Nerve injury and recovery after lateral lumbar interbody fusion with and without bone morphogenetic protein-2 augmentation: a cohort-controlled study

Spine J. 2014 Feb 1;14(2):217-24. doi: 10.1016/j.spinee.2013.06.109. Epub 2013 Nov 20.


Background context: Despite common use of intraoperative electrophysiologic neuromonitoring, injuries to the lumbar plexus during lateral lumbar interbody fusion (LLIF) have been reported. Emerging data suggest that recombinant human bone morphogenetic protein-2 (rhBMP-2) use during an anterior or transforaminal lumbar interbody fusion may be associated with an increased risk of neurological deficit. Clinical data on the sequelae of rhBMP-2 implantation in close proximity to the lumbosacral plexus during LLIF remains to be understood.

Purpose: The purpose of this study was to compare the incidence of neurologic deficits and pain in patients undergoing LLIF with and without rhBMP-2.

Study design/setting: Retrospective outcome analysis in controlled cohorts undergoing the lateral exposure technique for LLIF with and without rhBMP-2.

Methods: The electronic medical records of patients undergoing LLIF with and without supplemental posterior fusion for degenerative spinal conditions were retrospectively reviewed over a 6-year period. Patients with previous lumbar spine surgery or follow-up of less than 6 months were excluded. Patients were divided into 2 groups, Group 1 (rhBMP-2 use; n=72) and Group 2 (autograft/allograft use; n=72), and were matched according to the age at the time of surgery, gender, weight, body mass index, side of approach, total number of treated spinal segments, use of supplemental posterior fusion, and length of follow-up.

Results: Immediately after surgery, a sensory deficit was recorded in 33 patients in Group 1 and 35 patients in Group 2 (odds ratio [OR] 0.895; 90% confidence interval [CI] 0.516-1.550; p=.739). At last follow-up, a persistent sensory deficit was identified in 29 patients whose LLIF procedure was supplemented by rhBMP-2 and 20 patients in whom autograft/allograft was used (OR 1.754; 90% CI 0.976-3.151; p=.115). A motor deficit was recorded in 37 patients immediately after the rhBMP-2 procedure and 28 patients treated with autograft/allograft (OR 1.661; 90% CI 0.953-2.895; p=.133). A persistent motor deficit was recorded in 35 and 17 patients in Groups 1 and 2, respectively, at last follow-up (OR 3.060; 90% CI 1.681-5.571; p=.002). During the first postoperative examination, 37 patients in Group 1 and 25 patients in Group 2 complained of anterior thigh or groin pain (OR 1.987; 90% CI 1.133-3.488; p=.045). At last follow-up, there was a significantly higher number of patients in Group 1 who complained of persistent anterior thigh or groin pain than Group 2 (8 vs. 0 patients) (OR 16.470; 90% CI 1.477-183.700; p=.006).

Conclusions: Our results provide evidence of an increased rate of postoperative neurologic deficit and anterior thigh/groin pain after LLIF using rhBMP-2, when compared with matched controls without rhBMP-2 exposure. This study suggests a potential direct deleterious effect of rhBMP-2 on the lumbosacral plexus.

Keywords: LLIF; Nerve injury; Thigh pain; Transforming growth factor-β; XLIF; rhBMP-2.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Bone Morphogenetic Protein 2 / administration & dosage*
  • Bone Morphogenetic Protein 2 / adverse effects*
  • Bone Transplantation / adverse effects
  • Bone Transplantation / methods
  • Case-Control Studies
  • Cohort Studies
  • Female
  • Humans
  • Incidence
  • Lumbar Vertebrae / injuries
  • Lumbar Vertebrae / innervation
  • Lumbar Vertebrae / surgery
  • Lumbosacral Region / injuries
  • Lumbosacral Region / innervation
  • Lumbosacral Region / surgery
  • Male
  • Middle Aged
  • Postoperative Complications / epidemiology
  • Postoperative Complications / etiology*
  • Postoperative Complications / surgery
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / adverse effects
  • Retrospective Studies
  • Spinal Fusion / adverse effects*
  • Transforming Growth Factor beta / administration & dosage*
  • Transforming Growth Factor beta / adverse effects*
  • Treatment Outcome
  • Young Adult


  • Bone Morphogenetic Protein 2
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • recombinant human bone morphogenetic protein-2