title: Presence of anterior compression of the spinal cord after laminoplasty inhibits upper extremity motor recovery in patients with cervical spondylotic myelopathy.
abstract: METHODS
  A retrospective single-center study.
  
  
  OBJECTIVE
  To investigate how functional recovery is influenced by anterior compression of the spinal cord (ACS) and instability at the level of ACS after laminoplasty in patients with cervical spondylotic myelopathy.
  
  
  BACKGROUND
  There have been many reports that patients whose spinal cord cannot be decompressed sufficiently after laminoplasty are likely to show unsatisfactory neurologic outcomes. Notably, postoperative ACS is well known to cause problems. Clinically, however, it remains unknown how functional recovery is inhibited by postoperative ACS.
  
  
  METHODS
  Sixty-four consecutive patients who underwent expansive laminoplasty for the treatment of myelopathy at our hospital between 1998 and 2005 were reviewed. All 64 patients were available for follow-up. The average follow-up period was 97 months (60-156 months). Patients were divided into 2 groups: the ACS(+) group comprised 16 patients who had ACS 3 years postoperatively, and the ACS(-) group comprised 48 patients with no ACS. Clinical outcome was compared in terms of the Japanese Orthopaedic Association score (mean total score, mean score of each item, and recovery rates).
  
  
  RESULTS
  Demographics were similar between the 2 groups. Mean Japanese Orthopaedic Association score at final follow-up was 12.1 points (recovery rate 34.0%) in the ACS(+) group and 13.8 points (recovery rate 56.6%) in the ACS(-) group, and there was a significant difference in recovery rate between the groups (P < 0.05). Notably, a significant difference was found between the 2 groups in improvement of upper extremity motor function (P < 0.05). In addition, we found that not only the presence of ACS but also postoperative hypermobility of the intervertebral segment with ACS influenced clinical outcome negatively.
  
  
  CONCLUSIONS
  These results demonstrate that ACS after laminoplasty could be a risk factor for clinical outcome and might prevent improvement in upper extremity motor function in patients with myelopathy.
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical and Dental University, Tokyo, Japan. hirai.orth@tmd.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirai
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kawabata
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Enomoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kato
authors.forename: Shoji
authors.initials: S
authors.lastname: Tomizawa
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Sakai
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Yoshii
authors.forename: Kyohei
authors.initials: K
authors.lastname: Sakaki
authors.forename: Kenichi
authors.initials: K
authors.lastname: Shinomiya
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D007796:Laminectomy / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008875:Middle Aged; D010291:Paresis / Q000209:etiology* / Q000503:physiopathology; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology; D011859:Radiography; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D055009:Spondylosis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*