title: Direct repair of multiple levels lumbar spondylolysis by pedicle screw laminar hook and bone grafting: clinical, CT, and MRI-assessed study.
abstract: BACKGROUND
  A prospective analysis of 6 cases with multiple-level spondylolysis treated by direct repair with pedicle screw laminar hook is presented. The objective of the study was to evaluate the clinical outcome, plain radiographs, computed tomography (CT) scan, and magnetic resonance imaging to demonstrate the result of direct repair in the treatment of multiple-level spondylolysis.
  
  
  METHODS
  Ten patients with multiple-level spondylolysis of lumbar spine were treated with segmental pedicle screw hook fixation and autogenous bone graft. Four patients had lost follow-up. Six patients were followed up for a minimum of 2 years (mean 34.3 mo, range 24 to 55 mo). Patient's average age was 22 years old (range from 20 to 25 y old). All lytic defects were bilateral and located at 2 different lumbar vertebras (levels). CT scans and MR images were obtained at the latest follow-up postoperatively to assess the healing of the bony defects and the adjacent disc conditions. Fusion was considered to be presented when trabecula across the lytic defect was detected.
  
  
  RESULTS
  The union rate was 87% (21 pars/24 pars) on plain radiographs and 75% (18 pars/24 pars) on CT scans. Follow-up magnetic resonance imaging of lumbar spine showed no disc degeneration. All patients were satisfied (either excellent or good) with the postoperative outcomes.
  
  
  CONCLUSIONS
  Direct repair of multiple-level spondylolysis by pedicle screw laminar hook and autogenous bone graft would be the alternative of treating patients with persistent back pain after 6 months of conservative treatment The favorable clinical outcome was correlated with bony healing rate in this series.
authors.affiliation: Department of Orthopedic Surgery, Kaohsiung Military General Hospital, Kaohsiung City, Taiwan, Republic of China. icebone.chung@msa.hinet.net
authors.forename: Chen-Han
authors.initials: CH
authors.lastname: Chung
authors.forename: Huann-Min
authors.initials: HM
authors.lastname: Chiu
authors.forename: Shyu-Jye
authors.initials: SJ
authors.lastname: Wang
authors.forename: Shun-Yuan
authors.initials: SY
authors.lastname: Hsu
authors.forename: Yu-Shen
authors.initials: YS
authors.lastname: Wei
mesh_terms: D000328:Adult; D001863:Bone Screws / Q000592:standards* / Q000639:trends; D016025:Bone Transplantation / Q000379:methods* / Q000639:trends; D006085:Graft Survival / Q000502:physiology; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D010865:Pilot Projects; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D013169:Spondylolysis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014945:Wound Healing / Q000502:physiology