What’s New in the Field of Spinal Fusion Surgery

Orthopaedic & Spine Center
Dr. Jeffrey Carlson

Jeffrey R. Carlson, MD

Spinal fusion surgery has been the standard of care for treating spinal disorders for the past 120 years.  The basics of fusion surgery include making previously mobile bones in the spine not move anymore.  This is process is similar to that used in other bone fracture surgery.  Originally, bone fractures were stabilized with casts made of plaster, but as surgical technique has improved, internal metal implants provided a more secure method of maintaining the boney alignments, without movement, while healing.  The rationale for the surgical fixation of fractures was the impetus for development of surgeries that would provide for stability in the spine using the same techniques.

Spinal fusion surgery has been the standard of care for treating spinal disorders for the past 120 years.  The basics of fusion surgery include making previously mobile bones in the spine not move anymore.  This is process is similar to that used in other bone fracture surgery.  Originally, bone fractures were stabilized with casts made of plaster, but as surgical technique has improved, internal metal implants provided a more secure method of maintaining the boney alignments, without movement, while healing.  The rationale for the surgical fixation of fractures was the impetus for development of surgeries that would provide for stability in the spine using the same techniques.

In the early 1900’s, patients with spinal tuberculosis that affected their disc spaces, would become bent over as the infection weakened the spinal discs and adjacent bones.  Fracture fixation technology was applied to the spine to keep the bones from deforming and patients were able to heal from their tuberculosis infection without spinal deformity.  The initial techniques for spinal fusion used the same type of screws and plates that were used in fracture surgery.

Early spinal fixation techniques typically placed self-donated or cadaver bone in the disc space or near the bones to be fused, without any other instrumentation to hold the bones in place.  This was done with the intention that the natural bone would use the newly inserted bone as a scaffolding upon which to cross the spinal disc segment and fuse the bones together as one bone.  After this bone insertion surgery, patients would be placed in external braces to try to keep the bones as still as possible, in order to give them the best chance to fuse. As fracture treatment technologies changed from external casting to surgical fixation with internal hardware, spine surgeons got the tools needed to apply screws and plates to the spine for better stability, which limited the need for external bracing.  Instrumentation and hardware used in spinal fusion also evolved significantly into their own specialty area.  Now, there are multiple types of screws, plates, rods and implants that are used only in the spine.  From plates and screws that will fit securely to the skull to implants specifically designed for the sacrum, spinal implants now have become the standard in fusion surgery.

As using hardware for the spine has become more accepted among spine surgeons, improving the techniques for insertion of the hardware became the next frontier for improvement.  Making smaller incisions to insert the same implants was developed to decrease post-operative pain and return the patient to full function more quickly.   This has been the rise of what is commonly called “minimally invasive” surgery.  The procedure goals are the same: provide pain relief to patients with painful spinal conditions, but with smaller incisions and with the added benefit of less pain related to the procedure itself, patients are able to be active more quickly.  It was not long ago that lumbar and cervical spine fusion surgeries required in-patient hospital admissions of 3-4 days.  Now cervical and lumbar fusion surgeries can be done with smaller incisions and less pain, so patients are able to go home within a few hours of their surgery. Less pain = a need for less pain medication; therefore, patients are able to return to their normal activities more quickly. 

Another advancement has seen more and more spinal surgery cases move into the Ambulatory Surgery setting.  Obviously, outpatient spine surgery is less expensive than inpatient spine surgery.  What may not be as obvious is that outpatient surgery also carries less risk for patient infection.  Why?  Hospitals care for the sickest among us, but with that, also have the highest concentration of people with infections.  My patients scheduled for spine surgery are not sick, they just need surgery to repair a mechanical defect or abnormality caused by, injury, arthritis or other disease.  With outpatient spine surgery, patients are not admitted to the hospital floor to recover, hence, risking exposure to very sick patients; they are discharged the same day, after surgery, to recover in their home environment.  Therefore, they have much less risk of contracting an infection. 

As a leader in developing techniques that allow most surgeries for the lumbar and cervical spine to be done in the outpatient setting, it has been very satisfying to see patients recover their normal lifestyles more quickly than ever before.