collected data, 1057 AIS patients operated between 2012 and 2019 were included. Main outcome measures were operative time, intraoperative blood loss, allogeneic blood transfusion rate, length of hospital stay after surgery, complication rate, and mean drop of haemoglobin (Hb) level. We documented the number of fusion levels, screw density, and postoperative radiographic parameters. RESULTS: There were 917 females and 140 males. Majority were Lenke 1 curve type (46.9%). Mean age was 15.6 ± 3.7 years, with mean BMI of 18.6 ± 3.2 kg/m2. Mean operative time was 146.8 ± 49.4 min. Average intraoperative blood loss was 952.9 ± 530.4 ml with allogeneic blood transfusion rate of 5%. Mean screw density was 1.27 ± 0.21 screws per fusion level. Average hospital stay after surgery was 3.5 ± 0.9 days. Twenty-four complications were documented: twelve superficial infections (1.14%), five transient neurological deficits (0.47%), two deep infections (0.19%), two superior mesenteric artery syndrome, and one case each (0.09%) for massive intraoperative blood loss, intraoperative seizure, and lung atelectasis. CONCLUSION: AIS patients treated with single-staged PSF using pedicle screw construct had a 0.95% rate of major complications and 1.32% rate of minor complications. Rate of neurologic complication was 0.47% while non-neurologic postoperative complications was 1.80% with infection being the leading complication at 1.32%.

Tranexamic Acid in Pediatric Scoliosis Surgery: A Prospective Randomized Trial Comparing High-dose and Low-dose Tranexamic Acid in Adolescent Idiopathic Scoliosis Undergoing Posterior Spinal Fusion Surgery.

STUDY DESIGN: Prospective randomized double-blinded trial. OBJECTIVE: The objective of this study is to determine the efficacy of high-dose versus low-dose tranexamic acid (TXA) in adolescent idiopathic scoliosis (AIS) corrective surgery. SUMMARY OF BACKGROUND DATA: Corrective surgery for AIS is associated with significant blood loss. Evidence on the optimum TXA dose to reduce bleeding in pediatric population is scarce. METHODS: A total of 166 AIS patients aged between 10 and 21 years, of American Society of Anesthesiologists (ASA) physical status I and II, preoperative hemoglobin >10 g/dL, platelet count >150,000 cells/L and Cobb angle of >45° scheduled for elective single-stage posterior spinal fusion (PSF) surgery by two attending surgeons were included between March 2017 and November 2018. Patients were randomized into Group A (High Dose, 30 mg/kg TXA loading dose followed by 10 mg/kg/h infusion) and Group B (Low Dose, 10 mg/kg TXA loading dose followed by 1 mg/kg/h infusion). The primary outcome was total surgical blood loss between both groups. Secondary outcomes were transfusion requirement, perioperative changes in hemoglobin and coagulation profiles, adverse events, and factors that influence total blood loss. RESULTS: The mean total surgical blood loss between the two groups was not significant (Group A: 928.8 ±â€Š406.1 mL [range: 348-1857 mL]; Group B: 918.1 ±â€Š406.2 mL [range: 271-2000 mL], P = 0.865). The median duration of surgery was 120 minutes. One patient in each group received allogenic blood transfusion during the perioperative period. There were no significant changes in hemoglobin and coagulation profile at pre-operation, post-operation 0 hour and 48 hours. Sex, number of vertebral levels fused, and duration of surgery were independently associated with total surgical blood loss. No adverse events were observed perioperatively. CONCLUSION: Low-dose TXA was as efficacious as high-dose TXA in reducing blood loss and allogenic blood transfusion for AIS patients undergoing PSF surgery.Level of Evidence: 1.

Dual attending surgeon strategy learning curve in single-staged posterior spinal fusion (PSF) surgery for 415 idiopathic scoliosis (IS) cases.

BACKGROUND CONTEXT: The implementation of a dual attending surgeon strategy had improved perioperative outcomes of idiopathic scoliosis (IS) patients. Nevertheless, the learning curve of a dual attending surgeon practice in single-staged posterior spinal fusion (PSF) surgery has not been established. OBJECTIVE: To evaluate the surgical learning curve of a dual attending surgeon strategy in IS patients. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: 415 IS patients (Cobb angle <90°) who underwent PSF using a dual attending surgeon strategy OUTCOME MEASURES: Primary outcomes included operative time, total blood loss, allogenic blood transfusion requirement, length of hospital stay and perioperative complication rate. METHODS: Regression analysis using Locally Weighted Scatterplot Smoothing (LOWESS) method was applied to create the best-fit-curve between case number versus operative time and total blood loss in identifying cut-off points for the learning curve. RESULTS: The mean Cobb angle was 60.8±10.8°. Mean operative time was 134.4±32.1 minutes and mean total blood loss was 886.0±450.6 mL. The mean length of hospital stay was 3.0±1.6 days. The learning curves of a dual attending surgeon strategy in this study were established at the 115th case (operative time) and 196th case (total blood loss) respectively (p<.001). In comparison of cases before and after the cut-off points, mean operative time reduced significantly from 147.2±36.5 minutes to 129.5±28.9 minutes and mean total blood loss reduced significantly from 1015.1±506.6 mL to 770.4±357.3 mL (p<.001). No allogenic blood transfusion was required and there were 7 perioperative complications (n=7/415, 1.7%) recorded. CONCLUSION: The learning curve of a dual surgeon strategy in single-staged PSF surgery based on operative time and total blood loss were established at 115th case and 196th case respectively (p<.001).

Personal protective equipment usage, recycling and disposal among spine surgeons: An Asia Pacific Spine Society survey.

PURPOSE: In this study we investigated on the personal protective equipment (PPE) usage, recycling, and disposal among spine surgeons in the Asia Pacific region. METHODS: A cross-sectional survey was carried out among spine surgeons in Asia Pacific. The questionnaires were focused on the usage, recycling and disposal of PPE. RESULTS: Two hundred and twenty-two surgeons from 19 countries participated in the survey. When we sub-analysed the differences between countries, the provision of adequate PPE by hospitals ranged from 37.5% to 100%. The usage of PPE was generally high. The most used PPE were surgical face masks (88.7%), followed by surgical caps (88.3%), gowns (85.6%), sterile gloves (83.3%) and face shields (82.0%). The least used PPE were powered air-purifying respirators (PAPR) (23.0%) and shoes/boots (45.0%). The commonly used PPE for surgeries involving COVID-19 positive patients were N95 masks (74.8%), sterile gloves (73.0%), gowns (72.1%), surgical caps (71.6%), face shields (64.4%), goggles (64.0%), shoe covers (58.6%), plastic aprons (45.9%), shoes/boots (45.9%), surgical face masks (36.5%) and PAPRs (21.2%). Most PPE were not recycled. Biohazard bins were the preferred method of disposal for all types of PPE items compared to general waste. CONCLUSIONS: The usage of PPE was generally high among most countries especially for surgeries involving COVID-19 positive patients except for Myanmar and Nepal. Overall, the most used PPE were surgical face masks. For surgeries involving COVID-19 positive patients, the most used PPE were N95 masks. Most PPE were not recycled. Biohazard bins were the preferred method of disposal for all types of PPE.

Predictive factors for correction rate in severe idiopathic scoliosis (Cobb angle ≥ 90°): an analysis of 128 patients.

PURPOSE: Knowledge on the factors affecting the correction rate (CR) aids in the surgical planning among severe idiopathic scoliosis (IS) patients. This study aimed to investigate the independent factors affecting CR among patients with severe IS (Cobb angle ≥ 90°) who underwent single-staged posterior spinal fusion (PSF). METHODS: We retrospectively reviewed 128 severe IS patients who underwent single-staged PSF. Factors including age, height, weight, body mass index, Risser sign, Lenke subtypes, preoperative major Cobb angle, side bending major Cobb angle, side bending flexibility (SBF), motion segments of the major curve, AR curve, number of levels fused, screw density, operative time and postoperative major Cobb angle were analysed using linear regression analysis. RESULTS: The mean age was 15.5 ± 4.5 years with mean Risser sign of 3.1 ± 1.6. The mean preoperative Cobb, SBF, postoperative Cobb and CR were 102.8 ± 12.3°, 37.5 ± 13.7%, 44.4 ± 13.5° and 57.2 ± 10.8%, respectively. From stepwise multiple linear regression analysis, SBF, Risser sign and AR curve were the independent predictive factors for CR, with R2 value of 0.345 (p < 0.001). CR can be predicted using the formula: 47.21 + (0.34 × SBF)-(1.47 × Risser sign) + (3.69 × AR), where AR = 1 and non-AR = 0. CONCLUSION: The flexibility of the major curve, Risser sign and AR curve were the most important predictors for CR in a single-staged PSF among patients with severe IS.

Neuropathic Pain after Adolescent Idiopathic Scoliosis Correction Surgery.

STUDY DESIGN: Prospective study. PURPOSE: To investigate the prevalence and the associated risk factors of chronic neuropathic pain symptoms using painDETECT questionnaire in adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF) surgery. OVERVIEW OF LITERATURE: Post-lumbar surgery syndrome is a disease entity that describes neuropathic pain following spinal surgery. However, few studies have investigated the prevalence and risk factors for neuropathic pain in pediatric population undergoing corrective spinal surgery. METHODS: Forty AIS patients were recruited. Demographic, preoperative, and postoperative data were recorded. The magnitude and characteristics of postoperative pain were assessed using the painDETECT questionnaire through telephone enquiries at intervals of 2, 6, 12, and 24 weeks. Statistical analyses were followed by Pearson correlation test to determine the relationship between pain scores at 6, 12, and 24 weeks with the risk factors. RESULTS: Based on the painDETECT questionnaire, 90% of the patients had nociceptive pain, and 10% had a possible neuropathic pain component at 2 weeks postoperatively as per a mean painDETECT score of 7.1±4.5. Assessments at 6, 12, and 24 weeks showed that no patients had neuropathic pain with painDETECT scores of 4.4±3.2, 2.9±2.9, and 1.5±2.0, respectively. There was a significant correlation between total postoperative morphine use during 48 hours after the surgery and a tendency to develop neuropathic pain (p=0.022). CONCLUSIONS: Chronic neuropathic pain was uncommon in AIS patients who had undergone PSF surgery. Higher opioid consumption will increase the possibility of developing chronic neuropathic pain.