title: d-Dimer as a Screening Marker for Venous Thromboembolism After Surgery Among Patients Younger Than 50 With Lower Limb Fractures.
abstract: OBJECTIVE
  For the present study, the authors hypothesized that the d-dimer levels would be systematically raised in a postoperative population of patients younger than 50 with lower limb fractures and to define a feasible cutoff value for identification of venous thromboembolism (VTE).
  
  
  METHODS
  Doppler ultrasonography of lower limbs was performed pre- and postoperatively to evaluate for deep vein thrombosis in 150 patients who underwent open reduction and internal fixation (ORIF). Plasma d-dimer levels were assessed 2 days before surgery and on the 3rd, 7th, and 10th days after surgery. Statistical analysis was carried out to define a feasible threshold for the d-dimer levels.
  
  
  RESULTS
  Plasma d-dimer levels were found to be systematically raised postoperatively, and they differed between patients with and without VTE significantly. On the third day after surgery, d-dimer levels of more than 3 mg/L indicated VTE with a sensitivity of 88.37% and a specificity of 96.96%, allowing for the definition of a feasible cutoff value. Duration of surgery, duration of tourniquet, ventilation time, and time of postoperative immobility of lower limbs were identified as highly significant risk factors for the development of VTE.
  
  
  CONCLUSIONS
  Using a threshold of 3 mg/L, the d-dimer levels will screen out VTE with a high degree of sensitivity and specificity in younger patients who have undergone ORIF for lower limb fractures.
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, P. R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, P. R. China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Zan
authors.affiliation: Medical Department, Soochow University, Suzhou, Jiangsu, P. R. China.
authors.forename: Jinpeng
authors.initials: J
authors.lastname: Gong
authors.affiliation: Department of Orthopedics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, P. R. China cmdoctor@tongji.edu.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Cai
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000627:therapeutic use*; D050723:Fractures, Bone; D006801:Humans; D035002:Lower Extremity / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography / Q000379:methods*; D054556:Venous Thromboembolism / Q000517:prevention & control*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: 
  d-dimer; deep vein thrombosis; lower limb fractures; venous thromboembolism; young patients