We will be performing site maintenance on AAOS.org on February 8th from 7:00 PM – 9:00 PM CST which may cause sitewide downtime. We apologize for the inconvenience.

Stuart L. Weinstein, MD

AAOS Now

Published 3/1/2015
|
Jennie McKee

OREF Award Honors Scoliosis Research

Decades of study yield important data to guide AIS treatment

“Our research has profoundly changed clinical practice for the physicians treating patients with adolescent idiopathic scoliosis (AIS) and has given patients and parents a solid evidence base upon which to make informed, patient-centered choices,” said Stuart L. Weinstein, MD, Ignacio V. Ponseti Chair and professor of orthopaedic surgery at the University of Iowa.

Dr. Weinstein and Lori A. Dolan, PhD, have devoted their careers to following AIS patients throughout childhood, adolescence, and adulthood. Their paper, “The Evidence Base for the Prognosis and Treatment of Adolescent Idiopathic Scoliosis,” summarizes that research and was selected as the winner of the 2015 Orthopaedic Research and Education Foundation (OREF) Clinical Research Award.

“Our early work disputed the notion that all types of scoliosis have a grim prognosis,” wrote Dr. Weinstein. “We were able to let parents and patients know that AIS is a unique entity whose natural history is very different than that of early onset scoliosis or scoliosis caused by other etiologies.

“We now know,” he continued, “that untreated AIS does not lead to early disability or death, or the inability to have a normal life.”

Long-term follow-up
To shed light on outcomes for AIS patients, Dr. Weinstein and colleagues built upon research conducted by University of Iowa researchers Ignacio V. Ponseti, MD, and Dennis K. Collis, MD, by performing a 40-year follow-up study of untreated AIS patients. Over the long term, they concluded, pulmonary symptoms can develop in patients with large thoracic curves; however, noted Dr. Weinstein, “AIS was not associated with clinically important limitations in vital capacity or forced expiratory volume, except in patients with large, thoracic curves, approaching Cobb angles of 100 to 120 degrees.”

When he and his colleagues studied this same cohort at 50-year follow-up, they found no evidence associating AIS with greater mortality rates.

“By closely studying this group of patients for more than 50 years, we have learned that patients with untreated AIS can function well as adults, become employed, get married, have children, and grow to become active older adults,” noted Dr. Weinstein. “Unfortunately, patients with untreated AIS can develop increased back pain and significant deformity. The cosmetic aspect of this condition cannot be disregarded.”

Bracing effectiveness
Drs. Weinstein and Dolan have also conducted long-term follow-up studies to help provide high-quality data on the effectiveness of bracing in AIS patients.

In one study of patients treated with the Milwaukee brace—an orthotic that first came into use in the 1940s—they found that 42 percent of patients had eventually undergone arthrodesis, and 48 percent of patients had curve progression. Thus, they were unable to conclude that bracing had altered the natural history of AIS.

After the University of Iowa and other institutions moved from the Milwaukee brace to thoracolumbosacral orthoses (TLSOs) in the 1980s, Dr. Weinstein and colleagues conducted a study of patients who had been treated with the Rosenberger TLSO brace. They found that more than half of these patients had curve progression and one-third underwent arthrodesis for curves greater than 50 degrees prior to reaching skeletal maturity.

Stuart L. Weinstein, MD
Radiograph of a patient with adolescent idiopathic scoliosis.
Courtesy of Stuart L. Weinstein, MD

“The results of these papers caused us to question not only our clinical practice, but also the evidence base for bracing,” noted Dr. Weinstein. “We also questioned the use of curve progression as the definition of failure, as curve progression, per se, is not associated with suboptimal health and functioning in the future.”

Due to these concerns, Dr. Weinstein and colleagues conducted a systematic review of the bracing literature, including 15 primary studies of bracing and 3 studies of patients treated by observation. The surgery rates varied greatly across these studies, with 1 percent to 76 percent of patients who were treated with a brace eventually progressing to surgery.

Conducting BrAIST
Drs. Weinstein and Dolan then designed and performed the Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST), a randomized, controlled trial that compared bracing to watchful waiting.

BrAIST combined many different components that had not yet been included in a single bracing study, such as simultaneous comparison of treated and untreated subjects; comprehensive psychosocial, clinical, and radiographic testing; and independent, blinded determination of outcomes. The study was conducted in 25 institutions across the United States and Canada; its primary goal was to compare the risk of curve progression to 50 degrees or greater—a common indication for surgery—in patients who received brace treatment compared to patients who were simply observed.

Of the 242 patients in the primary analysis, 116 patients were in the randomized cohort, and 126 patients were in the “preference cohort,” meaning that they were given their choice of brace or no brace, according to their preference. In all, 146 patients received a brace, and 96 patients were simply observed.

The investigators found a treatment success rate of 72 percent in the bracing group, compared to just 48 percent in the observation group. Patients in the bracing group who wore the brace for an average of at least 12.9 hours per day had a treatment success rate of 90 percent to 93 percent.

This study provided Level 1 evidence that bracing is effective and can significantly decrease curve progression to a surgical threshold. When the brace was worn for at least 13 hours a day, there was a success rate of more than 90 percent. BrAIST has already started affecting medical practice, and may change future health policy, including reassessment of the U.S. Preventive Task Force’s current recommendation that screening of asymptomatic children for scoliosis is unwarranted.

“These efforts, if successful, should lead to a decrease in the numbers of surgeries, which we know now can definitely be prevented in a significant percentage of patients with AIS,” said Dr. Weinstein.

BRAIST was supported in part by the National Institutes of Health’s National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Don’t miss the Ceremonial Meeting
Attendees of the 2015 AAOS Annual Meeting in Las Vegas are encouraged to attend the Ceremonial Meeting on Thursday, March 26, to see the presentation of the Kappa Delta and OREF Clinical Research Awards. The Ceremonial Meeting will begin at 10 a.m. and will be held in the Venetian/Sands EXPO, Venetian Ballroom E.