title: Spinal neuromodulation as a novel surgical option for failed back surgery syndrome following rhBMP exuberant bony growth in instrumented lumbar fusion: A case report and literature review.
abstract: BACKGROUND
  Bone morphogenic protein (BMP) for instrumented lumbar fusion was approved in 2002, and since then has led to an increasing incidence of BMP-related neuropathic pain. These patients are usually resistant to conventional medical therapy and frequently undergo multiple surgical revisions without any pain relief.
  
  
  METHODS
  A 58-year-old male was referred to the author's outpatient clinic after four lumbar surgeries did not provide satisfactory pain relief. During his 10 years of suffering from low back pain after an injury, the patient was resistant to conventional and interventional treatment options. He was experiencing severe back pain rated 10/10, as well as right lower extremity pain, numbness, tingling, and motor deficits. Outside spine specialists had performed revision surgeries for BMP-related exuberant bone formation at L5-S1, which included the removal of the ipsilateral hardware and debridement of intradiscal and intraforamina heterotrophic exuberant bony formation. The author implanted the patient with a permanent continuous spinal cord stimulator, after which he achieved complete pain relief (0/10) and restoration of motor, sensory, autonomic, and sphincter functions.
  
  
  CONCLUSIONS
  This is the first reported case of restorative function with neuromodulation therapy in a BMP-induced postoperative complication, which is considered as a primarily inflammatory process, rather than nerve root compression due to exuberant bony formation. We hypothesize that neuromodulation may enhance blood flow and interfere with inflammatory processes, in addition to functioning by the accepted gate control theory mechanism. The neuromodulation therapy should be strongly considered as a therapeutic approach, even with confirmed BMP-induced postoperative radiculitis, rather than proposing multiple surgical revisions.
authors.affiliation: Ghaly Neurosurgical Associates, Aurora, Illinois, USA; Department of Neurosurgery, University of Illinois, Chicago, Illinois, USA; Department of Anesthesiology, University of Illinois, Chicago, Illinois, USA; Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
authors.forename: Ramsis F
authors.initials: RF
authors.lastname: Ghaly
authors.affiliation: Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
authors.forename: Alexei
authors.initials: A
authors.lastname: Lissounov
authors.affiliation: Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Tverdohleb
authors.affiliation: Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
authors.forename: David
authors.initials: D
authors.lastname: Kohanchi
authors.affiliation: Department of Anesthesiology, University of Illinois, Chicago, Illinois, USA; Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Candido
authors.affiliation: Department of Anesthesiology, University of Illinois, Chicago, Illinois, USA; Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
authors.forename: Nebojsa Nick
authors.initials: NN
authors.lastname: Knezevic
keywords: Bone morphogenetic protein; exuberant bony formation; failed-back surgery syndrome; instrumented lumbar fusion; neuromodulation