title: 540° Cervical Realignment Procedure for Extensive Cervical OPLL With Kyphotic Deformity.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  The aim of this study was to present a novel, two-stage [posterior and anterior-posterior (P-AP) 540°] procedure for extensive cervical ossification of the longitudinal ligament (OPLL) with kyphotic deformity.
  
  
  BACKGROUND
  The optimal surgical strategy for extensive cervical OPLL remains a controversial issue. Neurological injury and dural defect are complications of anterior surgery, while a posterior surgery can lead to poor clinical outcomes related to incomplete decompression.
  
  
  METHODS
  We analyzed consecutive cases of patients who underwent procedure described herein, which consists of two stages: the first (P: laminectomy and facet release with segmental screw fixations without rod assembly) and the second 1 week later (AP: multilevel anterior cervical discectomy with fusions (ACDFs) at the apex of the deformity without decompression, placement of lordotic grafts, and posterior fusion). To assess the radiographic parameters, extent of OPLL, maximal canal occupying ratio (%), the distances from the maximal compression to the K-line, and C2-7 angle were analyzed. Clinically, we analyzed visual analog scale of neck and arm pain, neck disability index (NDI), Japanese Orthopedic Association (JOA) score, and complications.
  
  
  RESULTS
  A total of 18 patients were enrolled (M:F = 15:3, mean age 64.5 yrs, mean follow-up was 30 months). The mean extent of the OPLL was 3.8 vertebral body levels. Posterior fusion was performed on a mean 4.5 segments and anterior fusion was on a mean 2.4 segments. The mean C2-7 Cobb angle was improved from 10.5° to -12.2° at follow-up. The K-line distance to the maximal compression and canal occupying ratio were improved from -3.3 mm, 73.5% to 3.8 mm, 38.4%, respectively. Preoperative NDI and JOA scores were significantly improved (18.5 to 9.4 and 8.2 to 14.8) at the last follow-up.
  
  
  CONCLUSIONS
  The 540° P-AP procedure could provide safe decompression, cervical realignment, and favorable outcomes without the disadvantages of the conventional anterior and/or posterior surgery for extensive cervical OPLL with kyphotic deformity.
  
  
  METHODS
  4.
authors.affiliation: Department of Orthopedic Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
authors.forename: Ki-Tack
authors.initials: KT
authors.lastname: Kim
authors.affiliation: Kyung Hee University Hospital, Seoul, Korea.
authors.forename: Jung-Hee
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Kyung Hee University Hospital, Seoul, Korea.
authors.forename: Kyung Chung
authors.initials: KC
authors.lastname: Kang
authors.affiliation: Department of Orthopedic Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Jang
authors.affiliation: Department of Orthopedic Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
authors.forename: Sang-Phil
authors.initials: SP
authors.lastname: Hwang
authors.affiliation: Department of Orthopedic Surgery, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
authors.forename: Kyung Tack
authors.initials: KT
authors.lastname: Yoon
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000601:surgery*; D007796:Laminectomy / Q000379:methods; D017846:Longitudinal Ligaments / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000601:surgery*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000379:methods; D016896:Treatment Outcome