title: Multilevel oblique corpectomy for cervical spondylotic myelopathy preserves segmental motion.
abstract: OBJECTIVE
  To document the neurological outcome, spinal alignment and segmental range of movement after oblique cervical corpectomy (OCC) for cervical compressive myelopathy.
  
  
  METHODS
  This retrospective study included 109 patients--93 with cervical spondylotic myelopathy and 16 with ossified posterior longitudinal ligament in whom spinal curvature and range of segmental movements were assessed on neutral and dynamic cervical radiographs. Neurological function was measured by Nurick's grade and modified Japanese Orthopedic Association (JOA) scores. Eighty-eight patients (81%) underwent either a single- or two-level corpectomy; the remaining (19%) undergoing three- or four-level corpectomies. The average duration of follow-up was 30.52 months.
  
  
  RESULTS
  The Nurick's grade and the JOA scores showed statistically significant improvements after surgery (p < 0.001). The mean postoperative segmental angle in the neutral position straightened by 4.7 ± 6.5°. The residual segmental range of movement for a single-level corpectomy was 16.7° (59.7% of the preoperative value), for two-level corpectomy it was 20.0° (67.2%) and for three-level corpectomies it was 22.9° (74.3%). 63% of patients with lordotic spines continued to have lordosis postoperatively while only one became kyphotic without clinical worsening. Four patients with preoperative kyphotic spines showed no change in spine curvature. None developed spinal instability.
  
  
  CONCLUSIONS
  The OCC preserves segmental motion in the short-term, however, the tendency towards straightening of the spine, albeit without clinical worsening, warrants serial follow-up imaging to determine whether this motion preservation is long lasting.
authors.affiliation: Section of Neurosurgery, Department of Neurological Sciences, Christian Medical College, Vellore, 632004 Tamil Nadu, India. agchacko@cmcvellore.ac.in
authors.forename: Ari George
authors.initials: AG
authors.lastname: Chacko
authors.forename: Mathew
authors.initials: M
authors.lastname: Joseph
authors.forename: Mazda Keki
authors.initials: MK
authors.lastname: Turel
authors.forename: Krishna
authors.initials: K
authors.lastname: Prabhu
authors.forename: Roy Thomas
authors.initials: RT
authors.lastname: Daniel
authors.forename: K S
authors.initials: KS
authors.lastname: Jacob
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000502:physiology* / Q000601:surgery*; D017586:Diskectomy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007738:Kyphosis / Q000453:epidemiology; D008141:Lordosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D017887:Ossification of Posterior Longitudinal Ligament / Q000503:physiopathology / Q000601:surgery*; D017063:Outcome Assessment, Health Care; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome