title: Lever reduction using polyaxial screw and rod fixation system for the treatment of degenerative lumbar spondylolisthesis with spinal stenosis: technique and clinical outcome.
abstract: BACKGROUND
  The management for degenerative lumbar spondylolisthesis with spinal stenosis remains controversial. Reduction of lumbar spondylolisthesis has been performed via numerous techniques. Most of them need extra reduction assembly.
  
  
  METHODS
  In this retrospective analysis, 27 patients of degenerative lumbar spondylolisthesis with spinal stenosis underwent reduction using polyaxial screw and rod constructs and posterolateral fusion. The average age at the time of surgery was 53 ± 3.23 years. The outcome measures consisted of a radiographic assessment of deformity and fusion rate and a clinical assessment of perioperative improvement in low back pain and function. Preoperative and postoperative radiographic evaluation included the percent slip, slip angle, and the lumbar lordosis between L1 and the sacrum measured using the Cobb method. Before surgery and at the final follow-up, the Oswestry Disability Index (ODI) and the visual pain analog scale (VPAS) between 0 (no pain) and 10 (maximal pain) were quantified.
  
  
  RESULTS
  The average follow-up period more than 5 years was available. The mean operative time was 90.19 ± 14.51 min, and the mean blood loss during surgery was 152.59 ± 45.71 ml. The mean length of incision was 4.83 ± 0.63 cm. The average percent slippage and the mean slip angle were, respectively, 19.8 ± 4.49% and 9.69 ± 3.79° before surgery, 5.09 ± 3.40% and 6.39 ± 3.16° after surgery, and 5.67 ± 3.92% and 7.21 ± 3.05° at the last follow-up. The average lumbar lordosis was 36.88 ± 2.64° before surgery, 41.96 ± 1.64° after surgery, and 40.27 ± 1.19° at the final follow-up. No neurologic deficit occurred. Solid fusion was achieved for all cases. Compared with the outcome preoperation, the data improved from 6.56 ± 1.40 to 2.48 ± 1.16 for VPAS pain scores and from 32.22 ± 3.57 to 10.93 ± 4.93 for the ODI at the final follow-up.
  
  
  CONCLUSIONS
  Lever slip reduction maneuver techniques using polyaxial screw and rod fixation system was simple and practicable. The treatment outcomes showed satisfactory radiographic characteristics and clinical results. The length of the incision was relatively small with a low intraoperative blood loss and short operation time.
authors.affiliation: Department of Orthopaedic Surgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. liuzude@yeah.net.
authors.forename: Zu-De
authors.initials: ZD
authors.lastname: Liu
authors.affiliation: Department of Orthopaedic Surgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. xinfengli@126.com.
authors.forename: Xin-Feng
authors.initials: XF
authors.lastname: Li
authors.affiliation: Department of Orthopaedic Surgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. spineli@yeah.net.
authors.forename: Lie
authors.initials: L
authors.lastname: Qian
authors.affiliation: Department of Radiology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. wlmssmu@gmail.com.
authors.forename: Lian-Ming
authors.initials: LM
authors.lastname: Wu
authors.affiliation: Department of Orthopaedic Surgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. spinelxf@gmail.com.
authors.forename: Li-Feng
authors.initials: LF
authors.lastname: Lao
authors.affiliation: Department of Orthopaedic Surgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. odowang@163.com.
authors.forename: Han-Tao
authors.initials: HT
authors.lastname: Wang
mesh_terms: D005260:Female; D006801:Humans; D016268:Internal Fixators; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013130:Spinal Stenosis / Q000209:etiology / Q000601:surgery*; D013168:Spondylolisthesis / Q000150:complications / Q000601:surgery*; D016896:Treatment Outcome