Regenerative medicine in spine surgery is on the rise, and there are many biologic tools that physicians say could be used more in the field.
Six spine surgeons share their thoughts on the most underutilized biologic tools.
Note: Responses were lightly edited for clarity.
Question: What is the most underutilized biologic tool in spine surgery?
Benjamin Elder, MD, PhD. Mayo Clinic (Rochester, Minn.): The most underutilized biologic tool in spine surgery is optimizing the patient's bone density prior to any instrumented procedure. A significant portion of patients getting spinal fusions have osteoporosis, but only a small portion are pretreated before surgery. We need to use the body's own biologic processes with anabolic medications in order to harness the body's own power to strengthen the bone. This improvement will be far more powerful than any additional biologic or mechanical tool for spinal fusion.
Additionally, we aren't capturing all patients who present with a fragility fracture (i.e. compression fracture) for referral for bone health optimization, and the greatest risk for a spine fracture is having a history of a prior spine fracture.
Tiffany Perry, MD. Cedars Sinai Spine Center (Los Angeles): Biologics in spine tumor surgery is a key area that needs to be developed. One of the questions I have when I operate on a metastatic tumor to the vertebral body is what should or can I use that is safe for biologics to aid in arthrodesis? Will this biologic survive radiation that the patient will get post-op? Will this biologic potentially promote recurrence of tumor in the bone? Development of a safe biologic to utilize in spine tumor surgery for arthrodesis that will survive the chemotherapy, immunotherapy and radiation post-operatively would be key as patients with metastatic disease are living longer with these diseases.
David Skaggs, MD. Cedars Sinai Spine Center (Los Angeles): I think the most underutilized biological tool in spine surgery today is the iliac crest bone graft. In the past, studies in both children and adults have demonstrated the standard open way of taking iliac crest bone graft often led to chronic pain, numbness or pain due to injury to cutaneous nerves, and donor site infection, so it has fallen out of favor.
New, less invasive ways of harvesting bone graft that do not violate the cortex allow us to harvest the best bone graft, with seemingly little risk of pain or infection. For fusions involving the lower lumbar spine, I do not hesitate to use an Acumed bone graft harvester. The harvester can be used through the surgical skin incision, then through an extra-fascial approach we identify the posterior superior iliac spine. Next, I rongeur down to cancellous bone and take the graft, being careful not to violate cortex and, especially not, the SI joint. I generally irrigate the site, fill it with marcaine and epinephrine, then stuff the whole with Gelfoam soaked in thrombin.
Postoperatively, a great majority of the patients cannot even tell me which side the bone graft was taken from.
William Taylor, MD. University of California San Diego Health: This is clearly the ability to affect the internal biology of the degenerative disc. There are a number of companies outside of the classic stem, cell attempt, Notogen and Discseal are two excellent examples. These procedures suffer from lack of continued scientific inquiry and the clear pathway towards appropriate patient care. Many spine surgeons are reluctant to give up fusions and or artificial disc as a treatment or as many pain clinics have decreased and totally abandoned the use of a discogram. To my mind, this is a missed opportunity as a treatment on the continuum of degenerative disease prior diffusion.
Vijay Yanamadala, MD. Hartford (Conn.) HealthCare: Native bone marrow is probably the most underutilized biological tool today. We tend to use the local autograft from a laminectomy as surgeons, and then we augment with cadaveric bone or bioactive bone matrix products in most surgeries. However, the power of local bone marrow (harvested for example from pedicle screw holes) is good as or better than most bioactive products.
Christian Zimmerman, MD. St. Alphonsus Medical Group and SAHS Neuroscience Institute (Boise, Idaho): The "new" gold standard for biologics in spinal arthrodesis are allograft bone products which temporally replaced the tried-and-true autologous standard of
iliac bone harvestation and usage. When queried, patient comfort, time allocation or coding/reimbursement issues and training biases have been posited as the response.