|
Displaying items by tag: scoliosis progression
When we here about scoliosis we generally think about the kids we knew in high school that had to wear a brace or maybe even had to deal with scoliosis surgery but we don’t often think about adults with scoliosis. The prevalence of adults with scoliosis is quite high, In this study, results indicate a scoliosis rate of 68% in a healthy adult population, with an average age of 70.5 years(1). So the reality is that 2/3 of the adult elderly population has scoliosis, a curve in their spine when viewed from the front of more than 10 degrees. According to this study and additional resources there is a very strong correlation of scoliosis to pain and dysfunction where about half of the adult scoliosis patients did have measurable social or physical limitations. There was a significant correlation between degeneration of the spine and discs and scoliosis which most likely impacts function levels of those with scoliosis especially on a segmental basis.
When dealing with scoliosis as an adult whether you had the condition from childhood or developed it later in life it seems the major concern is progression. Most adult patients especially the ‘baby boomers” are very concerned about their scoliosis getting worse. I think we have to consider the prevalence of scoliosis differs between the adolescent populations at a 3% incidence level versus the adult population having a 20% incidence level (3). In addition to the older populations of >60 being 40% and >70 year old population at 68%. So there definitely needs to be a distinction between adolescent scoliosis patients that are now adults versus later onset scoliosis induced almost entirely via environmental interaction with an effect on the lumbar spine primarily.
There is a very detailed and respectable study that was recently done regarding progression rates with scoliosis in the adult population (2). The truth is that scoliosis does progress in adulthood. Not only does it progress but it has a somewhat predictable nature to it based on where the curve is located or type of scoliosis. Lumbar and thoracolumbar single curves progress with the highest rate approximately 1.64 degrees per year, so a 10 year span would result in a 16 degree progression, WOW! whereas double major curves have the lowest rate of progression at .82 degrees per year or 8 degrees per decade. These progression statistics were based on very specific parameters. The patients observed in this study were separated into two very distinct groups, Type a double major curves and Type B single lumbar or thoracolumbar curves.
The double major group (type A) was often diagnosed in adolescence and in this particular study started being monitored at a mean age of 24 with a mean cobb angle measurement of 37 degrees (range 22° to 52° ). The single lumbar/thoracolumbar group (type B) began initial monitoring much later at a mean age of 46 with a mean cobb angle of only 20° (range 3° to 35°). The most significant difference between the two different scoliosis types was menopause. Type B single lumbar curves had a significant deterioration and progressed at a faster rate following menopause.
So when discussing whether or not scoliosis progresses in adulthood we have to make an initial distinction between the type of scoliosis that a patient has either adolescent scoliosis generally double major curves or adult onset scoliosis of the lumbar spine. If it is adult onset scoliosis of the lumbar spine then there are certain characteristics to look for and to monitor. If you are female then obviously menopause is a big component of the progression and all proactive steps available should be taken to prevent a big swing of the scoliosis in the wrong direction causing more dysfunction and pain in later years. Considering the progression is correlated and often caused by the rotation in the lumbar spine with adult onset scoliosis this needs to be a major component of the monitoring and scoliosis treatment process.
The adolescent double major has a lower progression rate and is not linked to menopausal deterioration but certainly should not be neglected based on a “ it’s not as bad” mentality, it still will worsen without any intervention and cause undo spinal dysfunction and pain. Interestingly the rotation in this scoliosis type appears to be secondary and a direct result of progression.
The progression of adult scoliosis is linear and therefore can be used to establish an individual prognosis and potentially generate treatment plan to accommodate each type and level of scoliosis.
Adult scoliosis: prevalence, SF-36, and nutritional parameters in an elderly volunteer population.
Marty-Poumarat C, Scattin L, Marpeau M, Garreau de Loubresse C, Aegerter P. Spine 2007 May 15;32(11):1227-34; discussion 1235.
Z. Anwara, E. Zana, S.K. Gujara, D.M. Sciubbaa, L.H. Riley IIIa, Z.L. Gokaslana and D.M. Yousema Published online before print January 6, 2010, doi: 10.3174/ajnr.A1962 AJNR 2010 31: 832-837
Please click here to receive a FREE SCOLIOSIS TREATMENT INFORMATION KIT.
As far as it looks right now, it looks like the environmental factors of idiopathic scoliosis seem to be falling into one of three catagories that all interact with each other and the genetic pre-disposition (via epigenetics or otherwise). Let's see how many we can list under these catagories and even add more catagories if appropriate.
Bio-mechanical
Activity related
Please click here to receive a FREE SCOLIOSIS TREATMENT INFORMATION KIT ASAP.
Please click here to receive a FREE SCOLIOSIS TREATMENT INFORMATION KIT ASAP.
Scoliosis generally experiences it's most rapid curve progression during a patients adolescents until they reach skeletal maturity. Often parents and patients are told that curvature won't continue to progress after that point. Unfortunately, that generally isn't the case and many adolescent idiopathic scoliosis patients do experience continued curve progression throughout life (average 1-3 degrees per year). This is particularly true in cases in which the curvature was over 25 degrees when the patient reached skeletal maturity (as discussed in the following study). It is absolutely imperative that a patient engaged in an effective early stage scoliosis intervention program that works to keep the spinal curvature under 20 degrees while the patient is still growing and allows them to reach skeletal maturity with the curvature measuring less than 25 degrees.
Curve Progression in Idiopathic Scoliosis Follow-up Study to Skeletal Maturity
Ken-Jin Tan, MBBS, MMed, MRCS,* Maung Maung Moe, MBBS,* Rose Vaithinathan, MBBS, MMed,† and Hee-Kit Wong, MBBS, FRCS* Study Design. This is a follow-up study to skeletal maturity on a cohort of students screened for a 1-year prospective epidemiological prevalence study for scoliosis.
Objectives. This study aims to identify the prognostic factors for curve progression to a magnitude of 30° at skeletal maturity in skeletally immature patients with adolescent idiopathic scoliosis.
Summary of Background Data. The natural history of idiopathic scoliosis is not well understood. Previous reports have focused on the characteristics of curve progression where progression has been predefined at specific angles of 5° to 6°. However, the absolute curve magnitude at skeletal maturity is more predictive of long-term curve behavior rather than curve progression of a defined magnitude over shorter periods of skeletal growth. It is generally agreed that curves less than 30° are highly unlikely to progress after skeletal maturity. Hence, defining the factors that influence curve progression to an absolute magnitude of more than 30° at skeletal maturity would more significantly aid clinical practice.
Methods. One hundred eighty-six patients who fulfilled the study criteria were selected from an initial 279 patients with idiopathic scoliosis detected by school screening, and who were followed-up till skeletal maturity. The initial age, gender, pubertal status, and initial curve magnitude were used as risk factors to predict the probability of curve progression to more than 30° at skeletal maturity.
Results. Curve magnitude at first presentation was the most important predictive factor for curve progression to a magnitude of more than 30° at skeletal maturity. An initial Cobb angle of 25° had the best receiver-operating characteristic of 0.80 with a positive predictive value of 68.4% and a negative predictive value of 91.9% for curve progression to 30° or more at skeletal maturity.
Conclusion. Initial Cobb angle magnitude is the most important predictor of long-term curve progression and behavior past skeletal maturity. We suggest an initial Cobb angle of 25° as an important threshold magnitude for longterm curve progression. Initial age, gender, and pubertal status were less important prognostic factors in our study. Key words: adolescent idiopathic scoliosis, natural history, Cobb angle, curve progression, skeletal maturity. Spine 2009;34:697–700 Knowledge of the natural history and factors that influence curve behavior over time is critical in the evaluation, prognostication, and management of patients with scoliosis. Particularly, in the case of school-based screening programs, the surgeon is often faced with the management of a large number of patients many of whom have relatively small curves at presentation. There have been relatively few studies on the natural history of adolescent idiopathic scoliosis, and these have largely been limited to the analysis of defined units of curve progression.1–3 Some factors that have been identified to be related to progression include the magnitude of the curve, the patient's age at presentation, the Risser sign, and the patient's menarchal status.1–3 Although previous authors have identified the risk of curve progression by a stipulated magnitude of usually 5° and the associated factors, this does not allow the physician to predict the longer-term behavior of the curve at skeletal maturity and into adulthood. An understanding of curve behavior into skeletal maturity and adulthood is important as it is now established that curves because of idiopathic scoliosis do not necessarily stop progressing after skeletal maturity. In a longterm follow-up study of patients with idiopathic scoliosis, Collis and Ponseti4 found that curves of larger degree did increase after skeletal maturity. In a separate study with an average follow-up of 40 years, Weinstein and Ponseti5,6 also found that a significant number of idiopathic curves increased after skeletal maturity. They reported that in thoracic curves, the Cobb angle, apical vertebral rotation, and the Mehta angle were important prognostic factors. For lumbar curves, the degree of apical vertebral rotation, the Cobb angle, the direction of the curve, and the relationship of the fifth lumbar vertebra to the intercrest line were of prognostic value. However, they also observed that curves that were less than 30° at skeletal maturity tended not to progress regardless of curve pattern. In this study, we report on a group of 279 patients with idiopathic scoliosis detected by school screening, and who were followed-up until skeletal maturity. One hundred eighty-six patients fulfilled the study criteria and for these adolescents, the initial age, gender, pubertal status, and initial curve magnitude were used as risk factors to predict the probability of curve progression to more than 30° at skeletal maturity.
Materials and Methods Our study population was derived from a cohort of school children screened for scoliosis in 1997 the results of which were From the *Department of Orthopaedic Surgery, National University Hospital, National University of Singapore, Singapore; and †Health Promotion Board, School Health Service, Singapore. Acknowledgment date: May 12, 2008. Acceptance date: October 21, 2008. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript. Address correspondence and reprint requests to Ken-Jin Tan, MBBS, MMed, MRCS, Department of Orthopaedic Surgery, National University Hospital, 5 Lower Kent Ridge Road, Main Building 1, Singapore 119074, Singapore; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it 697 previously reported.7 In this study, 72,699 children aged 6 to 14 years out of a total enrolment of 152,000 schoolchildren were screened for a 1-year prospective epidemiological prevalence study for scoliosis. Of the 72,699 screened, 279 were diagnosed to have idiopathic scoliosis on the basis of a single standing radiograph, which showed a Cobb angle equal to or greater than 10°. Of the 279, 17 were either uncontactable or did not attend more than once. The selection criteria for the present study on curve progression were that the adolescent must be skeletally immature at the beginning of the study and be skeletally mature at the last follow-up appointment. Skeletal maturity was defined as an age of 15 years or a Risser grade of 4 or 5.5 Patients with incomplete data on maturity or on factors studied were also excluded. Of the 262 patients, 36 patients were skeletally mature at presentation and excluded from the study. The remaining 226 patients were observed-up at regular intervals ranging from 3 to 6 months over the following years. The follow-up period ranged from 1 to 8 years. During the period of follow-up, some patients were referred for bracing or surgical fusion of the curve. Their final Cobb angle at the last follow-up appointment was used for the study. At the end of the study, 9 patients had not attained skeletal maturity and 31 patients had incomplete data or were lost to follow-up. These patients were excluded from the study. The remaining 186 patients formed the study group. 84.9% of the patients were girls, with 37.3% being of prepubertal status. The initial age of the patients ranged from 7 to 14 years of age. The median age was 12 years with a mean (standard deviation) of 12 (1.50) years with 34.9% less than 12 years of age. Of the 186 patients, 38 (20.4%) progressed to a Cobb angle of 30° or more at skeletal maturity. The study parameters analyzed were the age at first appointment, gender, initial or presentation Cobb angle and initial pubertal status. Both univariate and multivariate analyses were performed. The 2 test was used for univariate analysis and a logistic regression model was used for multivariate analysis. Receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off for Cobb angle at presentation.
Results ROC analysis demonstrated that the Cobb angle at presentation was the single most important factor that predicted further curve progression to a Cobb angle of 30° or more at skeletal maturity. Age, pubertal status, and gender were not found to be of predictive value (Figure 1). Furthermore, a Cobb angle of 25° at presentation had the best overall predictive value for curve progression to a Cobb angle of 30° or more at skeletal maturity. The ROC value for a Cobb angle of 25° at presentation was 0.80. This was associated with a positive predictive value of 68.4% and a negative predictive value of 91.9%for curve progression to 30° or more at skeletal maturity (Figure 2). These findings on ROC analysis closely agreed with the results of univariate and multivariate analysis. Using a cut-off presentation Cobb angle of 25° as determined by ROC analysis, 68.4% of patients with a Cobb angle of 25° or more at presentation progressed to a final Cobb angle of 30° or more. This compared with 8.1% of patients with a Cobb angle of less than 25° at presentation. This difference was highly significant on both univariate and multivariate analyses (P 0.001). Patients who had an initial age less than 12 years (26.2%) compared with patients aged 12 years and above (17.4%) had a final Cobb angle of 30° or more. This difference was not found to be of significance (P 0.158). Relatively similar percentages, 23.0% (17 patients) who were prepubertal initially and, 18.8% (21 patients) who had attained puberty initially, progressed to a final Cobb angle of 30° or more (P 0.485). The difference in gender between the patients that progressed and did not progress to a final Cobb angle of 30° was slightly more pronounced than that for age Figure 1. ROC plots for the various factors analyzed. The Cobb angle at presentation was the single factor that had an ROC curve that was significantly different from the reference line. The ROC plots for age, pubertal status, and gender all lie close to the reference line. Figure 2. The ROC plots for 16° to 29° cut-offs for the presentation Cobb angle are presented here. The 25° cut-off had the highest ROC. 698 Spine • Volume 34 • Number 7 • 2009 and pubertal status. 22.8% of girls compared with 7.1% of boys progressed to a final Cobb angle of 30° or more. This difference was close to statistical significance (P 0.076). Table 1 shows the univariate and multivariate analyses of age being less than 12 years, gender, pubertal status, and Cobb angle at presentation on curve magnitude of 30° or more at skeletal maturity. When factors were combined and analyzed by logistic regression, we found that a prepubertal girl less than 12 years of age with a Cobb angle of 25° or more at presentation had the highest chance of progression (82.23%) to a Cobb angle of 30° or more (Table 2). On the other hand, a boy who was postpubertal with an age of 12 years or more and an initial Cobb angle of less than 25° was least likely to progress to a Cobb angle of 30°. This probability was only 2.39%. Conversely, the same male patient would have a 97.61% probability of his curve not progressing to a Cobb angle of 30° or more (Table 2). For logistic regression analysis, the probability of progression to a final Cobb angle of 30° or more was calculated by the following equation. Probability of final Cobb angle 30 1/ (1 exp (z)) where z 3.709 0.931 (gender) 0.825 (pubertal status) 3.314 (initial Cobb angle) 0.171 (age at presentation). Where girl 1, boy 0; before puberty 1, after puberty 0, initial Cobb angle 25 0, initial Cobb angle 25 1; age at presentation 12 0, age at presentation 12 1.
Discussion The care of adolescents with mild curves because of idiopathic scoliosis is a constant clinical dilemma. Management decisions should ideally be based on accurate prediction of long-term curve behavior and not on risk for curve progression of a defined magnitude over shorter durations of skeletal growth. Studies on curve progression include those by Lonstein and Carlson and Soucacos et al, which examined for curve progression as defined by a limited increase in curve magnitude of 5 to 6°.1,2 Lonstein and Carlson1 found that the strongest predictive factors for curve progression were the curve magnitude, the Risser sign and the chronological age. Similarly, Soucacos et al observed a strong association between the incidence of curve progression and sex of the child, curve pattern, maturity (pubertal status), age, and curve magnitude.2 In addition, a recent French study, which retrospectively reviewed 205 patients with idiopathic scoliosis, found that curve pattern, Cobb angle at onset of puberty and curve progression velocity to be strong prognostic factors of curve progression during pubertal growth.3 In the above study, the authors found that juvenile scoliosis with magnitude more than 30° increased rapidly during pubertal growth and had a 100% prognosis for surgery.3 Weinstein and Ponseti, after following-up 102 patients over more than 4 decades, reported that curves that were less than 30° at skeletal maturity tended not to progress regardless of curve pattern. This was unlike curves with a magnitude above 30°, which had a higher Final Cobb refers to the Cobb angle at skeletal maturity. Curve Progression in Idiopathic Scoliosis • Tan et al 699 tendency to progress, even after skeletal maturity. In this study, skeletal maturity was defined as a Risser grade of 4 or 5.7 Hence, it would be more useful to have data on the risk of curve progression to a magnitude of 30° or more and the factors associated with this. This information would enable a more accurate prediction of curve behavior in the long-term and at the same time reducing the number of patients requiring follow-up. Available data suggests that curves with a magnitude of less than 30° at skeletal maturity do not continue to progress, whereas those of magnitude 30° or more behave differently and have a propensity for further progression. Our study aims to address this need by following-up adolescents with idiopathic scoliosis detected in our national screening program to skeletal maturity and analyzing the progression risk and associated risk factors. The main prognostic factor that we identified in our study was curve magnitude at presentation. Age, gender, and pubertal status had much less prognostic value than curve magnitude. There has been no agreement as to the most important factors that influence curve progression in previous studies. However, age, gender, and pubertal status have previously been found to be important factors. A possible reason why age, gender, and pubertal status were much less important in our study could be the different aspect of curve behavior studied. Therefore, it is likely that the factors involved would reflect the growth potential of the patient during the likely shorter period of curve progression of 5° to 6°. However, we followed-up the patients' curves to skeletal maturity regardless of the magnitude of curve progression. Hence, prognostic factors in our study may be less dependent on shorter periods of curve progression but instead be more reflective of the risk of final curve progression to a defined threshold magnitude of 30°. Our findings of a critical Cobb angle of 25° at first presentation suggests that regardless of previous curve magnitude or curve progression during skeletal growth, the absolute value of the curve at presentation is the most important factor in long-term prognostication. Our logistic regression model also identified that a Cobb angle at presentation of 25° or more when combined with a girl less than 12 years of age and prepubertal status gave the highest risk for curve progression to a Cobb angle of 30° or more at skeletal maturity. This was in contrast to a boy who was postpubertal with an age of 12 years or more and a Cobb angle at presentation of less than 25°. This profile was associated with only a 2.39% probability of the curve progressing to 30° or more at skeletal maturity.
Key Points ● Cobb angle on initial presentation is the most important predictor of long-term curve progression. ● Curves with a Cobb angle of 25° or more have a 68.4% probability of progressing to 30° or more at skeletal maturity. On the other hand, curves with a Cobb angle of less than 25° have a 91.9% probability of not progressing to 30° or more at skeletal maturity. ● A prepubertal girl less than 12 years of age with a Cobb angle of 25° or more at presentation had an 82.23% chance of progression to a Cobb angle of 30° or more. ● Conversely, a postpubertal boy, 12 years old or older, with a Cobb angle of less than 25° at presentation had only a 2.39% chance of progression to a Cobb angle of 30° or more.
References 1. Lonstein JE, Carlson JM. The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg Am 1984;66:1061–71. 2. Soucacos PN, Zacharis K, Gelalis J, et al. Assessment of curve progression in idiopathic scoliosis. Eur Spine J 1998;7:270–77. 3. Charles YP, Daures JP, Rosa VD, et al. Progression risk of idiopathic juvenile scoliosis during pubertal growth. Spine 2006;31:1933–42. 4. Collis DK, Ponseti IV. Long-term follow-up of patients with idiopathic scoliosis not treated surgically. J Bone Joint Surg Am 1969;51:425–45. 5. Weinstein SL, Ponseti IV. Curve progression in idiopathic scoliosis. J Bone Joint Surg Am 1983;65:447–55. 6. Weinstein SL, DC Zavala, Ponseti IV. Idiopathic scoliosis: long-term follow- up and prognosis in untreated patients. J Bone Joint Surg Am 1981;63: 702–12. 7. Wong HK, Hui JH, Rajan U, et al. Idiopathic scoliosis in Singapore schoolchildren: a prevalence study 15 years into the screening program. Spine 2005; 30:1188–96. 700 Spine • Volume 34 • Number 7 • 2009 |
