Failed back surgery syndrome (FBSS) is a poorly defined term. This term is frequently and inappropriately used to describe any person who has had previous back surgery and did not get adequate symptom relief. This definition is conveniently used to justify interventional pain management, including spinal cord stimulators (SCS) for pain control.
SCS devices have several disadvantages. The most important disadvantage is that the patient cannot have any further magnetic resonance imaging (MRI) scans to their spine. Although some of the newer stimulators have been described as MRI-compatible, most are limited in their compatibility; often MRI is permitted for the head but not for the spine because of the risk of heating of the electrode inside the spinal canal. The other disadvantage is the lack of efficacy, particularly in controlling axial back pain. SCS are more effective in addressing radicular pain in the legs. Radicular pain, or leg pain secondary to spinal diseases can be more efficiently and adequately addressed by direct surgical decompression. Axial mechanical back pain, which often fails to respond adequately to surgery, presents situations for interventional pain management, but it is difficult to control these cases by SCS. These devices are expensive, and offer no significant cost savings in comparison to surgical procedures. The typical SCS battery has a limited life span and requires periodic replacement. Insertion of the SCS is not always without complication, and may result in lead migration even after proper implantation.
Surgical intervention to the degenerative conditions in the spine is not always the end of the road. The magnitude of the initial surgeries may often be limited to minimize the risk and to address the most pressing symptoms rather than every possible symptom. For example, a decompressive laminectomy or discectomy may be done to address radicular symptoms or claudication pain very effectively without fusion or instrumentation. But this may eventually lead to axial mechanical back pain or post-laminectomy instability with collapse of disc height or degenerative spondylolisthesis. This is more appropriately described as a sequela, rather than a failed surgery. Postlaminectomy instability may respond well to further surgery with instrumented fusion, and may not necessarily be treated with SCS implantation.
Degenerative kyphoscoliosis occurs frequently after previous back surgeries. Surgical intervention to address kyphoscoliosis may be more extensive, and may require spinal osteotomies and long spinal fusion surgery to restore sagittal and coronal balance, as well as to correct the compensatory pelvic retroversion. This kind of surgery may address the high energy cost of maintaining upright posture and ambulation in the presence of kyphoscoliosis deformity of the spine.1 An SCS is frequently used in this patient population, but they frequently fail because the stimulator does not reduce the fatigue from the high energy cost associated with standing or walking in kyphotic posture.
It is likely to see patients who have failed to have adequate symptoms relief, and come back for further spinal surgery. Preoperative MRI is essential for proper surgical planning in these cases, which may not be possible if these patients have SCS implanted.
SCS should be used more appropriately when there is no surgical plan available that may offer symptom relief, such as adhesive arachnoiditis, peripheral neuropathy, among others.2
Figures 1 and 2 present 2 case examples in which SCS was used inappropriately, and they improved by removal of the SCS followed by further surgery.
1. Sengupta DK. Rao RD, Smuck M. Adult spinal deformity. AAOS,Orthopaedic Knowledge Update: Spine 4
. Chicago: 2012.
2. Turner JA, Loeser JD, Deyo RA, et al. Spinal cord stimulation for patients with failed back surgery syndrome
or complex regional pain syndrome: a systematic review of effectiveness and complications.Pain
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failed back surgery syndrome; kyphoscoliosis; spinal cord stimulator