Association of the LBX 1 Gene Promoter Methylation in Deep Paraspinal Muscles of Patients with Idiopathic Scoliosis with Disease Severity

/0 Comments/in /by

Piotr Janusz1 , Małgorzata Tokłowicz2 , Mirosław Andrusiewicz2 , Małgorzata Kotwicka2 , Tomasz Kotwicki1

1) Department of Spine Disorders and Pediatric Orthopedics, Poznan University of Medical Sciences 2) Department of Cell Biology, Poznan University of Medical Sciences

Introduction

Idiopathic scoliosis (IS) is a multifactorial disease with significant genetic background. The LBX1 gene polymorphisms are associated with IS. However the pathogenesis of this phenomenon is not established. Epigenetic modifications alter genes expression but do not change the DNA sequence. In recent years, the role of epigenetic factors in the etiopathogenesis of IS has been increasingly investigated.



Research Question

The aim of this study was to evaluate the association of the LBX1 promoter methylation level in deep paraspinal muscles of patients with idiopathic scoliosis with disease severity.



Methods

The study involved 57 girls (171 tissue samples from deep paravertebral muscles, both on the convex and the concave side of the curve and back superficial muscles) who underwent an operation due to IS. Patient subgroups were analyzed according to Cobb angle ≤70° (28 cases) vs. >70° (29 cases).  Level of methylation was evaluated in two promoter regions: proximal (28 CpG sites) and distal (23 CpG sites) using the pyrosequencing method.



Results

The methylation level within proximal promoter region was higher in patients with Cobb angle >70° than in patients with Cobb angle ≤ 70° in 22 of 28 analyzed CpGs (P < 0.05) at the convex side and in 1 of 28 analyzed CpGs (P < 0.05) at the concave side.  There was no difference in superficial muscles between the groups.

The methylation level within distal promoter region was higher in patients with Cobb angle >70° than in patients with Cobb angle ≤ 70° in 3 of 23 analyzed CpGs (P < 0.05) at the convex side, in 7 of 23 analyzed CpGs (P < 0.05) at the concave side and in 7 of 23 analyzed CpGs (P < 0.05) at the superficial muscles.



Conclusions

The level of DNA methylation at the LBX1 promoter region in deep paravertebral muscle tissue may be associated with the severity of idiopathic scoliosis.



Discussion

The risk of developing scoliosis and curvature progression is the result of an additive effect of genetic and the impact of environmental factors. This study revealed a new factor associated with a tendency to scoliosis progression.



Disclosures (any Conflicts of Interest)

The authors declare that they have no competing interests. This study was supported by the National Science Centre grant 2016/23/D/NZ5/02606.

Clinical utility of ultrasonography for the assessment of skeletal maturity using the Sanders radiological classification as a reference in patients with juvenile idiopathic scoliosis

/0 Comments/in /by

Introduction and main objective:

Adolescent idiopathic scoliosis (AIS) is a progressive three-dimensional spinal deformity whose progression is directly related to the stages of growth. The definition of the stage of skeletal maturity becomes a key factor in the prognosis and treatment of the disease. Currently, the Sanders radiographic classification is the most widely used tool to define it. However, technological advances in the field of ultrasound have opened a new window of opportunity. Thus, the main objective of this study was to assess whether ultrasound can be used to determine the state of skeletal maturity based on the Sanders radiological classification.

Methodology:

A case-control study was carried out, in which the case group included patients aged 10 to 16 years diagnosed with AIS; and the control group included those with diagnoses unrelated to scoliosis. For each patient, the Sanders classification was performed radiologically and by ultrasound. Each ultrasound parameter was measured by at least 4 investigators, in order to control for intra and interobserver error. Data were collected on collection sheets specifically designed for the study. Statistical analysis was performed using IBM SPSS Statistics software.

Results:

A sample of 70 patients was obtained, with no statistically significant differences between groups. No statistically significant differences were observed between the radiological and ultrasound Sanders classification. Excellent concordance (Kappa coefficient > 0.90) was obtained when assessing interobserver variability in the ultrasound Sanders classification.

Conclusion:

Skeletal maturity status can be determined by radiographic or sonographic Sanders classification. Ultrasound measurement has a small learning curve and is easily reproducible if performed consistently.

Splitting Growth into 3 Phases with Cut-offs at Pubertal Spurt and Risser 3 Facilitates Prediction of Progression. A Study of Natural History of Idiopathic Scoliosis Patients from age 6 to End of Growth

/0 Comments/in /by

Stefano Negrini1,2 , Maryna Yaskina3 , Sabrina Donzelli4 , Alberto Negrini4 , Giulia Rebagliati4 , Claudio Cordani2 , Eric Parent3

1) Università “La Statale”, Milan (Italy) 2) IRCCS Istituto Ortopedico Galeazzi, Milan (Italy) 3) University of Alberta (Canada) 4) ISICO (Italian Scientific Spine Institute), Milan (Italy)

Introduction

We developed a model to predict the curve progression in patients with idiopathic scoliosis starting from a dataset including 2317 previously untreated patients from age 6 to 25. We were able to predict only 55% of the observed values with adequate precision. Consequently, we decided to move to another data analysis, starting from Duval—Beaupère papers, which recognized 3 phases of progression: one up to the start of puberty, a second from puberty to Risser 3 and a third from Risser 3 to the end of growth.



Research Question

Are three age-specific prediction models able to predict idiopathic scoliosis evolution better than an overall model spanning from age 6 to the end of growth?



Methods

We tried two strategies to divide the age groups. Strategy 1. We searched the exact timing of the start of growth (Point P). We searched all patients with radiographs with Risser 1 stage (after point P) and one or more previous consultations with radiographs while untreated. We hypothesized point P (sudden height growth) as a consultation with 1 standard deviation above average pubertal growth and looked for the time distance (months) from Risser 1. Strategy 2. We looked at the percentage of patients who reached Risser 1 in the different age groups.

We considered the following variables: Cobb angle at the baseline, time (squared and cubic too), Risser score, sex. A linear mixed-effect model analysis with random effects (SAS procedure MIXED) and maximum likelihood estimate was used to examine the effect of the different candidate variables on maximum Cobb angle accounting for repeated measures from the same patient. The data set was divided into subgroups for multiple-fold cross-validation. 



Results

Strategy 1 failed. With strategy 2 we found 1.3% Risser 1 up to age 9, 3.2% up to 10 and 10.2% up to 11. Consequently, we set the cut-off at age 11.

The prediction models we found were:

  • A (up to age 10, n.342): 1.64 +1.09 Cobb +0.82 time (years) +0.73 time2 –0.08 time3
  • B females (age 11 to Risser 2, n.916): –1.01 –1.85 (Risser 1) –2.53 (Risser 2) +1.12 Cobb +6.88 time -1.81 time2 +0.35 time3
  • C (Risser 3 to end of growth, n.469): 1.44 –2.04 (Risser 4) –1.44 (female) +1.03 Cobb +1.71 time –0.14 time2

The cross-validation results for the percentage of observed values falling within the prediction interval ±5° were 63.9-76.9% for A, 61.1-71.3% for B-females and 85.9-88.2% for C. 



Conclusions

The preliminary results of a model based on 3 ages show better prediction than an overall model including all these ages. 



Discussion

Our results are promising and confirm that the pubertal period is the most difficult for prediction. Prognosis is a crucial part of idiopathic scoliosis evaluation and the development of accurate prediction models coming from natural history data is of great importance. This work is still in progress, but results will offer clinicians new tools to be used to decide on treatment together with patients, within a shared-decision making model of care.



Disclosures (any Conflicts of Interest)

SN-AN: ISICO stock





Is surface topography useful in the diagnosis of scoliosis? : Validation of the Biometrical Holistic Of Human Body (BHOHB)

/0 Comments/in /by


Angelo Gabriele Aulisa1 , Diletta Bandinelli1 , Francesco Falciglia1 , Marco Giordano1 , Renato Maria Toniolo1

1) U.O.C. Orthopaedics and traumatology, Children Hospital Bambin Gesù, Rome

Introduction

To date, the gold standard for scoliosis diagnosis and surveillance in children’s spinal deformity is standing full-column radiographs, but repeated exposure to X-rays motivates all physicians involved in scoliosis to find a new solution. One of them is the modern system of surface topography (ST).



Research Question
The aim of the study is to validate the new BHOHB technology for the diagnosis of scoliosis in children respect to radiographic examination and evaluate the reliability of intra-operator and inter-operator.

Methods

113 Consecutive patients affected by idiopathic Scoliosis were examinate in our study. Inclusion criteria were age 10-18; diagnosis of scoliosis measuring ≥10, positive adam’s test and no prior treatment with brace. 

Standing radiographs and back surfaces of the patients with the BHOHB (Banyan Technologies GmbH, Maestrale Information Technology SRL) were obtained on all patients. All patients were analysed, with BHOHB, twice by two independent operators (t0) and once again after 2/3 months (t1). The examination consisted in positioning the patient on a special platform after placing 11 markers in pre-set points of the trunk.

The correlation between the measurements made with BHOHB and the gold standard was expressed by the Pearson correlation coefficient. The intra and inter-operator reliability was assessed using the intraclass correlation coefficient (ICC). The analysis was carried out with the GraphPad Prism 8 software.



Results

A total of 95 patients were enrolled. The mean age was 12.51 years. The scoliosis magnitude was 20.54 ± 9 Cobb degrees. The measurements in Cobb degrees obtained at t0 with the BHOHB by the first operator were 20.87 ° (± 9.1 SD), while those of the second were 20.82 ° (± 8.67 SD). Instead at t1 were respectively 20.23 ° (± 8.93 SD) and 19.90 ° (± 8.96 SD). 

The average hump measured with the humpmeter was 6.11 mm (± 5.14 SD) while that measured with the BHOHB was 6.58 mm (± 4.94 SD) and the correlation was significant (r=0.94; p <0.0001).

The correlations between the measurements made with the BHOHB and radiography showed a very good to excellent r for both the first and second operators. In particular:  X-rays vs 1st operator at t0 r = 0.9846; X-rays vs 2nd operator at t0 r = 0.9791; X-rays vs 1st operator at t1 r = 0.9745; X-rays vs 2nd operator at t1 r = 0.9563.

 

The intra-operator reliability was evaluated by ICC and was found to be very reliable for both the 1st operator r = 0.99 and the 2nd r = 0.936. The inter-operator reliability was also very reliable both at the first control r = 0.980 and at the second r = 0.961.



Conclusions

The results confirm that the BHOHB give results comparable to those obtained with radiography and these results are not influenced by the operator.



Discussion

We can affirm that even today the ST can be useful in the diagnosis and treatment of scoliosis, but the advice is to use it above all to evaluate the evolution of the curves, in this way it is possible to reduce the exposure of patients to X-rays



Disclosures (any Conflicts of Interest)
I have no conflict of interest.






Prediction of Future Curve Angle using Prior Visit Information in Previously Untreated Idiopathic Scoliosis: Natural History in Patients under 26 Years Old with Prior Radiographs

/2 Comments/in /by

Eric Parent1 , Sabrina Donzelli2 , Maryna Yaskina5 , Alberto Negrini2 , Giulia Angela Antonela Rebagliati2 , Claudio Cordani3 , Stefano Negrini4

1) Department of Physical Therapy, University of Alberta, Edmonton, Canada 2) ISICO (Italian Scientific Spine Institute), Milan, Italy 3) IRCCS Galeazzi Orthopaedic Institute, Milan, Italy 4) Department of Biomedical, Surgical and Dental Sciences, University of Milan, IRCCS Istituto Ortopedico Galeazzi, Milan , Milan,Italy 5) Women & Children Health Resarch Institute, University of Alberta, Edmonton, Canada

Introduction

Treatment selection for idiopathic scoliosis is informed by the risk of curve progression if untreated. Previous models predicting curve progression were limited by lack of validation, not including the full growth spectrum or including treated patients.



Research Question

The objective was to develop and validate a model to predict future curve angles using clinical and radiographic data collected prior to an initial specialist consultation in idiopathic scoliosis.



Methods

This is an analysis from all 2317 patients with juvenile, adolescent or adult idiopathic scoliosis between 6 and 25 years old who were previously untreated and presented with at least one prior radiograph in addition to the one captured when entered prospectively in the database (since 2003) at first consult. We excluded those previously treated using scoliosis-specific exercises, bracing or surgery. All radiographs were re-measured by evaluators blinded to the predicted outcome: the maximum Cobb angle on the last radiograph while untreated. Linear mixed-effect models with random effects (SAS procedure Mixed) and maximum likelihood estimate were used to examine the effect of age at the baseline visit, sex, maximum baseline Cobb angle, retrospective Max Cobb angle, time (from baseline to prediction), Risser, and curve type on Cobb angle outcome. Interactions of baseline angle with time, quadratic time, and cubic time; of time with sex and time with Risser were also tested. A variance components structure was used in the covariance matrix. The models accounting for repeated measures from the same patient were evaluated by the smallest Akaike and Bayesian Information Criterion.



Results

We included 2317 patients (83% were females) with 3255 total prior x-rays where 71% had 1, 21.1% had 2, 5.6% had 3, and 1.9% had 4 or more (with maximum 8). Mean age was 13.9±2.2yrs and 81% had AIS. Curve type was: 50% Double, 26% Thoracolumbar-Lumbar, 16% Thoracic, and 8% other. Cobb angle at first x-ray was 20±10o (0-80) vs 29±13o (6-122) at the specialist visit. Time between the first x-ray and the outcome clinic visit was 28±22mths.

In the best model (Table 1), larger values of the following variables predicted larger future curves: Max Cobb Angle at baseline, Retrospective Max Cobb angle (on a previous x-ray), time to the target prediction (in half-years), and time cubed. Larger values on the following variables predicted a smaller future Max Cobb angle: Time squared, Baseline Risser, Baseline Age, Time*Risser interaction, and time*female sex interaction.

Ten-fold cross-validation found a median error of 4.5o (worst interquartile range limits 1.8-8.9o, 54.9% within prediction interval, 84% within 10o of observed value). (Figure 2 and 3)



Conclusions

A novel internally validated model predicted future Cobb angle with good accuracy in non-treated idiopathic scoliosis over the full growth spectrum.



Discussion

The model can help clinicians predict how much curves would progress without treatment at future timepoints of their choice using six simple variables. Predictions can inform treatment prescription or show families why no treatment is recommended. The non-linear effects of time account for the rapid increase in curve angle at the beginning of growth and the slowed progression after maturity. 



Disclosures (any Conflicts of Interest)

No relevant COI disclosures.





Predicting Surgery: Accuracy of the BrAIST Endpoint Definitions at 2-Year Follow-up

/0 Comments/in /by

Lori Dolan1 , Stuart Weinstein1

1) University of Iowa Department of Orthopaedics and Rehabilitation

Introduction

BrAIST defined “success” as Risser 4+ and Sanders 7 with a Cobb angle of <50 degrees, at point where future surgery would be unlikely, whereas surgery was expected in the “failed” group (>50 degrees prior to maturity). The prognostic accuracy of these endpoints has been questioned, as curves may continue to progress and surgery may still occur post-maturity. Thus, this study evaluated the predictive value of the BrAIST endpoints via a minimum 2-year radiographic/surgical follow-up.

Research Question
What is the prognostic accuracy of the BrAIST definitions of success and failure?

Methods

The 272 subjects who completed BrAIST were eligible for follow-up if surgery occurred or at 2 years-post BrAIST. The 25 BrAIST sites located and consented their own subjects. A pre-op or follow-up film was submitted to the coordinating center for measurement. Progression was calculated as the difference between the maximum Cobb angle at BrAIST exit and at follow-up. The surgery rate, and the mean length of follow-up and curve progression were calculated. Prognostic accuracy was judged via the positive predictive value (PPV, % surgery in the “failed” group) and negative predictive value (NPV,% no surgery in the “success” group).

Results

Of 272 subjects, we obtained documentation of surgery (date only or pre-op x-ray) or a new x-ray for 198(73%); 115 (85%)in the success group(SG)and 83(94%)in the failed group(FG). 15% of the SG group underwent surgery compared to 94% of the FG. X-rays were available for 108 patients in the SG; of 83 (78%) with no curve progression 8 had surgery; 25 curves progressed and 6 of these were operated on. The mean pre-op Cobb angle was 48.1(range 40-58). Surgery in the SG occurred at an average of 2.5 years (range 6 mo to 4.2 years)after skeletal maturity. In this sample, the PPV was 94% (all but 6% of the FG had surgery) and the NPV was 85% (15% of the SG had surgery).  Overall, the BrAIST definitions predicted surgery correctly in 89% of subjects. 

Conclusions
BrAIST endpoints were set with future curve behavior in mind, yet surgery decisions not solely based on Cobb angles. Curves as small as 40 degrees were operated in this sample, but one at 63 degrees was not. Despite this variation, the BrAIST definitions of “success” and “failure” were correct for 89% of this sample at a minimum of 2-year follow-up.

Discussion

These endpoints therefore seem reasonable for use in future studies. 

Disclosures (any Conflicts of Interest)
The authors have no conflicts of interest related to this work.  The work was funded by the Joan and Phill Berger Charitable Fund.