3 Spine Products to Know With Neurosurgeon Dr. James B. Macon

James B. Macon, MD, is a neurosurgeon based in Framingham, Mass., who performs surgical procedures at several west suburban Boston hospitals. We sat down with Dr. Macon, whose practice is dedicated to spine and pain surgery, and asked him to discuss three new spine products which have benefited his practice.

1. Holmed Swivel Port System
The Holmed Swivel Port System, designed by South Easton, Mass.-based Spine Surgical Innovation (with Dr. Macon serving as the design consultant), was developed to give spine surgeons minimally invasive access to the spine while cutting down on potential morbidity associated with some muscle dilator tubular access systems, Dr. Macon says.

In other systems, “the initial placement of the dilator — in order to achieve access to the spine — usually involves putting a sharp K-wire down to the spine,” he says. “That K-wire, if it’s not watched very carefully under x-ray control with fluoroscopy, can get pushed into places you don’t want it to go such as into the spinal canal or into a nerve root. Also, the inner dilator is fairly small — small enough to go into the spinal canal and cause nerve root or spinal cord injury.”

The Swivel Port System eliminates both the use of the K-wire and dilators and improves spinal access, says Dr. Macon. The way the device works is that following an incision, a blunt instrument such as a Penfield dissector is used to split the muscle, as opposed to the use of a K-wire. After the dissector has reached the spine, biplane fluoroscopy confirms the proper level and trajectory for the port placement. Once the muscle is split, a Cobb periosteal elevator is inserted to scrape the muscle and ligament off the intended docking area for the port that will provide access to the spine for the surgeon.

The Swivel Port System works like a hand-held retractor when closed and becomes a tube when opened. The retractor is placed through the muscle split down to the bone. What makes the Swivel Port System different from other systems is that rather than using dilators to obtain access to the spine, this system uses blades that are opened by rotating (swiveling) the port base. The blades on the port have a flange which prevents the port from migrating out once positioned. , Dr. Macon says.

“We open the port by turning the blade at the port base using a ring-type device that fits over the port,” he says. “Once the port is open, then we put in expander blades, and they allow increased exposure and minimize muscle creep so we can see more than just a straight cylindrical tube and yet you have eliminated the dilator and the K-wire problems, so it is safer and very fast to insert. You just split the muscle, put it in and you open the port with the ring. It’s both safe and provides excellent exposure.”

In addition, the port can be fixed to the operating table with the handle attached to a flexible arm. This arm can then be firmly attached to an operating table, allowing a surgeon to position the trajectory of the port in different angles, even changing the trajectory angle during a procedure. This allows a surgeon to perform procedures such as multiple-level decompressions through one port placement, Dr. Macon says.

The Swivel Port System includes a number of retractors with blades of varying sizes which allow for a wide range of procedures, he says. These include minimally invasive posterior decompressions in the lumbar spine such as microdiscectomies and foraminotomies as well as large decompressions such as two-level laminectomies or fusions and pedicle screw fixations from the postlateral approach.

While the long-term outcome might not be different from other open approaches, Dr. Macon has found that the minimally-invasive approach has much less morbidity in the short term. He also notes that a particularly interesting trait about the Swivel Port System is that it actually has greater benefits for obese patients. “In the Swivel Port technique, there’s no change in the incision size — the port just gets longer to accommodate the depth of the incision,” he says. “Those patients who are larger benefit the most from this particularly procedure because they have much smaller incisions and less risk of wound problems than when standard open exposures are used. It’s really a paradox that the larger the patient the smaller incision is better. This is one of the surprising benefits of the minimally invasive approach to the spine.”

2. SpineJet HydroDiscectomy
The SpineJet HydroDiscectomy was developed by HydroCision, which is based in North Billerica, Mass. This device essentially allows a surgeon to make incisions using a water jet. “The SpineJet MicroResector can be placed in a disc space for removing discs either percutaneously through a cannula or through the Swivel Port,” he says The SpineJet Microresector will perform a microdiscectomy through a very small incision with a minimal annulotomy.

“The HydroCision discectomy is an interesting adjunct for a surgeon wanting to perform outpatient spine surgery for contained lumbar disc protrusions,” Dr. Macon says. “I have successfully used this technique for lumbar microdiscectomies.”

Dr. Macon also finds the use of HydroCision’s SpineJet XL curette beneficial. He uses this device to prepare the disc space for receiving an inter-body fusion when performing lumbar transforaminal interbody fusions through the Swivel Port.

“There are several different handles which you can use for different parts of your operation,” he says. “I developed a bayonet handle for the curette and microdiscetomy device which allows use through the Swivel Port without obscuring your vision. Initially, their system was just a straight handle that blocked your vision when used with tubular access systems.”

3. Allen Spine System
The Allen Spine System developed by Allen Medical Systems in Acton, Mass., is an extension attachment that connects to a standard operating room table and allows a surgeon to perform spine procedures in an optimal position with no interference of the fluoroscopic imaging required for accurate placement of the Swivel Ports, Dr. Macon says. The Allen Spine extension attachment also offers excellent padding for patients which decreases the likelihood of pressure sores and other complications of lying in a prone position for spine procedures.

“The Allen Spine System is a very good product for an outpatient center because it is cost-efficient for the facility,” Dr. Macon says. “Because it’s not a whole table and can be attached to the operating table we already have, it is less expensive than competing products.”