title: Is cervical lordosis relevant in laminoplasty?
abstract: BACKGROUND
  Laminoplasty aims to decompress the spinal cord and stabilize the cervical spine in patients with multilevel cervical lesions. Not every patient with cervical compressive myelopathy is a good candidate for laminoplasty. Most studies recommend that neutral or kyphotic alignments are contraindications for laminoplasty. However, cervical sagittal alignment does not have a strong and consistent effect on the clinical outcomes of laminoplasty. Moreover, many reports on the effect of cervical sagittal alignment did not designate the ideal definition of alignment and used different definitions of lordosis.
  
  
  OBJECTIVE
  To identify the effect of preoperative cervical alignment according to two different definitions after midline splitting double-door laminoplasty.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  From August 2008 to September 2010, 58 patients were diagnosed with cervical myelopathy and treated with midline splitting double-door laminoplasty.
  
  
  METHODS
  The clinical results were assessed with the modified Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and visual analog scale (VAS) and were compared to analyze the rate of change between preoperative and postoperative values. Postoperative radiological results at the final follow-up examinations were compared between groups to obtain the change in range of motion and sagittal alignment.
  
  
  METHODS
  The effect of cervical alignment on JOA, NDI, and VAS scales and also on change of alignment and change of range of motion (ROM) at the final follow-up examinations was analyzed statistically between two groups according to two different definitions such as Toyama classification and Cobb angle.
  
  
  RESULTS
  No difference was found between the two groups according to Toyama classification in terms of the postoperative improvement rate of the modified JOA score (p=.086), decreasing rate of the VAS (p=.940) or NDI (p=.211), postoperatively. Additionally, no difference was found for the decreasing rate of ROM (p=.427) or sagittal alignment (p=.864) based on the radiological evaluation results. Also, there was no difference between two groups according to Cobb angle in terms of the modified JOA score (p=.743), VAS (p=.548), or NDI (p=.32), postoperatively. Additionally, no difference was found for the ROM (p=1.000) or sagittal alignment (p=.440) based on the radiological evaluation results.
  
  
  CONCLUSIONS
  Despite nonlordosis cervical sagittal alignment, double-door laminoplasty would be effective for patients with cervical myelopathy because of cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament. Furthermore, sagittal alignment is not the absolute and sole factor that surgeons should consider when determining the optimal treatment strategy.
authors.affiliation: Spine Center, Hallym University Sacred Heart Hospital, College of Medicine, Hallym University, 896, Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do 431-070, South Korea.
authors.forename: Seok Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Dinh Manh
authors.initials: DM
authors.lastname: Hai
authors.forename: Shanmuga
authors.initials: S
authors.lastname: Sundaram
authors.forename: Yong Chan
authors.initials: YC
authors.lastname: Kim
authors.forename: Moon Soo
authors.initials: MS
authors.lastname: Park
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Paik
authors.forename: Yoon-Hae
authors.initials: YH
authors.lastname: Kwak
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000379:methods*; D008141:Lordosis / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome
keywords: Cervical myelopathy; Laminoplasty; Midline splitting double-door laminoplasty; Sagittal alignment