title: Nerve injury after lateral lumbar interbody fusion: a review of 919 treated levels with identification of risk factors.
abstract: BACKGROUND
  Lateral lumbar interbody fusion (LLIF) has become an increasingly common minimally invasive procedure for selective degenerative deformity correction, reduction of low-grade spondylolisthesis, and indirect foraminal decompression. Concerns remain about the safety of the transpsoas approach to the spine due to proximity of the lumbosacral plexus.
  
  
  OBJECTIVE
  To address risk factors for iatrogenic nerve injury in a large cohort of patients undergoing LLIF.
  
  
  METHODS
  Retrospective analysis of 919 LLIF procedures to identify risk factors for lumbosacral plexus injuries.
  
  
  METHODS
  The medical charts of patients who underwent transpsoas interbody fusion with or without supplemental posterior fusion for degenerative spinal conditions over a 6-year period were retrospectively reviewed. Patients with prior lumbar spine surgery or follow-up of less than 6 months were excluded. Factors that may affect the neurologic outcome were investigated in a subset of patients who underwent stand-alone LLIF.
  
  
  RESULTS
  Four hundred fifty-one patients (males/females: 179/272) met the inclusion criteria and were followed for a mean of 15 months (range, 6-53 months). Average age at the time of surgery was 63 years (range, 24-90 years). Average body mass index was 29 kg/m(2) (range, 17-65 kg/m(2)). A total of 919 levels were treated (mean, 2 levels per patient). Immediately after surgery, 38.5% of the patients reported anterior thigh/groin pain, whereas sensory and motor deficits were recorded in 38% and 23.9% of the patients, respectively. At the last follow-up, 4.8% of the patients reported anterior thigh/groin pain, whereas sensory and motor deficits were recorded in 24.1% and 17.3% of the patients, respectively. When patients with neural deficits present before surgery were excluded, persistent surgery-related sensory and motor deficits were identified in 9.3% and 3.2% of the patients, respectively. Among 87 patients with minimum follow-up of 18 months, persistent surgery-related sensory and motor deficits were recorded in 9.6% and 2.3% of the patients, respectively. Among patients with stand-alone LLIF, the level treated was identified as a risk factor for postoperative lumbosacral plexus injury. The use of recombinant human bone morphogenetic protein 2 was associated with persistent motor deficits.
  
  
  CONCLUSIONS
  Although LLIF is associated with an increased prevalence of anterior thigh/groin pain as well as motor and sensory deficits immediately after surgery, our results support that pain and neurologic deficits decrease over time. The level treated appears to be a risk factor for lumbosacral plexus injury.
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA. Electronic address: mariolyk@yahoo.com.
authors.forename: Marios G
authors.initials: MG
authors.lastname: Lykissas
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Aichmair
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Hughes
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Sama
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Darren R
authors.initials: DR
authors.lastname: Lebl
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Fadi
authors.initials: F
authors.lastname: Taher
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Jerry Y
authors.initials: JY
authors.lastname: Du
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Frank P
authors.initials: FP
authors.lastname: Cammisa
authors.affiliation: Department of Orthopedic Surgery, Spine and Scoliosis Service, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA.
authors.forename: Federico P
authors.initials: FP
authors.lastname: Girardi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008160:Lumbosacral Plexus / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D059348:Peripheral Nerve Injuries / Q000209:etiology*; D011183:Postoperative Complications / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods; D055815:Young Adult
keywords: Complications; LLIF; Nerve injury; Risk factors; Transpsoas approach