A new bone classification system developed by researchers at the Yale Department of Orthopaedics and Rehabilitation to assesses bone maturity in patients with scoliosis will aid physicians in making treatment decisions.
A new study published in the Journal of Bone and Joint Surgery shows how these researchers developed and assessed this system to evaluate proximal humerus bone maturity in children with scoliosis, a curve in the spine. The x-ray of the proximal humerus, the upper part of the bone of the arm that meets the shoulder, is used to determine the maturity or “bone age” in children, which is critical component in making an accurate treatment plan.
Bones mature at different rates in children, depending on each child's specific physiology. Determining how far along a child may be in their growth is important detective work done by physicians. Orthopaedists treating scoliosis, typically look to determine “peak height velocity” – the point at which bone tissues are growing at the maximum rate, because this is the time when scoliosis is most likely to appear and/or increase in severity. The existence and severity of scoliosis can be measured on a standard spine x-ray.
Knowing how close a child is to peak height velocity can make the difference in which treatment is prescribed.
“The goal for us when we see patients is to determine whether their bone age is prior to, at, or past peak height velocity,” says Professor Daniel Cooperman, MD, an author on the study. “If they are prior to or at peak height velocity, they are at risk for their scoliosis becoming more severe and they may benefit from treatment. If they are after peak height velocity, their curve is unlikely to worsen, so treatment is seldom necessary. As treatment can be a bulky back brace or even surgery, this information is vital when treating scoliosis.”
Currently, most physicians use the Sanders hand system, a classification system where doctors examine hand x-rays to determine the bone age of a patient. The hand is used to determine bone age because there are many different bones in the hand and they all change x-ray appearance with growth, and its appearance can help to determine the maturity or “bone age” of a child. “However, there is radiation associated with taking the x-ray. Additional radiation is never a good thing if it can be avoided,” says Cooperman. “We must also consider the cost of taking the x-ray and the cost of interpreting it. Our technique uses spinal x-rays already obtained by physicians to look at the curve of the spine.” Those newer x-rays already capture the proximal humerus and can be used to judge the maturity of the child. The system has twofold benefits: less radiation for young patients and cost-savings, Cooperman says.
When we started this study, we looked for something that could determine bone age using information that was already available on the spine x-ray. That would be beneficial to patients and would not increase the cost of the patient’s care
Daniel Cooperman, MD
The researchers analyzed 414 randomly selected x-rays from 216 modern-day patients with scoliosis to test their new classification system, comparing the radiographs to 606 proximal humeral x-rays for 70 children from a historical collection. What they found was that their new system produced accurate results. As an added benefit, the new system provides a cost-savings to healthcare providers and patients.
“When we started this study, we looked for something that could determine bone age using information that was already available on the spine x-ray. That would be beneficial to patients and would not increase the cost of the patient’s care,” Cooperman says.
The paper was first introduced to the Scoliosis Research Society earlier this year where it received the Hibbs Award for best clinical paper. Cooperman said he was honored to be a part of the research team winning the award, and hopes the new system provides a benefit to the surgeons and patients.
“We’re truly excited to offer this system to the orthopaedic community,” Cooperman says.