What matters is not just having all of the tools of the trade available but having experienced physicians and surgeons who know which tool to use with which patient.
“We don’t just hit one nail,” said Charles A. Reitman, M.D., co-director of the center. “We approach the patient from a comprehensive point of view. Patients will always get the best treatment they can get, whether they have a simple problem, a complicated problem, or one that benefits from newer technology.”
“We’re not just using new technology; we’re running trials to develop it here,” said center co-director Bruce M. Frankel, M.D.
For most patients, non-surgical management will resolve their pain, and the center offers these patients a full spectrum of services to meet their needs, including rehabilitation, injections, counseling, and support for weight loss.
But for the ten percent of patients whose pain does not resolve with non-surgical management, a wide variety of open and minimally invasive surgeries are available. The decision as to which surgical procedure is best suited to each patient’s needs is informed by the collective wisdom of the Spine Center’s many surgeons, representing decades of combined experience.
For many patients, especially those with complex degenerative disease, more traditional open approaches will be the treatment of choice. But in select patients, newer minimally invasive options can result in very good clinical outcomes with minimal surgical trauma, shorter hospital stays, and a faster return to work and other activities.
A more detailed discussion follows of three minimally invasive procedures available at the center—cervical disc arthroplasty, endoscopic discectomy, and sacroiliac joint fusion.
When a cervical disc ruptures, its contents can leak out and impinge on a nerve root, causing pain to radiate to the upper chest and arms.
For young, active patients who need to return to work or other activity quickly, cervical disc arthroplasty, in which the damaged disc is removed and replaced by an artificial disc, may offer an attractive alternative to traditional fusion.
“If I have a parent with an active family or someone who has to get back to work quickly, this is a phenomenal operation because the recovery time is so fast,” said Reitman. “It’s really a game changer.”
Successes with knee and hip replacements fueled interest in the development of artificial discs, which typically consist of a polyurethane cushion between two end plates that attach to adjacent vertebrae, and several have obtained investigational device exemption approval and been the basis of clinical trials.
Because these artificial discs preserve a good range of motion, proponents argue that they could prevent adjacent segment degeneration, which some believe to be a consequence of spinal fusion. Immobilizing one section of the spine could put additional pressure on adjacent areas, leading to degeneration.
Cervical disc arthroplasty is generally indicated in younger patients with strong bone and mild disease and is not recommended in patients with advanced osteoarthritis because, unlike fusion, it will not stop the degeneration. The durability of the artificial discs is not yet known, and, since they are often implanted in younger patients, it is possible that reoperation may be necessary decades later to replace the disc, as is sometimes the case with hip and knee replacements.
Herniation of a lumbar disc can compress nerve roots and lead to pain that radiates to the lower back, groin, buttocks, or legs (i.e., sciatica). Substantial pain relief can be attained in many patients by decompressing the nerve root through removal of the ruptured content of the disc and any bony debris. The remainder of the disc remains in place to help maintain the stability of the spinal column.
Open discectomy (OD) and microdiscectomy (MD) are the gold standards for lumbar nerve decompression. Microdiscectomy is a much less invasive but still open procedure that achieves clinical outcomes rivaling OD. A small tube is inserted through a dime-sized incision on the back to serve as the channel through which tiny surgical instruments can be used to extract the disc remnants. A specialized operating microscope is used to enhance the vision of the surgeons as they look down the tube into the site of the affected disc. The tube is advanced into place without cutting the spinal muscles—instead, sequential dilators spread the spinal muscles apart. Endoscopic discectomy takes things a step further. Surgeons rely not on a microscope for visualization of the disc but on a monitor displaying images captured by an endoscope—a tube with a tiny attached camera—that has been advanced through a small channel to the disc of interest. To ensure proper positioning of the channel, a wire is introduced under fluoroscopic guidance at the level of the disc herniation and first a dilator and then the tube or channel is advanced over the wire to the affected disc.
“Endoscopic discectomy is an excellent minimally invasive option to treat patients suffering from sciatica,” said Frankel.
Endoscopic discectomy can often be done as outpatient surgery, enabling patients to return to work in a matter of weeks, making it ideal for younger, active patients. The ideal candidate has little spinal degeneration and a relatively contained disc herniation (i.e., a single-level herniation that does not span the entire disc). Although endoscopic discectomy has a steep learning curve, in experienced hands, such as those of the surgeons at the center, it has been shown to achieve very good short-term clinical outcomes.1
Careful patient selection is important to reduce the risk of reoperation due to residual fragments. Patients with broad-based herniation are not good candidates for this procedure because its restricted access compared with OD could make reaching and removing all fragments more difficult and revision surgery more likely. For these patients, the center also offers OD/MD.
In recent meta-analyses,2,3 endoscopic discectomy, when performed in appropriate patient populations, was shown to have shorter hospital stays than MD/OD and similar long-term functional outcomes and rates of complication and reoperation. Clinical trials are needed to definitively evaluate its efficacy relative to MD/OD.
“Looseness” or movement in the sacroiliac joint (SIJ), which connects the iliac crest of the pelvis with the sacrum, could account for 15 to 23 percent of cases of chronic lower back pain4 and 40 percent of cases of chronic lower back pain after lumbar or lumbosacral fusion.5 In addition to adjacent segment degeneration secondary to lumbar fusion, other causes of SIJ dysfunction include trauma, pregnancy, inflammatory disease, infection, and tumors.
The capacity of the SIJ to move and generate pain has remained a point of considerable controversy, but evidence is growing that the SIJ can do both.6 Indeed, recent clinical trial evidence suggests that SIJ fusion can provide substantial pain relief in select patients.4
Dr. John Glaser
Several devices have been developed to enable minimally invasive fusion of the SIJ. MUSC Health Spine Center surgeons John A. Glaser, M.D., and Stephen P. Kalhorn, M.D., serve as principal investigators for the MUSC site of the trials of two such devices.
Glaser, who was among the first surgeons in the nation to take an interest in minimally invasive SIJ fusion and who has over a decade of experience performing them, NCT01681004). INSITE is randomizing 148 patients with SIJ pain to either fusion with the iFuse Implant System (SI Bone, San Jose, CA) or non-surgical management to compare how many of each group meet the study’s primary endpoint: pain reduction (≥20 mm decrease from baseline score on the Visual Analogue Scale [VAS]) by six months without device-related serious adverse events, neurological worsening related to lumbosacral nerve roots, or reintervention.
Early results from the INSITE trial provided for the first time Level 1 evidence that SIJ fusion, in this case using triangular titanium implants, provided superior pain relief and functional outcomes and a better quality of life than did non-surgical management.4 At six months, 83 (81.4%) of the 102 patients undergoing SIJ fusion successfully reached the study’s primary end point vs. only 12 (26.1%) of the 46 study patients receiving non-surgical management. After their six-month follow-up visit, patients were allowed to cross over from the non-surgical to the surgical arm of the trial and most (35 of 44) chose to do so. Crossover patients, who had achieved a clinically negligible reduction in VAS pain score after 6 months of non-surgical management, saw a dramatic decrease (from 79.0 to 35.8) six months after minimally invasive SIJ fusion using the study device.
Glaser and the other INSITE investigators recently reported two-year results from the trial.7 Greater improvements in pain, disability, and quality of life were seen with SIJ fusion vs. non-surgical management, with a low rate of adverse events and reoperations.7
“These findings suggest that SIJ fusion is going to hold out hope for a small subset of patients with chronic lower back pain who until now have been unable to obtain pain relief,” said Glaser.
Kalhorn is leading the MUSC site of the Evolusion study (NCT02074761), a multi-center prospective surgical analysis of patients undergoing minimally invasive SIJ fusion with the Simmetri SIJ Fusion System (Zyga Technology, Minnetonka, MN). The MUSC Health Spine Center was one of only 15 U.S. centers asked to participate. The study will assess pain scores before and after surgery as well as short- and long-term outcomes, including fusion rates. To learn more, contact Aparna Choudhury at email@example.com.
Surgeons at the center offer this minimally invasive SIJ fusion as an outpatient procedure, using biplanar imaging to ensure efficiency, accuracy, and safety. Lateral and anteroposterior views are acquired simultaneously; these 2D images are then transformed into 3D ones that can be used to plan and direct surgery.
Only motivated patients who have not benefitted from conservative (non-surgical) management and in whom SIJ pain has been definitively diagnosed should be considered for SIJ fusion. Asking the patient to perform a series of five physical maneuvers known to provoke SIJ pain can be informative—elicitation of pain by three or more of the maneuvers suggests SIJ dysfunction.4,6 For a definitive diagnosis, a 75% reduction must be achieved on at least two separate occasions by injecting the SIJ with an anesthetic.4,6 SIJ fusion will not ease pain associated with lumbar degeneration. It is not recommended for smokers or patients with osteoporosis or active infection.
Other key members of the MUSC Health Spine Center team include surgeons Sunil J. Patel, M.D., Barton L. Sachs, M.D., W. Alex Vandergrift III, M.D., and Abhay K. Varma, M.D., as well as specialists in neurointervention, neuromodulation, and pain management and rehabilitation.
1 Sencer A, et al World Neurosurg. 2014 Nov;82(5):884-890.
2 Ruan W, et al. Int J Surg. 2016 Jul;31:86-92.
3 Li X, et al. J Clin Neurosci. 2016 Jul 27. S0967-5868(16):30350-30352.
4 Polly DW, et al. Neurosurgery. 2015 Nov;77(5):674-690; discussion 690-691.
5 Liliang PC, et al. Pain Med. 2011 Apr;12(4):565-570.
6 Rashbaum RF, et al. Clin Spine Surg. 2016 Mar;29(2):42-48.
7 Polly DW, et al. Intl J Spine Surg. 2016; Volume 10, Article 28 doi:10.14444/3028