title: Viability and long-term survival of short-segment posterior fixation in thoracolumbar burst fractures.
abstract: BACKGROUND
  Short-segment pedicle screw instrumentation constructs for the treatment of thoracolumbar fractures gained popularity in the 1980s. The load-sharing classification (LSC) is a straightforward way to describe the extent of bony comminution, amount of fracture displacement, and amount of correction of kyphotic deformity in a spinal fracture. There are no studies evaluating the relevance of fracture comminution/traumatic kyphosis on the long-term radiologic outcome of burst fractures treated by short-segment instrumentation with screw insertion in the fractured level.
  
  
  OBJECTIVE
  To evaluate the efficacy of the six-screw construct in the treatment of thoracolumbar junction burst fractures and the influence of the LSC score on the 2-year radiologic outcome.
  
  
  METHODS
  Case series of consecutive patients of a single university hospital.
  
  
  METHODS
  Consecutive patients from one university hospital with nonosteoporotic thoracolumbar burst fractures.
  
  
  METHODS
  Being a radiology-based study, the outcome measures are radiologic parameters (regional kyphosis [RK], local kyphosis, and thoracolumbar kyphosis [TLK]) that evaluate the degree and loss of correction.
  
  
  METHODS
  Retrospective analysis of all consecutive patients with nonosteoporotic thoracolumbar burst fractures managed with a six-screw construct in a single university hospital, with more than 2 years' postoperative follow-up.
  
  
  RESULTS
  Eighty-six patients met the inclusion criteria, and 72 (83.7%) with available data were ultimately included in the study. The sample included 53 men and 19 women, with a mean (standard deviation [SD]) age of 35.6 years (14.4 years) at the time of surgery. Mean LSC score was 6.3 (SD 1.6, range 3-9). Forty-four of 62 (70.9) fractures had a score greater than 6. Mean (SD) RK and TLK deteriorated significantly during the first 6 months of follow-up: 2.90° (4.54°) p=.005 and 2.78° (6.45°) p=.069, respectively. Surgical correction correlated significantly (r=0.521, p<.0001) with the time elapsed until surgery. Loss of surgical correction (postoperative to 6-month RK and TLK increase) correlated significantly with the LSC score (r=0.57, p=.004; r=0.51, p=.022, respectively). Further surgery because of correction loss was not required in any case.
  
  
  CONCLUSIONS
  The six-screw construct is effective for treating thoracolumbar junction burst fractures. The medium-to-long-term loss of correction is affected by the amount of bony comminution of the fracture, objectified through the LSC score.
authors.affiliation: Spine Unit, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119-129, 08035 Barcelona, Spain. Electronic address: 24361fpu@comb.cat.
authors.forename: Ferran
authors.initials: F
authors.lastname: Pellisé
authors.affiliation: Orthopaedics, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119-129, 08035 Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Barastegui
authors.affiliation: Spine Unit, Hospital Universitario Donostia, San Sebastián, Calle Doctor Begiristain, 117, 20080 San Sebastián, Guipúzcoa Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Hernandez-Fernandez
authors.affiliation: Hand and Upper Extremity Unit, ICATME - Institut Universitari Quirón-Dexeus, Carrer de Sabino Arana, 5, 08028 Barcelona, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Barrera-Ochoa
authors.affiliation: Spine Unit, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119-129, 08035 Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Bagó
authors.affiliation: Spine Research, Vall d'Hebron Institut de Recerca, Passeig Vall d'Hebron, 119-129, 08035 Barcelona, Spain.
authors.forename: Daniela
authors.initials: D
authors.lastname: Issa-Benítez
authors.affiliation: Spine Unit, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119-129, 08035 Barcelona, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Cáceres
authors.affiliation: Clinica del Pilar, Carrer de Balmes, 271, 08006 Barcelona, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Villanueva
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation; D018460:Fractures, Comminuted / Q000601:surgery*; D006801:Humans; D007738:Kyphosis / Q000209:etiology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D013904:Thoracic Vertebrae / Q000601:surgery; D055815:Young Adult
keywords: Burst fracture; Load sharing classification; Pedicle screw; Post-traumatic kyphosis; Short-instrumentation; Thoracolumbar junction