Simultaneous translation on two rods improves the correction and apex translocation in adolescent patients with hypokyphotic scoliosis

OBJECTIVE The objectives of this study were to apply the simultaneous translation on two rods (ST2R) maneuver involving rods contoured with a convexity at the desired thoracic kyphosis (TK) apex level and to assess the effects on the ability to support triplanar deformity corrections, including TK apex improvement, in patients with hypokyphotic adolescent idiopathic scoliosis (AIS). METHODS Using retrospective analysis, the authors examined the digital records that included 2- to 4-week, 1-year, and 2-year postoperative radiographic follow-up data of female hypokyphotic (TK < 20°) AIS patients (Lenke type 1–3) treated with ST2R. The authors assessed the corrections of triplanar deformities by examining the main Cobb angle, TK, rib hump, apical vertebral rotation, Scoliosis Research Society 22-item questionnaire scores, and TK apex translocation. In order to better grasp the potential of ST2R, the outcomes were compared with those of a historical matched case-control cohort treated with a standard rod rotation (RR) maneuver. RESULTS Data were analyzed for 25 AIS patients treated with ST2R and 27 patients treated with RR. The ST2R group had significant improvements in the main Cobb angle and TK, reduction in the rib hump size at each time point, and a final correction rate of 72%. ST2R treatment significantly increased the kyphosis apex by an average of 2.2 levels. The correction rate was higher at each time point in the ST2R group than in the RR group. ST2R engendered favorable TK corrections, although the differences were nonsignificant, at 2 years compared with the RR group (p = 0.056). The TK apex location was significantly improved in the ST2R cohort (p < 0.001). At the 1-month follow-up, hypokyphosis was resolved in 92% of the ST2R cohort compared with 30% of the RR cohort. CONCLUSIONS Resolving hypokyphotic AIS remains challenging. The ST2R technique supported significant triplanar corrections, including TK apex translocation and restoration of hypokyphosis in most patients. Comparisons with the RR cohort require caution because of differences in the implant profile. However, ST2R significantly improved the coronal and sagittal corrections. It also allowed for distribution of correctional forces over two rod implants instead of one, which should decrease the risk of screw pullout and rod flattening. It is hoped that the description here of commercially available reducers used with the authors’ surgical technique will encourage other clinicians to consider using the ST2R technique.

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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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Postoperative translation of the upper instrumented vertebra in thoracic adolescent idiopathic scoliosis

Journal of Neurosurgery Pediatrics ◽

10.3171/2018.6.peds18256 ◽

2018 ◽

Vol 22 (6) ◽

pp. 694-700 ◽

Cited By ~ 1

Author(s):

Katsuhisa Yamada ◽

Hideki Sudo ◽

Kiyoshi Kaneda ◽

Yasuhiro Shono ◽

Yuichiro Abe ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Pulmonary Function ◽

Research Society ◽

Forced Expiratory Volume ◽

Postoperative Results ◽

Scoliosis Research Society ◽

Correction Rate ◽

Upper Instrumented Vertebra

OBJECTIVEThe aim of this retrospective study was to analyze the influence of upper instrumented vertebra (UIV) translation from the C7 plumb line (C7PL) on the long-term postoperative results of patients with main thoracic (MT) adolescent idiopathic scoliosis (AIS).METHODSTwenty-five patients had been treated surgically for AIS with a Lenke type 1 curve and had been followed up for a mean period of 18.2 years. Radiographic parameters, pulmonary function measurements, and clinical outcomes were compared between the patients (n = 15) with UIV translation < 20 mm and those (n = 10) with UIV translation ≥ 20 mm at the final follow-up. Correlations between UIV translation and radiographic or pulmonary function parameters were analyzed.RESULTSPatients with ≥ 20 mm UIV translation at the final follow-up had a significantly larger preoperative UIV translation than that in the patients with < 20 mm UIV translation at follow-up. The former group also had a significantly lower correction rate of the MT curve, higher chest cage ratio, and lower radiographic shoulder height (p = 0.01, 0.005, and 0.025, respectively) at the final follow-up. The Scoliosis Research Society (SRS)–30 Questionnaire scores were equivalent between the two groups. Correlation analysis showed that the following parameters were significantly associated with UIV translation: MT curve correction rate (r = -0.481, p = 0.015), chest cage ratio (r = 0.673, p < 0.001), and percent-predicted forced expiratory volume in 1 second (r = -0.455, p = 0.033).CONCLUSIONSThe UIV translation should be considered an important factor that influences postoperative results. In MT AIS patients whose preoperative upper end vertebra (UEV) is distant from the C7PL, the UIV should be selected above the UEV to prevent large UIV translation at the postoperative follow-up.

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Scoliosis Research Society-Schwab Grade 6 Osteotomy for Severe Congenital Angular Kyphoscoliosis: An Analysis of 17 Cases With a Minimum 2-Year Follow-up

Neurosurgery ◽

10.1093/neuros/nyaa055 ◽

2020 ◽

Vol 87 (5) ◽

pp. 925-930 ◽

Cited By ~ 1

Author(s):

Bo Shi ◽

Benlong Shi ◽

Dun Liu ◽

Yang Li ◽

Sanqiang Xia ◽

...

Keyword(s):

Cobb Angle ◽

Clinical Outcomes ◽

Vertical Axis ◽

Research Society ◽

Sagittal Vertical Axis ◽

Vertebral Column Resection ◽

Scoliosis Research Society ◽

Rod Breakage ◽

The Mean

Abstract BACKGROUND For some patients with severe congenital angular kyphoscoliosis (SCAK), 1-level vertebral column resection is insufficient and the Scoliosis Research Society (SRS)-Schwab Grade 6 osteotomy may be necessary. However, the indications and clinical outcomes of SRS-Schwab Grade 6 osteotomy in patients with SCAK have not been investigated in depth. OBJECTIVE To investigate the middle-term radiographic and clinical outcomes, and to evaluate the safety of this high technique-demanding procedure. METHODS Patients with SCAK undergoing SRS-Schwab Grade 6 osteotomy from 2005 to 2016 followed up at least 2 yr were retrospectively reviewed. The potential indications of SRS-Schwab Grade 6 osteotomy were analyzed. The coronal Cobb angle, segmental kyphosis (SK), deformity angular ratio (DAR), coronal balance, and sagittal vertical axis (SVA) were measured in the preoperative, postoperative, and final follow-up. The intraoperative and postoperative complications were recorded. RESULTS A total of 17 patients with SCAK (10 M and 7F) were included, and the mean follow-up was 30.8 ± 16.4 mo. The indications of SRS-Schwab Grade 6 osteotomy were as follows: multiple “pushed-out” hemivertebrae (13, 76.5%) and multilevel anterior block (4, 23.5%). Compared with preoperation, the coronal Cobb angle, SK and SVA at postoperation were significantly improved (P < .05 for all). The mean total DAR was 33.4 ± 9.9 at preoperation. Three patients were found to have postoperative neurological deficit. Rod breakage occurred in 3 patients at 15- to 48-mo follow-up, and revision surgeries were performed. At the last follow-up, firm bony fusion was observed in all patients. CONCLUSION The technique-demanding SRS-Schwab Grade 6 osteotomy, if well indicated, could provide satisfying correction of the SCAK deformity.

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Proximal junctional kyphosis in Lenke 5 AIS patients: the important factor of pelvic incidence

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04052-8 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Quan Zhou ◽

Bowen Hu ◽

Xi Yang ◽

Yueming Song ◽

Limin Liu ◽

...

Keyword(s):

Cobb Angle ◽

Pelvic Incidence ◽

Research Society ◽

Scoliosis Research Society ◽

Significant Difference ◽

Correction Surgery ◽

The Mean ◽

Radiographic Data ◽

Selection Of

Abstract Background The purpose of the study was to investigate whether pelvic incidence (PI) will affect the occurrence of PJK in Lenke 5 AIS patients after correction surgery and try to explore a better surgical scheme based on PI. Methods Lenke 5C AIS patients that underwent correction surgery with a minimum of a 2-year follow-up were identified. Demographic and radiographic data were collected preoperatively, postoperatively, and at the final follow-up. The comparison between the PJK and the Non-PJK group was conducted and the subgroup analysis was performed based on the preoperative value of PI to investigate the potential mechanism of PJK. Clinical assessments were performed using the Scoliosis Research Society (SRS)-22 questionnaire. Results The mean preoperative Cobb angle of the TL/L curve was 53.4°±8.6. At the final follow-up, the mean TL/L Cobb angle was drastically decreased to 7.3°±6.8 (P < 0.001). The incidence of PJK in Lenke 5 AIS was 18.6 %, 21.9 % (7/32) in the low PI group (PI < 45°) and 15.8 % (6/38) in the high PI group (PI ≥ 45°), and there was no statistical difference between the two groups (χ2 = 0.425, P = 0.514). For low PI patients, there is no significant difference where the UIV is located with regards to the TK apex between the PJK and Non-PJK subgroups (χ2 = 1.103, P = 0.401). For high PI patients, PJK was more likely to occur when UIV was cephalad to than caudal to the TK apex (31.25 % vs. 4.7 %, P = 0.038). There was no significant difference in the selection of LIV between the two groups. Conclusions There is no difference in the incidence of PJK between the Lenke 5 AIS patients with low PI (< 45°) and high PI (≥45°), but the main risk factor of PJK should be different. For patients with low PI, overcorrection of LL should be strictly avoided during surgery. For patients with high PI, the selection of UIV should not be at or cephalad to the apex of thoracic kyphosis to retain more mobile thoracic segments.

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Influence of Cobb Angle and ISIS2 Surface Topography Volumetric Asymmetry on Scoliosis Research Society-22 Outcome Scores in Scoliosis

Spine Deformity ◽

10.1016/j.jspd.2013.07.012 ◽

2013 ◽

Vol 1 (6) ◽

pp. 452-457 ◽

Cited By ~ 4

Author(s):

Paul Brewer ◽

Fiona Berryman ◽

De Baker ◽

Paul Pynsent ◽

Adrian Gardner

Keyword(s):

Cobb Angle ◽

Surface Topography ◽

Research Society ◽

Scoliosis Research Society ◽

Outcome Scores

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Correlation of 2-year SRS-22r and ODI patient-reported outcomes with 5-year patient-reported outcomes after complex spinal fusion: a 5-year single-institution study of 118 patients

Journal of Neurosurgery Spine ◽

10.3171/2018.2.spine171142 ◽

2018 ◽

Vol 29 (4) ◽

pp. 422-428 ◽

Cited By ~ 3

Author(s):

Owoicho Adogwa ◽

Isaac O. Karikari ◽

Aladine A. Elsamadicy ◽

Amanda R. Sergesketter ◽

Diego Galan ◽

...

Keyword(s):

Mental Health ◽

Spinal Fusion ◽

Patient Reported Outcomes ◽

Research Society ◽

Scoliosis Research Society ◽

Self Image ◽

Patient Reported ◽

Spinal Arthrodesis

OBJECTIVEPatient-reported outcomes (PROs) are often measured up to 2 years after surgery; however, prospective collection of longitudinal outcomes for 5 years postoperatively can be challenging due to lack of patient follow-up. The aim of this study was to determine whether PROs collected at 2-year follow-up accurately predict long-term PROs 5 years after complex spinal fusion (≥ 5 levels).METHODSThis was an ambispective study of 118 adult patients (≥ 18 years old) undergoing ≥ 5-level spinal arthrodesis to the sacrum with iliac fixation from January 2002 to December 2011. Patient demographics and radiographic parameters as well as intraoperative variables were collected. PRO instruments (Scoliosis Research Society [SRS]-22r function, self-image, mental health, pain, and Oswestry Disability Index [ODI]) were completed before surgery then at 2 and 5 years after surgery. Primary outcome investigated in this study was the correlation between SRS-22r domains and ODI collected at 2- and 5-year follow-up.RESULTSOf the 118 patients, 111 patients had baseline PROs, 105 patients had 2-year follow-up data, and 91 patients had 5-year follow-up PRO data with 72% undergoing revision surgery. The average pre- and postoperative major coronal curve Cobb angles for the cohort were 32.1° ± 23.7° and 19.8° ± 19.3°, respectively. There was a strong correlation between 2- and 5-year ODI (r2 = 0.80, p < 0.001) and between 2- and 5-year SRS-22r domains, including function (r2 = 0.79, p < 0.001), self-image (r2 = 0.82, p < 0.001), mental health (r2 = 0.77, p < 0.001), and pain (r2 = 0.79, p < 0.001). Of the PROs, ODI showed the greatest absolute change from baseline to 2- and 5-year follow-up (2-year Δ 17.6 ± 15.9; 5-year Δ 16.5 ± 19.9) followed by SRS-22r self-image (2-year Δ 1.4 ± 0.96; 5-year Δ 1.3 ± 1.0), pain (2-year Δ 0.94 ± 0.97; 5-year Δ 0.80 ± 1.0), function (2-year Δ 0.60 ± 0.62; 5-year Δ 0.49 ± 0.79), and mental health (2-year Δ 0.49 ± 0.77; 5-year Δ 0.38 ± 0.84).CONCLUSIONSPatient-reported outcomes collected at 2-year follow-up may accurately predict long-term PROs (5-year follow-up).

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Health-related quality of life and sagittal balance at two to 25 years after posterior transfixation for high-grade dysplastic spondylolisthesis

Bone & Joint Open ◽

10.1302/2633-1462.23.bjo-2020-0194.r1 ◽

2021 ◽

Vol 2 (3) ◽

pp. 163-173

Author(s):

Tom P C. Schlösser ◽

Enrique Garrido ◽

Athanasios I. Tsirikos ◽

Michael J. McMaster

Keyword(s):

Young Patients ◽

Research Society ◽

Sacral Slope ◽

High Grade ◽

Partial Reduction ◽

Scoliosis Research Society ◽

Pelvic Inclination ◽

Self Image ◽

Related Quality

Aims High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique. Methods SRS-22r and full-spine lateral radiographs were collected for the 28 young patients (age 13.4 years (SD 2.6) who underwent surgery for high-grade dysplastic spondylolisthesis in our centre (Scottish National Spinal Deformity Service) between 1995 and 2018. The mean follow-up was nine years (2 to 25), and one patient was lost to follow-up. The standard surgical technique was an all-posterior, partial reduction, and S1 to L5 transfixation screw technique without direct decompression. Parameters for segmental (slip percentage, Dubousset’s lumbosacral angle) and regional alignment (pelvic tilt, sacral slope, L5 incidence, lumbar lordosis, and thoracic kyphosis) and global balance (T1 spino-pelvic inclination) were measured. SRS-22r scores were compared between patients with a balanced and unbalanced pelvis at final follow-up. Results SRS-22r domain and total scores improved significantly from preoperative to final follow-up, except for the mental health domain that remained the same. Slip percentage improved from 75% (SD 15) to 48% (SD 19) and lumbosacral angle from 70° (SD 11) to 101° (SD 11). Preoperatively, 35% had global imbalance, and at follow-up all were balanced. Preoperatively, 63% had an unbalanced pelvis, and at final follow-up this was 32%. SRS-22r scores were not different in patients with a balanced or unbalanced pelvis. However, postoperative pelvic imbalance as measured by L5 incidence was associated with lower SRS-22r self-image and total scores (p = 0.029). Conclusion In young patients with HGDS, partial reduction and transfixation improves local lumbosacral alignment, restores pelvic, and global balance and provides satisfactory long-term clinical outcomes. Higher SRS-22r self-image and total scores were observed in the patients that had a balanced pelvis (L5I < 60°) at two to 25 years follow-up. Cite this article: Bone Jt Open 2021;2(3):163–173.

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Quality metrics in adult spinal deformity surgery over the last decade: a combined analysis of the largest prospective multicenter data sets

Journal of Neurosurgery Spine ◽

10.3171/2021.3.spine202140 ◽

2021 ◽

pp. 1-9

Author(s):

Ferran Pellisé ◽

Miquel Serra-Burriel ◽

Alba Vila-Casademunt ◽

Jeffrey L. Gum ◽

Ibrahim Obeid ◽

...

Keyword(s):

Quality Of Life ◽

Spinal Deformity ◽

Oswestry Disability Index ◽

Adult Spinal Deformity ◽

Research Society ◽

Data Sets ◽

Scoliosis Research Society ◽

Sagittal Deformity

OBJECTIVE The reported rate of complications and cost of adult spinal deformity (ASD) surgery, associated with an exponential increase in the number of surgeries, cause alarm among healthcare payers and providers worldwide. The authors conjointly analyzed the largest prospective available ASD data sets to define trends in quality-of-care indicators (complications, reinterventions, and health-related quality of life [HRQOL] outcomes) since 2010. METHODS This is an observational prospective longitudinal cohort study. Patients underwent surgery between January 2010 and December 2016, with > 2 years of follow-up data. Demographic, surgical, radiological, and HRQOL (i.e., Oswestry Disability Index, SF-36, Scoliosis Research Society-22r) data obtained preoperatively and at 3, 6, 12, and 24 months after surgery were evaluated. Trends and changes in indicators were analyzed using local regression (i.e., locally estimated scatterplot smoothing [LOESS]) and adjusted odds ratio (OR). RESULTS Of the 2286 patients included in the 2 registries, 1520 underwent surgery between 2010 and 2016. A total of 1151 (75.7%) patients who were treated surgically at 23 centers in 5 countries met inclusion criteria. Patient recruitment increased progressively (2010–2011 vs 2015–2016: OR 1.64, p < 0.01), whereas baseline clinical characteristics (age, American Society of Anesthesiologists class, HRQOL scores, sagittal deformity) did not change. Since 2010 there has been a sustained reduction in major and minor postoperative complications observed at 90 days (major: OR 0.59; minor: OR 0.65; p < 0.01); at 1 year (major: OR 0.52; minor: 0.75; p < 0.01); and at 2 years of follow-up (major: OR 0.4; minor: 0.80; p < 0.01) as well as in the 2-year reintervention rate (OR 0.41, p < 0.01). Simultaneously, there has been a slight improvement in the correction of sagittal deformity (i.e., pelvic incidence–lumbar lordosis mismatch: OR 1.11, p = 0.19) and a greater gain in quality of life (i.e., Oswestry Disability Index 26% vs 40%, p = 0.02; Scoliosis Research Society-22r, self-image domain OR 1.16, p = 0.13), and these are associated with a progressive reduction of surgical aggressiveness (number of fused segments: OR 0.81, p < 0.01; percent pelvic fixation: OR 0.66, p < 0.01; percent 3-column osteotomies: OR 0.63, p < 0.01). CONCLUSIONS The best available data show a robust global improvement in quality metrics in ASD surgery over the last decade. Surgical complications and reoperations have been reduced by half, while improvement in disability increased and correction rates were maintained, in patients with similar baseline characteristics.

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Orthopedic disease burden in adult patients with symptomatic lumbar scoliosis: results from a prospective multicenter study

Journal of Neurosurgery Spine ◽

10.3171/2021.1.spine201911 ◽

2021 ◽

pp. 1-9

Author(s):

Justin S. Smith ◽

Christopher I. Shaffrey ◽

Christine R. Baldus ◽

Michael P. Kelly ◽

Elizabeth L. Yanik ◽

...

Keyword(s):

Surgical Treatment ◽

Multicenter Study ◽

Disease Burden ◽

Health Impact ◽

Research Society ◽

Leg Pain ◽

Prospective Multicenter Study ◽

Scoliosis Research Society ◽

Lumbar Scoliosis

OBJECTIVE Although the health impact of adult symptomatic lumbar scoliosis (ASLS) is substantial, these patients often have other orthopedic problems that have not been previously quantified. The objective of this study was to assess disease burden of other orthopedic conditions in patients with ASLS based on a retrospective review of a prospective multicenter cohort. METHODS The ASLS-1 study is an NIH-sponsored prospective multicenter study designed to assess operative versus nonoperative treatment for ASLS. Patients were 40–80 years old with ASLS, defined as a lumbar coronal Cobb angle ≥ 30° and Oswestry Disability Index ≥ 20, or Scoliosis Research Society-22 questionnaire score ≤ 4.0 in pain, function, and/or self-image domains. Nonthoracolumbar orthopedic events, defined as fractures and other orthopedic conditions receiving surgical treatment, were assessed from enrollment to the 4-year follow-up. RESULTS Two hundred eighty-six patients (mean age 60.3 years, 90% women) were enrolled, with 173 operative and 113 nonoperative patients, and 81% with 4-year follow-up data. At a mean (± SD) follow-up of 3.8 ± 0.9 years, 104 nonthoracolumbar orthopedic events were reported, affecting 69 patients (24.1%). The most common events were arthroplasty (n = 38), fracture (n = 25), joint ligament/cartilage repair (n = 13), and cervical decompression/fusion (n = 7). Based on the final adjusted model, patients with a nonthoracolumbar orthopedic event were older (HR 1.44 per decade, 95% CI 1.07–1.94), more likely to have a history of tobacco use (HR 1.63, 95% CI 1.00–2.66), and had worse baseline leg pain scores (HR 1.10, 95% CI 1.01–1.19). CONCLUSIONS Patients with ASLS have high orthopedic disease burden, with almost 25% having a fracture or nonthoracolumbar orthopedic condition requiring surgical treatment during the mean 3.8 years following enrollment. Comparisons with previous studies suggest that the rate of total knee arthroplasty was considerably greater and the rates of total hip arthroplasty were at least as high in the ASLS-1 cohort compared with the similarly aged general US population. These conditions may further impact health-related quality of life and outcomes assessments of both nonoperative and operative treatment approaches in patients with ASLS.

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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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