Sacral Neurostimulator Mimics Low Back Pain After a Fall: A Case Report
Joanne Eash, D.C.1, Sean T. Norkus, D.C.2
1Assistant Professor, Clinical Affairs – Palmer College of Chiropractic, Port Orange, Florida
2Assistant Professor, Clinical Sciences – Palmer College of Chiropractic, Port Orange, Florida
Published: August 2020
Journal of the International Academy of Neuromusculoskeletal Medicine
August 2020, Volume 17, Issue 1
The original article copyright belongs to the original publisher. This review is available from: http://ianmmedicine.org ©2020 Eash/Norkus and the International Academy of Neuromusculoskeletal Medicine. This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
To discuss a case of female patient with musculoskeletal complications related to damage to her sacral neuromodulation device which occurred as a result of a slip and fall.
46-year-old female patient with low back pain after slip and fall. The physical exam of this patient involved palpation and orthopedic exams, including Laslett’s criteria for identifying sacroiliac joint pain. Segmental overpressure, with prone hip extension, demonstrated right sacroiliac joint restriction along with left sacroiliac joint pain.
Intervention and Outcomes
Treatment consisted of spinal manipulation, using Thompson drop technique, on the left sacroiliac joint. The patient reported only transient improvement. A careful review of the chief complaint was conducted. The patient reported that she had a sacral neural stimulator implanted in her left gluteal tissue, for the management of urinary incontinence. The patient was asked to turn off her device, via remote control, and her pain was instantly relieved. Urology explanted the device to the opposite gluteal region, with no complications.
This case illustrates the importance of reviewing past medical history and ROS for visceral/surgical causes for MSK pain. This appears to be the first case in the literature of adverse event due to accidental damage to a sacral neurostimulator medical device.
Sacral neuromodulation (SNM) has increased in frequency in the last two decades for the treatment of various conditions, including urinary voiding dysfunction, fecal incontinence, sexual dysfunction, and pelvic pain.  SNM is an intervention that stimulates the sacral nerves that control bowel and bladder function by delivering mild electrical pulses, below sensory threshold, using an implantable pulse generator (IPG).  Stimulation can be tested immediately using the Brindley- Stimulator, where patients are able to induce voiding by activating the IPG . Patient can test the outcome of the intervention for 2-4 weeks using an external pulse generator, before a more permanent device is implanted through the third sacral foramen; the wire is placed adjacent to the pudendal nerves, using the Seldinger technique.. The IPG is implanted in the superior gluteal region.
The success rates for urinary and fecal incontinence are 68% and 89%,  but there have been multiple reports of adverse events resulting in surgical revisions or removal include loss of efficacy, pain at the IPG, painful stimulation, or painful stimulation down the leg [1, 2, 4, 6-9]. Adverse events occur highest within the first year of implantation [6, 8]. Medtronic lists “lead migration” as a possible adverse event causing pain in 2.5% of all recipients in its initial Summary of Effectivenes . Lead migration occurs when the quadripolar lead do not adhere in the fascia of the gluteal region. Bielefeldt stated that “isolated lead replacement accounted for only 4.3% of reports”. According to Medtronic, between 2010 and October 2018, 74.2% of the adverse events were related to the lead, but only 1.8% of subjects  A literature review identified over 500 references for “adverse effects of SNM”, but none described an accidental lead fracture as described in this case. This patient reported low back pain after a fall on her buttocks. She was evaluated for sacroiliac involvement and treated with only transient improvement. After a re-assessment of her surgical history, the diagnosis was amended to a failure of her SNM device.
46-year-old female patient presented with a new complaint of ankle pain after a slip and fall. The patient had stepped off a boat and onto a floating dock where she slipped on a wet step. She sought chiropractic care for her right ankle pain, which presented with marked discoloration and edema. She also had noticeably altered gait, due to her ankle pain. The patient was diagnosed with an ankle sprain and began a course of conservative care, which involved manual therapy, active care exercises, home icing instructions, and kinesiology tape.
With three weeks of treatment, her ankle pain had resolved, but the patient also began to complain of low back pain, which she attributed to her altered gait. Subsequently, a low back examination was performed, including Laslett’s criteria for identifying low back pain that originates from one or more painful sacroiliac joints. Visual inspection of the area was unremarkable. The test item cluster in Laslett’s criteria (thight thrust, distraction, Gaenslen’s, Iliac compression, sacral thrust) were negative in this case. Segmental overpressure with prone hip extension demonstrated right sacroiliac joint joint restriction, and pain in the right sacroiliac joint on hip extension. The patient rated her pain as a constant 7/10. Treatment consisted of prone high-velocity, low-amplitude spinal manipulation, using a Thompson table-assisted drop technique applied to the right sacroiliac joint. The patient only experienced transient improvement, stating only a few hours of relief between visits. Since this patient was not responding to treatment as expected, a review of the patient’s history of present illness was performed, along with a review of the patient’s past, family, and social history. The patient stated that she had a sacral neural stimulator implanted for urinary dysfunction approximately two years prior. A detailed review of the complaint revealed that when the patient had fallen, she landed on her buttocks on a flight of wooden stairs. She did not attribute her back pain to the fall, but to her altered gait from the ankle injury. Her implant was in the right gluteal region. The patient was advised to go home and turn off the device, using the external remote control. She cycled on and off several times; each time abolishing her pain and reproducing it. The patient was immediately referred to her urologist for follow up, where she was scheduled for exploratory surgery due to the suspected broken lead in her device. Surgery consisted of relocating her device to the opposite gluteal region with no further complications.
This case is important because there were no published cases wherein a minor trauma was able to cause damage to an implanted neurostimulator. While this patient had received her neurostimulator as a treatment for urinary dysfunction, it is important to note that neurostimulators are used in healthcare for a wide array of conditions and/or symptoms. For both clinicians and academics, acknowledgement that minor trauma can alter surgically installed devices should be noted, and a more in-depth history should be examined in patients with implanted neurostimulators. Providers should assess pain generators throughout the care plan, and revise the diagnosis if treatment is not successful. In this case, somatic pain was confounded by the broken lead, which reproduced musculoskeletal pain that mimicked sacroiliac joint pain.
In a case that presents like a simple musculoskeletal injury, it is important to thoroughly explore the patient’s complete history, including previous surgeries. This is especially true if a short trial of conservative care is associated with a lack of improvement. This appears to be the first published case involving this traumatic etiology. It is the hope of the authors that introducing this case into the literature may help those patients who may experience a similar patient presentation.
List of Abbreviations
SNS: Sacral Nerve Stimulation, Sacral Neurostimulation
IPG: Implantable Pulse Generator
SNM: Sacral neuromodulation
The author(s) declare that they have no competing interests.
1. Sutherland, S.E., et al., Sacral nerve stimulation for voiding dysfunction: One institution’s 11-year experience. Neurourol Urodyn, 2007. 26(1): p. 19-28; discussion 36.
2. Medtronic, Summary of Safety and Effectiveness Data, FDA, Editor. 2014, FDA. p. 1-25.
3. Baxter, C. and J.H. Kim, Contrasting the percutaneous nerve evaluation versus staged implantation in sacral neuromodulation. Curr Urol Rep, 2010. 11(5): p. 310-4.
4. Engelberg, S., et al., Sacral Neuromodulation – Evolution of Techniques, Procedures and Outlook into the Future. Biomedical Engineering / Biomedizinische Technik, 2014. 59: p. s352-s355.
5. Spinelli, M., et al., New tined lead electrode in sacral neuromodulation: experience from a multicentre European study. World J Urol, 2005. 23(3): p. 225-9.
6. Gajewski, J.B. and A.A. Al-Zahrani, The long-term efficacy of sacral neuromodulation in the management of intractable cases of bladder pain syndrome: 14 years of experience in one centre. BJU Int, 2011. 107(8): p. 1258-64.
7. Medtronic. Therapies. [cited 2019 October 10, 2019]; A Medtronic page discussing various bladder control therapies and associated information.]. Available from: https://www.medtronic.com/us-en/patients/treatments-therapies/bladder-control/therapies.htm.
8. Bielefeldt, K., Adverse events of sacral neuromodulation for fecal incontinence reported to the federal drug administration. World J Gastrointest Pharmacol Ther, 2016. 7(2): p. 294-305.
9. Blandon, R.E., et al., Re-operation rates after permanent sacral nerve stimulation for refractory voiding dysfunction in women. BJU Int, 2008. 101(9): p. 1119-23.
10. Medtronic, Product Performance Report: Summary of Data from the Medtronic Post-Market Registry. 2018.
11. Laslett, M., et al., Diagnosing painful sacroiliac joints: A validity study of a McKenzie evaluation and sacroiliac provocation tests. Australian Journal of Physiotherapy, 2003. 49(2): p. 89-97.