SCS offers a promising treatment option to patients with persistent postoperative neuropathic pain. When Melzack and Wall published their iconic paper on gate control theory in 1965, and Norman Shealy first discovered the potential therapeutic value of SCS, so began a revolution in the way pain management is achieved [27, 28]. Though evidence for the efficacy of SCS for patients with FBSS was established in the 1990s, its mechanism of action and optimization are still being explored, with current research focusing on the delivery of new stimulation parameters [29]. Despite the many unknowns associated with SCS, the use of SCS for the treatment of patients with chronic back and neuropathic pain has gained popularity, and has even proven to be cost effective for health care as well [30]. Currently, the annual number of stimulators implanted is increasing, and has become critical in the armamentarium of clinicians treating such patients [31, 32].

Multiple studies have demonstrated significant improvements in neuropathic extremity pain, with or without back pain in a majority of patients with few complications [33, 34]. In one of the first large series of SCS for FBSS, patients were treated with SCS and followed for 4 years [35]. Overall, patients reported more than 60 % subjective improvement of pain, a significant reduction in medication usage, and an increased working capacity [36]. A study by North et al. also demonstrated the efficacy of SCS for FBSS [37]. The authors found a successful outcome, defined as at least 50 % sustained relief of pain and patient satisfaction, in a majority of 50 FBSS patients after SCS implantation. A subsequent study of 153 patients with FBSS had similar findings, with 52 % of patients achieving pain relief after SCS with an average follow-up period of 7 years [35]. In a large multicenter study, the PROCESS trial, SCS was compared to conservative medical management [38–40]. The results were impressive, showing the superiority of SCS treatment over CMM; specific outcome data can be seen in Table 5.1. Several other investigators have since affirmed SCS efficacy with respect to improvements in functional capacity in addition to pain [41–45]. As such, various American and international regulatory and pain societies have confirmed the role of SCS for the treatment of FBSS. A summary of these recommendations can be found in Table 5.2. Even when compared to other treatment options such as repeat spinal surgery which can carry an improvement of 20–30 %, there are few modalities that can carry such success as SCS.

In order to optimize the efficacy of SCS treatment for patients suffering from FBSS, these patients need to meet certain selection criteria [32]. Up to 36–40 % post-SCS implant patients still have ongoing disability and pain, underscoring the need for stringent inclusion and exclusion criteria [51]. As with any intervention, patient selection is crucial. To qualify for an SCS treatment trial for chronic LBP and lower extremity radicular pain, patients need to have failed at least 3–6 months of adequate conservative medical management. This includes physical therapy, analgesics, both opioid and nonopioid, and epidural steroid injections. Completion of a pain psychology evaluation is typically advised prior to SCS, and for placement of paddle SCS leads, thoracic imaging is recommended to ensure sufficient space for the lead without causing spinal cord compression. Furthermore, a completed successful SCS trial, defined as ≥50 % pain relief prior to permanent stimulator and lead implant is essential to ensure efficacy of the treatment [52]. Patients with a positive SCS trial have increased success post-implantation when compared to those who fail to respond [53].

However, as with any surgery, SCS may have complications. In the PROCESS trial, 19 (45 %) of the 42 patients still receiving SCS at 24-months experienced a total of 34 SCS-related complications, primarily related to hardware migration and biological events including wound breakdown or pain at the incision site [40]. Only a small proportion of events (15 %) were attributed to loss of therapeutic effect.

When directly comparing SCS versus reoperation for treatment of FBSS, there is clear superiority of SCS treatment [51]. In 2005, North et al. published a randomized control trial to investigate the issue of surgical revision; he randomly assigned patients with FBSS to receive either SCS or reoperation. SCS was more successful than reoperation (9 of 19 patients vs. 3 of 26 patients, p < 0.01), and patients initially randomized to SCS were significantly less likely to cross over than were those randomized to reoperation (5 of 24 patients vs. 14 of 26 patients, p < 0.02) [51].

There is also evidence to suggest that the sooner a diagnosis of FBSS can be recognized and subsequently treated with SCS, the better the prognosis for treatment efficacy [54]. SCS performed early in the course of a patient’s chronic pain process is associated with better outcomes than SCS performed late in the disease [52].

Intrathecal pain pumps function by delivering programmable doses of drugs, such as an opioid alone or in combination with a local anesthetic agent, directly to the cerebrospinal fluid. At present approved labeling is for either Morphine or Ziconatide to be delivered via an intrathecal therapy. Although the efficacy of intrathecal pain pumps for the treatment of FBSS has yet to be demonstrated in a large-scale randomized clinical trial [55], there is evidence supporting the use of implantable intrathecal infusion systems for FBSS for both short-term and long-term relief of symptoms, particularly for the nociceptive back pain component [56]. Similar to SCS, patients are encouraged to undergo a successful trial prior to initiation of therapy.