title: Risk factors for a poor outcome following surgical treatment of cervical spondylotic amyotrophy: a multicenter study.
abstract: BACKGROUND
  Cervical spondylotic amyotrophy (CSA) is characterized by muscle atrophy in the upper extremities without gait disturbance. However, the indications and outcomes of surgical treatment for CSA have not been clarified. The purpose of this study was to determine the risk factors for a poor outcome following surgical treatment of CSA.
  
  
  METHODS
  We performed a retrospective review of CSA in patients from 1991 to 2010 through a multicenter study. We collected information regarding age, type of muscle atrophy, preoperative manual muscle test (MMT), duration of symptoms, high-intensity areas on T2-weighted MR images, low-intensity areas on T1-weighted MR images, levels of spinal canal stenosis, cervical kyphosis and surgical procedures (laminoplasty, anterior cervical discectomy and fusion and posterior spinal fusion), and calculated overall risk factors related to a poor outcome following surgery. Univariate analyses and multivariate logistic regression analysis were performed to identify correlates of a poor outcome.
  
  
  RESULTS
  Fifty-nine patients, 95 % male (56 patients), were included in our analysis with a mean age of 59 years (range 32-78 years). Eighteen patients did not improve after surgery. Symptom duration (OR = 1.263), preoperative MMT grade (OR = 0.169) and distal type of CSA (OR = 9.223) were all associated with an increased risk of a poor surgical outcome.
  
  
  CONCLUSIONS
  Early surgery is recommended for CSA patients in whom conservative treatment has not been successful. We also recommend surgery for patients who have severe preoperative muscle weakness or have the distal type of CSA.
authors.affiliation: Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya 4668550, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Tauchi
authors.forename: Shiro
authors.initials: S
authors.lastname: Imagama
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Inoh
authors.forename: Yasutsugu
authors.initials: Y
authors.lastname: Yukawa
authors.forename: Tokumi
authors.initials: T
authors.lastname: Kanemura
authors.forename: Koji
authors.initials: K
authors.lastname: Sato
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsubara
authors.forename: Atsushi
authors.initials: A
authors.lastname: Harada
authors.forename: Yudo
authors.initials: Y
authors.lastname: Hachiya
authors.forename: Mistuhiro
authors.initials: M
authors.lastname: Kamiya
authors.forename: Hisatake
authors.initials: H
authors.lastname: Yoshihara
authors.forename: Zenya
authors.initials: Z
authors.lastname: Ito
authors.forename: Kei
authors.initials: K
authors.lastname: Ando
authors.forename: Naoki
authors.initials: N
authors.lastname: Ishiguro
mesh_terms: D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae; D017586:Diskectomy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D013118:Spinal Cord Diseases / Q000150:complications / Q000473:pathology* / Q000601:surgery*; D013123:Spinal Fusion; D055009:Spondylosis / Q000150:complications / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome; D034941:Upper Extremity