It’s Not Your Father’s Back Surgery
By Paul T. Geibel, M.D.
With 80 percent of adult Americans sustaining at least one episode of severe disabling lumbar back pain in their lives, lumbar surgical treatment alternatives are always in the news. Approximately 85 percent of these patients will improve with non-surgical interventions in the form of physical therapy, medications, pain management, or a significant lifestyle change. The remaining patients may be left with surgical decisions to alleviate their lumbar symptoms.
Have the surgical options changed? Indeed they have. A myriad of new surgical techniques and a pipeline of new technologies are being developed. Not all can be addressed in this short article, so we will concentrate on some of the newer and more efficacious surgical advances.
For patients who present with symptoms of lower extremity radicular pain or sciatica due to lumbar herniated nucleosus pulposus (HNP) or stenosis, a minimally invasive posterior approach is frequently recommended. The procedure, termed MITR (minimal invasive tubular retraction), uses a 16 mm to 18 mm skin incision with a series of cannulated tubes docked onto the appropriate intervertebral space. The exact position and location is verified by fluoroscopic guidance. The decompression procedure is then usually accomplished with the aid of an operating microscope and specialized instrumentation through this cannulated apparatus. Lumbar disc fragments, synovial cysts, or osteophytic stenotic lesions can be treated in this manner in one or two level procedures. Most patients obtain a 90 percent to 95 percent improvement in their symptoms.
Significant advantages of this procedure include minimal tissue destruction, the fact that it can be performed in an outpatient surgical center, and patients often are able to return to light work activities within three to seven days. A majority of patients have a successful outcome from this minimally invasive procedure that avoids the increased morbidity and pain of an open procedure.
Lumbar fusion procedures for various instabilities have been greatly improved by the emergence of new osteoinductive biologic products. The most notable is bone morphogenic protein, or rhBMP-2. This peptide is commercially available as INFUSE®, and is FDA approved for several musculoskeleletal indications. As an osteoinductive agent, it is one million times more biologically active than autologous iliac crest graft. Patients who need spinal fusion but are at high risk for non-union may achieve successful arthrodesis and
avoid donor site morbidity with the use of BMP.
The emergence of new spinal instrumentation, implant technology, and biologics such as BMP open the door to minimally invasive fusions for selected patients. The advantages of neural decompression accomplished through a minimal posterior approach include minimal tissue dissection and denervation. This significantly reduces the infection rate, post-op pain, and the duration of hospitalization. Already a number of patients have benefited from this.
However, there are disadvantages to this new approach. The greatest is a steep surgical learning curve for new surgeons. Also, some of the available percutaneous posterior instrumentation systems are awkward and cost-prohibitive to hospitals.
As a solution to some of these difficulties, a stand-alone interbody implant is being developed to reduce the need for these posterior segmental fixation devices. This technological improvement offers the possibility of outpatient fusions in the very near future. Having personally performed minimal invasive lumbar fusions with current technologies, the difference in short- and long-term recovery for patients is truly remarkable when compared to current open techniques.
Total disc replacement is a promising development in the treatment of severe lumbar back pain in patients with degenerative disc disease. It is indicated in younger patients with one level disc disease who have clinical and diagnostic findings of lower lumbar degenerative disc disease. The Charité artificial disc was approved by the FDA in 2004, and the Prodisc in 2006. In selected patients, implants are inserted through an anterior retroperitoneal approach, creating an artificial disc at that segment. Ideally, motion is preserved,
avoiding such fusion problems as adjacent level disc and facet degeneration. This has been a longterm problem in many fusion patients who may require repeated fusions for adjacent level degeneration or instability.
While the theoretical advantages of artificial discs are evident, there remain important questions regarding patient selection, early adverse events, and the uncertain long term clinical outcomes. I feel that continued improvement in artificial disc implant technology will occur with better generations of artificial discs ahead, much as was seen in the evolution of total joint arthroplasty.
For older patients with severe spinal stenosis creating significant lumbar back pain and neurogenic claudication of their lower extremities, a promising, less-invasive surgical procedure exists. The FDA approved the X-Stop device in 2005, which is an implant placed between spinous processes to prevent extension of the spine at the symptomatic level. This effectively unloads the respective motion segment and increases spinal canal diameter and foraminal height at this level, thereby indirectly decompressing the stenotic nerve root. This avoids any laminectomy or laminotomy procedure and may be ideal for the patient unable to undergo a more invasive surgical procedure due to significant over-riding comorbidities.
This represents a new technology. There are no long-term prospective randomized studies that represent its long-term success, but there are some studies showing a higher re-operation rate due to dislodgement of the implant. I feel it will not replace the “gold standard” of decompressive laminectomy for those patients who can tolerate the more invasive procedure.
We have reviewed some of the recent advances in technology and lumbar spinal surgery. The scope of this article, however, is limited, and the advances discussed are not intended to be comprehensive. As in other surgical specialties, minimal invasive surgical techniques are currently available in lumbar surgery. With new advances, the surgical outcomes for future patients remain bright.
Patients often recount a relative’s earlier experience with lumbar spinal surgery. They are apprehensive about lumbar surgery due to some of the extended recovery periods their relatives incurred. With the advent of minimally invasive lumbar surgery, their concerns are greatly alleviated. At the conclusion of the surgical consultation, I remind them: “Remember, it is not your father’s back surgery anymore.” My prospective surgical patients seem to find this comforting.
Paul T. Geibel, MD earned his M.D. degree from Tulane University School of Medicine in 1983. His postgraduate training included serving as Orthopaedic Chief Resident at Tulane Medical Center and Charity Hospital, New Orleans. After residency training, he entered the Spinal Fellowship program at the University of Louisville, Leatherman Spine Clinic in Louisville, Kentucky, and the Tulane Spine Fellowship in New Orleans. He has served as Clinical Instructor and Assistant Clinical Professor of Orthopaedic at the University of Texas Health Science Center at San Antonio. Currently he serves as Chairman of the Department of Orthopaedic at Southwest Methodist Hospital and is the lead investigator of clinical studies with interbody fusions and Bone Morphogenic Protein (BMP). Dr. Geibel may be contacted at email@example.com or at 210-293-2921. His office is at 18626 Hardy Oak Blvd, No. 300, San Antonio, TX 78258.