title: C5 palsy after cervical laminectomy and fusion: does width of laminectomy matter?
abstract: BACKGROUND
  A common complication of cervical laminectomy and fusion with instrumentation (CLFI) is development of postoperative C5 nerve palsy. A proposed etiology is excess nerve tension from posterior drift of the spinal cord after decompression. We hypothesize that laminectomy width will be significantly increased in patients with C5 palsy and will correlate with palsy severity.
  
  
  OBJECTIVE
  The purposes of this study were to evaluate laminectomy width as a risk factor for C5 palsy and to assess correlation with palsy severity.
  
  
  METHODS
  This is a retrospective, single-institution clinical study.
  
  
  METHODS
  Patient population included all patients with cervical spondylotic myelopathy who underwent CLFI between 2007 and 2014 by a single surgeon. Patients who underwent CLFI for trauma, infection, or tumor or had previous or circumferential cervical surgery were excluded. All patients with a new C5 palsy received a postoperative magnetic resonance imaging. An additional computed tomography (CT) scan was ordered to assess hardware. All control patients received a CT scan at 6 months postoperatively to evaluate fusion.
  
  
  METHODS
  The association between width of laminectomy and development of postopeative C5 palsy was measured.
  
  
  METHODS
  Patient comorbidities including obesity, smoking history, and diabetes were recorded in addition to preopertaive and postoperative deltoid and biceps motor strength. Sagittal alignment was measured with C2-C7 Cobb angle preopertaive and postoperative radiographs. The width of laminectomy was measured in a blinded fashion on the postoperative CT scan by two observers.
  
  
  RESULTS
  Seventeen patients with C5 nerve palsy and 12 controls were identified. There were no baseline differences in age, sex, diabetes, smoking history, number of surgical levels, or sagittal alignment. Body mass index was significantly higher in the control cohort. There was no significant increase in the C3-C7 laminectomy width in patients with postoperative C5 palsy. The width of laminectomy measurments were highly similar between the two observers. There was no correlation between laminectomy width and palsy severity.
  
  
  CONCLUSIONS
  This is the largest series of C5 palsies after laminectomy documented with CT imaging. Laminectomy width was not associated with an increased risk of postoperative C5 palsy at any level. Reduction in laminectomy width may not reduce rate of postoperative nerve palsy.
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3000, Durham, NC 27710, USA. Electronic address: mitchell.klement@dm.duke.edu.
authors.forename: Mitchell R
authors.initials: MR
authors.lastname: Klement
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3000, Durham, NC 27710, USA.
authors.forename: Lindsay T
authors.initials: LT
authors.lastname: Kleeman
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3000, Durham, NC 27710, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Blizzard
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3000, Durham, NC 27710, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gallizzi
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3000, Durham, NC 27710, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Eure
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Box 3000, Durham, NC 27710, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Brown
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D019299:Decompression, Surgical / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010243:Paralysis / Q000209:etiology*; D011183:Postoperative Complications; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed
keywords: C5 nerve root palsy; Cervical decompression; Cervical laminectomy; Cervical spine; Posterior spinal cord drift; Width of laminectomy