Risk Factors For Curve Progression Research Articles

Discontinuation of brace treatment in adolescent idiopathic scoliosis (AIS): a scoping review.

Brace treatment for adolescent idiopathic scoliosis (AIS) is usually prescribed for 20-40° curves in patients with growth potential. The aim is to reduce the risk of curve progression during growth and to avoid the curve reaching a surgical threshold. Having as small a curve as possible at skeletal maturity will reduce the risk of curve progression during adult life. While evidence exists for brace treatment in AIS, there is disagreement on how and when to discontinue bracing. The purpose of this review was to investigate what criteria have been reported for initiating brace cessation and published weaning protocols and to look at estimates of the number of patients that may progress > 5 degrees after the end of growth. This scoping review summarizes existing knowledge on the best time to stop bracing in AIS patients, how to "wean," and what happens to spinal curves after bracing. Searches were carried out through MEDLINE, EMBASE, and PsycINFO in April 2022. A total of 1936 articles were reduced to 43 by 3 reviewers. Full papers were obtained, and data were extracted. Weaning was most commonly determined by Risser 4 (girls) and 5 (boys). Other requirements included 2years post-menarche and no growth in standing/sitting height for 6months. Skeletal maturity assessed from hand and wrist radiographs, e.g., Sanders' stage; distal radius and ulnar physes, could determine the optimal weaning time to minimize curve progression. Complete discontinuation was the most common option at skeletal maturity; variations on weaning protocols involved gradual reduction of bracing over 6-12months.Curve progression after weaning is common. The 12 studies reporting early curve progression after brace weaning found a mean Cobb angle progression of 3.8° (n = 1655). From the seven studies reporting early curve progression by > 5 degrees, there were 236/700 (34%) patients. There is limited information on risk factors to predict early curve progression after finishing brace treatment with larger curves, especially those over 40 degrees possibly having more chance of progression. Curve progression after bracing cessation is a negative outcome for patients who have tolerated bracing for several years, especially if surgery is required. The literature shows that when to start brace cessation and weaning protocols vary. Approximately 34% of patients progressed by more than 5 degrees at 2-4years after brace cessation or weaning. Larger curves seem more likely to progress. More research is needed to evaluate the risk factors for curve progression after brace treatment, defining the best time to stop bracing based on the lowest risk of curve progression and whether there is any benefit to weaning.

Providence Bracing: Predicting the Progression to Surgery in Patients With Braced Idiopathic Scoliosis.

Idiopathic scoliosis (IS) is a common spinal abnormality, in which orthotic management can reduce progression to surgery. However, predictors of bracing success are still not fully understood. We studied a large patient population treated with the nighttime Providence orthosis, utilizing multivariable logistic regression to assess results and predict future spine surgery. We retrospectively reviewed patients with IS meeting Scoliosis Research Society inclusion and assessment criteria presenting from April 1994 to June 2020 at a single institution and treated with a Providence orthosis. A predictive logistic regression model was developed utilizing the following candidate features: age, sex, body mass index, Risser classification, Lenke classification, curve magnitude at brace initiation, percentage correction in a brace, and total months of brace use. Model performance was assessed using the area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity. The importance of individual features was assessed using the variable importance score. There were 329 consecutive patients with IS with a mean age of 12.8 ± 1.4 years that met inclusion and assessment criteria. Of these, 113 patients (34%) ultimately required surgery. The model's area under the curve (AUC) was 0.72 on the testing set, demonstrating good discrimination. The initial curve magnitude (Importance score: 100.0) and duration of bracing (Importance score: 82.4) were the 2 most predictive features for curve progression leading to surgery. With respect to skeletal maturity, Risser 1 (Importance score: 53.9) had the most predictive importance for future surgery. For the curve pattern, Lenke 6 (Importance score: 52.0) had the most predictive importance for future surgery. Out of 329 patients with IS treated with a Providence nighttime orthosis, 34% required surgery. This is similar to the findings of the BrAist study of the Boston orthosis, in which 28% of monitored braced patients required surgery. In addition, we found that predictive logistic regression can evaluate the likelihood of future spine surgery in patients treated with the Providence orthosis. The severity of the initial curve magnitude and total months of bracing were the 2 most important variables when assessing the probability of future surgery. Surgeons can use this model to counsel families on the potential benefits of bracing and risk factors for curve progression.

Scoliosis and Kyphosis Prevalence in Turner Syndrome: A Retrospective Review at a Pediatric Tertiary Care Medical Center.

The prevalence of major coronal and sagittal spinal curves (scoliosis and kyphosis) in Turner syndrome (TS) is not well established due to limited reporting. The relationship between growth hormone (GH) therapy and its effect on TS spinal curve incidence is also not well established. A retrospective chart review of 306 TS patients from 2007 to 2021 evaluated major coronal and sagittal spinal curves, progression of the curve, and treatment with GH. Statistical significance (defined as P <0.05) between curvature rates and curve progression was compared between GH-treated patients and non-GH-treated patients using a χ 2 or Fisher exact test when appropriate. Thirty-seven of 306 (12%) TS patients had a radiographically relevant spinal deformity. Twenty-seven of 37 (73%) had mild; 4 of 37 (11%) had moderate, and 6 of 37 (16%) had severe curves. Of those with severe, 4 underwent spinal fusion, 1 was treated with bracing, and 1 was braced before a cardiovascular-related death. Regarding GH use among TS patients, 190 of 306 (62%) used GH versus 116 of 306 (38%) who did not. Of those with a spinal curve, 24 of 37 (65%) used GH compared with 13 of 37 (35%) who did not. On univariate analysis, GH therapy was not a risk factor for the diagnosis of a major spinal curve, a more severe degree of the curve at the time of diagnosis, or spinal curve progression ( P >0.05 for all). This is the largest single institution retrospective review of a TS cohort known to the authors assessing spinal curve prevalence and relation to GH treatment and demonstrates a TS spinal curve rate of 12% (37/306). Four of six (11%) TS patients with a severe curve underwent corrective spine fusion. There was no relationship between the use of GH and the presence of a spinal curve or curve progression. Further study is warranted to determine risk factors for curve progression. Level III. This retrospective case series serves to review and address the prevalence of spinal deformity in TS patients and whether GH impacts worsening deformity.

Brace treatment for scoliosis secondary to chiari malformation type 1 or syringomyelia without neurosurgical intervention: A matched comparison with idiopathic scoliosis.

To evaluate the effectiveness of brace treatment in patients with Chiari malformation type 1 (CM-1) or syringomyelia associated scoliosis without neurosurgical intervention. This was a retrospective case-control study. 34 CM-1 or syringomyelia (CMS) patients who received brace treatment without neurosurgical intervention were recruited. Another 68 matched patients with idiopathic scoliosis who received bracing served as the control group. The matching criteria included gender, age (± 1years), Risser sign (± 1 grade), initial curve magnitude (± 5°), curve patterns and follow-up time (± 6months). Patients who encountered curve progression and scoliosis surgery were compared between different groups. Until the last visit, 16 (47%) patients in CMS group and 18 (26%) patients in IS group occurred curve progression; 9 (26%) patients and 15 (22%) patients underwent scoliosis surgery, respectively. Compared to idiopathic scoliosis, patients with CMS-associated scoliosis had a significantly higher rate of curve progression (P = 0.038). However, no significant difference was observed between two groups regarding to the rate of surgery (P = 0.867). Patients with combined CM-1 and syringomyelia had a higher rate of surgery than patients with isolated CM-1 or syringomyelia (P = 0.049). The double major curve pattern was identified as the risk factor for curve progression. Brace treatment is effective for CMS-associated scoliosis without neurosurgical intervention. Compared to idiopathic scoliosis, brace can provide similar prevention for scoliosis surgery in CMS patients, but slight or moderate curve progression may occur. Specifically, patients with combined CM-1 and syringomyelia should be followed closely with a higher expectation of curve progression.

Are craniocervical angulations or syrinx risk factors for the initiation and progression of scoliosis in Chiari malformation type I?

The pathophysiology behind the instigation and progression of scoliosis in Chiari malformation type I (CMI) patients has not been elucidated yet. This study aims to explore the initiating and progressive factors for scoliosis secondary to CMI. Pediatric patients with CMI were retrospectively reviewed for radiological characteristics of tonsillar herniation, craniocervical anomaly, syrinx morphology, and scoliosis. Subgroup analyses of the presence of syrinx, scoliosis, and curve progression were also performed. A total of 437 CMI patients were included in the study; 62% of the subjects had syrinx, and 25% had scoliosis. In the subgroup analysis of 272 CMI patients with syrinx, 78 of them (29%) had scoliosis, and multiple logistic regression analysis showed that tonsillar herniation ≥ 10 mm (OR 2.13; P = 0.033) and a clivus canal angle ≤ 130° (OR 1.98; P = 0.025) were independent risk factors for scoliosis. In the subgroup analysis of 165 CMI patients without syrinx, 31 of them (19%) had scoliosis, and multiple logistic regression analysis showed that a clivus canal angle ≤ 130° (OR 3.02; P = 0.029) was an independent risk factor for scoliosis. In the subgroup analysis of curve progression for 97 CMI patients with scoliosis, multiple logistic regression analysis showed that anomalies of the craniocervical junction and syrinx were not risk factors for curve progression. Many complex factors including craniocervical angulation, tonsillar herniation, and syrinx might participate in the instigation of scoliosis for CMI patients, and the relationship between craniocervical angulation and scoliosis deserves further study.

Risk Factors for Reoperation Following Final Fusion After the Treatment of Early-Onset Scoliosis with Traditional Growing Rods.

Although there is a high rate of reoperation after final fusion following the treatment of early-onset scoliosis with use of traditional growing rods, the risk factors for reoperation are unknown. The purpose of the present study was to identify risk factors associated with the need for reoperation after final fusion for the treatment of early-onset scoliosis. A multicenter database for patients with early-onset scoliosis was retrospectively analyzed. Patients managed with traditional growing rods and final fusion were identified (n = 248). The inclusion criteria were ≥1 lengthening procedure with traditional growing rods and ≥2 years of follow-up after final fusion or revision surgery within 2 years after final fusion (167 patients; 67%). Patients requiring reoperation following final fusion were compared with patients who did not require reoperation. The data that were analyzed included demographic characteristics, comorbidities, spinal deformity characteristics, radiographic measurements, perioperative details, and complications during all stages of treatment. A multivariate regression model was used to identify independent risk factors. The mean duration of follow-up from the initial visit to the latest visit was 10.7 ± 4.1 years, and the mean duration of follow-up after final fusion was 4.9 ± 3.1 years. Thirty-two (19%) of the 167 patients required reoperation following final fusion. Curve progression requiring revision surgery during lengthening with traditional growing rods (adjusted odds ratio [aOR], 21.137 per event; p = 0.028), the number of levels spanned with traditional growing rods (aOR, 1.378 per level; p = 0.007), and the duration of treatment with traditional growing rods (aOR, 1.220 per year; p = 0.035) were independently associated with revision surgery after final fusion. Independent risk factors for curve progression requiring reoperation during lengthening with traditional growing rods that require operative intervention include increasing number of levels spanned with traditional growing rods and longer duration of treatment with traditional growing rods. These findings may help with patient counseling and potentially guide surgeon decision-making. Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Effects of Low Bone Mineral Status on Biomechanical Characteristics in Idiopathic Scoliotic Spinal Deformity.

Low bone mass in patients with adolescent idiopathic scoliosis has been well reported. Poor bone quality was regarded as a new and unique prognostic factor in aggravating curve progression. However, the potential biomechanical correlation between them remains unclear. Three-dimensional finite element models of idiopathic scoliotic spine with different bone mineral status were created for axial loading simulation. An axial load of 3 different body weights was applied on different bone mineral mass models. The mechanical responses of the vertebral cortical and cancellous bone, facet joints, end plate, and intervertebral disc were analyzed. Accompanied with the low bone mineral status, thoracic scoliosis produced asymmetric and higher stress in the cortical bone, lumbar facet joints, and end plate at the concave side of the thoracic structure curve. Stress increased in the disc at the apex of the scoliosis, whereas it mildly decreased in the L4-5 and L5-S1 disc. Body weight gain increased the stress in scoliotic spine structures in all bone mineral statues. Biomechanical simulations indicated that low bone mineral mass might aggravate curve progression and induce more serious lumbar compensatory scoliosis in patients with adolescent idiopathic scoliosis. Weight gain was also a risk factor for curve progression.

The Risk of Curve Progression and Surgery in African Americans With Adolescent Idiopathic Scoliosis

Study DesignRetrospective clinical cohort study. ObjectiveTo determine if certain risk factors (age, curve magnitude, skeletal maturity, gender, and curve pattern) traditionally associated with curve progression and surgical intervention in the general population apply equally to African Americans. Summary of Background DataCurrently, information is limited on the role that a patient's race plays in the risk of curve progression of adolescent idiopathic scoliosis (AIS), and existing studies have conflicting results. MethodsRetrospective search of records identified patients who were African American, had been diagnosed with AIS, had a major curve Cobb angle of 10 degrees or more, and had at least two clinical visits with spinal radiographs at least 90 days apart to determine the risk factors for surgical treatment, and 2 years apart to determine the risk factors for curve progression. Patients with a medical condition likely to cause scoliosis were excluded. ResultsOf 738 African American patients with AIS, 223 were assessed for surgical risk factors, and 72 were assessed for curve progression risk factors. Fifty-six (29.17%) had progression of the major coronal curve, and 38 (17.04%) underwent surgery. Age at presentation and curve magnitude at presentation were significant risk factors for surgical intervention. Curve magnitude at presentation was a significant risk factor for curve progression. No significant relationships were found for gender or curve type as they relate to surgical intervention or curve progression. ConclusionAge and curve magnitude at presentation were significantly associated with surgery, as is true in other scoliosis populations. Curve magnitude at presentation was associated with curve progression. In contrast to studies in other populations, however, no significant association was observed between curve progression and age at presentation, curve type, or gender, or between surgery and curve type or gender. Level of EvidenceLevel III, prognostic cohort study.

Efficacy of Task Oriented Exercise Program Based on Ergonomics on Cobb's Angle and Pulmonary Function Improvement in Adolescent Idiopathic Scoliosis- A Randomized Control Trial.

Scoliosis is lateral curvature of the spine greater than 100 accompanied by vertebral rotation. The prime risk factors for curve progression are a large curve magnitude, skeletal immaturity and female gender. The curve progression can be recorded by measuring the curve magnitude using the Cobb's method on radiographs. To assess the effect of task oriented exercises based on ergonomics on Cobb's angle and pulmonary functions on one year outcome of Adolescent Idiopathic Scoliosis(AIS) (defined as curves < 150 for thoracolumbar region and < 200 for thoracic region). A total of 36 patients were enrolled in the study and 18 patients in each group (experimental and control group) were allocated randomly. The subjects in control group underwent spinal strengthening exercises, active self-correction and breathing exercises, whereas subjects in the experimental group followed task oriented exercises based on ergonomics in addition to exercises for conventional group for one year. Chi square test was used to compare the categorical/ dichotomous variables between the groups. Unpaired t-test was used to compare continuous variables between the groups at pre and post intervention. Paired t-test was used to compare the changes in continuous variables from pre to post intervention within the group. Forced Vital Capacity (FVC) was found to be significantly (p=0.001) higher in experimental group (2.68±0.37) than control group (2.20±0.41) at post-intervention. Force Expritatory Volume 1 (FEV1) (p=0.01) and Vital Capacity (VC) (p=0.002) were also found to be significantly higher in experimental group compared to control group at postintervention. Also, there was significant (p=0.001) mean reduction in Cobb's angle from pre to post intervention in both the groups being higher in Experimental group than control group. The task oriented exercise protocol benefited patients with AIS which had a significant improvement of their pulmonary functions and Cobb's angle.

De novo degenerative lumbar scoliosis: a systematic review of prognostic factors for curve progression.

To identify prognostic factors for curve progression in de novo degenerative lumbar scoliosis (DNDLS) by performing a systematic review of the literature. Studies were selected for inclusion following a systematic search in the bibliographic databases PubMed and EMBASE prior to September 2015 and hand searches of the reference lists of retrieved articles. Two authors independently assessed methodological quality. Data were extracted and presented according to a best evidence synthesis. The literature search generated a total of 2696 references. After removing duplicates and articles that did not meet inclusion criteria, 12 studies were included. Due to the lack of statistical analyses, pooling of data was not possible. Strong evidence indicates that increasing intervertebral disk degeneration, lateral vertebral translation ≥6mm, and an intercrest line through L5 (rather than L4) are associated with DNDLS curve progression. Moderate evidence suggests that apical vertebral rotation Grade II or III is associated with curve progression. For the majority of other prognostic factors, we found limited, conflicting, or inconclusive evidence. Osteoporosis, a coronal Cobb angle <30°, lumbar lordosis, lateral osteophytes difference of ≥5mm, and degenerative spondylolisthesis have not been shown to be risk factors. Clinical risk factors for progression were not identified. This review shows strong evidence that increased intervertebral disk degeneration, an intercrest line through L5, and apical lateral vertebral translation ≥6mm are associated with DNDLS curve progression. Moderate evidence was found for apical vertebral rotation (Grade II/III) as a risk factor for curve progression. These results, however, may not be directly applicable to the individual patient.

Curve progression after decompression surgery in patients with mild degenerative scoliosis

The authors undertook this study to evaluate curve progression, risk factors for curve progression, and outcomes after decompression surgery in patients with degenerative lumbar scoliosis with minimal to moderate curvature. Of 852 patients with lumbar canal stenosis treated by posterior decompression surgery, 50 patients had a lumbar curve greater than 10° at final follow-up. These patients were divided into 2 groups according to curve progression during the follow-up period: the P group (11 patients), with a curve progression of more than 5°, and the NP group (39 patients), with a curve progression of 5° or less. The authors compared preoperative parameters in these 2 groups to elucidate risk factors associated with curve progression and other surgical outcomes. The average lumbar curve progression in the total group of 50 patients was 3.4° ± 3.9° (range -2.0° to 22.0°). In the P group the average curve progression was 8.5°, and in the NP group it was 2.0°. Multivariate logistic regression analysis showed no significant association between curve progression and any of the potential risk factors evaluated (including curve magnitude, decompression method, and degenerative intervertebral disc changes). Spur formation, evaluated with the Nathan classification at the concave side of the curve, tended to be greater in the P group, although the difference was not statistically significant. There was no significant difference in revision surgery rate, and none of the patients required arthrodesis due to curve progression. Clinical outcomes, evaluated with the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and the Scoliosis Research Society 22-question questionnaire, were also similar in the 2 groups. Surgical outcomes did not deteriorate in the P group. While curve progression after decompression surgery could not be predicted from the preoperative factors considered, spur formation at the concave side of the curve may be a candidate factor. The results of this study indicate that spinal fixation to halt deformity progression is not always necessary if the patient's pathological condition derives mainly from canal stenosis.

The natural history of adolescent idiopathic scoliosis

There have been great advances in the conservative and surgical treatment for adolescent idiopathic scoliosis in the last few decades. The challenge for the physician is the decision for the optimal time to institute therapy for the individual child. This makes an understanding of the natural history and risk factors for curve progression of significant importance. Reported rates of curve progression vary from 1.6% for skeletally mature children with a small curve magnitude to 68% for skeletally immature children with larger curve magnitudes. Although the patient's age at presentation, the Risser sign, the patient's menarchal status and the magnitude of the curve have been described as risk factors for curve progression, there is evidence that the absolute curve magnitude at presentation may be most predictive of progression in the long term. A curve magnitude of 25° at presentation may be predictive of a greater risk of curve progression. Advances in research may unlock novel predictive factors, which are based on the underlying pathogenesis of this disorder.

Factors Associated with Spinal Deformity Progression in Adolescent Idiopathic Scoliosis

The implementation of school-based screening has resulted in a large number of adolescents with idiopathic scoliosis with relatively small curve magnitudes presenting to the clinician. Deciding on appropriate management requires an understanding of the natural history and factors associated with progression of spinal deformity. This is a challenging field and has not been fully defined. The physician will need to make the most use of available data and individualize treatment for the child. Although the patient’s age at presentation, the Risser sign, the patient’s menarchal status and the magnitude of the curve have been described as risk factors for curve progression, there is evidence that the absolute curve magnitude at presentation may be most predictive of progression in the long term.

Adolescent idiopathic scoliosis, bracing, and the Hueter-Volkmann principle

Background context: Evidence demonstrating the biomechanical effects of the Hueter-Volkmann principle on vertebral body growth in spinal deformities is lacking. Bracing a scoliotic curve should, in theory, unload the growth plates on the concave side of the vertebral bodies near the curve's apex. Growth stimulation, leading to structural remodeling of the vertebral bodies, on the curve's concave side may explain the improvement or lack of curve progression, as measured by Cobb angles, reported with successful brace management of adolescent idiopathic scoliosis (AIS). Purpose: To determine whether brace treatment stimulated asymmetric chondrogenesis in the apical three vertebral bodies. Study design: A prospective cohort of patients with AIS receiving brace treatment were followed from the initiation of brace treatment until skeletal maturity. Patients were then retrospectively divided into those with and without radiographic progression. This post hoc analysis was included to determine risk factors for curve progression. Patient sample: Forty-one skeletally immature patients with AIS meeting criteria for brace treatment were followed until skeletal maturity. All patients were treated with thoracolumbosacral orthotics (TLSOs). Outcome measures: The positional derotation of the TLSO on the spine was measured by comparing the initial radiograph with the first radiograph in a brace. The long-term structural changes of the vertebral bodies were determined by comparing the initial and final radiographs. Differences in initial radiographic parameters between the groups of patients with AIS with and without curve progression indicated predictive factors for successful brace treatment. Methods: Initial radiographic measurements were compared with those observed in a brace and those observed at final follow-up. The same analysis was retrospectively repeated comparing patients with AIS with and without radiographic progression. Results: Cobb measurements (p=.0001) and concave-to-convex height ratios of the apical three vertebral bodies improved when the brace was initially applied (p=.0035). Structural remodeling or a rotational correction of the apical three vertebral bodies was appreciated only in patients with flexible curves (p=.01). Conclusion: Brace application results in immediate positional derotations of the spine in patients with AIS. These positional derotations were maintained only in patients with flexible curves, at final follow-up. Brace treatment was not recommended in patients whose curves did not correct at least 20% in a TLSO.