title: [Comparative study on microplate and anchor fixation in open-door cervical expansive laminoplasty].
abstract: OBJECTIVE
  To evaluate the effectiveness of microplate fixation in open-door cervical expansive laminoplasty (ELP) by comparing with anchor fixation.
  
  
  METHODS
  Between January 2005 and October 2008, 35 patients with multi-segment cervical spondylotic myelopathy were treated. Of them, 15 patients underwent ELP by microplate fixation (microplate group) and 20 patients underwent ELP by anchor fixation (anchor group). In microplate group, there were 10 males and 5 females with the age of (51.2 +/- 11.5) years; the disease duration ranged from 6 to 60 months (mean, 14 months); and the preoperative Japanese Orthopaedic Association (JOA) score was 7.7 +/- 2.5. In anchor group, there were 13 males and 7 females with the age of (50.7 +/- 10.8) years; the disease duration ranged from 3 to 58 months (mean, 17 months); and the preoperative JOA score was 7.8 +/- 2.9. There was no significant difference in the general data, such as gender, age, and JOA score between 2 groups (P > 0.05).
  
  
  RESULTS
  All incisions healed by first intention. Thirty-five cases were followed up 24-68 months (mean, 32 months). The operation time was (113 +/- 24) minutes in anchor group and (111 +/- 27) minutes in microplate group, showing no significant difference (t = 0.231 3, P = 0.818 5). The rate of spinal canal expansion in microplate group (60% +/- 24%) was significantly higher than that in anchor group (40% +/- 18%) (t = 2.820, P = 0.008). The JOA scores of 2 groups at 3 months and 24 months after operation were significantly higher than the preoperative scores (P < 0.01). There was no significant difference in JOA score between 2 groups at 3 months after operation (t = 1.620 5, P = 0.114 6), but the JOA score of microplate group was significantly higher than that of anchor group at 24 months after operation (t = 3.454 3, P = 0.001 5). X-ray film, MRI, and CT scan at 3-6 months after operation displayed that door spindle reached bony fusion. There was no occurrence of "re-close of door" in 2 groups. The rate of complication in microplate group (13.3%, 2/15) was significantly lower than that in anchor group (25.0%, 5/20) (chi2 = 7.160 0, P = 0.008 6).
  
  
  CONCLUSIONS
  ELP by microplate fixation can achieve the stability quickly after operation, which can help patients to do functional exercises early, and has satisfactory effectiveness and less complications.
authors.affiliation: Department of Spine Surgery, Dongfeng General Hospital, Hubei University of Medicine, Shiyan Hubei 442000, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zeng
authors.forename: Min
authors.initials: M
authors.lastname: Xiong
authors.forename: Hualong
authors.initials: H
authors.lastname: Yu
authors.forename: Ning
authors.initials: N
authors.lastname: He
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Wang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Liu
authors.forename: Heng
authors.initials: H
authors.lastname: Han
authors.forename: Sen
authors.initials: S
authors.lastname: Chen
mesh_terms: D000328:Adult; D001178:Arthroplasty / Q000295:instrumentation* / Q000379:methods*; D001860:Bone Plates; D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D007796:Laminectomy; D008297:Male; D008875:Middle Aged; D013128:Spinal Osteophytosis / Q000601:surgery*; D053441:Suture Anchors; D016896:Treatment Outcome