Patients' Guide to Bone Growth Stimulation
Improving spinal bone healing in at-risk patients
Bone growth stimulation (BGS) is a therapy your surgeon may prescribe following a spinal fusion procedure. A bone growth stimulator is a supplemental device worn following cervical (neck) or lumbar (low back) spine surgery. BGS may be utilized to help spinal bone fuse after a fusion procedure or as a treatment for failed fusion. Naturally, you have questions about this technology.
The information provided in this patient guide can help you learn:
- How bone heals
- Risk factors for a poor or failed fusion
- Role of bone growth stimulation in spine fusion aftercare
- Questions to ask your spine surgeon
About spinal fusion
Spinal fusion is performed to stop movement of the spine and neurologic deficit. During the procedure two or more vertebral bodies are joined together using instrumentation and bone graft. Spinal instrumentation includes rods, screws, plates, and interbody devices (implants). Bone graft may include your own bone (autograft), donor bone (allograft), or other types of graft.
Bone graft helps stimulate new bone to grow through three stages:
- Inflammatory stage: cells begin to form new tissue
- Repair stage: small blood vessel ingrowth starts
- Remodeling stage: bone structure becomes strong
Spinal instrumentation creates an internal cast, which allows the inflammatory process to stimulate bone healing. With time, new bone grows into and around the implanted instrumentation healing into a solid construct.
Some patients are at-risk for spinal fusion to fail. A failed fusion is also called pseudarthrosis or non-union. Pseudarthrosis and non-union are medical terms your surgeon may use to define a fusion problem.
Common spinal problems treated surgically with fusion include:
Cervical (neck) / Lumbar (low back)
- Degenerative disc disease
- Herniated disc
- Spinal stenosis
- Adult degenerative scoliosis
How can a bone growth stimulator help spinal fusion?
A BGS sends low level electrical signals to the fusion site. The electrical signals activate the body's natural bone healing process, which may be impaired in at-risk patients.
Bone growth stimulation has been used for decades to help bone heal.
Over 50 years ago scientists discovered that low-level electrical fields stimulate the body's bone-healing process. Other advances included finding different types of energy that stimulate bone growth, electromagnetic coil technology and simply better devices— supported by scientific and clinical research—have improved bone healing in patients who undergo spinal fusion.
Different types of bone growth stimulators
All bone growth stimulators are different. Certain types are designed to be surgically implanted (internal BGS) and other stimulators are worn outside the body (external BGS). Other differences include the type of electrical current or magnetic field generated by the device and how stimulation is transmitted to the spine.
The types of bone growth stimulation devices approved by the U.S. Food and Drug Administration (FDA) use direct current1,capacitive coupling2, combined magnetic fields3 or pulsed electromagnetic fields.4-6 Overall, it has been proven that fusion success can be increased in a patient treated with BGS compared to surgery without the use of BGS.