"The back is not like any other joint in the body. It follows different rules - Learn the rules and you will rule the back." - Stuart McGill"In between the vertebrae of the human spine are 23 Oreo-sized, cartilage-filled discs that hold the vertebrae together and allow for spine movement," according to Brigham Young University. The soft, collagen-rich shock absorbers in our backs, known as intervertebral discs, both add to our height (a full quarter of the spinal column's total length) and cushion our vertebrae from contacting one another, reads an article from the new and emerging technology news site Gizmag.
Unfortunately, aging, accidents and overuse can damage them and lead to the costly phenomenon of chronic back pain. Replacement of damaged discs, rather than spinal fusion, is an option that's growing in popularity, especially because it helps maintain mobility in the spine.According to the release:
While the discs are critical for movement, they can become the source of back pain when they degenerate or herniate. This major health problem affects 85% of Americans and drains $100 billion from the U.S. economy each year.Currently, the most common surgical treatment for chronic low back pain is spinal fusion surgery. Fusion replaces the degenerative disc with bone in order to fuse the adjacent segments to prevent motion-generated pain.
The principle role of the skeleton is to provide structural support for the body. While the skeleton also serves as the bodies mineral reservoir, the mineralized structure is the very basis of posture, opposes muscular contraction resulting in motion, withstands functional load bearing, and protects internal organs. Although the mass and morphology of the skeleton is defined, to some extent, by genetic determinants, it is the tissue's ability to remodel --the local resorption and formation of bone -- which is responsible for achieving this intricate balance between competing responsibilities. - from The Use of Bone Substitutes in Spine Surgery: A State of the Art Review:Unfortunately, patient satisfaction with fusion surgery is less than 50 percent.
A research report on a new biomedical device to surgically treat chronic back pain will be published in a study in a forthcoming issue of the International Journal of Spine Surgery. The article highlights the mechanism’s ability to facilitate natural spine movement via an artificial spinal disc that duplicates the natural motion of the spine.
The release says that, the artificial disc was conceived by engineering professors Anton Bowden and Larry Howell along with Peter Halverson. It will be developed to market by Crocker Spinal Technologies.
“Low back pain has been described as the most severe pain you can experience that won’t kill you,” said Bowden, a biomechanics and spine expert. “This device has the potential to alleviate that pain and restore the natural motion of the spine – something current procedures can’t replicate.”The solution researched by the team, and now being developed, consists of a compliant mechanism that facilitates natural spine movement and is aimed at restoring the function of a healthy spinal disc.
Compliant mechanisms are jointless, elastic structures that use flexibility to create movement. Examples include tweezers, fingernail clippers or a bow-and-arrow. Howell is a leading expert in compliant mechanism research, according to the news release.
“To mimic the response of the spine is very difficult because of the constrained space and the sophistication of the spine and its parts,” Howell said. “A compliant mechanism is more human-like, more natural, and the one we’ve created behaves like a healthy disc.”The team built prototypes, machine tested the disc and then tested the device in cadaveric spines. The test results show the artificial replacement disc behaves similarly to a healthy human disc.
“Putting it in a cadaver and having it do what we engineered it do was really rewarding,” Howell said. “It has a lot of promise for eventually making a difference in a lot of people’s lives.”There is talk among practicioners about how fusion, which is the current standard of care for back pain, leaves a lot to be desired. Disc replacement is an emerging alternative to fusion that has the potential to make a significant difference in the lives of millions.
This innovation is a radical step forward in the advancement of disc replacement technology.