The Effect of Thoraco-Lumbo-Sacral Orthosis Wear Time and Clinical Risk Factors on Curve Progression for Individuals with Adolescent Idiopathic Scoliosis.

BACKGROUND CONTEXT: The effectiveness of bracing with a thoraco-lumbo-sacral orthosis (TLSO) for adolescent idiopathic scoliosis (AIS) has been studied extensively, with a growing body of evidence supporting TLSO use. In this study we examine the effect of wear time and other important causal factors affecting curve progression and develop a risk model that can be applied to individual patients and is based on important casual factors. PURPOSE: Understand the impact of TLSO wear time and other risk factors in order to guide optimal treatment. STUDY DESIGN/SETTING: Prospective, multi-center, cohort study PATIENT SAMPLE: Individuals with a diagnosis of AIS, age of 10-16 years, primary Cobb angle of 20-45°, Risser 0-2, <1 year post menarche if female, who were to be treated with a TLSO OUTCOME MEASURES: (1) Rate of primary curve progression, (2) surgery recommendation during TLSO treatment METHODS: Wear time was monitored with thermochrons. Participants were followed until the end of growth. We examined the causal effects of wear time and baseline skeletal maturity as measured by triradiate cartilage (TRC) status, Cobb angle, and age. We then fit an outcome prediction model (logistic regression) based on important casual factors. RESULTS: Our final cohort consisted of 145 individuals (baseline age 12.1 - 13.4 years). Wear time was an important cause of response to treatment, including an interaction with TRC status. Baseline Cobb angle and age were also meaningful causes of response. The prediction model was accurate (79%) and had good specificity (81%) and moderate sensitivity (68%) and an area under the receiver operating characteristic curve (AUC) of 0.81. Additionally, we were able to independently confirm previous estimates of treatment efficacy, with an odds ratio around 2.0. CONCLUSIONS: Our study showed the explicit causal effects of wear time, and baseline skeletal maturity, Cobb angle and age. The risk model we developed can be used for counseling patients and their families regarding TLSO wear and expectations for outcome.

Is nighttime bracing effective in the treatment of adolescent idiopathic scoliosis? A meta-analysis and systematic review based on scoliosis research society guidelines.

PURPOSE: Standard treatment for skeletally immature adolescents with moderate Adolescent Idiopathic Scoliosis (AIS) is a full-time spinal orthosis. However, adherence to full-time wear (≥ 18 h/day) is often challenging for these patients. Nighttime bracing is an alternative option that may improve patient adherence and/or satisfaction. This systematic review and meta-analysis assessed the effectiveness of nighttime bracing in patients with AIS. METHODS: A systematic review of studies evaluating nighttime bracing was performed. PubMed, Medline, Embase, CINAHL and Cochrane library databases were searched (01/1975-03/2020); two reviewers assessed eligibility. Eligible articles were peer reviewed, in English, and reported outcomes for patients who met Scoliosis Research Society (SRS) criteria. The primary outcome was curve progression ≥ 6°. Pooled progression rates were calculated from random effects meta-analyses with inverse-variance weights; 95% CIs were calculated. RESULTS: Nine studies (n = 595) were included. The overall pooled progression rate to ≥ 6° was 40.7% (95% CI: 30.4-51.5%). The pooled progression rate to surgical magnitude was 24.8% (95% CI: 4.5-53.6%). The most successful outcomes were in subjects with thoracolumbar/lumbar curves and subjects who initiated bracing at Risser 1/2 (pooled progression rates were 27.8% (95% CI: 17.0-40.0%) and 16.5% (95% CI: 11.7-21.8%), respectively). Univariate sub-analyses were conducted due to sample sizes. CONCLUSIONS: Progression rates in patients with primary thoracolumbar/lumbar curves and in patients who initiated nighttime bracing at Risser 1/2 were comparable to published progression rates for full-time bracing, indicating that nighttime bracing may be equally effective for these patients. However, the strength of these conclusions is limited by the sample size and the overall quality of included studies.

Validation of a miniature thermochron for monitoring thoracolumbosacral orthosis wear time.

STUDY DESIGN: Prospective validation study. OBJECTIVE: To establish the accuracy of miniature thermochrons for estimating thoracolumbosacral orthosis (TLSO) wear time in patients with adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: There has been an emphasis in recent years on measuring wear time as opposed to using subjective methods such as relying on the patient or parent estimation. By measuring the amount of time that was spent in the orthosis, uncertainty is reduced and the validity of the research is improved. Several types of devices have been employed for direct monitoring of orthosis wear time including strap tension monitors, pressure sensors, and temperature-time sensors (thermochrons). Direct monitoring studies have shown that relying on patient or parent report is inaccurate; the patient/parent report is clearly biased towards overestimation of wear time. METHODS: Three miniature thermochrons (DS1922L iButton, Maxim Integrated Products, Inc., Sunnyvale, CA) were mounted underneath padding in the TLSOs of 7 participants diagnosed with adolescent idiopathic scoliosis. The participants wore their TLSO for 1 month. During this time, participants kept meticulous records of wear time in diaries. An algorithm was developed to automatically detect donning/doffing of the orthosis, and the results of the data reduction algorithm were compared with the diary (gold standard). RESULTS: Total wear time accuracy was 98.5% (0.37 hours/day), while the precise timing of donning/doffing was 92% accurate. CONCLUSION: An inexpensive, commercially available miniature thermochron and a simple robust algorithm can estimate TLSO wear time to a high degree of accuracy. This method is suitable for large-scale prospective studies examining the efficacy of bracing in adolescent idiopathic scoliosis, which remains a topic of controversy.

Calix[4]arene, calix[4]resorcarene, and cyclodextrin derivatives and their lanthanide complexes as chiral NMR shift reagents.

Calix[4]arenes, calix[4]resorcarenes, and anionic cyclodextrin derivatives were examined as chiral NMR solvating agents. The calix[4]arenes were prepared by attachment of amino acids through the hydroxyl groups of the phenol rings. Chloroform-, methanol-, and water-soluble derivatives were prepared and tested with a range of substrates. Chloroform-soluble chiral calix[4]resorcarenes were prepared by attachment of chiral primary and secondary amines and examined in NMR applications with a variety of substrates. Sulfated and carboxymethylated beta-cyclodextrin are effective at causing enantiomeric discrimination in the (1)H NMR spectra of organic cations. Lanthanide ions associate at the carboxymethyl groups and cause sizeable shifts and enhancements in enantiomeric discrimination in the spectra of organic cations. The enhancements caused by the lanthanide ion are large enough that much lower concentrations of the cyclodextrin can be used as compared to conventional analyses.