title: Unilateral Versus Bilateral Pedicle Screw Fixation in Transforaminal Lumbar Interbody Fusion: A Monocentric Study of 215 Patients With a Minimum of 4-Year Follow-up.
abstract: METHODS
  A retrospective clinical study.
  
  
  OBJECTIVE
  This study sought to retrospectively compare the mid-term to long-term outcomes between unilateral pedicle screw (UPS) and bilateral pedicle screw (BPS) augmented transforaminal lumbar interbody fusion (TLIF) in lumbar degenerative diseases.
  
  
  BACKGROUND
  Recently, UPS fixation has been applied in TLIF, for its satisfactory clinical outcome, less implants and less invasiveness. However, only short-term outcome has been reported, the mid-term to long-term outcome has not been well characterized.
  
  
  METHODS
  From June 2007 to February 2011, 215 of 348 consecutive patients suffering from lumbar degenerative diseases were operated in our hospital and accomplished a minimum of 4-year follow-up. These patients were divided into 2 groups according to the operative techniques: UPS group (n=109), and bilateral pedicle screw group (n=106). Operative time, blood loss, length of hospital stay, hospital bill, fusion status, and complications were recorded and analyzed statistically. Visual analog scale, Oswestry disability index, and Japanese Orthopaedic Association scores were used to assess the preoperative and postoperative pain and functional outcome.
  
  
  RESULTS
  The mean follow-up duration was 52.2 months. A significant decrease occurred in operative time, blood loss, and hospital bill in unilateral group, compared with bilateral group (P<0.05). The average postoperative visual analog scale, Oswestry disability index, and Japanese Orthopaedic Association scores improved significantly in each group than the preoperative counterparts (P<0.05); however, there were no significant difference between groups at any follow-up time point (P>0.05). No statistically difference was detected regarding fusion rate and complication rate between the 2 groups (P>0.05), except the cage migration rate (P<0.05).
  
  
  CONCLUSIONS
  UPS fixation could achieve satisfactory clinical outcome similar to bilateral fixation in TLIF at a mid-term to long-term follow-up. To avoid cage migration, bullet-shaped cages should not be used in the unilateral group.
authors.affiliation: Department of Orthopaedics, Zhongshan Hospital of Fudan University, Shanghai, China.
authors.forename: Fubing
authors.initials: F
authors.lastname: Liu
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Feng
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Zhou
authors.forename: Yun
authors.initials: Y
authors.lastname: Liang
authors.forename: Chun
authors.initials: C
authors.lastname: Jiang
authors.forename: Xilei
authors.initials: X
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Li
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Jiang
authors.forename: Jian
authors.initials: J
authors.lastname: Dong
mesh_terms: D003710:Demography; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D005539:Foramen Magnum / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws / Q000009:adverse effects; D019990:Perioperative Care; D011183:Postoperative Complications / Q000209:etiology; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery; D013123:Spinal Fusion / Q000009:adverse effects; D014057:Tomography, X-Ray Computed; D064232:Visual Analog Scale