title: Unilateral versus bilateral fixation for lumbar spinal fusion: a systemic review and meta-analysis.
abstract: OBJECTIVE
  The objective of this study was to systematically compare the efficacy and safety of unilateral fixation to bilateral fixation for the lumbar degenerative disease.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  We searched databases including PubMed Central, MEDLINE (from 1966), EMBASE (from 1980), and Cochrane Central Register of Controlled Trials databases for randomized controlled trials or non-randomized controlled trials that compare unilateral fixation with bilateral fixation for the treatment for lumbar disease. Exclusion criteria were non-controlled studies, follow-up <6 months, combined anterior and posterior surgery, lumbar tumors, and non-English writing paper. Methodologic quality was assessed, relevant data were retrieved, and the appropriate meta-analysis was performed. Two review authors independently selected studies, extracted data, and assessed the risk of bias. The main end points included the rate of fusion, visual analogue scale (VAS), Oswestry disability index (ODI), intra-operative blood loss, operating time, and the rate of complications.
  
  
  RESULTS
  A total of seven studies were included in the meta-analysis. Four relevant randomized controlled trials, one prospective study, and two retrospective studies involving 499 patients were identified. Patients in unilateral pedicle fixation group compared with bilateral pedicle screw fixation group on the fusion rate, VAS, ODI scores, and complication rate demonstrated no significant differences (P > 0.05, respectively). However, intra-operative blood loss and operating time in unilateral fixation group were significantly less than bilateral fixation group (P < 0.0001, respectively).
  
  
  CONCLUSIONS
  Unilateral fixation seems to be an effective, feasible, and safe procedure in one or two segmental disease when compare with bilateral instrumentation.
authors.affiliation: Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Xi
authors.initials: X
authors.lastname: Lin
authors.forename: Chang-Peng
authors.initials: CP
authors.lastname: Xu
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Qing-Shui
authors.initials: QS
authors.lastname: Yin
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Xia
mesh_terms: D016063:Blood Loss, Surgical; D004185:Disability Evaluation; D006801:Humans; D061646:Operative Time; D010149:Postoperative Pain / Q000209:etiology; D011475:Prosthesis Failure; D013123:Spinal Fusion / Q000009:adverse effects* / Q000379:methods*; D016896:Treatment Outcome