Are torso asymmetry and torso displacements in a computer brace model associated with initial in-brace correction in adolescent idiopathic scoliosis?

BACKGROUND: Lack of initial in-brace correction is strongly predictive for brace treatment failure in adolescent idiopathic scoliosis (AIS) patients. Computer-aided design (CAD) technology could be useful in quantifying the trunk in 3D and brace characteristics in order to further investigate the effect of brace modifications on initial in-brace correction and subsequently long-term brace treatment success. The purpose of this pilot study was to identify parameters obtained from 3D surface scans which influence the initial in-brace correction (IBC) in a Boston brace in patients with AIS. METHODS: Twenty-five AIS patients receiving a CAD-based Boston brace were included in this pilot study consisting of 11 patients with Lenke classification type 1 and 14 with type 5 curves. The degree of torso asymmetry and segmental peak positive and negative torso displacements were analyzed with the use of patients' 3D surface scans and brace models for potential correlations with IBC. RESULTS: The mean IBC of the major curve on AP view was 15.9% (SD = 9.1%) for the Lenke type 1 curves, and 20.1% (SD = 13.9%) for the type 5 curves. The degree of torso asymmetry was weakly correlated with patient's pre-brace major curve Cobb angle and negligible correlated with major curve IBC. Mostly weak or negligible correlations were observed between IBC and the twelve segmental peak displacements for both Lenke type 1 and 5 curves. CONCLUSION: Based on the results of this pilot study, the degree of torso asymmetry and segmental peak torso displacements in the brace model alone are not clearly associated with IBC.

Validity and reliability of the adapted Dutch version of the Brace Questionnaire (BrQ).

BACKGROUND AND PURPOSE: The Brace Questionnaire (BrQ) is a disease-specific health-related quality of life (HRQOL) instrument for measuring perceived health status of scoliosis patients undergoing brace treatment. The purpose of this study is to evaluate the validity and reliability of a translated and culturally adapted Dutch version of the BrQ. PATIENTS AND METHODS: The original Greek BrQ was translated into Dutch and a cross-cultural adaptation and validation processes were conducted. Subsequently, 80 adolescent idiopathic scoliosis (AIS) patients undergoing active brace treatment were included from 4 scoliosis centers to evaluate the validity and reliability of the Dutch version of the BrQ. The questionnaire's floor and ceiling effects, internal consistency, and test-retest reliability were assessed. Concurrent validity was evaluated by comparing the BrQ with the revised Scoliosis Research Society 22-item questionnaire (SRS-22r) scores. RESULTS: The mean total BrQ score was 75.9 (standard deviation [SD] 11.3) and the mean domain scores varied between 3.4 (SD 0.9) and 4.2 (SD 0.7) for the domains "vitality" and "bodily pain," respectively. There were no floor and ceiling effects for the total BrQ score. The BrQ showed satisfactory internal consistency in most subdomains with a Cronbach's α ranging between 0.35 for the domain "general health perception" and 0.89 for the domain "self-esteem and aesthetics." Excellent test-retest reproducibility was observed for the total BrQ score (ICC 0.91), and the BrQ was successfully validated against the SRS-22r. CONCLUSION: The translated and culturally adapted Dutch version of the BrQ is a valid and reliable HRQOL instrument for AIS patients undergoing brace treatment.

Predicting the peak growth velocity in the individual child: validation of a new growth model.

Predicting the peak growth velocity in an individual patient with adolescent idiopathic scoliosis is essential or determining the prognosis of the disorder and timing of the (surgical) treatment. Until the present time, no accurate method has been found to predict the timing and magnitude of the pubertal growth spurt in the individual child. A mathematical model was developed in which the partial individual growth velocity curve was linked to the generic growth velocity curve. The generic curve was shifted and stretched or shrunk, both along the age axis and the height velocity axis. The individual age and magnitude of the PGV were obtained from the new predicted complete growth velocity curve. Predictions were made using 2, 1.5, 1 and 0.5 years of the available longitudinal data of the individual child, starting at different ages. The predicted values of 210 boys and 162 girls were compared to the child's own original values of the PGV. The individual differences were compared to differences obtained when using the generic growth velocity curve as a standard. Using 2 years of data as input for the model, all predictions of the age of the PGV in boys and girls were significantly better in comparison to using the generic values. Using only 0.5 years of data as input, the predictions with a starting age from 13 to 15.5 years in boys and from 9.5 to 14.5 years in girls were significantly better. Similar results were found for the predictions of the magnitude of the PGV. This model showed highly accurate results in predicting the individual age and magnitude of the PGV, which can be used in the treatment of patients with adolescent idiopathic scoliosis.

Predictive Factors on Initial in-brace Correction in Idiopathic Scoliosis: A Systematic Review.

STUDY DESIGN: Systematic literature review. OBJECTIVE: The aim of this study was to systematically review the literature and provide an overview of reported predictive factors on initial in-brace correction in patients with idiopathic scoliosis (IS). SUMMARY OF BACKGROUND DATA: Brace therapy is the best proven non-surgical treatment for IS. There is strong evidence that lack of initial in-brace correction is associated with brace treatment failure. To improve initial in-brace corrections and subsequently long-term brace treatment success, knowledge about factors influencing initial in-brace correction is a prerequisite. METHODS: A systematic literature search was performed in Pubmed, Embase, Web-of-Science, Scopus, Cinahl, and Cochrane in November 2020. Studies which reported factors influencing initial in-brace correction in IS patients treated with brace therapy were considered eligible for inclusion. RESULTS: Of the 4562 potentially eligible articles identified, 28 studies fulfilled the inclusion criteria and were included in this systematic review. Nine studies (32%) were classified as high quality studies and the remaining 19 studies (68%) as low quality. Thirty-four different reported factors were collected from the included studies. Strong evidence was found for increased curve flexibility as favorable predictive factor for initial in-brace correction. Moderate evidence was found for thoracolumbar or lumbar curve pattern as favourable predictive factor, and double major curve pattern as unfavourable predictive factor for initial in-brace correction. Also moderate evidence was found that there is no significant difference on initial in-brace correction between computer-aided design and manufacturing systems (CAD/CAM) braces with or without finite element models (FEM) simulation, and braces fabricated using the conventional plaster-cast. CONCLUSION: The results of this systematic review indicate that increased curve flexibility is strongly associated with increased initial in-brace correction.Level of Evidence: 1.

In-Brace versus Out-of-Brace Protocol for Radiographic Follow-Up of Patients with Idiopathic Scoliosis: A Retrospective Study.

The purpose of this retrospective study was to compare two standardized protocols for radiological follow-up (in-brace versus out-of-brace radiographs) to study the rate of curve progression over time in surgically treated idiopathic scoliosis (IS) patients after failed brace treatment. In-brace radiographs have the advantage that proper fit of the brace and in-brace correction can be evaluated. However, detection of progression might theoretically be more difficult. Fifty-one IS patients that underwent surgical treatment after failed brace treatment were included. For 25 patients, follow-up radiographs were taken in-brace. For the other 26 patients, brace treatment was temporarily stopped before out-of-brace follow-up radiographs were taken. Both groups showed significant curve progression compared to baseline after a mean follow-up period of 3.4 years. The protocol with in-brace radiographs was noninferior regarding curve progression rate over time. The estimated monthly Cobb angle progression based on the mixed-effect model was 0.5 degrees in both groups. No interaction effect was found for time, and patients' baseline Cobb angle (p = 0.98), and for time and patients' initial in-brace correction (p = 0.32). The results of this study indicate that with both in-brace and out-of-brace protocols for radiographic follow-up, a similar rate of curve progression can be expected over time in IS patients with failed brace treatment.

The growth of different body length dimensions is not predictive for the peak growth velocity of sitting height in the individual child.

The aim of this study was to determine whether the differences in timing of the peak growth velocity (PGV) between sitting height, total body height, subischial leg length, and foot length can be used to predict whether the individual patient with adolescent idiopathic scoliosis is before or past his or her PGV of sitting height. Furthermore, ratios of growth of different body parts were considered in order to determine their value in prediction of the PGV of sitting height in the individual patient. Ages of the PGV were determined for sitting height (n=360), total body height (n=432), subischial leg length (n=357), and foot length (n=263), and compared for the whole group and for the individual child in particular. Furthermore, the ages of the highest and lowest ratios between the body length dimensions were determined and compared to the age of the PGV of sitting height. The mean ages of the highest and lowest ratios were significantly different from the mean age of the PGV of sitting height in 3 out of 12 ratios in girls and 8 out of 12 ratios in boys. The variation over children was large and the ratios were too small, leading to a too large influence of measurement errors. The mean ages of the PGV all differed significantly from the mean age of the PGV of sitting height. However, the variation over individual children of the age differences in PGV between body dimensions was large, and the differences in timing of the PGV were not useful to predict whether the individual child is before or past his or her PGV of sitting height.

Predicting growth and curve progression in the individual patient with adolescent idiopathic scoliosis: design of a prospective longitudinal cohort study.

BACKGROUND: Scoliosis is present in 3-5% of the children in the adolescent age group, with a higher incidence in females. Treatment of adolescent idiopathic scoliosis is mainly dependent on the progression of the scoliotic curve. There is a close relationship between curve progression and rapid (spinal) growth of the patient during puberty. However, until present time no conclusive method was found for predicting the timing and magnitude of the pubertal growth spurt in total body height, or the curve progression of the idiopathic scoliosis.The goal of this study is to determine the predictive value of several maturity indicators that reflect growth or remaining growth potential, in order to predict timing of the peak growth velocity of total body height in the individual patient with adolescent idiopathic scoliosis. Furthermore, different parameters are evaluated for their correlation with curve progression in the individual scoliosis patient. METHODS/DESIGN: This prospective, longitudinal cohort study will be incorporated in the usual care of patients with adolescent idiopathic scoliosis. All new patients between 8 and 17 years with adolescent idiopathic scoliosis (Cobb angle >10 degrees) visiting the outpatient clinic of the University Medical Center Groningen are included in this study. Follow up will take place every 6 months. The present study will use a new ultra-low dose X-ray system which can make total body X-rays. Several maturity indicators are evaluated like different body length dimensions, secondary sexual characteristics, skeletal age in hand and wrist, skeletal age in the elbow, the Risser sign, the status of the triradiate cartilage, and EMG ratios of the paraspinal muscle activity. Correlations of all dimensions will be calculated in relationship to the timing of the pubertal growth spurt, and to the progression of the scoliotic curve. An algorithm will be made for the optimal treatment strategy in the individual patient with adolescent idiopathic scoliosis. DISCUSSION: This study will determine the value of many maturity indicators and will be useful as well for other clinicians treating children with disorders of growth. Since not all clinicians have access to the presented new 3D X-ray system or have the time to make EMG's, for example, all indicators will be correlated to the timing of the peak growth velocity of total body height and curve progression in idiopathic scoliosis. Therefore each clinician can chose which indicators can be used best in their practice. TRIAL REGISTRATION NUMBER: NTR2048.

The value of shoe size for prediction of the timing of the pubertal growth spurt.

BACKGROUND: Knowing the timing of the pubertal growth spurt of the spine, represented by sitting height, is essential for the prognosis and therapy of adolescent idiopathic scoliosis. There are several indicators that reflect growth or remaining growth of the patient. For example, distal body parts have their growth spurt earlier in adolescence, and therefore the growth of the foot can be an early indicator for the growth spurt of sitting height. Shoe size is a good alternative for foot length, since patients can remember when they bought new shoes and what size these shoes were. Therefore the clinician already has access to some longitudinal data at the first visit of the patient to the outpatient clinic.The aim of this study was to describe the increase in shoe size during adolescence and to determine whether the timing of the peak increase could be an early indicator for the timing of the peak growth velocity of sitting height. METHODS: Data concerning shoe sizes of girls and boys were acquired from two large shoe shops from 1991 to 2008. The longitudinal series of 242 girls and 104 boys were analysed for the age of the "peak increase" in shoe size, as well as the age of cessation of foot growth based on shoe size. RESULTS: The average peak increase in shoe size occurred at 10.4 years (SD 1.1) in girls and 11.5 years (SD 1.5) in boys. This was on average 1.3 years earlier than the average peak growth velocity of sitting height in girls, and 2.5 years earlier in boys. The increase in shoe size diminishes when the average peak growth velocity of sitting height takes place at respectively 12.0 (SD 0.8) years in girls, and 13.7 (SD 1.0) years in boys. CONCLUSIONS: Present data suggest that the course of the shoe size of children visiting the outpatient clinic can be a useful first tool for predicting the timing of the pubertal growth spurt of sitting height, as a representative for spinal length.This claim needs verification by direct comparison of individual shoe size and sitting height data and than a step forward can be made in clinical decision making regarding adolescent idiopathic scoliosis.

Ten to twelve-year results with the Zweymüller cementless total hip prosthesis.

Between January 1987 and December 1990, 221 Zweymüller cementless total hip arthroplasties were performed in 211 patients with idiopathic osteoarthritis. A total of 136 patients (142 prostheses) were evaluated at a mean follow-up of 134 months (SD 9.5). The study group consisted of 78 Hochgezogen and 64 Stepless stem prostheses, all with a threaded titanium cup and ceramic head. No clinical and radiological differences were found between the 2 stem prostheses. Seven cups had been revised because of aseptic loosening; 17 cups showed radiolucent lines, osteolysis, or migration. Mean linear polyethylene wear of 105 (74%) cups was 0.46 mm (SD 0.27), with an annual wear of 0.04 mm (SD 0.02). Wear did not correlate with pain, cup migration, radiolucent lines, or osteolysis. Cumulative survival was 96%. Zweymüller cementless total hip arthroplasty showed good midterm results.