Q. I broke my left femur when I missed a transfer to my chair. The fracture runs straight across and the bone is lined up, but my orthopedist doesn’t want to fix it surgically because the break is too close to the knee to repair with a rod, and screws with a plate would likely pull out of my osteoporotic bone. Instead, he prescribed a soft splint that keeps my fracture aligned and enables me to check my skin.
An eight-week follow-up X-ray didn’t show any signs of healing, so my orthopedist wrote a prescription for a PEMF bone growth stimulator. He said sometimes bone growth stimulators will jump-start the healing process. Now I’m waiting to see if my insurance will cover it.
What is a PEMF bone growth stimulator? How does it work? Have you heard of other people with SCI using one to heal fractures?
— Sarah, 47, T6 complete para for 30 years
A. Sarah, I had a similar fracture 22 years after my T10 complete SCI. While throwing a tennis ball for my dog, I took a forward tumble out of my chair. It was the kind of tumble I’d taken hundreds of times over the years — only this time it resulted in a fracture just above my right knee. When a follow-up X-ray six weeks later didn’t show any healing, my orthopedist said, “Sometimes these fractures in SCI fail to heal, and you might end up with an extra knee joint.” This was not an option.
He said a bone growth stimulator might help and wrote me a prescription. After using the stimulator for eight weeks, another X-ray showed the fracture had completely healed.
Unfortunately, leg fractures are common for those of us with long-term SCI. Many studies, including one from 2015 published in Spinal Cord, found that chronic SCI often leads to long bone fractures of the lower extremities, which are often the result of a “low energy insult,” such as a fall out the chair while wheeling or a failed transfer.
For in-depth answers to your questions, I turned to Dr. Douglas Garland, a retired orthopedic surgeon and former director of neurotrauma at Rancho Los Amigos Rehab Center. He spent over 20 years researching osteoporosis and fractures in SCI and has many peer-reviewed papers on the subject. Garland has also studied and published research on PEMF and fracture.
When a bone breaks, the body sends out a low-level electrical field that signals the immune system to deliver healing materials to the area of the fracture. PEMF stands for “pulsed electromagnetic field,” and a bone growth stimulator is an external device that sends pulses of electromagnetic frequencies to stimulate production of the proteins and growth factors needed to heal bones. In essence, it is like a loudspeaker telling the body, “We need healing materials here, now!”
The portable device is about the size of a TV remote and has a wire that goes to a pad shaped to fit over the fracture area. The pad is held in place with a Velcro strap. The device is used for approximately four hours a day until the fracture is healed.
Garland suggests that the prevalence of low energy fractures goes hand-in-hand with the prevalence of progressive osteoporosis among those with chronic SCI.
Osteoporosis starts when a person loses 32% of their bone mineral density. On average, a person with a complete SCI injury loses 28% of the BMD in their legs within the first year and a half of their injury. By two years post-injury, BMD decline slows to a loss of 1% a year. After 20 years, the legs of the average person with SCI have lost 46% BMD. This is close to the “fracture breakpoint” of 50% of BMD loss, after which a simple twist or fall is likely to break a bone.
Garland’s early studies found that lower extremity fractures have a significantly higher rate of delayed union for people with SCI, meaning the fracture takes longer to heal or fails to heal. A 2018 study in the Journal of Spinal Cord Medicine found similar results. Depending on the fracture, surgery on osteoporotic bones is difficult because screws and hardware don’t get a solid fixation and can loosen and pull out. “This is where a PEMF bone stimulator is a very viable alternative,” says Garland.
In a 1991 study on PEMF, Garland followed 139 people with established non-union fractures and found that using PEMF at least three hours or more each day produced an 80% success rate of healing. A 2012 study in the Journal of Orthopedic Research reports similar results. Other recent studies support the use of a bone growth stimulator for healing and point out the need for conducting larger and more definitive trials. Garland explains that doing larger trials is difficult because most orthopedists operate on these fractures in spite of the complication risk.
Because of the added complications that come with SCI and osteoporosis, sometimes a bone growth stimulator is used at the onset of a fracture. Five years ago, Candace Cable, then 60, had a slow-motion fall into a kneeling position while transferring out of a friend’s car. After 40 years with a T10 complete injury, she knew the signs of a leg fracture. “At first, I thought I was OK, but within two hours I felt sick, my heart was racing and my blood pressure spiked,” she recalls.
A trip to the ER and X-rays confirmed a hairline fracture in the top of her shinbone. X-rays done at her orthopedist’s office a few days later showed the crack was widening, so she was prescribed a straight splint. Cable suggested using a bone growth stimulator, and her orthopedist agreed. Once she got the stimulator and started using it, her fracture healed in two months.
Although research on the benefits of bone growth stimulators is inconclusive, the evidence for healing non-union fractures is strong enough that they have been covered by Medicare since 1999. Remember that, like many specialists, orthopedists may not have experience in treating people with SCI. So it benefits you to know treatment options, including bone growth stimulators, to present and discuss. That way you can ensure you have the best odds of healing successfully.
• Bone Loss at the Knee in Spinal Cord Injury, archive.scijournal.com/doi/abs/10.1310/KP8E-K7H7-6072-G8GB
• Long bone fractures in persons with spinal cord injury, ncbi.nlm.nih.gov/pubmed/25987003
• Lower extremity fractures in patients with spinal cord injury characteristics, outcome and risk factors for non-unions, ncbi.nlm.nih.gov/pubmed/28545316
• Pulsed electromagnetic fields for the treatment of tibial delayed unions and non-unions. A prospective clinical study and review of the literature, ncbi.nlm.nih.gov/pubmed/22681718
New Mobility Coverage
• Fracture Risk and Treatment Options with SCI, newmobility.com/2016/04/fracture-risk-treatment-options-sci
• Osteoporosis: Avoiding the Breaks, newmobility.com/2009/12/osteoporosis-update