title: Anterior fusion technique for multilevel cervical spondylotic myelopathy: a retrospective analysis of surgical outcome of patients with different number of levels fused.
abstract: OBJECTIVE
  The anterior approach for multilevel CSM has been developed and obtained favorable outcomes. However, the operation difficulty, invasiveness and operative risks increase when multi-level involved. This study was to assess surgical parameters, complications, clinical and radiological outcomes in the treatment of 2-, 3- and 4-level CSM.
  
  
  METHODS
  A total of 248 patients with 2-, 3- or 4-level CSM who underwent anterior decompression and fusion procedures between October 2005 and June 2011 were divided into three groups, the 2-level group (106 patients), the 3-level group (98 patients) and the 4-level group (44 patients). The clinical and Radiographic outcomes including Japanese Orthopedic Association (JOA) score, Neck Disability Index (NDI) score, Odom's Scale, hospital stay, blood loss, operation time, fusion rate, cervical lordosis, cervical range of motion (ROM), and complications were compared.
  
  
  RESULTS
  At a minimum of 2-year follow-up, no statistical differences in JOA score, NDI score, Odom's Scale, hospital stay, fusion rate and cervical lordosis were found among the 3 groups. However, the mean postoperative NDI score of the 4-level group was significantly higher than that in the other two groups (P<0.05), and in terms of postoperative total ROM, the 3-level group was superior to the 4-level group and inferior to 2-level group (P<0.05). The decrease rate of ROM in the 3-level group was significantly higher than that in the 2-level group, and lower than that in the 4-level group (P<0.05).
  
  
  CONCLUSIONS
  As the number of involved levels increased, surgical results become worse in terms of operative time, blood loss, NDI score, cervical ROM and complication rates postoperatively. An appropriate surgical procedure for multilevel CSM should be chosen according to comprehensive clinical evaluation before operation, thus reducing fusion and decompression levels if possible.
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Shunzhi
authors.initials: S
authors.lastname: Yu
authors.affiliation: Department of Orthopedics, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai, China.
authors.forename: Fengning
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Yan
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Chaoqun
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Shisheng
authors.initials: S
authors.lastname: He
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Tiesheng
authors.initials: T
authors.lastname: Hou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D015897:Comorbidity; D019299:Decompression, Surgical / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D013117:Spinal Cord Compression / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery*; D016896:Treatment Outcome