title: Relationship between fracture-relevant parameters of thoracolumbar burst fractures and the reduction of intra-canal fracture fragment.
abstract: OBJECTIVE
  Posterior longitudinal ligament reduction (PLLR) has been widely used for treatment of thoracolumbar burst fractures. However, there are no systemic studies assessing the influence of position parameters of intra-canal fracture fragment (IFF) itself on outcome of reduction. The aim of this study was to analyze the relationship between position parameters of IFF and the reduction efficacy of PLLR.
  
  
  METHODS
  Sixty-two patients (average age, 36.9 years) with single thoracolumbar burst fractures and intact posterior longitudinal ligaments were recruited. Patients were divided into reduced and unreduced groups based on IFF reduction situations by PLLR. Preoperative and intraoperative computed tomography (CT) were used to evaluate reduction and location parameters of IFF, such as position, width, height, inversion, and horizontal angle, ratio of width of IFF to the transverse diameter of vertebral canal (R 1), and ratio of height of IFF to height of injured vertebrae (R 2) before and after PLLR.
  
  
  RESULTS
  There were significant differences in width (P < 0.001), height (P = 0.0141; R 1, P < 0.001), and R 2 (P = 0.0045) between the two groups. When width of IFF was more than 75 % of transverse diameter of vertebral canal and height of IFF was more than 47 % of height of injured vertebrae, the IFF could not be reduced by PLLR.
  
  
  CONCLUSIONS
  In patients with thoracolumbar burst fractures, IFF in apterium of the posterior longitudinal ligament cannot be reduced by PLLR. For thoracolumbar burst fractures that cover the posterior longitudinal ligament, the width and height of IFF are important parameters that influence reduction quality.
authors: Department of Orthopedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China.
authors: Ye
authors: Y
authors: Peng
authors: Department of Orthopedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China.
authors: Licheng
authors: L
authors: Zhang
authors: Department of Orthopedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China.
authors: Tao
authors: T
authors: Shi
authors: Department of Orthopedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China.
authors: Houchen
authors: H
authors: Lv
authors: Department of Orthopedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China. zhanglihai74@qq.com.
authors: Lihai
authors: L
authors: Zhang
authors: Department of Orthopedics, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing, 100853, People's Republic of China. tangpeifu@sohu.com.
authors: Peifu
authors: P
authors: Tang
mesh_terms: D000328:Adult; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D017846:Longitudinal Ligaments / Q000000981:diagnostic imaging; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D011859:Radiography; D013115:Spinal Canal / Q000000981:diagnostic imaging / Q000601:surgery*; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*