Dr. Ian Johnson of Saint Agnes Care Brain & Spine Institute shows part of the model he uses to demonstrate the artificial disc joint. Thanks to breakthroughs in medicine and practices, surgeons like Johnson can replace joints in the neck on an outpatient basis.
Written by Donald A. Promnitz
For spinal surgeons like Dr. Ian Johnson, treating a patient with a herniated disc in their neck was an issue with little prospect of an ideal outcome.
If a disc in the cervical spine pressed down on the nerve, a doctor’s first choice is to treat the situation conservatively with medication, but if necessary, surgery will be performed. Traditionally, the primary method was a procedure known as anterior cervical discectomy and fusion (or ACDF), which involved removal of the patient’s disc, and putting in something that would cause the bones to become one.
Over the past decade, however, artificial disc replacement surgery has been catching on in the medical community. A minimally invasive procedure, it involves putting a new disc into the patient’s neck, allowing for greater mobility after the surgery is complete.
“When this was not an option, then patients did have more stiffness of their neck and some more neck pain on occasion,” Johnson said. “However, with the artificial disc, it allows for just a little bit of movement. It’s changed the outcomes.”
At the Saint Agnes Care Brain & Spine Institute in Fresno, Johnson performs roughly 30 to 50 of these procedures a year. And while artificial disc replacement can be found throughout the entire Central Valley, Johnson stated that Saint Agnes is the only group to offer it on an outpatient basis. Still, some patients may have anatomical issues that make the joint unable to fit. In these patients, the traditional ACDF approach is warranted.
There are a number of artificial discs currently being manufactured, and at Saint Agnes, the most commonly used disc is the Mobi-C by Zimmer Biomet Holdings, Inc.(formerly LDR Global). Consisting of two metal plates and a plastic insert in the middle of the device, the Mobi-C is inserted between the patient’s vertebrae. Typically, this procedure takes about an hour, and is a relatively easy operation, despite the anxiety a patient may feel about surgery on their spine.
“Scary for you,” Johnson laughed. “Not for us.”
Johnson, however, is not the only doctor performing outpatient replacements for Saint Agnes. At theCare Orthopaedic Institute,Dr. Matthew Knedel has been on the staff since September, specializing in hip and knee joints, which make up approximately 90 percent of replacement procedures nationwide and are performed predominantly on the elderly.
For hips, doctors will typically perform starting at the patient’s thigh. This used to mean a foot-long incision, but due to breakthroughs in minimally invasive surgery, this cut has been reduced to four inches. Instead of cutting the muscle, Knedel can now spread it, reducing pain and contributing to faster healing periods. Meanwhile, smaller cuts are now being performed on the knee as well, and the procedures in both areas are leading to more active lives after surgery.
The hips used by Knedel are created by DePuy Synthes, a subsidiary of Johnson & Johnson, while the knee joints are the product of Smith & Nephew plc, a British company. This joint is made of special materials for patients who have allergies to metals, while the thigh portion of the DePuy hip contains a special ceramic material known as oxinium.
Regardless of breakthroughs for the hip, knee and neck, however, Knedel added that at the end of the day, the biggest game-changer has not been the material itself, but the methods being used in the field.
“I think most of it actually is surgical technique,” Knedel said. “So there are some newer implants that do a little better and last longer… but really, it’s the technique of surgery that has changed this, not the actual implants.”
For further information, Johnson and Knedel can be reached at 450-BACK and 450-BONE.