Initial Cobb angle reduction velocity following bracing as a new predictor for curve progression in adolescent idiopathic scoliosis

Aims The aim of this study was to assess whether supine flexibility predicts the likelihood of curve progression in patients with adolescent idiopathic scoliosis (AIS) undergoing brace treatment. Methods This was a retrospective analysis of patients with AIS prescribed with an underarm brace between September 2008 to April 2013 and followed up until 18 years of age or required surgery. Patients with structural proximal curves that preclude underarm bracing, those who were lost to follow-up, and those who had poor compliance to bracing (<16 hours a day) were excluded. The major curve Cobb angle, curve type, and location were measured on the pre-brace standing posteroanterior (PA) radiograph, supine whole spine radiograph, initial in-brace standing PA radiograph, and the post-brace weaning standing PA radiograph. Validation of the previous in-brace Cobb angle regression model was performed. The outcome of curve progression post-bracing was tested using a logistic regression model. The supine flexibility cut-off for curve progression was analyzed with receiver operating characteristic curve. Results A total of 586 patients with mean age of 12.6 years (SD 1.2) remained for analysis after exclusion. The baseline Cobb angle was similar for thoracic major curves (31.6° (SD 3.8°)) and lumbar major curves (30.3° (SD 3.7°)). Curve progression was more common in the thoracic curves than lumbar curves with mean final Cobb angles of 40.5° (SD 12.5°) and 31.8° (SD 9.8°) respectively. This dataset matched the prediction model for in-brace Cobb angle with less mean absolute error in thoracic curves (0.61) as compared to lumbar curves (1.04). Reduced age and Risser stage, thoracic curves, increased pre-brace Cobb angle, and reduced correction and flexibility rates predicted increased likelihood of curve progression. Flexibility rate of more than 28% has likelihood of preventing curve progression with bracing. Conclusion Supine radiographs provide satisfactory prediction for in-brace correction and post-bracing curve magnitude. The flexibility of the curve is a guide to determine the likelihood for brace success. Cite this article: Bone Joint J 2020;102-B(2):254–260.

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Alternate In-Brace and Out-of-Brace Radiographs Are Recommended to Assess Brace Fitting and Curve Progression With Adolescent Idiopathic Scoliosis Follow-Up

Global Spine Journal ◽

10.1177/21925682211032559 ◽

2021 ◽

pp. 219256822110325

Author(s):

Sachiko Kawasaki ◽

Prudence Wing Hang Cheung ◽

Hideki Shigematsu ◽

Masato Tanaka ◽

Yuma Suga ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Curve Progression ◽

Brace Treatment ◽

Correction Rate ◽

Angle Correction ◽

Clinically Significant ◽

Deterioration Group

Study Design: Retrospective cohort study. Objective: To determine the prevalence of missed curve progression in patients with adolescent idiopathic scoliosis (AIS) undergoing brace treatment with only in-brace follow-up radiographs, and to provide recommendations on when in-brace and out-of-brace should be obtained during follow-up. Methods: 133 patients who had documented clinically significant curve progression during brace treatment or only when an out-of-brace radiograph were studied. Of these, 95 patients (71.4%) had curve progression noted on in-brace radiographs while 38 patients (28.6%) showed curve progression only after brace removal. We analyzed differences in age, sex, curve types, Risser stage, months after menarche, standing out-of-brace Cobb angle, correction rate, and flexibility rate between the groups. Multivariate logistic regression was performed to determine factors contributing to curve progression missed during brace treatment. Results: There were no differences in initial Cobb angle between out-of-brace and in-brace deterioration groups. However, the correction rate was higher (32.7% vs 25.0%; P = .004) in the in-brace deterioration group as compared to the out-of-brace deterioration group. A lower correction rate was more likely to result in out-of-brace deterioration (OR 0.970; P = .019). For thoracic curves, higher flexibility in the curves was more likely to result in out-of-brace deterioration (OR 1.055; P = .045). For double/triple curves, patients with in-brace deterioration had higher correction rate (OR 0.944; P = .034). Conclusions: Patients may develop curve progression despite good correction on in-brace radiographs. Those with higher flexibility and suboptimal brace fitting are at-risk. In-brace and out-of-brace radiographs should be taken alternately for brace treatment follow-up.

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APSS-ASJ Best Clinical Research Award: Predictability of Curve Progression in Adolescent Idiopathic Scoliosis Using the Distal Radius and Ulna Classification

Asian Spine Journal ◽

10.4184/asj.2018.12.2.202 ◽

2018 ◽

Vol 12 (2) ◽

pp. 202-213 ◽

Cited By ~ 10

Author(s):

Jason Pui Yin Cheung ◽

Prudence Wing Hang Cheung ◽

Dino Samartzis ◽

Keith Dip-Kei Luk

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Distal Radius ◽

Skeletal Maturity ◽

Curve Progression ◽

Close Monitoring ◽

Skeletally Immature ◽

Increased Risk ◽

Curve Magnitude

<sec><title>Study Design</title>Prospective study.</sec><sec><title>Purpose</title>To determine the risk of clinically significant curve progression in adolescent idiopathic scoliosis (AIS) based on the initial Cobb angle and to test the utility of the distal radius and ulna (DRU) classification in predicting these outcomes.</sec><sec><title>Overview of Literature</title>Determining the remaining growth potential in AIS patients is necessary for predicting prognosis and initiating treatment. Limiting the maturity Cobb angle to <40° and <50° reduces the risk of adulthood progression and need for surgery, respectively. The risk of curve progression is the greatest with skeletally immature patients and thus warrants close monitoring or early intervention. Many parameters exist for measuring the skeletal maturity status in AIS patients, but the DRU classification has been shown to be superior in predicting peak growth and growth cessation. However, its predictive capabilities for curve progression are unknown.</sec><sec><title>Methods</title>Totally, 513 AIS patients who presented with Risser 0–3 were followed until either skeletal maturity or the need for surgery, with a minimum 2-year follow-up period. Outcomes of 40° and 50° were used for probability analysis based on the cut-offs of adulthood progression risk and surgical threshold, respectively.</sec><sec><title>Results</title>At the R6/U5 grade, most curves (probability of ≥48.1%–55.5%) beyond a Cobb angle of 25° progressed to the 40° threshold. For curves of ≥35°, there was a high risk of unfavorable outcomes, regardless of skeletal maturity. Most patients with the R9 grade did not progress, regardless of the initial curve magnitude (probability of 0% to reach the 50° threshold for an initial Cobb angle of ≥35°).</sec><sec><title>Conclusions</title>This large-scale study illustrates the utility of the DRU classification for predicting curve progression and how it may effectively guide the timing of surgery. Bracing may be indicated for skeletally immature patients at an initial Cobb angle of 25°, and those with a scoliosis ≥35° are at an increased risk of an unfavorable outcome, despite being near skeletal maturity.</sec>

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Upper instrumented vertebra to the right of the lowest instrumented vertebra as a predictor of an increase in the main thoracic curve after selective posterior fusion for the thoracolumbar/lumbar curve in Lenke type 5C adolescent idiopathic scoliosis: multicenter study on the relationship between fusion area and surgical outcome

Journal of Neurosurgery Spine ◽

10.3171/2019.5.spine181469 ◽

2019 ◽

Vol 31 (6) ◽

pp. 857-864 ◽

Cited By ~ 1

Author(s):

Hiroki Oba ◽

Jun Takahashi ◽

Sho Kobayashi ◽

Tetsuro Ohba ◽

Shota Ikegami ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Posterior Fusion ◽

Main Thoracic ◽

Lowest Instrumented Vertebra ◽

Line Tilt ◽

The Right ◽

Upper Instrumented Vertebra

OBJECTIVEUnfused main thoracic (MT) curvatures occasionally increase after selective thoracolumbar/lumbar (TL/L) fusion. This study sought to identify the predictors of an unacceptable increase in MT curve (UIMT) after selective posterior fusion (SPF) of the TL/L curve in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS).METHODSForty-eight consecutive patients (44 females and 4 males, mean age 15.7 ± 2.5 years, range 13–24 years) with Lenke type 5C AIS who underwent SPF of the TL/L curve were analyzed. The novel “Shinshu line” (S-line) was defined as a line connecting the centers of the concave-side pedicles of the upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV) on preoperative radiographs. The authors established an S-line tilt to the right as S-line positive (S-line+, i.e., the UIV being to the right of the LIV) and compared S-line+ and S-line− groups for thoracic apical vertebral translation (T-AVT) and MT Cobb angle preoperatively, early postoperatively, and at final follow-up. The predictors for T-AVT > 20 mm at final follow-up were evaluated as well. T-AVT > 20 mm was defined as a UIMT.RESULTSAmong the 48 consecutively treated patients, 26 were S-line+ and 22 were S-line−. At preoperative, early postoperative, and final follow-up a minimum of 2 years later, the mean T-AVT was 12.8 mm (range −9.3 to 32.8 mm), 19.6 mm (range −13.0 to 41.0 mm), and 22.8 mm (range −1.9 to 68.7 mm) in the S-line+ group, and 10.8 mm (range −5.1 to 27.3 mm), 16.2 mm (range −11.7 to 42.1 mm), and 11.0 mm (range −6.3 to 26.9 mm) in the S-line− group, respectively. T-AVT in S-line+ patients was significantly larger than that in S-line− patients at the final follow-up. Multivariate analysis revealed S-line+ (odds ratio [OR] 23.8, p = 0.003) and preoperative MT Cobb angle (OR 7.9, p = 0.001) to be predictors of a UIMT.CONCLUSIONSS-line+ was defined as the UIV being to the right of the LIV. T-AVT in the S-line+ group was significantly larger than in the S-line− group at the final follow-up. S-line+ status and larger preoperative MT Cobb angle were independent predictors of a UIMT after SPF for the TL/L curve in patients with Lenke type 5C AIS. Surgeons should consider changing the UIV and/or LIV in patients exhibiting S-line+ during preoperative planning to avoid a possible increase in MT curve and revision surgery.

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Clinical predictive model of lumbar curve Cobb angle below selective fusion for thoracic adolescent idiopathic scoliosis: a longitudinal multicenter descriptive study

European Journal of Orthopaedic Surgery & Traumatology ◽

10.1007/s00590-021-03054-5 ◽

2021 ◽

Author(s):

Federico Solla ◽

Walid Lakhal ◽

Christian Morin ◽

Jerome Sales de Gauzy ◽

Gaby Kreichati ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Predictive Model ◽

Descriptive Study ◽

Lumbar Curve ◽

Selective Fusion ◽

Clinical Predictive Model

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Sagittal profile modifications in hybrid versus all screw technique in adolescent idiopathic scoliosis

Scientific Reports ◽

10.1038/s41598-020-79523-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Laura Scaramuzzo ◽

Antonino Zagra ◽

Giuseppe Barone ◽

Stefano Muzzi ◽

Leone Minoia ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Thoracic Kyphosis ◽

Sagittal Alignment ◽

Vertical Axis ◽

Sagittal Profile ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Lenke Classification

AbstractAim of the study was to evaluate sagittal parameters modifications, with particular interest in thoracic kyphosis, in patients affected by adolescent idiopathic scoliosis (AIS) comparing hybrid and all-screws technique. From June 2010 to September 2018, 145 patients were enrolled. Evaluation included: Lenke classification, Risser scale, coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Patients were divided in two groups (1 all-screws and 2 hybrid); a further division, in both groups, was done considering preoperative TK values. Descriptive and inferential statistical analysis was conducted. 99 patients were in group 1, 46 in group 2 (mean follow-up 3.7 years). Patients with a normo-kyphotic profile developed a little variation in TK (Δ pre–post = 2.4° versus − 2.0° respectively). Hyper-kyphotic subgroups had a tendency of restoring a good sagittal alignment. Hypo-kyphotic subgroups, patients treated with all-screw implants developed a higher increase in TK mean Cobb angle (Δ pre–post = 10°) than the hybrid subgroup (Δ pre–post = 5.4°) (p = 0.01). All-screws group showed better results in restoring sagittal alignment in all subgroups compared to hybrid groups, especially in hypo-TK subgroup, with the important advantage to give better correction on coronal plane.

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Comparison of Changes in SRS-22 Values with Improvement in Cobb Angles after Posterior Fusion Surgery in Adolescent Idiopathic Scoliosis

Zeitschrift für Orthopädie und Unfallchirurgie ◽

10.1055/a-1401-0477 ◽

2021 ◽

Author(s):

Kadir Gem ◽

Sertan Hancioglu ◽

Abdulkadir Bilgiç ◽

Serkan Erkan

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Posterior Instrumentation ◽

Research Society ◽

Posterior Fusion ◽

Improvement Rate ◽

Scoliosis Research Society ◽

Correction Rate ◽

Group B

Abstract Introduction The purpose of this study was to evaluate the relationship between the correction rate in Cobb angle and the improvement in quality of life profile in terms of Scoliosis Research Society (SRS)-22 values. Patients and Methods Between January 2007 and December 2013, posterior instrumentation and fusion was performed to 30 patients with adolescent idiopathic scoliosis (AIS). Patients were grouped according to their improvement rate in Cobb angles after surgery. Patients with an improvement rate of > 80% were grouped as Group A; those with an improvement rate of > 60% and ≤ 80% as Group B and those with an improvement rate of ≤ 60% were grouped as Group C. The SRS-22 questionnaire of these three groups was calculated and their relationship with the improvement in Cobb angle was evaluated. Results No statistical difference was found among the three groups in terms of pain, appearance, function, spirit, satisfaction, and SRS-22 values (all p > 0.05). Conclusion The results of this study demonstrate that the degree of correction rate does not correlate with the degree of improvement in the SRS-22 questionnaire in patients with AIS that underwent posterior fusion and instrumentation.

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Should L3 be selected as the lowest instrumented vertebra in patients with Lenke type 5C adolescent idiopathic scoliosis whose lowest end vertebra is L4?

Journal of Neurosurgery Spine ◽

10.3171/2020.11.spine201807 ◽

2021 ◽

pp. 1-10

Author(s):

Tomohiro Banno ◽

Yu Yamato ◽

Hiroki Oba ◽

Tetsuro Ohba ◽

Tomohiko Hasegawa ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Curve Progression ◽

Global Alignment ◽

Fusion Surgery ◽

Radiographic Outcomes ◽

Lowest Instrumented Vertebra ◽

Upper Instrumented Vertebra ◽

Coronal Decompensation

OBJECTIVE L3 is most often selected as the lowest instrumented vertebra (LIV) to conserve mobile segments in fusion surgery; however, in cases with the lowest end vertebra (LEV) at L4, LIV selection as L3 could have a potential risk of correction loss and coronal decompensation. This study aimed to compare the clinical and radiographic outcomes depending on the LEV in adolescent idiopathic scoliosis (AIS) patients with Lenke type 5C curves. METHODS Data from 49 AIS patients with Lenke type 5C curves who underwent selective thoracolumbar/lumbar (TL/L) fusion to L3 as the LIV were retrospectively analyzed. The patients were classified according to their LEVs into L3 and L4 groups. In the L4 group, subanalysis was performed according to the upper instrumented vertebra (UIV) level toward the upper end vertebra (UEV and 1 level above the UEV [UEV+1] subgroups). Radiographic parameters and clinical outcomes were compared between these groups. RESULTS Among 49 patients, 32 and 17 were in the L3 and L4 groups, respectively. The L4 group showed a lower TL/L curve correction rate and a higher subjacent disc angle postoperatively than the L3 group. Although no intergroup difference was observed in coronal balance (CB), the L4 group showed a significantly higher main thoracic (MT) and TL/L curve progression during the postoperative follow-up period than the L3 group. In the L4 group, the UEV+1 subgroup showed a higher absolute value of CB at 2 years than the UEV subgroup. CONCLUSIONS In Lenke type 5C AIS patients with posterior selective TL/L fusion to L3 as the LIV, patients with their LEVs at L4 showed postoperative MT and TL/L curve progression; however, no significant differences were observed in global alignment and clinical outcome.

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