title: Is It Beneficial to Remove the Pedicle Screw Instrument After Successful Posterior Fusion of Thoracolumbar Burst Fractures?
abstract: METHODS
  Case-control study.
  
  
  OBJECTIVE
  To investigate the clinical and radiological outcomes of pedicle screw removal after successful fusion of thoracolumbar burst fractures.
  
  
  BACKGROUND
  Implant removal is a common procedure in orthopedic surgery, although the benefits of and indications for removal remain controversial. Previous studies on pedicle screw removal have reported conflicting outcomes, because the study subjects and surgical goals were heterogeneous in nature.
  
  
  METHODS
  We studied 45 consecutive patients who underwent implant removal and a control cohort of 45 age- and sex-matched patients who retained their spinal implants after successful posterior fusion of thoracolumbar burst fractures using pedicle screw instrument. In most cases, long-segment instrumentation with short-segment posterior fusion was performed. The mean elapsed period prior to implant removal after index fracture surgery was 18.3 ± 17.6 months. A visual analogue scale for back pain was applied, the Oswestry disability index calculated, and radiological parameters derived at the time of implant removal and 1 and 2 years postoperatively obtained. These data were compared with those of the control group evaluated at the same times after index fracture surgery.
  
  
  RESULTS
  Patient demographics, mechanisms of injury, fracture morphologies, and the outcomes of index fracture surgery were similar between the 2 groups. The mean visual analogue scale and Oswestry disability index scores were better at both the 1- and 2-year follow-ups in the implant removal group than in the control group (all P values = 0.000). The segmental motion angle of the implant removal group was 1.6° ± 1.5° at the time of implant removal, and increased significantly to 5.8° ± 3.9° at 1-year follow-up (P = 0.000), and was maintained at this level at the 2-year follow-up (5.9° ± 4.1°) (P = 0.000).
  
  
  CONCLUSIONS
  In patients treated successfully for thoracolumbar burst fractures, pedicle screw removal is beneficial because it alleviates pain and disability. Restoration of the segmental motion angle after implant removal may contribute to the clinical improvement.
  
  
  METHODS
  3.
authors.affiliation: From the Department of Orthopaedic Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Jeon
authors.forename: Han-Dong
authors.initials: HD
authors.lastname: Lee
authors.forename: Yu-Sang
authors.initials: YS
authors.lastname: Lee
authors.forename: Jeong-Hyeon
authors.initials: JH
authors.lastname: Seo
authors.forename: Nam-Su
authors.initials: NS
authors.lastname: Chung
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001416:Back Pain / Q000209:etiology; D001863:Bone Screws; D016022:Case-Control Studies; D020878:Device Removal; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D017102:Fracture Healing; D050815:Fractures, Compression / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011859:Radiography; D016059:Range of Motion, Articular; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation; D013904:Thoracic Vertebrae / Q000503:physiopathology / Q000601:surgery*; D055815:Young Adult